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THE ENGINEERS ENCYCLOPEDIA.
THE
"--
v -
ENGINEERS ENCYCLOPEDIA
cowa.AINING A History or the discovery Awd APPLICAtroN or
STEAM, WTTH ITS PI&ACTICE AND ACHIEVEMENTS FROM
• THE EAIELIEST PIERIOD TO THE PRESENT TIME.
THE WHOLE BEING A PRACTICAL GUIDE TO
THE MOST RECENT APPROVED METHODs of construction, witH
EXAMPLES DRAWN TO SCALE IN. SIMPLE WORKSHOP FORM.
WITH RULES AND FORMULAE REB,ATING TO
BOILERS, STATIONARY ENGINES, MARINE ENGINES, LOCOMOTIVES, AND THE
TREATMENT AND REGULATION OF STEAM.
BY
JoHN G. WINTON, Engineer, AND W. J. MILLAR, Civil Engineer,
Author of “Modern-Warkshop A ractice.” Author gy “Principles of Mechanics,” etc.
THE “Old IRoNSIDEs,” 1832.
ILLUSTRATED BY OVER SIX. HUNDRED ENGRAVINGs IN THE TEXT AND
A SERIES OF SEPARATE PLATES.
- PHILADELPHIA:
GEBBIE & CO., Publish ERs.
I888.
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275
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Copyright, 1888, by GEBBIE & Co
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2 2-
PREFACE.
HE object of this publication is to supply the practical Engineer and
Mechanic with a trustworthy guide to the varied operations of the
Workshop in a convenient form and at a moderate price. It is written
by practical men, well acquainted with the operations which they describe,
and seeks to convey to the workman detailed directions regarding his
work in language such as he is familiar with, and at the same time to
state clearly the higher principles upon which these operations are based,
and on which they depend for success.
The importance df this book for those engaged in all branches of Engi-
neering, etc., will at once be seen by an examination of the Summary
of Contents. From this summary may also be gathered a general
idea of the scope of the work, and of the manner in which the various
subjects are treated. After a brief notice of Coal and Coal-mining,
the author discusses the forms of Boilers, their construction, the use of
Steel and the treatment of Steam ; the Land or Stationary Engine in its
many forms and uses; the Marine Engine of the present day as well as
that of fifty years ago, and the important subject of the Screw Propeller;
the Locomotive Engine and Tender, British and American, including
details of recent improvements and special forms made for different rail-
ways. Numerous Tables, Rules and Formulae are given throughout the
book, rendering it a useful companion in the counting-houses and design-
ing rooms of locomotive works and machine shops.
Much care has been bestowed upon the illustrative engravings, which
consist of a series of about forty pages of plates descriptive of some of the
more recent examples of Engine-making skill and nearly eight hundred
figures printed in the text. These illustrations teach through the eye in a
clear and perspicuous manner. They are executed without shade lines in
order that they may all the better meet the requirements of practical men.
This book will be found a most useful assistant not only to those
charged with the duty of carrying on and superintending work, but also
to intelligent workmen who seek to understand the best modes of per-
forming the operations in which they are engaged, as well as to all learn-
ers, whose aim should be to acquire thoroughly principles as well as hand
PREFACE.
skill, and so qualify themselves for the higher positions of their trades.
It will also be found of great service as a means of preparing those who
desire to pass the special examination recently proposed by the Trades
Union Congress in England and Scotland to be instituted for men having
charge of steam engines or boilers. As an example of the importance of
this subject to all who are in any way interested in or have the care of
Boilers, it was stated in the House of Commons, on the second reading
of the Boilers Explosion Bill (22d Feb., 1882), that through Boiler
Explosions one man was killed on an average every four days, and two
thousand persons maimed from the same cause during the past few years.
In order that the reader may thoroughly understand all the subject, the
practical part of the work is prefaced by a thorough and concise history
of the discovery and progress of perfecting the application of steam to its
present power and perfection.
The story of the glimpse that the ancients had of its possibilities, 130
B. c., in the AEolipile of Hero, and next the somewhat uncertain statement
that Blaxo de Garay showed a steamboat in the harbor of Barcelona in
1543; then Solomon de Caus in 1615, Giovanni Branca in 1629, the
Marquis of Worcester in 1663, Papin, the real discoverer of the first prac-
tical step, in 1689, Savary in 1699, and Newcomen in 1705, who improved
on Papin and Savary, and by using both air and steam first applied the
power to pumping water out of mines, until Watt, in 1765, on getting
one of Newcomen's models to repair, made the discovery of improvements
which have revolutionized the industries and commerce of the world.
The story of its practical adoption in steamship propulsion and in rail-
road locomotion will be found circumstantially related, and the share of
each ; the two Stephensons, Trevethick, Symington, Murdoch, Ericsson
and others of England, and Oliver Evans, Fulton, John Fitch, Stevens,
Long, Baird, Norris, Harrison, Eastwick, Baldwin, etc., of America, all
receive due notice and their record of improvements.
This plan of minutely tracing and describing each successive improve-
ment must prove both interesting and instructive, because the student
interested in these details, when fully informed as to how the present per-
fection has been won step by step, will be better able to understand the
present condition of Modern Mechanics, and in his turn may conclude
that improvements are yet possible.
CONTENTS OF THE HISTORY OF STEAM.
JAMES WATT :
Birth and Ancestry © c e * © O ©
Childhood and Education º & 4. * <º ſe
Settles in Glasgow as a Mathematical Instrument Maker
Marries his Cousin, Miss Miller . *
Gets a Small Model of Newcomen’s Steam Engine to Repair
The Discovery of the Application of Steam to Mechanics
HISTORY OF THE STEAM ENGINE BEFORE THE TIME OF WATT :
Hero refers to it Three Centuries B. C. . * tº gº
The AEolipile, B. c. 130 g º © tº sº º
The AEolipile the same Principle as the Rotary Engine
Blaxo de Gary's Steamboat in Barcelona, 1543 © G
Solomon de Caus’ Steam Toy, 1615 tº. * > c
Giovanni Branca’s Steam. Wheel, 1629 . tº & e
The Marquis of Worcester's Engine, 1663 . * > ſº
Savary’s Steam Engine, 1699 * e e * ſº
Papin's Air Engine, with which he Combined Steam, 1689
Newcomen's Steam Engine, 1705 . & tº e e
Humphrey Potter's Skulking Gear º sº tº +º
WATT's IMPROVEMENTS ON THE STEAM ENGINE As A DRAwiNG AND PUMP-
ING MACHINE :
Discovery of the Condenser . & • ‘ e tº tº
Watt’s “Modified” really the First Steam Engine . *
Economizing Fuel * * } * * sº ſe
Watt Associates with Dr. Roebuck Jº g ſº &
Watt's Partnership with Bolton { } tº º &
Occupation as a General Engineer $º *
Surveys the Caledonian Canal tº e {º $ º
Extension of Patent on Steam Engine . tº &
Impulse to Mining Enterprise ve e º &
First Introduces Parallel Motion . * e to
Double-acting Engine . tº iº s º
Watt's Governor .
*
Model of a Steam Engine, by Murdock, Watt's Assistant, 1784
THE LIFE OF GEORGE STEPHENSON:
Birth and Parentage ſº g * > * >
Works in the Fields at Eight Years tºp
Assistant Fireman at Fifteen Years ſº º • e
Good Engineer at Eighteen, but did not know his Alphabet
Self-Taught, Married, and a Cobbler at Twenty-One ©
Birth of his son, Robert Stephenson, the Great Engineer.
Boss Colliery Engineer and Planner of Machinery at Thirty-One
Cugnot's Engine, 177O . e se * * * sº e
Trevethick's Engine, 1803 . wº © * e ©
Blenkinsop's Tooth-Wheeled Locomotive, 1811 . *
Brunton's Stilt Locomotive, 1813 . e & e tº
Blackett's Theory, 1812 . wº º we te * ©
Stephenson's Locomotive, 1815 Q G º * tº
Stephenson’s Draught for the Furnace Discovered . Q
Education of Robert Stephenson . tº º º ©
&
*
PAGE
V
vii
ix
xi
xi
xi
xii
xii
xiii
xiv.
XV
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xvii
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. xxiii
XXV
xxvi
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xxviii
. xxix
• XXX
xxxi
xxxii
xxxii
xxxiii
XXXV
. xxxviii
. xxxix
xl
xliii
xliv
xlv.
xlvi
xlviii
xlviii
xlix
xlix
l
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li
(i)
ii CONTENTS.
PAGE
George Stephenson's Discovery of the Safety Lamp © { } ſº , lii
George Stephenson, Engineer of Stockton & Darlington R. R. Q ... lii
George Stephenson's Locomotive Works at Newcastle . © ge ... lii
George Stephenson Starts a Train (1825) at Twelve Miles an Hour ... lii
6 & & © Examined Before a Committee of Parliament in Ref.
erence to Railroads g * g Q ... liii
6 & &&. Competes with the Rocket Against the Wovelty and
Sanspareil, and won the prize of £550, making
over Twenty-nine Miles an Hour (1829) . lv.
Manchester and Liverpool Regularly Connected by Steam Railway, 1830 Ivi
London & Northwestern Railroad Opened, 183r . sº * cº, . lvii
George Stephenson the Head of the Railroad World, 1840 . . . lvii
Death of George Stephenson, 1848 . o o º tº º • . lx
THE HISTORY OF STEAM IN AMERICA : $
The Share and Claims of Americans and Others in the Discovery and
Application of Steam * * tº © & gº gº * . lxii
John Fitch’s Steamboat, Philadelphia, 178 ſº is & * gº . lxiii
James Rumsey's Steamboat at Washington, D.C., 1784 . ſe * . lxiv
Apollos Kingsley's Locomotive, Hartford, Conn., 1798 . tº * . lxiv.
. Robert Fulton–First Steamboat, 1803 . & & tº tº iº . lxiv,
& 4 “ — Zhe Clermont, 1807 g © ſº © * © . lxv
Oliver Evans' Steam Engine, Oructor Amphibolis, 1804 . tº . lxvi
First Small Railroad on Beacon Hill, Boston,’ 1807 . . . lxxii
Second “ & & at Leiper's Quarries, Delaware Co., Pa., 1809 . lxxii
First Locomotive on Raihroad in America, 1829 gº e sº . lxxii
First Regular Railway—B. & O. in Maryland, 1830 * > g º . lxxiii
Second “ 6 & —South Carolina, 1830 g & tº . lxxiii
Third & “ —The Columbia (Penna. Central), 1830 sº . lxxiii
Fourth “ “ –Philadelphia, Germantown & Norristown, 1830 lxxiii
Fifth “ “ –Camden & Amboy, N.J., 1831 * e . lxxiii
Sixth “ “ —Newcastle & Frenchtown, Delaware, 1831 . lxxiii
The B. & O. Offer $4,000 for the Best American Locomotive, 1831 . lxxiv.
Colonel Long's First Engine on the Newcastle & Frenchtown Road, 1831 lxxiv.
Matthias Baldwin’s Model Engine & ge lxxvi
The B. & O.'s Prize of $4,000 Won in 1834 by Phineas Davis, of York, Pa. lxxvii
Stacey Costell’s Engine, 1834 & & * ë & . lxxvii
Thomas Halloway's Engine, 1831 . ſe & {º e . lxxviii
English Locomotives Imported, 1832 * de te e . lxxviii
The Old Ironsides, 1832. e ſº * tº tº ſº e e . lxxix
Ilong & Norris' Black Hawk, 1832. tº . lxxx
William & Richard Norris' George Washington, 1836
. . º . lxxxi
The Norris Engine, 1837 * © {º tº {º & . lxxxii
The Baldwin Engine, 1834. * tº . ę © * . lxxxiii
Garrett & Eastwick, 1835 º º © ſº e * . lxxxv
The Samuel D. Angham, . jº * cº sº § ſe sº . lxxxv
The Bury Boiler e tº tº * e * tº . lxxxv
Henry R. Campbell's Patent . ſº wº tº e wº 4. . lxxxvii
The Hercules, 1837 & sº * * , † g e e tº . lxxxvii .
Joseph Harrison, Jr's., Connecting Rod . • Q º ſº tº . lxxxviii
Eastwick & Harrison's Gowan & Marx, 1839 g tº & © . Xci
Eastwick, Harrison & Winans. & e tº te e º . xcii
#
}
CONTENTS. iii
PAGE
Russian Engine . * ſº •º * @ Q & © & . xciii
Baldwin's Austrian Order, 184 © sº fe ſº * tº * . xciv
Baldwin’s Patents . wº gº tº * o * > g se ſº ... xciv
Six-wheeled Engine, 1842 . * * * * sº gº * > • XCV
Flexible Beam Truck, 1842 . gº sº jº * º * cº . xcvi
Central Railroad of Georgia . tº ſº tº * & º g . xcviii
Levi Bissell's Air Spring o tº & g e ſº o º . xcviii
Asa Whitney joins Mr. Baldwin—the firm of Baldwin & Whitney . . xcix
The French & Baird Stack . * © º * tº Q * > • C
The Grimes Stack . . . . . . . . . . . . c
The Radley & Hunter Stack . e ſº * } º s * tº • C
The Cut-off Valve . . g e ſº wº tº tº º tº . ci
Baldwin’s Eight-wheels-connected “C” Engine . * gº & . cii
The M. G. Bright for Madison & Indianapolis Railroad. * e . ciii
The John Brough for Madison & Indianapolis Railroad. g * . ciii
The Governor Paine, first sixty-miles-an-hour Engine, made by Baldwin &
Whitney, 1849. $º ſº º ge * gº tº § tº . civ
The Mifflin, Blair and Indiana Engines, Pennsylvania Railroad . • CW
Matthew Baird and M. W. Baldwin partners . © & * te . cvi
John Brandt’s Ten-wheeled Engine . tº e º º e . cvii
Charles Whitney, of Central Railroad, Georgia, Three Engines, Clinton,
Athens, and Sparta . sº * & § * i.e. e * . cviii
Thomas Rogers', of Rogers' Locomotive Works, Link Motion * . cik
Baldwin's Variable Cut-off Adjustment . º * * * * . cxi
David Clark and M. Baldwin’s Feed-water Heater . . . . . cxii
#:
g
M. Baird's Fire Brick Arch for Combustion . ſº tº te & . cxiii
The Delano Grate . gº ſº g º tº & tº & ſº . cxiv.
A. F. Smith’s Combustion Chamber * & * } gº wº tº . cxiv.
The Dimpfel Boiler g º & * e * * sº tº . cxiv.
Mr. Wilder’s New Boiler g & * > º * ſº tº * • CXV
The Bissell Pony Truck . tº ſº * g tº ſº sº gº . cxvi
Steel Tires first used for Engines—the Dom Pedro II (Brazil) Railway
of South America, 1862 . * tº tº * ſº e © . cxvi
Steel Fire Boxes first used by Pennsylvania Railroad in 1861 . * . cxvi.
Horizontal Cylinders . . . . . . . . . . cxvii
Death of M. W. Baldwin, 1866, founder of Baldwin's Locomotive Works czvii
Alexander Mitchell’s Consolidation Engine . * * * e . cxix
The Thomas Iron Works Mogul Fngine . * & º * & • CXX
Steel Flues First Used, 1868, Pennsylvania Railroad sº º tº . cxxi
Steel Boilers First Used, 1868, Pennsylvania Railroad . * ę . cxxi
Straight Boilers revived, 1866 tº tº Q tº º º * . cxxi
Freight Locomotive, Consolidation type, 1873. & & c g . cxxii
Freight and Passenger Mogul type for the Hango-Hyvinge Railroad,
Finland . * & e tº e te * e * º . cxxiv.
First American Locomotives for New South Wales . tº & te . cxxvi
First American Locomotives for New Zealand and Victoria . e . cxxvi
Highest Speed Attained in Great Britain by Locomotives, August 6, 1888,
Report of a Race . ſº tº Ç wº ‘e * e . cxxix
Highest Speed Record on American Railroads * 4- & g . cxxxii
Poetry of The Locomotive (Wm. D. Lewis) . . © º • , CXXXV
The Song of Steam (Geo. Cutter) . . . . . . . . cxxxvi



ILLUSTRATIONS IN THE HISTORY OF STEAM.
PORTRAIT of JAMES WATT . .
AEOLIPILE OF HERO, B. c. 130 .
DE CAUS” ENGINE (STEAM Toy), 1615 º © e
GIOVANNI BRANCA’s STEAM WHEEL, 1629 . Q
THE MARQUIS of WoRCESTER’s ENGINE, 1663 . e
SAVARY's ENGINE, 1699 º º
PAPIN's ENGINE, 1689 e e
NEWCOMEN's ENGINE, 1705 º
WATT's Gover NOR wº º º
MURDOCK's MoDEL OF STEAM LocoMotive, 1785 .
PORTRAIT OF GEORGE STEPHENSON
CUGNOT's ENGINE, 1770 & e
TREVETHICK's STEAM CARRIAGE, 1803
BLENKINSOP's Tooth-WHEELED LOCO
BRUNTON'S STILT LocoMotive, 1813
STEPHENSON's LocoMotive, 1815
66 “Rocket,” 1829 .
MOTIVE, 1811 .
te º gº e
TREVETHICK's CIRCULAR RAILWAY, LONDON, 1808 .
PoRTRAIT of JAMES FULTON º
FITCH’s STEAMBOAT . e º
FULTON's FIRST STEAMBOAT, 1803
& & “THE CLERMONT,” 1807
o º c e
gº © & ©
OLIVER Evans’ “ORUCTOR AMPHIBoLIs,” 1804 ©
THE “OLD IRoNSIDEs,” 1832 .
BALDWIN's ENGINE, 1834 . ſº
CAMPBELL’s FIRST DESIGN for AN EIGHT-WHEELED LocoMotive,
GARRETT & EASTwick’s “HERCULEs,” 1837 e e
EASTwick & HARRIson’s “GowAN AND MARx,” 1839
HARRISON & WINANs’ RUSSIAN ENGINE, 1844 . &
BALDw1N’s SIx-WHEELS-CONNECTED ENGINE, 1842 .
FLExIBLE BEAM TRUCK, 1842, ELEvation AND HALF PLAN
BALDw1N’s EIGHT-WHEELs-Con NECTED “C” ENGINE, 1846
&g FAST PASSENGER ENGINE,
VARIABLE CUT-OFF ADJUSTMENT, 185
HoRIzoNTAL CYLINDERs, 1858 .
FREIGHT LocoMotive, “CoNSOLIDATION’” TYPE, 1870
STEAM YACHT “ATALANTA” (CRAMP
(iv)
1848 o o
3 e o º
e º & tº
& Sons), 1884
©
e
º
PAGE
i
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XV’
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XXXV
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lxxxviii
XC
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XCV
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cii
CV
cxi
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cxxii
cxxxviii
THE HISTORY OF STEAM
AND ITS PRACTICAL APPLIANCES.
§#
º#
-º-º-º:
e Jºs VººDºº,
JAMES WATT, the improver of the steam-engine, was born at
Greenock in Renfrewshire, Scotland, on the 19th of January, 1736.
He was the descendant of a family the members of which, for several
generations, had exhibited no small degree of ability. His great-
grandfather was the proprietor and farmer of a small estate in Aber-
deenshire; but taking part in the insurrection headed by Montrose,
he was killed in one of the battles then fought, and his little property
was confiscated. This person's son, Thomas Watt, was but an in-
fant at the time of his father's death. Left almost destitute by that




(v)
V1 º
HISTORY OF THE STEAM-ENGINE.
event, he was taken care of by relations till he grew up, when, man-
ifesting a decided taste for mathematical science, in which he had
already attained great proficiency, he removed to Greenock, and
settled there as a teacher of navigation, surveying, and general
mathematics. In this situation he acquired great reputation, and
became one of the most respected and influential persons in the
neighborhood, filling for several years the office of baron-bailie, or
chief magistrate of the burgh of Crawford's Dike. He died in
1734, at the advanced age of ninety-two years, and was buried in
the West Churchyard of Greenock, where, in the inscription on his
tombstone, he is styled “Professor of Mathematics.” He had two
sons, John and James; the elder of whom inherited his father's
mathematical talent, and followed his profession, first at Ayr, and
afterwards in Glasgow, where he also enjoyed a large business as a
surveyor. Among his qualifications was that of drawing with very
great neatness and accuracy. He died in 1737, at the age of fifty
years; and a chart of the course of the river Clyde which he left
was published a few years afterwards by his younger brother James.
This James Watt, the father of the great engineer, had settled in his
native town of Greenock, exercising his abilities, not in the special
occupation to which his father and elder brother had devoted them-
selves, but in the more general sphere of a merchant and public-
spirited citizen. During a quarter of a century he held the offices
of town-councillor and magistrate of Greenock; and in the discharge
of these offices he was noted for his activity and zeal for improve-
ment. It was only in consequence of his own refusal that he did
not fill the chair of provost, or chief-magistrate, in Greenock. IHis
special occupations were those of a block-maker and ship-chandler;
but, in addition to these, he engaged in house and ship building and
general trading. The failure of some of his commercial speculations
deprived him, long before his death, of a great part of the fortune
which he had acquired. He died in 1782, at the age of eighty-four,
laving for some years lived retired from business. His wife, Agnes
Muirhead, the mother of the illustrious Watt, was of a very respect-
able family; of her disposition, and the character of her mind, we
have no particular account.
The subject of our memoir was the elder of two sons, the only
children of the Greenock merchant and his wife. The younger, who
was named John, had resolved to follow his father's profession, but
HISTORY OF THE STEAM-ENGINE. vii
was drowned in 1763 on a voyage from Greenock to America, at
the age of twenty-three years. James Watt, who was then in his
twenty-seventh year, was thus left the only surviving son.
WATT'S CHILDHOOD AND EDUCATION.—SETTLES IN GLASGOW
AS A MATHEMATICAL INSTRUMENT MAKER.
Regarding Watt's childhood and the course of his early education,
we have not much information. From the extreme delicacy of his
health when a child, he was able to attend the public school at
Greenock only irregularly and at intervals; so that much of his
elementary instruction was received at home. His mother taught
him reading, and his father writing and arithmetic; and in his
confinement to the house, of which his almost constant indisposition
was the cause, he acquired those habits of inquisitiveness and
precocious reflection so often observed in feeble-bodied children.
“A gentleman one day calling upon his father, observed the child
bending over a marble hearth with a piece of colored chalk in his
hand. “Mr. Watt,” said he, “you ought to send that boy to school,
and not allow him to trifle away his time at home.’ ‘Look how my
child is employed before you condemn him,' replied the father. The
gentleman then observed that the child had drawn mathematical
lines and circles on the hearth. He put various questions to the
boy, and was astonished and gratified with the mixture of intelligence,
quickness, and simplicity displayed in his answers: he was then
trying to solve a problem in geometry.”* In this way, not by means
of regular lessons, but by incessant employment on some subject of
interest or other, Watt in early years acquired much of that general
information for which he was in after-life remarkable. His father
having, as a means of amusement, presented him with a number of
tools such as are used in cabinet-work, he became exceedingly ex-
pert in handling them, and began to exhibit his mechanical taste in
the fabrication of numerous toys, among which is mentioned a small
electrical machine, with a bottle, probably for a cylinder.
An anecdote related of him when he was about fourteen years of
age, indicates the extreme restlessness and activity of his mind as a
boy. Once having accompanied his mother on a visit to a friend in
Glasgow, he was left behind on her return. The next time, however,
*Arago's Zife of Watt.
viii HISTORY OF THE STEAM. ENGINE.
that Mrs. Watt came to Glasgow, her friend said to her: “You must
take your son James home; I cannot stand the degree of excite-
ment he keeps me in ; I am worn out for want of sleep. Every
evening before ten o'clock, our usual hour of retiring to rest, he
contrives to engage me in conversation, then begins some striking
tale, and, whether humorous or pathetic, the interest is so over-
powering, that the family all listen to him with breathless attention,
and hour after hour strikes unheeded.” This wonderful faculty of
story-telling, which robbed the Glasgow lady of her sleep, Watt
preserved throughout his life to a degree unparalleled perhaps
except in Sir Walter Scott.
As he advanced into youth, Watt began to occupy himself with
the sciences. The whole range of physics had attractions for him.
In excursions in all directions from Greenock, and especially to the
banks of Loch Lomond, he studied botany, entered eagerly into the
geological speculations then beginning to awaken interest, and col-
lected traditions and ballads—all with equal enthusiasm. At home,
during his hours of less robust health, he devoured books on
chemistry and general science, among which was Gravesande's
Elements of Matural Philosophy. Medicine, surgery and anatomy
obtained their share of his attention; the detailed descriptions of
diseases given in medical works were familiar to him; and he was
one day detected carrying into his room the head of a child recently
dead, which he had managed somehow to procure, with the intention
of dissecting it. In short, by incessant reading and mental activity,
he had, before he entered on his nineteenth year, acquired and
digested a vast mass of miscellaneous scientific information.
Whether from the prevailing bend of his genius towards me-
chanical contrivance, or from some other cause connected with the
nature of his father's trade in Greenock, the profession which Watt
chose was that of a mathematical and nautical instrument maker.
To learn this art, or rather to perfect himself in it, he went to Lon-
don in 1755, and placed himself under Mr. John Morgan, an instru-
ment-maker in Finch Lane, Cornhill. Thus, says M. Arago, “the
man who was about to cover England with engines, in comparison
with which the antique and colossal machine of Marly is but a
pigmy, commenced his career by constructing with his own hands
instruments which were fine, delicate, and fragile—those small but
admirable reflecting sextants to which navigation is so much in-
$
HISTORY OF THE STEAM-ENGINE. ix
debted for its progress.” After a residence of little more than a
year in London, his continued feeble health obliged him to return
to Scotland, where, in accordance with his own wishes and the
advice, of his friends, he commenced business as a mathematical
instrument maker in Glasgow. The date of his settlement in this
city, where he was afterwards to work out some of his greatest tri-
umphs, was 1757, when he had just passed his twenty-first year.
At first he experienced considerable opposition, and a great deal of
annoyance—one of the privileged corporations of the town regard-
ing him as an intruder, and not entitled to practice the business
which he professed, at that time a comparatively rare one in Scot-
land. Various means were tried to soothe down the offended par-
ties, but without effect; they would not even allow the young
tradesman to set up a workshop on the smallest scale. At length,
apparently through the exertions of the friends of his family, he
was rescued from the dilemma by the authorities of the university,
who gave him a convenient room within their precincts, and con-
ferred on him the designation of Mathematical Instrument Maker to
the College of Glasgow, a proceeding which was sufficient to quash
all corporation enmity. In the workshop thus afforded him, Watt
continued for a number of years to pursue his trade of making sex-
tants, compasses, etc., for which articles he found customers both
within and without the walls of the university. “There are still in
existence,” says M. Arago, “some small instruments which were at
this time made entirely by Watt's own hand, and they are of very
exquisite workmanship. I may add that his son has lately shown
me some of his first designs, and that they are truly remarkable for
the delicacy and precision of the drawing. It was not without rea-
son that Watt used to speak with complacency of his manual dex-
terity.” This, as we have seen, was a gift which seemed to be
hereditary in the family.
At the time when Mr. Watt took up his residence in Glasgow,
there was a cluster of eminent men gathered together within the
university such as is rarely to be found. Adam Smith was Professor
of Moral Philosophy; Robert Simson of Mathematics; the illus-
trious Black filled the chair of Chemistry; and Mr. Dick, who,
though less known to fame, is said to have been a man of great
powers, held the professorship of Natural Philosophy. Robison,
afterwards so celebrated for his attainments in physical science,
X IIISTORY OF THE STEAM-ENGINE.
which he displayed as a professor both in Edinburgh and Glasgow,
was then a student. Watt's position within the college brought him
into contact with all these able men; and the shop of the young
mathematical instrument maker soon became a lounging-place for
both professors and students—the former of whom found in him a
man equal to themselves in acquirements, and of a remarkable
originality of mind; the latter, a good-natured and willing assistant
in their speculations and researches in physics. “I had always,”
says Professor Robison, referring to those days when he first became
acquainted with Watt, “a great relish for the natural sciences, and
particularly for mathematical and mechanical philosophy. When I
was introduced by Drs. Simson, Dick, and Moor to Mr. Watt, I saw
a workman, and expected no more; but was surprised to find a
philosopher, as young as myself, and always ready to instruct me.
I had the vanity to think myself a pretty good proficient in my
favorite study, and was rather mortified at finding Watt so much
my superior. Whenever any puzzle came in the way of us students,
we went to Mr. Watt. He needed only to be prompted; for every-
thing became to him the beginning of a new and serious study, and
we knew that he would not quit it till he had either discovered its
insignificancy or made something of it. He learned the German
language in order to peruse Leopold's Theatrum Machinarum. So
did I, to know what he was about. Similar reasons made us both
learn the Italian language. When to his superiority of knowledge
is added the naïve simplicity and candor of Mr. Watt's character, it
is no wonder that the attachment of his acquaintances was strong.
I have seen something of the world, and I am obliged to say I never
saw such another instance of general and cordial attachment to a
person whom all acknowledged to be their superior. But that
superiority was concealed under the most amiable candor, and a
liberal allowance of merit to every man. Mr. Watt was the first to
ascribe to the ingenuity of a friend things which were nothing but
his own surmises, followed out and embodied by another. I am the
more entitled to say this, as I have often experienced it in my own
case.”
This and similar accounts enable us to figure Mr: Watt during his
early residence in Glasgow—a young, amiable, and ingenious man,
a great favorite with professors and students, occupied during the
greater part of the day in his workshop, but constantly engaged in
HISTORY OF THE STEAM-ENGINE. xi
the evening in some profound or curious question in mathematics
or physical science; quite aware of all that was going on in the
Scientific world, and taking an interest in all new discoveries, par-
ticularly those of his friend Dr. Black in chemistry. As a remark-
able instance of the extent of his theoretical research, and of his
perseverance in whatever undertaking struck his fancy, it is men-
tioned that although he had no ear for music, and could never, all
his life, distinguish one note from another, or derive pleasure from
any musical performance, he astonished all his friends by construct-
ing an organ, which, besides exhibiting numerous ingenious me-
chanical improvements, was particularly admired by musicians for its
greatly superior powers of harmony. His only guide in this diffi-
cult achievement must have been the Harmonies of Dr. Smith, of
Cambridge, a work treating of some of the extreme problems of
acoustics, but so profound and obscure, that few persons in the
kingdom could have understood a page of it.
In the year 1763, Mr. Watt married his cousin, Miss Miller, who
is described as a person cf much wit and accomplishment, with great
sweetness of temper. At the same time he removed from his apart-
ments in the college to a house in town, in which he continued his
profession, enlarging it, however, so as to include engineering. He
accordingly began to be consulted in the construction of canals,
bridges, and other works of large dimensions requiring science and
skill. In the midst of these engineering avocations, a circumstance
occurred which exercised a more important influence upon his
career than any of them. In the winter of 1763–64, Mr. Anderson,
who had succeeded Dr. Dick as Professor of Natural Philosophy,
and who is still remembered as the founder of the Andersonian
University, Glasgow, finding that a small model of Newcomen's
steam-engine, which he had among his apparatus, would not work,
sent it to Mr. Watt for repair. The subject of steam-machinery had
several times before come under Mr. Watt's notice. His friend Mr.
Robison had, in 1759, broached to him the idea of applying steam-
power to wheel-carriages; and in 1761–62, he had occupied himself
with various experiments on a Papin's Digester, with a view to
measure the force of steam. These discussions and experiments,
however, terminated in no particular result; and it was Professor
Anderson's model of Newcomen's engine that begot in Watt's mind
the germ of those ideas respecting the use of steam-power which
2
xii HISTORY OF THE STEAM-ENGINE.
have led to such gigantic consequences. As Newcomen's engine
represents the point of progress to which steam-machinery had been
brought before Watt applied himself to the subject, this seems the
proper place for introducing a sketch of the history of steam-power
up to that period. The little black model on the instrument-maker's
table was the condensed epitome, as it were, of all that the world
knew of steam-power before that time; in the brain of the young
newly-married instrument-maker, bending by candlelight over the
model, lay, as yet undeveloped, all that the steam-engine has since
become. *
HISTORY OF THE STEAM-ENGINE BEFORE THE TIME OF WATT.
Steam, or, as they called it, “water transformed into air by the
action of fire,” was of course known to the ancients, and was used
for various ordinary purposes in the arts. The first description,
however, of the application of steam as a mechanical power occurs
in the writings of Hero, a Greek of Alexandria, who lived in the
third century before Christ. This writer, whose attainments in
science were very great for his age, describes a toy called the
AEolipile, the purpose of which is to produce a rotatory motion by
the action of steam. The best familiar illustration of the appearance
of such an apparatus, in one of its simplest forms, would be one of
those turnstiles, with four horizontal spokes, which are sometimes
placed in by-paths. Were one of these revolving stiles made of
iron, and hollow throughout, with a hole in the corresponding side
of each of the spokes, and were the upright shaft to be fixed into a
socket beneath, entering a boiler, then the steam rushing up the
shaft arid along the four spokes would hiss out in four jets at the
side openings, and the whole would, owing to the force of reaction,
whirl round in the opposite direction.
Here, therefore, nearly two thousand years ago, we find steam
applied to produce a rotatory motion. By connecting the simple
rotatory apparatus above described with additional machinery, mills
could be driven, and other important mechanical effects produced.
Indeed, the construction of rotatory steam-engines has, in recent
times, occupied much attention; and, under the name of Barker's
Mill, the principle of the AEolipile has been turned to account—the
reaction caused by the escape of steam having been made in some
instances to do the work of six or eight, or even fifteen horses.
HISTORY OF THE STEAM. ENGINE. xiii
The principle of the AEolipile, however, and of the rotatory engines
which are modifications of it, is evidently different from that of
steam-engines usually so called, in which the power consists not in
the mere reaction caused by steam violently escaping into the atmo-
sphere, but in the prodigious expansive force of steam itself. Water,
when converted into steam by the application of heat under the
ordinary pressure of the atmosphere, occupies, it is well known, 1728
times its original bulk; in other words, a cubic inch of water is, on
its conversion into steam, expanded so as to fill a space of a cubic
foot. This is nearly eight times as great as the expansive force of
gunpowder. Now, if by any means we could catch water in the act,
as it were, of passing into steam, so as to obtain the use of the enor-
mous expansive force for our own
purposes, it is evident that we
could produce most powerful
effects by it. To do this—to catch
water in the act of passing into
steam, and turn the expansive force
to account—is the purpose of
steam-engines properly so called.
Even this use of the expansive
force of steam was in some degree
known to the ancients. Often, as
M. Arago observes, in casting the
fine metal statues for which ancient
art is so famous, a drop of water
or other liquid would be left enclosed in the plaster or clay moulds
when the molten metal was poured in; and the consequence would
be an explosion, and, in many cases, a fearful accident, from the
instantaneous conversion of the enclosed drop of liquid into steam.
Arguing from such instances, the ancient naturalists accounted for
earthquakes and submarine explosions on a similar principle, by
supposing the sudden vaporization of a mass of water by volcanic
heat. Nor were the ancients afraid of handling the power which
they thus recognized. In the images of the ancient gods were con-
cealed crevices containing water with the means of heating it; and
tubes proceeding from these crevices conducted the steam, so as to
make it blow out plugs from the mouths and foreheads of the images
with loud noise and apparent clouds of smoke. A more ingenious
THE AEO LIPILE OF HERO OF
ALEXANDRIA, B. C. I 3O.

xiv. HISTORY OF THE STEAM ENGINE.
device still, and which represents the utmost extent to which the
ancients carried their use of the expansive force of steam, is one
described by Hero, the purpose of which seems likewise to have
been priestly imposition. To accomplish this trick, Hero directs
vessels half full of 'wine to be concealed inside of two figures, in
the shape of men standing on each side of an altar. From these
vessels, tubes, in the form of bent siphons, with the short end in the
wine, proceed along the extended arms of the figures to the tips of
their fingers, which are held over the flame of the sacrifice. Other
tubes proceed from the same vessels downwards, through the feet
of the figures, communicating through the floor with the altar and
the fire. “When, therefore,” says Hero, “you are about to sacrifice,
you must pour into the tubes a few drops, lest they should be injured
by heat, and attend to every joint, lest it leak; and so the heat of the
fire, mingling with the water, will pass in an aérial state through
these tubes to the vases inside the figures, and, pressing on the wine,
make it to pass through the bent siphons, until, as it flows from the
hands of the living creatures, they will appear to sacrifice as the
altar continues to burn.” Here we have the expansive force of
steam employed directly to raise a liquid, by pressure, above its
natural height.
From the time of Hero down to the beginning of the sixteenth
century no advance appears to have been made in the application
of steam-power. It would appear that as early as I543 a Spanish
captain named Blaxo de Garay showed a steamboat in the harbor
of Barcelona of his own invention : it is said that this was on the
principle of the AEolipile. Solomon de Caus, a Frenchman of
Normandy, who, after a residence in England, where he was
employed in designing grottos, fountains, etc., for the palace of
the Prince of Wales, afterwards Charles I., at Richmond, returned
to the continent, and published an account of these and other
inventions at Frankfort in the year 1615. De Caus's steam
invention is a modification, in a more patent and distinct form,
of the last-mentioned artifice of Hero. A hollow copper globe
is filled to the extent of two-thirds or thereby with water, through
a funnel-shaped pipe, which enters it, and which is furnished with
a stop-cock. Besides this pipe, another descends nearly to the
bottom of the globe, so as to have its termination beneath the
water. It is likewise furnished with a stop-cock, and its nozzle is
HISTORY OF THE STEAM-ENGINE. x,y
small. If now the vessel be placed over a fire, with the stop-cock
of the first pipe shut, and that of the other open, it is evident that
when the water begins to boil, the steam being enclosed, will press
down the water, and
compel it to rush up the
second pipe, forming a
jet.
Such is the steam toy
of De Caus, upon which
many French writers
have founded the claim
that steam should be
considered a French
invention. If, however,
the merit of a man, with
regard to an invention
with the origin of which
he is concerned, is to be
measured by his own
perception of its impor-
tance, the merit of Solo-
mon de Caus, with re-
gard to steam-machinery,
cannot be compared with
that of the Marquis of
Worcester (known in
political history as the
Earl of Glamorgan), who,
in his Century of Inven-
tions, published in 1663,
describes “an admirable
and most forcible way
to drive up water by
fire, not by drawing or
sucking it upward,” but
DE CAUS, A. D. 1615.
by a method according to which “one vessel of water rarefied
by fire driveth up forty vessels of cold water.” What value the
marquis attached to this invention appears from the striking lan-
guage he uses with regard to other modifications of it. Of one he

xvi HISTORY OF THE STEAM-ENGINE.
says: “I call this a semi-omnipotent engine, and do intend that a
model thereof be buried with me.” He also describes a water-work
capable, he says, of raising water with the utmost facility to the
height of a hundred feet, and which will, therefore, “drain all sorts
of mines, and furnish cities with water though never so high
seated.” This he pronounces “the most stupendous work in the
whole world—an invention which crowns his labors, rewards his
expenses, and makes his thoughts acquiesce in the way of further
inventions.” -
In 1629 Giovanni Branca, an Italian machinist, invented and pub-
Es
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lished a highly suggestive contribution to steam discovery. This
represents the operation of pounding, the pestles being acted on by
pulleys and cog-wheels, set in motion by a jet of steam issuing from
a pipe against the vane of a horizontal wheel. This was the first
practical steam-engine. - -
It is ascertained that the Marquis of Worcester had actually con-
structed a steam model apparatus. Although, however, it would
thus seem that steam-power, in one of its most imposing forms, was
in actual operation so early as 1656, the invention does not appear
to have taken root; and it is not till 1699, upwards of thirty years
after the Marquis of Worcester's death, that we find the steam-





HISTORY OF THE STEAM-ENGINE. - xvii
engine again pressed on public notice. In that year Captain Thomas
Savary exhibited to the Royal Society a model of an engine for
draining mines, and raising water to great heights. The difference
between the Marquis
of Worcester's inven-
tion and Savary's con-
sisted in this, that
whereas “the mar-
quis's model appears
to have been placed
on or below the level
of the water to be
raised, so that the
water was forced up
solely by the elastic
force of the steam, Sa-
vary, on the other hand,
erected his engine at
a height of nearly thir–
ty feet above the level
of the water.”
The improvement
of Savary consists in
combining the force
of atmospheric suction,
as it is usually called,
with that of steam-
pressure; using the
first to raise the water
thirty feet, and then
the other to raise it
thirty feet or more
additional; and when
it is considered that,
in the actual working
;
º
†:
THE MARQUIS OF worcestER ENGINE, 1663.*
engine, there was not only one receiver, but two, which could be
* The Marquis of Worcester's “Water Commanding Engine” was patented in 1663,
but the inventor was engaged on the mechanical arrangements of it as early as 1647.





xviii HISTORY OF THE STEAM-ENGINE.
alternately filled with steam and cooled, so as to prevent the loss of
time, the value of the improvement will be seen to be very great.
sº … sº ,-
§º
#: . .
"Er:E:
º: ---
º
:#E:
-**
i.e.
-*E=E
-
-º---
SAVARY's ENGINE, 1699.”
Savary called his machine the “Miner's Friend;” it seems, however,
to have been used only for the purpose of raising water in houses.
On page xvii is a drawing of this engine. A, A* are two cold water vessels connected
by B, B1–the steam pipe—with C, the boiler, set in D, the furnace. The cold water ves-
sels A, A], also are connected with E, the vertical water pipe, by means of F, F, con-
tinuations of the same pipe conducted into and nearly touching the bottom of each vessel
A, Al. G, G1 are two water supply pipes with valves, a, a”, dipping into H, the well.
It is obvious that by uniting these pupes and placing the valves in the upper bend of
each, it would be sufficient for a single pipe to dip into the water to be raised. On the
steam pipe B, B1 is b, a four-way steam cock, operated by b", its lever handle; and on
the horizontal portion of the water pipe F, F1 is c, a four way water cock operated by
c1, its lever handle. - *
# In the 21st volume of Philosophical Transactions, published in 1700, there is a de-

HISTORY OF THE STEAM-ENGINE. xix
The next great contribution to the steam-
engine came from a French engineer, Denis
Papin, known for other important mechanical
inventions. His important service to steam-
power consisted in the idea of making it act
through the cylinder and piston. In De Caus's
and Savary's apparatus the steam pressed di-
rectly upon the surface of the water; but
Papin conceived the idea of introducing the
steam into the bottom of the receiver, so as to
force up, by its elasticity, a tightly-fitting plate
or piston, which would again descend by the
pressure of the atmosphere as soon as the
steam beneath was condensed. The importance
of this modification can hardly be overrated,
when it is considered that it amounts to the ap-
plication of steam-power to produce the mo-
tion of a rod up and down in a cylinder. This PAPIN's STEAM AND
was the great step, the conciliation of steam, AIR ENGINE,
as it were, into a regular moving power at the MAY, 1689.”
command of man; and, as M. Arago observes,
the procuring afterwards, from the strokes of the piston, the power
scription, with an engraving, being “An account of Mr. Thomas Savery's engine for
raising water by the help of fire.” The engine may be understood by the double diagram,
see page xviii. The drawing on the left is the front of the engine; that on the right is a
side view. A, is the furnace; B, the boiler; C, two cocks which convey the steam from
the bottom in order to discharge it again at the top; D, the vessels which receive the
water from the bottom in order to discharge it again at the top; E, valves; F, cocks
which keep up the water, while the valves on occasion are cleaned; G, the force pipe;
H, the sucking pipe; and I, the water.
* AA is a tube of uniform diameter throughout, close shut at the bottom; BB is a
piston fitted to the tube; DD, a handle fixed to the piston; EE, an iron rod movable
round an axis F; G, a spring pressing the cross-rod EE, so that the said rod must be
forced into the groove H, as soon as the piston with the handle has arrived at such a
height as that the said groove H appears above the lid II; L is a little hole in the
piston, through which the air can escape from the bottom of the tube AA, when first the
piston is forced into it. The use of this instrument is as follows:—A small quantity of
water is poured into the tube AA, to the depth of three or four lines; then the piston is
inserted and forced down to the bottom, till a portion of the water previously poured in
comes through the hole L; then the said hole is closed by the rod M.M. Next the lid
II, pierced with the apertures requisite for that purpose, is put on, and a moderate fire
being applied, the tube AA soon grows warm (being made of thin metal), and the

XX HISTORY OF THE STEAM-ENGINE.
to turn millstones, or the paddles of a steamboat, or to uplift the
massy hammer, or to move the huge clipping shears—these were
but secondary problems. Papin, however, did not work out his
own conception—did not perceive all its consequences.
The next modification of the steam-engine, and its ultimate one
before it came into the hands of Watt, consisted, it may be said, in
the union of Savary's idea with that of Papin. The authors of this
invention—which may in reality be considered as the first working
steam-engine—were Thomas Newcomen, an ironmonger, and John
Cawley, a glazier, both of Dartmouth, in Devonshire. In the year
I705 these two individuals “constructed a machine which was meant
to raise water from great depths, and in which there was a distinct
vessel where the steam was generated. This machine, like the small
model of Papin, consisted of a vertical metallic cylinder, shut at the
bottom and open at the top, together with a piston accurately fitted,
and intended to traverse the whole length, both in ascending and
descending. In the latter, as in the former apparatus also, when the
steam was admitted into the lower part of the cylinder, so as to fill
it, and counterbalance the external atmospheric pressure, the ascend-
ing movement of the piston was effected by means of a counter-
poise. Finally, in the English machine, in imitation of Papin's, as
soon as the piston reached the limit of its ascending stroke, the
steam which had impelled it was refrigerated; a vacuum was thus
produced, and the external atmosphere forced the piston to de-
scend.” “ The only novelty in Newcomen's engine, over and above
what had existed either in Papin's or in Savary's model, was the
mode of condensing the steam in the cylinder. This was effected
not by simply withdrawing the heat from the bottom of the cylinder,
as Papin had done, nor by dashing cold water on the outside of it,
as in Savary's apparatus, but in directing a stream of cold water
water within it being turned into steam, exerts a pressure so powerful as to overcome
the weight of the atmosphere and force up the piston BB, till the grove H, of the handle
DD, appears above the lid II, and the rod EE is forced, with some noise, into the said
groove by the spring G. Then forthwith the fire is to be removed, and the steam in the
thin metal tube is soon resolved into water, and leaves the tube entirely void of air.
Next the rod EE, being turned round so far as to come out of the groove H, and allow
the handle D to descend, the piston BB is forthwith pressed down by the whole weight
of the atmosphere, and causes the intended movement; which is of an energy great in
proportion to the size of the tube. , -
* Arago's Life of Watt.
HISTORY OF THE STEAM-ENGINE. xxi
into the inside of the cylinder at every rise of the piston. This
improvement—an important one at the time—is said to have been
made by accident, from the circumstance of water once finding its way
into the cylinder through a hole in the piston, and astonishing the
onlookers by its results. The entire action of Newcomen's engine
will be understood from the annexed cut, representing a section of
it. B is the boiler, built over a furnace, and kept about two-thirds
full of water; the quantity of water being regulated by means of
two vertical tubes with stop-cocks (GG), which descend into the
boiler, the one to a greater depth than the other, so that when the
boiler contains its proper quantity of water, the longer tube shall
dip into it, while the shorter
does not reach it. When the
boiler is heated, the pressure
of the steam in its upper part
will, if the proper quantity of
water be in the boiler, force
the water up the longer pipe,
while only steam issues from
the shorter. Should both pipes
emit water, then it is known
that the boiler is too full;
should both emit steam, that it
is not full enough; and the
supply can be regulated ac-
cordingly. Besides these gauge-
pipes there is in the boiler a
safety-valve (SV), loaded so as
to lie tight until the steam in
the boiler accumulates to a degree sufficient to force it up. From
the boiler the steam passes through the connecting tube, guarded
by the regulating-valve (V), made so as to open and shut easily,
into the cylinder (C). Up and down in this cylinder, which is
open at the top, moves the piston (P), attached by means of
the piston-rod (M) to a flexible chain, which is fastened to the
top of the arch at the end of a beam, moving on the pivot (I).
The end of the beam to which the piston-rod is attached is made
lighter than the other end, so that when the engine is at rest, it
ascends and pulls up the piston to the top of the cylinder. The
NEWCOMEN's ENGINE, 1705.

xxii HISTORY OF THE STEAM-ENGINE.
piston thus lying at the top of the cylinder, lets the steam from the
boilér be admitted through the regulating-valve (V). The steam
rushing in expels the air which was in the cylinder through the
snifting-valve (H), which is at the bottom of the cylinder, and so
Constructed, that although it permits the escape of the air, it allows
none to enter. The whole space of the cylinder underneath the
piston being now filled with steam, the next operation is to con-
dense it. This is done by turning a cock (R) in the tube (A), which
descends from a cistern kept constantly full of cold water. The
water, tending to rise to the height from which it has fallen, spouts
into the cylinder, striking against the bottom of the piston, and fall-
ing down in a shower of drops, which cool the cylinder and con-
dense the steam. This condensation of the steam produces a
vacuum in the cylinder; and the piston, pressed down by the
weight of the atmosphere outside, rapidly descends—the water
which was thrown into the cylinder being carried off by the long
eduction-pipe which, having a valve at its extremity opening only
outwards, leads to a cistern (S), whence the boiler is supplied. The
descent of the piston pulls down the piston-rod and chain, and the
end of the beam to which they are attached. The other end of the
beam accordingly rises, pulling up a chain which is attached to the
pump-rod (N), working the pump by which the mine is to be
drained. The purpose of the smaller pump-rod working parallel to
N, is, by the action of the engine, to raise a portion of the water
through the tube (EE) to the cistern from which the water is sent
into the cylinder. The piston is now at the bottom of the cylinder,
and would remain there by the pressure of the atmosphere on its
upper surface; but by opening the valve (V), the steam from the
boiler is admitted under it, and the pressure of the atmosphere
being thus counterbalanced, the superior weight of the pump-rod
end of the beam causes it to descend, elevating the other end with
the piston attached to it. The cylinder being again filled with steam
as before, the stop-cock (R) is turned, and the water spouts in; the
steam is condensed; the piston descends; the pump-rod rises; and
so on, stroke after stroke. The use of the small tube (T), proceed-
ing from the cistern, is to pour a little water above the piston, to
keep it air-tight.
As may be supposed, much care and attention was at first required
in Newcomen's engine on the part of the person whose work it was
d
HISTORY OF THE STEAM-ENGINE. xxiii
to keep incessantly turning the stopcocks (V and R); the first for
the admission of steam from the boiler, the second for the admission
of the cold water for the condensation of the steam. The whole
action of the machine depended on the attention of the person who
watched these two cocks. A curious accident, however, remedied
this inconvenience. A boy of the name of Humphrey Potter being
employed to tend one of Newcomen's engines, found the constant
watching so troublesome that he set himself to contrive a way by
which the cocks might be turned at the right time, and yet he might
enjoy himself for an hour or so at a time with the boys in the street.
Observing that the particular moment at which the valve (V) required
to be opened for the admission of the steam was that at which the
pump-rod end of the beam was raised to its highest and that the
moment at which the other cock (R) required to be opened was
when the piston-rod end was at its highest, he saw that, by attaching
strings to the stop-cocks, and connecting them with various parts
of the beam, the rising and falling of the two ends would turn the
cocks regularly as was necessary. Such was the Scogging or Sku/8-
ing gear of the Boy Potter, so called because it enabled him to scog
or play truant from his work, and afterwards improved by the sub-
stitution of rods for strings. The steam-engine was now entirely
self-working; the only attendant necessary was the fireman to tend
the furnace.
Such was the atmospheric engine of Newcomen, used to a con-
siderable extent for the purpose of draining mines, and upon which
various engineers employed their skill during the first half of the
eighteenth century, with a view to render it applicable to other
mechanical purposes, such as driving mills, etc. Among those who
thus directed their attention to the steam-engine was the celebrated
Smeaton; and some of the finest specimens of Newcomen's engine
were of his construction. No improvement of essential conse-
quence, however, was effected in the steam-engine until it came into
the hands of Watt, whose successive contrivances to render it per-
fect we now proceed to describe.
WATT's IMPROVEMENTS ON THE STEAM-ENGINE As A DRAINING AND
PUMPING MACHINE.
Watt was a man with whom, to repeat the words of Professor,
Robinson, “everything became the beginning of a new and serious
xxiv. HISTORY OF THE STEAM - ENGINE.
study;” accordingly, not content with merely repairing Professor
Anderson's model, so that it should work as before in presence of
the students in the class-room, he devoted himself to the thorough
investigation of all parts of the machine and of the theory of its
action. Directing his attention first, with all his profound physical
and mathematical knowledge, to the various theoretical points in-
volved in the working of the machine, “he determiſed,” says M.
Arago, “the extent to which the water dilated in passing from its
liquid state into that of steam. He calculated the quantity of water
which a given weight of coal could vaporize—the quantity of steam,
in weight, which each stroke of one of Newcomen's machines of
known dimensions expended—the quantity of cold water which
required to be injected into the cylinder to give the descending
stroke of the piston a certain force—and, finally, the elasticity of
steam at different temperatures. All these investigations would
have occupied the lifetime of a laborious philosopher; whilst Watt
brought all his numerous and difficult researches to a conclusion,
without allowing them to interfere with the labors of his work-
shop.”
Leaving Watt's theoretical researches into the mode and power
of action by steam, let us attend to the practical improvements
which he made in the construction of the engine itself. Newcomen's
machine labored under very great defects. In the first place, the
jet of cold water into the cylinder was a very imperfect means of
condensing the steam. The cylinder, heated before, not being
thoroughly cooled by it, a quantity of steam remained uncondensed,
and, by its elasticity, impeded the descent of the piston, lessening
the power of the stroke. Again, when the steam rushed into the
cylinder from the boiler, it found the cylinder cold in consequence
of the water which had recently been thrown in, and thus a con-
siderable quantity of steam was immediately condensed and wasted,
while the rest did not attain its full elasticity till the cylinder became
again heated up to 212 degrees. These two defects—the imperfec-
tion of the vacuum created in the cylinder when hot and the loss
of steam in rushing into the cylinder when cold—were sources of
great expense. Both defects, it will be observed, had their origin
in the alternate heating and cooling of the cylinder; and yet, ac-
cording to Newcomen's plan, this alternate heating and cooling was
inevitable.
HISTORY OF THE STEAM-ENGINE, XXV
Watt remedied the evil by a simple but beautiful contrivance—his
SEPARATE CONDENSER. The whole efficacy of this contrivance con-
sisted in his making the condensation of the steam take place, not
in the cylinder, but in a separate vessel communicating with the
cylinder by a tube provided with a stop-cock. This vessel being
exhausted of air, it is evident that, on the turning of the stop-cock
in the tube connecting it with the cylinder, the steam from the
cylinder will rush into it so as to fill the vacuum ; and that this will
continue until the steam be equally distributed through both ves-
sels—the cylinder and the other. But if, in addition to being free
from air, the separate vessel be kept constantly cool by an injection
of cold water, or other means, so as to condense the steam as fast
as it rushes in from the cylinder, it is evident that all the steam will
quit the cylinder, and enter the separate vessel, to be condensed
there. The cylinder will be thus left a perfect vacuum, without hav-
ing lost any of its heat by the process; the piston will descend with
full force, and when the new steam rushes in from the boiler no por-
tion of it will be wasted in reheating the cylinder.
So far the invention was all that could be desired; an additional
contrivance was necessary, however, to render it complete. The
steam in the act of being condensed in the separate vessel would
give out its latent heat; this would raise the temperature of the
condensing water; * from the heated water vapor would rise, and
this vapor, in addition to the atmospheric air which would be dis-
engaged from the injected water by the heat, would accumulate in
the condenser and spoil its efficiency. In order to overcome this
defect, Watt attached to the bottom of the condenser a common air-
pump, called the condenser pump, worked by a piston attached to
the beam, and which, at every stroke of the engine, withdrew the
accumulated water, air and vapor. This was a slight tax upon the
power of the machine, but the total gain was enormous—equivalent
to making one pound of coal do as much work as had been done
by five pounds in Newcomen's engine.
This, certainly, was a triumph; but Watt's improvements did not
* The effect of the latent heat of the steam in heating the water in the condenser may
be judged of from the fact that, if two pounds of steam be condensed by ten pounds of
freezing water, the result will be twelve pounds of water at the boiling-point; in other
words, two pounds of steam at 212 degrees contain latent heat sufficient to boil ten
pounds of freezing water.
xxvi HISTORY OF THE STEAM-ENGINE.
stop here. In the old engine the cylinder was open at the top, and
the descent of the piston was caused solely by the pressure of the
atmosphere on its upper surface. Hence the name of Atmospheric
Engine, which was always applied to Newcomen's machine, the real
moving power being not the steam, which served no purpose ex-
cept to produce the necessary vacuum, but the atmosphere pressing
on the piston with the force (supposing the vacuum to be complete)
of about fifteen pounds to a square inch. This was attended with
the inconvenience that, the atmosphere being cold, tended to cool
the inside of the cylinder in pushing down the piston, which, of
course, caused a waste of steam at every stroke. The inconvenience
was avoided, and the whole engine improved, by entirely shutting
out the atmospheric action and employing the steam itself to force
down the piston. This was accomplished in the following way. In-
stead of a cylinder open at the top Watt used one with a close
metallic cover, with a nicely-fitted hole in it, through which the
greased piston-rod could move freely, while it did not allow the
passage of air or steam. Thus the cylinder was divided into two
chambers quite distinct from each other—that above and that below
the piston. Now, in addition to the former communications be-
tween the cylinder and the boiler and condenser, a tube was made
to connect the boiler with the upper chamber, so as to introduce
steam above the piston. This steam, by its elastic force, and no
longer the atmosphere by its pressure, drove down the piston when
the vacuum had been formed by the condensation of the steam be-
neath; and as soon as the descending stroke was complete, the
turning of a cock could admit steam from the boiler equally into
both chambers, thus restoring the balance and enabling the piston
to ascend, as before, by the mere counterpoise of the beam. The
engine with this improvement Watt named the Modified Engine; it
was, however, properly the first real steam-engine; for in it, for the
first time, steam, besides serving to produce the vacuum, acted as
the moving force. In this substitution of steam as the moving force
instead of the atmosphere, there was, moreover, this peculiar advan-
tage—that whereas the force of the atmosphere was uniform, and
could in no case exceed fifteen pounds on every square inch of the
piston's surface, the force of the steam could, within certain limits,
be varied.
Another improvement less striking in appearance, but of value in
HISTORY OF THE STEAM-ENGINE. xxvii
economizing the consumption of fuel, was the enclosing of the
cylinder in a jacket or external drum of wood, leaving a space be-
tween which could be filled with steam. By this means the air was
prevented from acting on the outside of the cylinder so as to cool
it. A slight modification was also necessary in the mode of keep-
ing the piston air-tight. This had been done in Newcomen's engine
by water poured over the piston; but in the closed cylinder this was
obviously impossible; the purpose was therefore effected by the use
of a preparation of wax, tallow and oil smeared on the piston-rod
and round the piston-rim.
The improvements which we have described had all been thor-
oughly matured by Mr. Watt before the end of 1765, two years
after his attention had been called to the subject by the model of
Newcomen's engine sent him for repair. During these two years
he had been employing all his leisure hours on the congenial work,
performing his experiments in a delft manufactory at the Broomielaw
quay, where he set up a working model of his engine, embodying
all, the new improvements and having a cylinder of nine inches
diameter. One would anticipate, as M. Arago remarks, that when
the fact of the construction of so promising and economical an en-
gine was made generally known, “it would immediately displace, as
a draining apparatus, the comparatively ruinously expensive machines
of Newcomen. This, however, was far from being the case. Watt's
grand invention and most felicitous conception, that steam might be
condensed in a vessel quite separated from the cylinder, was com-
pleted in the year 1765; and in two years scarcely any progress was
made to try its applicability upon the great scale.” Watt himself
did not possess the necessary funds for that purpose. “At length,”
says Lord Brougham, “he happily met with Dr. Roebuck, a man of
profound scientific knowledge and of daring spirit as a speculator.
He had just founded the Carron iron-works, not far from Glasgow,
and was lessee, under the Hamilton family, of the Kinneil coal-
works.” Such a man, so extensively employed in engineering, was
precisely the person to introduce Watt's invention into practice;
and accordingly a partnership was formed between him and Watt,
according to the terms of which he was to receive two-thirds of the
profits in return for the outlay of his capital in bringing the new
machines into practice. A patent was taken out by the partners in
1769, and an engine of the new construction, with an eighteen-inch
xxviii HISTORY OF THE STEAM-ENGINE.
cylinder, was erected at the Kinneil coal-works with every prospect.
of complete success, when, unfortunately, Dr. Roebuck was obliged
by pecuniary embarrassments to dissolve the partnership, leaving
Watt with the whole patent, but without the means of rendering it
available.
WATT's OCCUPATIONS AS A GENERAL ENGINEER—HIS PARTNERSHIP
WITH MR. BOULTON OF SOHO.
Watt, rather than apply to the money-lenders for funds, which
they would very probably have been glad to invest in so hopeful a
speculation, devoted himself for some time exclusively to the proper
business of his profession as a civil engineer, allowing his steam-,
engine model to lie like mere lumber in the Broomielaw delft-work.
Between the years 1769 and 1774 he was employed in various
engineering enterprises of great importance—“the extensive opera-
tions of which Scotland then became the scene giving,” says Lord
Brougham, “ample Scope to his talents. He was actively engaged
in the surveys and afterwards in the works for connecting by a canal
the Monkland coal-mines with Glasgow. He was afterwards em-
ployed in preparing the canal, since completed by Mr. Rennie, across
the Isthmus of Crinan; in the difficult and laborious investigations .
for the improvement of the harbors of Ayr, Greenock and Glasgow;
in improving the navigation of the Forth and Clyde, and in the
Campbelton Canal, besides several bridges of great importance, as
those of Hamilton and Rutherglen.”.” “What Johnson said of
Goldsmith may with equal justice be applied to Watt— he touched
nothing that he did not adorn.” In the course of his busy surveys
lis mind was ever bent on improving the instruments he employed,
or in inventing others to facilitate or correct his operations. During
the period of which we have been speaking he invented two microm-
eters, for measuring distances not easily accessible, such as arms
of the sea. Five years after the invention of these ingenious instru-
ments one Mr. Green obtained a premium for an invention similar
to one of them, from the Society of Arts, notwithstanding the
evidence of Smeaton and other proofs that Watt was the original
contriver.
* Memoir of Watt in Lord Brougham's Men of Zetters of the Reign of George
III.
HISTORY OF THE STEAM-ENGINE. xxix
“In 1773 the importance of an inland navigation in the northern
part of Scotland between the eastern and western seas became so
great that Mr. Watt was employed to make a survey of the Cale-
donian Canal and to report on the practicability of connecting that
remarkable chain of lakes and valleys. These surveys he made
and reported so favorably of the practicability of the undertaking
that it would have been immediately executed had not the forfeited
lands from which the funds were to be derived been restored to their
former proprietors. This great national work was afterward exe-
cuted by Mr. Telford on a more magnificent scale than had been
originally intended.”
At the end of the year 1773 Watt was left a widower by the death
of his wife in Glasgow while he was absent on his survey of the
Caledonian Canal. Two children, a son and a daughter, survived
their mother. This event would probably have the effect of with-
drawing his attention still more from his steam inventions. For
five years his patent “for methods of lessening the consumption of
steam and consequently of fuel in the steam-engine" had been run-
ning without bringing him any returns, the dissolution of his part-
nership with Dr. Roebuck having thrown the entire risks of intro-
ducing the new machine into practice upon himself, and either his
cautious temperament or his actual want of means preventing him.
from abandoning the certainties of his profession for the sake of
pushing his steam-engine into public notice. This indifference is
certainly in itself not entitled to be considered a merit; we point it
out merely as characteristic.
At length, in 1774, Mr. Watt entered into a partnership most for-
tunate for himself and for the world. This was with Mr. Matthew
Boulton, of the Soho Foundry, near Birmingham—a gentleman of
remarkable scientific abilities, of liberal disposition and of unbounded
enterprise, who, having his attention called to the improvements on
Newcomen's steam-engine effected by the Glasgow surveyor, im-
mediately formed a connection with him, sharing the patent, as Dr.
Roebuck had formerly done.
Almost the first business of the partners was to procure a pro-
longation of Watt's patent, which, having commenced in 1769, had
but a few years to run. Whether because the value of Watt's im-
provements had, by the mere course of time, become more generally
recognized than at first, or because the enthusiasm with which so
XXX HISTORY OF TIHE STEAM-ENGINE.
well-known an individual as Mr. Boulton patronized them, roused
many parties to a sense of their importance, it was only after a very
keen opposition in Parliament that the extension of the patent for
twenty-five years was obtained. At the head of those who opposed
the renewal of the patent in the House of Commons was the cele-
brated Edmund Burke; the opponents out of the house were the
engineers and miners whom the patent would prevent from employ-
ing the engine without paying the inventor for permission to do so.
The extension of the patent having been procured, the partners
began to construct, at their manufactory at Soho, draining-machines
of the largest dimensions, which immediately supplanted New-
comen's engines in all the mining districts. The bargain which the
partners made with those mine proprietors who applied for permis-
sion to use the improved engine was certainly the most reasonable
that could have been expected. They stipulated for receiving “a
third part of the value of the coal saved by the use of the new engine.”
Yet this agreement brought ample profits to the partners, as may be
judged from the fact, that the proprietors of the single mine of Chase-
water in Cornwall, where three pumps were employed, commuted
the proposed third of the coal saved into £2500 a year for each of the
engines. Thus the saving effected by one engine amounted to at
least £7500, which had been expended formerly in waste fuel. As
there was a possibility that, if the mine proprietors had been left to
estimate for themselves the value of the saving, they might cheat the
partners of their fair dues, Watt rendered himself independent of
them by confiding the duty of rendering an account to a meter,
invented on purpose, and which, kept in a box under a double lock,
registered every stroke of the engine.
As the engine was one of large dimensions, it was scarcely possible
to pirate it secretly; but so numerous were the attempts made to
plagiarise it, or, by ingenious ways, to infringe the patent right, that
Messrs. Watt and Boulton were almost perpetually engaged in law-
suits to defend their property. In several cases, the opposition
which Mr. Watt experienced on account of his defending his rights
amounted to positive persecution—to attacks on his character.
These attacks, however, failed; and in their lawsuits the partners
were uniformly successful. “I have been so beset with plagiaries,”
says Mr. Watt in one of his letters, “that if I had not a very distinct.
recollection of my doing it, their impudent assertions would lead me .
**
HISTORY OF THE STEAM-ENGINE. xxxi
to doubt whether I was the author of any improvement on the
steam-engine.”
As the foundry at Soho was one of the largest establishments in
Great Britain, Watt's new position, as a partner with Mr. Boulton,
was one of great wealth and consequence. He had hardly entered
upon it, when, in the year 1775, after two years of widowhood, he
married Miss Macgregor, the daughter of a rich Glasgow merchant.
The first consequence of the introduction of Watt's improved
steam-engine into practice was to give an impulse to mining specu-
lations. New mines were opened; and old mines, which could not
be profitably worked when taxed with such a consumption of fuel
for draining as Newcomen's engines required, now yielded a return.
This was the only obvious consequence at first. Only in mines,
and generally for the purpose of pumping water, was the steam-
engine yet used; and before it could be rendered applicable to other
purposes in the arts—before it could promise, even to the most
sanguine expectation, to perform such a universal part in machinery
as that which we now witness it performing—the genius of Watt
required once again to stoop over it, and bestow on it new creative
touches.
\.
IMPROVEMENTS BY WATT, RENDERING THE STEAM-ENGINE APPLICABLE
FOR GENERAL PURPOSES.
Any one, on considering the steam-engine, will perceive that the
original motion in it, and the source of all others, is that of the
piston up and down in the cylinder. It is by connecting the piston-
rod with other pieces of machinery through a beam that the work
is done. Now, in the draining-engine the piston-rod was attached
to the beam by a flexible chain. Where the purpose was the mere
pumping of water, the inconvenience of this was not so great; but
to render the steam-engine useful for other purposes, it was necessary
to do away with the flexible chain, and connect the piston-rod with
the end of the beam by some rigid communication. Watt effected
this by a beautiful invention, known as the parallel motion. At the
end of the beam of a steam-engine of the construction common
some years ago,” may be observed a curious jointed parallelogram,
* In engines of modern construction the beam is seldom used; the crank-rod is jointed
directly to the piston-rod, and the piston-rod is made to preserve its parallelism by means
of a cross-head moving in guides.
Xxxii HISTORY OF THE STEAM-ENGINE.
with the piston-rod attached to one of its angles. When the engine
is in action, if the movements of this parallelogram be watched
attentively, it will be perceived that while three of the angles of the
parallelogram move in small circular arcs, the fourth—that to which
the piston-rod is attached—is so pulled upon by opposite forces,
that although tending to move in a curve, it moves in a straight
line. This result depends on a very recondite mathematical prin-
ciple; the contrivance, however, practically, is one of the Ivaost
simple imaginable. “I myself,” says Watt, speaking of his first trial
of the parallel motion, “have been much surprised with the regularity
of its action. When I saw it in movement, it afforded me all the
pleasure of a novelty, and I had quite the feeling as if I had been
examining the invention of another.”
Another improvement, which, in point of the additional power
gained, was more important than the parallel motion, and which
indeed preceded it in point of time, was the Double-acting Engine.
In the steam-engine, so far as we have yet described it, the whole
force consisted in the downward stroke; in the depression of the
piston in Newcomen's engine by the atmosphere; and in Watt's
improved engine by the steam admitted into the upper chamber
of the cylinder. When the piston had reached the bottom of the
cylinder, it arose again by the mere counterpoise of the other end of
the beam, just as the lighter end of a weighing-beam ascends when
the pressure which kept it down is removed. Watt remedied this
defect, by giving the piston an upward as well as a downward
stroke; that is, by employing the steam to push up the piston as
well as to push it down. After the whole cylinder is first filled with
steam, a communication is opened between the upper chamber and
the condenser; thus the steam in the upper chamber is condensed,
and a vacuum is formed, upon which the elasticity of the steam in
the lower chamber pushes up the piston. This is the ascending
stroke. To procure the descending stroke, a communication is
next opened between the lower chamber of the cylinder and the
condenser; by this means a vacuum is formed below the piston;
steam is then admitted into the upper chamber, and its elasticity
pushes the piston down. And thus, by the alternate admission and
condensation of steam above and below the cylinder, the double
action is procured, giving a double power for the same size of
cylinder, and there is no longer any necessity for one end of the
beam being heavier than the other.
HISTORY OF THE STEAM-ENGINE. xxxiii
Besides the double-stroke engine Mr. Watt also indicated an im-
provement, which he did not fully carry out, but which has since
been attended with results so surprising as regards the economizing
of the steam that its utility ranks as high as that of the separate
condenser. This consists in shutting off the steam from the boiler
before the whole length of the stroke, whether upward or downward,
is completed, leaving the quantity admitted to perform the rest of
the stroke by its expansive force. When the steam is shut off at
half-stroke it is found that the efficacy of the steam is increased by
considerably more than a half; at quarter-stroke, the same quantity
of steam—and, therefore, the same quantity of fuel—will do more
than twice the work it would do if steam were admitted during the
whole stroke.
Watt had thus gone as far as it was possible to go in increasing
the power of the steam - engine.
“Power, however,” observes M. Ar-
ago, “is not the only element of suc-
cess in the labors of industry. Regu-
Marity of action is of no less impor-
tance; and what degree of regularity
is to be expected from a moving
power which is procured from the
fire, under the influence of the poker
and shovel, and supplied by coals of WATT's GoverNOR.
very different qualities: under the &
influence, too, of workmen often far from intelligent and almost al-
ways inattentive P. We should expect that the propelling steam would
be sometimes superabundant; that hence it would rush into the cylin-
der with greater rapidity, so making the piston work more rapidly ac-
cording as the fire was more powerful, and from such causes great ine-
qualities of movement appear almost inevitable.” Watt's genius pro-
vided a remedy for this by an ingenious application of an apparatus
called the governor, which should regulate the quantity of steam ad-
mitted from the boiler into the cylinder. The nature of this piece of
mechanism will be understood by the annexed figure. A spindle or
upright log, with a pulley on its lower part by which it is moved,
receiving motion through a strap attached to the shaft or axle, has
two balls, which revolve along with it. These balls, by the means
of joints, may be separated considerably from, or brought nearer to,

xxxiv. HISTORY OF THE STEAM - ENGINE.
the spindle. Two levers are connected with the rods to which the
balls are attached, having a free movement on other levers similar in
length and thickness, but which meet in a metallic ring movable up-
wards and downwards on the spindle. Immediately above the ring
a lever is placed transversely across the ring, fixed at one point, but
connected to another which is bent, to the end of which the throttle-
valve of the steam-pipe is attached. This valve, it may be here
noticed, is intended to regulate the supply of steam, allowing it to
escape when horizontal in full stream and obstructing it proportion-
ately as it assumes a vertical direction. When, therefore, the engine
acts with increased speed or velocity, and the main shaft to which
this spindle is attached is revolved with a proportionate degree of
rapidity, the balls will recede to a greater distance from each other,
and accordingly the levers, acting on the throttle valve, will raise it
so as to diminish the flow of steam. But if the shaft revolves slowly,
the spindle also having its velocity regulated by it, the balls will
naturally approximate each other, and the lever will now so act on
the valve as to throw it completely open, and thereby permit the
steam to enter in a full current to the cylinder and accelerate the
motion. Such is the efficacy of this apparatus that by its means a
steam-engine may be made to give motion to a clock which shall
keep good time. “It is this regulator of Watt's,” says M. Arago,
“and a skilful employment of fly-wheels, which constitute the true
secret of the astonishing perfection of the manufactures of our epoch.
It is this which confers on the steam-engine a working movement
which is wholly free from irregularity and by which it can weave
the most delicate fabrics as well as communicate a rapid movement
to the ponderous stones of a flour-mill.”
To describe all the other inventions of a minor kind connected
with the steam-engine which came from the prolific genius of Watt
would occupy too much space. Rotary engines, already alluded
to in the present History, and which have engaged much attention of
late years, were not only thought of by Watt, but actually con-
structed ; “he subsequently abandoned them, however, not because
they did not work, but because they appeared to him decidedly in-
ferior, in an economical point of view, to machines of double powers
and rectilineal oscillations.” The earliest results of his improvements
in the application of steam will be found in Cugnot's (French)
“Road Steam Engine,” I 77O, page xlviii.; and about ten years later,
HISTORY OF THE STEAM-ENGINE. XXXV
in 1784, William Symington, one of the early inventors of the
steamboat, was similarly occupied in Scotland in endeavoring to
perfect the steam carriage; but, chiefly because of the bad roads in
Scotland at that period, he had to abandon it.
The same year William Murdock, the friend and assistant of Watt,
constructed his model of a locomotive at Redruth, in Cornwall.
It was of small dimensions, standing little more than a foot high ;
and it was until recently in the possession of the son of the inventor.
The annexed section will give an idea of the arrangements of this
machine.
It acted on the high-
pressure principle, the
boiler being heated by
a spirit lamp. Small
though the machine
was, it went so fast on
one occasion that it
fairly outran the speed
of the inventor. It
was a dark night, and
Murdock set out alone
to try his experiment.
Having lit his lamp,
the water shortly be—
gan to boil, and off
started the engine with the inventor after it. He soon heard dis-
tant shouts of despair. It was too dark to perceive objects; but he
shortly found, on following up the machine, that the cries proceeded
from the worthy pastor of the parish, who, going towards the town
on business, was met on this lonely road by the hissing and fiery
little monster, which he subsequently declared he had taken to be
the Evil One in propria persona. No further steps, however, were
taken by Murdock to embody his idea of a locomotive carriage in
a more practical form.
To express by any ordinary terms in our language the advantages
resulting from Watt's improvements of the steam-engine would be
altogether impossible. We have only to look abroad on the world
and see what mighty applications of this wonderful engine are
everywhere visible. Steam navigation, railway travelling, automatic
factory labor, steam printing, mining and hundreds of other arts
MURDOCK's MODEL OF A LOCOMOTIVE EN-
GINE, I784.

xxxvi HISTORY OF THE STEAM-ENGINE.
have been brought to their present state by means of Watt's
discoveries. In its adaptation to mills and factories steam is
doubtless more costly than water-power; but, being independent of
situation or season, it is in general circumstances preferable. Its
placid steadiness, and the ease with which it may be managed, are
also great recommendations in its favor. As a motive-power in the
arts, steam takes the lead of all others, and, viewing it as an
economizer of labor, it must assuredly be pronounced the greatest
help of mankind. What electricity is doing or will do in the future
is not pertinent to our present history.
It is in consequence of the improved mechanical arrangements
and employment of inanimate forces in Great Britain that that com-
paratively small country has hitherto been enabled to manufacture
goods cheaper, and with greater profit, than can be done by the
largest and most populous countries in which mechanism is imper-
fect and labor performed exclusively by living agents.
The profits of manufactures so produced spread their beneficial
influence over the whole mass of society, every one being less or
more benefited. Thus almost all the luxuries and comforts of life,
all the refinements of social existence, may be traced to the use of
tools and machinery. Machinery is the result of mechanical skill,
and mechanical skill is the result of experience and a long course
of investigations into the workings of principles in nature which are
hidden from the inattentive observer. Much of the present mechan-
ical improvement is also owing to the pressure of necessities, or
wants, which have always a tendency to stimulate the dormant
powers of man. What are to be the ultimate limits and advantages
of mechanical discoveries no one can foresee. The investigation of
natural forces is yet far from being finished. Every day discloses
some new scientific truth, which is forthwith impressed into the ser-
vice of mankind and tends to diminish the sum of human drudgery.
In this manner are we usefully taught that the study of nature forms
a never-failing source of intellectual enjoyment and that “KNOWL-
EDGE IS POWER.”
**-mm-
§§§)=== §:
* * * * * * * -- º
ſººn ſº gºrgºt gº º #:
THE LIFE OF GEORGE STEPHENSON.
WHEN we see a railway train drawn by a locomotive at the rate
of forty miles an hour and carrying as many as five hundred pas-
sengers, how little are we apt to think that this marvel of science
and art is due mainly to two men, who, in the outset of their career,
occupied an obscure position—James Watt and George Stephenson,
one a Scotsman, the other a native of the north of England, and
both affording bright examples of what may be done in adverse cir-
cumstances by dint of well-directed labor, united with that degree
of prudence without which ingenuity and toil are usually in vain.
Of James Watt and the steam-engine we have already treated.
Here we have to speak of Stephenson—plain old George, with his
Northumbrian burr–the perfecter of the locomotive, but for whom
(xxxvii)

xxxviii HISTORY OF THE STEAM-ENGINE.
it might have been long before we should have seen a train running
at the speed which now astonishes everybody.
George had a very humble beginning. His father, Robert
Stephenson, with his wife Mabel, were a decent couple, living at a
small colliery village, called Wylan, situated on the north bank of
the Tyne, about eight miles from Newcastle. Here “old Bob,” as
Robert was usually styled by the neighbors, was employed as fire-
man to the engine which pumped water from the coal-pit, an em-
ployment of a toilsome kind, but requiring no great skill, and ac-
cordingly requited by the wage of a common laborer. It is said
that Bob was descended from a Scottish family which had emigrated
into Northumberland and had some pretensions to be of a superior
class. But now the family had settled down as hand workers, a po-
sition in no respects dishonorable, for in every department of honest
labor, no matter how humble, there is a dignity which nothing can
overshadow. Lowly as was his situation in life, Robert Stephenson
had tastes of no grovelling kind. Amiable in disposition, he was
fond of animals, and loved to tell stories of one kind or other,
which made him a great favorite with young persons. Mabel, his
wife, good, “canny Mabel,” is reported to have been a woman of a
thoughtful, nervous temperament, and it is not unlikely that, in this
as in many other instances, the mother communicated the impress
of her character to her children.
Robert Stephenson had six children, of whom George, the hero
of our story, was the second, born June 9, 1781. The lot of the
family was to work, and work they did. We do not know whether
the father, with all his tastes, had any wish to give his children a
fair country education. Perhaps there were no schools near at
hand, but be this as it may, Bob's children, like their neighbors in
like circumstances, were left entirely to themselves in the way of
book-learning. When George was about eight years of age his
father removed to another colliery concern at Dewley Burn, where
he filled a similar situation—that of shovelling in coal to a furnace
which kept a steam-engine at work. It requires no stretch of
imagination to fancy Bob here laboring daily in front of a glowing
fire, with a big shovel in hand, clothed in coarse blue woollen
trousers and shirt and wiping the drops of perspiration from his face
with a bunch of coarse tow. Could any one, looking at that toil-
ing, perspiring man, have supposed that he was the father of one
HISTORY OF THE STEAM-ENCINE. xxxix
of England's great men P Bob, indeed, had not the slightest no-
tion himself that he had a son who was to come to honor, and how
could he P
Shortly after coming to Dewley Burn George was put to work,
for he was eight years old and it was believed he could earn some-
thing to help on the family. A job was found for him; it was to
herd a few cows, for which light duty he was paid twopence a day.
We are now, as it were, introduced to George. He comes on the
stage as a bare-legged herd-boy, driving cows, chasing butterflies
and amusing himself by making water-mills with reeds and straws,
and even going the length of modelling small steam-engines with
clay. In these pursuits we have a glimpse of his mechanical turn.
Often we see that boys take a bent towards what first excites their
fancy. Brought up among coal-pits and pumps, and wheels and
engines, it was not surprising that his mind should have a bias to
mechanics. Some boys, indeed, are so dull or heedless that they
may see the most curious works of art without giving them any sort
of attention. But that was not George Stephenson's way. He
pried into every mechanical contrivance that came under notice and
acquired a knack of making things with no other help than an old
knife. There was the poor boy's genius. He did not stare at
things stupidly or with an affected air of indifference; neither did he
pretend to take an interest in works of art in order to appear clever.
He liked to work out his own ideas in his simple way, without a
thought of results. From being a herd-boy he was promoted to
lead horses when ploughing, hoe turnips and do other farm work,
by which he rose from twopence to fourpence a day. He might
have advanced to be an able-bodied ploughman, but his tastes did
not lie in the agricultural line. What he wished was to be em-
ployed about a colliery, so as to be among bustle of wheels, gins
and pulleys. Accordingly, quitting farm work, he got employment
at Dewley Burn to drive a gin-horse, by which change he had
another rise of twopence a day, his wages being now three shillings
a week. In a short time he went as gin-horse driver to the colliery
of Black Callerton, and as this was two miles from the parental
home, he walked that distance morning and evening. This walk,
however, was nothing to George, who was getting to be a big, stout
boy, fond of rambling about after birds' nests and keeping tame
rabbits and always taking a part in country sports. His next rise
xl IHISTORY OF THE STEAM-ENGINE.
was to act as an assistant fireman to his father at Dewley. Gladly
he accepted this situation, for besides that he was allowed a shilling
a day, he looked to being promoted to be engineman, which now,
in his fourteenth year, was the height of his ambition. George did
not long remain here. The coal-pit was wrought out and deserted,
and the workmen and apparatus were removed to a colliery at Jolly's
Close, a few miles distant. The Stephenson family removed with
the others, and now occupied a cottage of only a single apartment,
situated in a row of similar dwellings, with a run of water in front
and heaps of debris all around.
In this miserably confined cottage there were accommodated the
father and mother and six children, some of them pretty well grown
up, and as all helped by their work there was nothing like poverty
in the household. George and his elder brother James were as-
sistant firemen, two younger boys performed some humble labor
about the pit and two girls assisted their mother in household
affairs. The total earnings of the father and sons amounted to from
35s. to 40s. a week. As this was equal to about 4, IOO per annum,
we are entitled to say that on that sum old Bob ought to have
brought up his family respectably and given them at least the ele-
ments of education. But in this, as in thousands of cases, little
else was thought of than to consume the whole weekly earnings in
a coarse kind of plenty, leaving chance or the parish to provide for
the future. No doubt, humble as it was, this was a most extrava-
gant way of living, and it is obviously by such improvidence that
many of the manual laboring classes keep themselves ever on the
brink of poverty. The only excuse we can find for Bob and Mabel
is that they did not know any better and, deprived of suitable house
accommodation, had perhaps no heart to aspire to a more economic
mode of life. Nor should we fail to remember that unless school
instruction is obtruded in some shape or other on colliery villages
and rural hamlets the residents can scarcely be blamed for their ig-
norance. Recent statutes and arrangements have probably done
much to remedy this social defect among the Northumbrian colliers,
and their children must in many respects be better looked to than
was the fortune of their predecessors. From whatever cause, the
want of education was a serious disadvantage to the young Stephen-
sons. Not one of them was taught to read. George, at fifteen years
of age, when working as assistant fircuman, and forming one of a
HISTORY OF THE STEAM-ENGINE, xli
family who were earning about a hundred a year, and paying no
house-rent, did not know a letter. To one with much natural
sagacity and an ambition to improve in circumstances we cannot
easily conceive a more dreary condition. Let any one picture to
himself the situation of a friendless lad, totally uneducated, living
in a colliery village, and then try to conceive by what force of cir-
cumstances that lad was to attain to eminence in wealth and station
and as a benefactor to mankind. In vain we make the effort, yet
we shall see by what simple means Providence brings out great re-
sults, which no man can possibly discover by the most penetrating
foresight.
Every man, no matter how lowly his lot, may be said to have a
choice of two paths. He may fall in with the multitude of those
who seek immediate self-indulgence and take no thought of the
future; or, shrinking from this too common routine, he may, in the
face of untold difficulties, make a sacrifice, for the sake of moral
and intellectual improvement, with which not unusually comes an
improvement in circumstances. We are now called on to notice
which of the two paths was taken by George Stephenson. He
chose immediate sacrifice, and lived to thank God for inspiring him
to do so. Let us see how he set about it and how he carried it
through. His duty consisted in attending to the furnace of one of
those gigantic steam-engines which pumped water from a coal-pit.
From Dewley he went to Mid Mill, and after that to the colliery of
Throckley-bridge, at which his wages were twelve shillings a week.
He felt he was getting on. It was a proud moment for him when
one Saturday evening he got his first twelve shillings. “Now,” said
he, enthusiastically, “I am a made man for life.”
While at this occupation he acquired a character for steadiness—
that was a great point gained. The world is always groping about
for steady men, and sometimes it is not easy getting hold of them.
George was rigorously sober, and was never so happy as when he
was at work, though it is also related of him that he took pleasure
after work-hours in wrestling, putting or throwing the stone, and
other feats of muscular skill. He possessed a powerful frame, and
could lift heavy weights in a manner that was thought surprising,
Rather a general favorite from his good-nature and dexterity at
rustic sports, George likewise gave satisfaction to his employers,
and, reputed as a clever, handy young man, was promoted to the
xlii HISTORY OF THE STEAM-ENGINE.
situation of engineman or plugman at Newburn. From looking
after a furnace, he had now to attend to the working of a steam-
engine, and to watch that the pumps were kept properly working. It
was a post of responsibility, and not without trouble. If the pumps
went wrong, he had to descend the pit, and do his best to rectify
them by plugging; that is, stuffing any hole or crevice to make
them draw; and if the defect was beyond his power of remedy, his
duty was to report it to the chief engineer. In these services George
took immense delight. He was now in his element; could handle,
and scour, and work about among pistons, cylinders, wheels, levers,
pumps, and other mechanical contrivances, and regarded the entire
engine under his charge with feelings of keen admiration and affec-
tion. One likes to hear of this, for there is always something pleas-
ing in the idea that a youth is an enthusiast in the kind of labor to
which he has addressed himself, for there are then good hopes of his
SUl CCCSS.
George was so fond of his engine that he was never tired looking
at it, as it worked with regularity and almost with sublimity the
enormous pumps. Stooping like a giant, down went the great lever
or pump-handle; a moment's pause ensues, and then without an
effort up is drawn the prodigious volume of water, which runs away
like a small river. In the constant contemplation of this magnifi-
cent triumph of art the mind of any one not lost to good feeling
cannot fail to be elevated. At all events, George Stephenson ex-
perienced enviable sensations. Oh, that dear engine, how he did
love it! to him, with its continuity and regularity of motion, it was
like a living creature. As a mother fondles and dresses her child,
so did George never tire fondling, dressing and undressing his en-
gine. It was not enough that he saw the outside of the mechanism.
It became a kind of hobby with him to take her—a steam-engine is
/ier—to pieces, and after cleaning and examining all the parts, to put
her again into working order. Then what joy, when the steam is
let on, to see her begin to move—to come to life, as it were—and to
commence her grand pumping operations.
When the engine was going in excellent trim, and nothing was
wrong with the pumps, there was little to do. The mechanism went
on of itself and required a look-only now and then. Being so far
an easy job for the engineman, there was time to spare. By way
of occupying these idle minutes and hours George began to model
HISTORY OF THE STEAM-ENCINE. xliii
miniature steam-engines in clay, in which he had already some ex-
perience. It was a mere amusement, but it helped to fix shapes
and proportions in his memory. While so engaged he was told of
engines of a form and character he had never seen. They were not
within reach, but were described in books. If he read these he
would learn all about them. Alas! George, though now eighteen
years of age, was still ignorant of the alphabet. He clearly saw
that unless he learned to read he must inevitably stick where he was.
The knowledge of past times, and much of the busy present, was
shut out from him. With these convictions, it is not surprising that
our hero resolved to learn to read—in fact, to put himself to school
and so remedy, if it could be remedied, the neglect on this score of
old Bob, his father.
Having settled in his own mind that he would go to school, cost
what it might, George found out a poor teacher, named Robin
Cowens, in the village of Walbottle, who agreed to give him lessons
in the evening at the rate of threepence a week, a fee which he
cheerfully paid. By Robin he was advanced so far as to be able to
write his own name, which he did for the first time when he was
nineteen years of age. To improve his acquirements he afterwards,
in the winter of 1799, went to an evening school, kept by Andrew
Robertson, a Scotch dominie, in the village of Newburn. Here he
was advanced in a regular way to penmanship and arithmetic. But
as there was not much time for arithmetical study during the limited
school hours, George got questions in figures set on his slate, which
next day he worked out while attending the engine. And that was
all the education in the way of schooling he ever got. Very imper-
fect it was in quality and extent, but it admitted him within the
portals of knowledge, and, getting that length, he was enabled to
pick up and learn as he went on. The next event in his life was his
removal, in 1801, to the Dolly pit, at Callerton, where he received
somewhat higher wages, a point of some importance, for at this
time the cost of living was very high. Perhaps it was owing to this
dearth in food that George fell upon the expedient of devoting his
leisure hours in the evening to the making and mending of shoes.
Some may think that the craft of shoemaking was quite out of his
way, but we have known several instances of shepherds and plough-
men being makers and menders of shoes in a homely style for their
families, and, therefore, the “gentle craft” is not so very difficult to
4
xliv HISTORY OF THE STEAM-ENGINE.
learn as might be imagined. George Stephenson became a toler-
able shoemaker, though he kept chiefly to cobbling or mending. If
anything could have spurred him on, it was the desire to sole the
shoes of his sweetheart, Fanny Henderson, and of these he is said
to have made a “capital job.” By means of his cobbling he was
able to save a guinea, which is recorded as being the nest-egg of
his fortune. Of course he never could have laid by so much as a
guinea had he, like most of his acquaintances, frequented public
houses and consumed quantities of beer. But no one ever saw him
the worse for drink, and while others were soaking in taverns, or
amusing themselves with cock-fighting and dog-fighting, he was at
home, either trying to increase his sum of knowledge or applying
himself to some useful occupation which was in itself an amuse-
ment. His sobriety and industry had their reward. He was en-
abled to furnish a house decently and to marry Fanny Henderson.
The marriage was celebrated on November 28, 1802, and the pair
betook themselves to the neat home that had been prepared at
Willington Ballast Quay, a place on the Tyne, about six miles from
Newcastle.
Settling down as a married man, George continued to devote
leisure hours to study or to some handicraft employment. From
making and mending shoes, he proceeded to mend clocks and be-
came known among his neighbors as a wonderfully clever clock-
doctor. It is said that he was led into this kind of employment by
an accident. His chimney having gone on fire, the neighbors in
putting it out deluged the house with water and damaged the eight-
day clock. Handy at machinery, and wishing to save money, George
determined to set the clock to rights. He took it to pieces, cleaned
it, reorganized it and made it go as well as ever. There was a tri-
umph After this he was often employed as a repairer of clocks,
by which he added a little to his income. On December 16, 1803,
was born his only son Robert, who lived to be at the head of the
railway engineering profession. But before either George or his
son could arrive at distinction, there was not a little to be done. As
a brakeman George had charge of the coal-lifting machinery at
Willington, and subsequently at Killingworth, and in this depart-
ment, as well as engineman, he gradually but Surely gained the
reputation of being an ingenious and trustworthy workman. At
Killingworth, which is about seven miles north of Newcastle, he
HISTORY OF THE STEAM. ENGINE. xlv.
suffered the great misfortune of losing his wife. This sad blow fell
upon him in 1804, with his son still an infant.
The next thing we hear of him is that, leaving his child in charge
of a neighbor, he went by invitation to superintend an engine at
some works near Montrose, in Scotland, which journey, about a
hundred and fifty miles, he performed on foot. Disagreeing after a
short period with the owners, he trudged back to his home at Kil-
lingworth, bringing with him £28 as savings. One of the first
things he did after his return was to succor his father, now an aged
and blind man, whom, with his old mother, he placed in a comfort-
able cottage in his own neighborhood. Again he followed the em-
ployment of brakesman at West Moor pit, and was continuing to
save, when, in 1807, his small accumulations were in a moment
wholly swept away. He was drawn for the militia, and every shil-
ling he had saved was paid away for a substitute. To be thrust
back into poverty in so hateful a manner almost upset his philoso-
phy, and he strongly meditated emigrating to America. Fortu-
nately for England, his spirits revived, and he held on his course. In
addressing a society of young operatives many years afterwards, he re-
ferred as follows to this dark period in his life: “Well do I remember
the beginning of my career as an engineer, and the great perseverance
that was required of me to get on. Not having served an appren-
ticeship, I had made up my mind to go to America, considering that
no one in England would trust me to act as engineer. However, I
was trusted in some small matters, and succeeded in giving satisfac-
tion. Greater trusts were reposed in me, in which I also succeeded.
Soon after, I commenced making the locomotive engine; and the
results of my perseverance you have this day witnessed.”
It says much for Stephenson, that under pinching difficulties he
did not only take care of his old parents, but gave his child as good
an education as was in his power. The want of learning he had
himself acutely felt, and this deficiency, if at all practicable, he wished
to avert from his son. In one of his public speeches late in life, he
observed: “In the earlier period of my career, when Robert was a
little boy, I saw how deficient I was in education, and I made up my
mind that he should not labor under the same defect, but that I
would put him to a good school, and give him a liberal training. I
was, however, a poor man; and how do you think I managed P I
betook myself to mending my neighbors' clocks and watches at
xlvi HISTORY OF THE STEAM-ENGINE.
nights, after my daily labor was done, and thus I procured the means
of educating my son.” i
In 18 IO, an opportunity occurred for George Stephenson signaliz-
ing himself. A badly-constructed steam-engine at Killingworth
High pit could not do its work; one engineer after another tried to
set it to rights, but all failed; and at last in despair they were glad
to let “Geordie” try his hand, though with his reputation for clever-
ness they did not expect him to succeed. To their mortification and
astonishment, he was perfectly successful. He took the engine to
pieces, rearranged it skilfully, and set it to work in the most effectual
manner. Besides receiving a present of 4, Io for this useful service,
he was placed on the footing of a regular engineer, and afterwards
Consulted in cases of defective pumping apparatus.
Although thus rising in public estimation, he still knew his defi-
ciencies, and strove to improve by renewed evening studies. One
of his acquaintances, named John Wigham, gave him some useful
instructions in branches of arithmetic, of which he had an imperfect
knowledge, and the two together, with the aid of books, spent many
pleasant evenings in getting an insight into chemistry and other
departments of practical science. His steadiness was at times sorely
tried by the solicitations of neighbors in his own rank “to come
and take a glass o' yill ; ” but resolutions to be temperate and to
save for the sake of Robert's education, enabled him to withstand
tempters of all kinds. By dint of such reserve, he was able to save
a hundred guineas, which, in consequence of the demand for bullion
during the French war, he sold to money-brokers for twenty-six
shillings each. At intervals in his ordinary labor, he employed
himself in building an oven and some additional rooms to his cot-
tage, which he likewise rendered attractive by a garden cultured
with his own hands. --
The year 1812 marked Stephenson's rise to the position of a
colliery engineer and planner of machinery for working pits and
wheeling off coal. Proprietors and managers began to entertain a
high idea of his qualities, which were obviously not those of a pre-
tender. Referring to this period, when in 1835 he gave evidence
before a select committee of the House of Commons on accidents
in mines, he said: “After making some improvements in the steam-
engines above ground, I was then requested by the manager of the
colliery to go underground along with him to see if any improve-
HISTORY OF THE STEAM-ENGINE. xlvii
ments could be made in the mines, by employing machinery as a
substitute for manual labor and horse-power in bringing the coals
out of the deeper workings of the mine. On my first going down
the Killingworth pit, there was a steam-engine underground for the
purpose of drawing water from a pit that was sunk at some distance
from the first shaft. The Killingworth coal-field is considerably dis-
located. After the colliery was opened, at a very short distance from
the shaft, they met with one of those dislocations, or dikes, as they
are called. The coal was thrown down about forty yards (or
abruptly lay at that much lower level). Considerable time was
spent in sinking another pit to this depth. And on my going down
to examine the work, I proposed making the engine, which had
been erected some time previously, to draw the coals up an inclined
plane, which descended immediately from the place where it was
fixed. A considerable change was accordingly made in the mode
of working the colliery, not only in applying the machinery, but
employing putters instead of horses in bringing the coals from the
hewers; and by those changes the number of horses in the pit was
reduced from one hundred to fifteen or sixteen. During the time I
was engaged in making these important alterations, I went round
the workings in the pit with the viewer almost every time that he
went into the mine—not only at Killingworth, but at Mountrmoor,
Derwentcrook, Southmoor, all which collieries belonged to Lord
Ravensworth and his partners; and the whole of the machinery in
all these collieries was put under my charge.”
Leaving George engaged in these useful pursuits, which were
intermingled with scientific studies with his son, when he came
home from school at Newcastle, we may take a glance at the begin-
nings of railways and locomotives. It is certain there were railways
of a rude kind in England as early as the commencement of the
eighteenth century. The rails were at first of wood, then the wood
was shod with slips of iron, and lastly, they were altogether rods or
bars of iron. These old railways, which were better known by the
name of tramways, were devised for the transit of coals from pits,
the carriages being deep wooden wagons pulled by horses.
Strangely enough, there was a railway of this kind across the
fields from the coal-pits of Tranent to the small seaport Cockenzie,
when the battle of Prestonpans was fought on the ground in 1745—
which line of rails, honored by having been the site of Cope's can-
xlviii HISTORY OF THE STEAM-ENGINE.
non, still exists. Wherever there were coal or iron mines, these
tramways were introduced; nor could they fail to get into use, for a
single horse could draw upon them a load that would have required
twenty horses on a common highway. -
CUGNOT's ENGINE, 1770.
To Nicholas Joseph Cugnot, an officer of engineers in the French
army, born 1725, is due the honor of the first successful application
of steam to locomotion; it was designed for common roads and was
in 1770 run at the rate of about four miles an hour in the neighbor-
hood of Versailles, in the presence of a multitude of Scientific and
Curious spectators.
TREVETHICK's STEAM-CARRIAGE, 18O3.
The credit of inventing a carriage moved by steam in England is due
to Richard Trevethick, a Cornish tin-miner, and a clever but some-
what eccentric person. He made a steam-carriage to run on common
roads or rails in 1802, and exhibited it in the metropolis. Improv-


HISTORY OF THE STEAM-ENGINE. xlix
ing on this, he, in 1804, completed a locomotive to draw coal on
the Merthyr-Tydvil Railway in South Wales. It did its work well,
drawing wagons with ten tons of iron at the rate of five miles an
22.3%2-
% º
% Ø % %
Wºź.
%
BLENKINSOP's Tooth-wheelFD LOCOMOTIVE, 181 I.
hour; but it was an ill-constructed machine, and having gone out
of order, it was deserted by its inventor, and no more was heard of
locomotives for some years. Next came the invention of Mr.
Blenkinsop, who planned a locomotive for coal traction, which was
Kº
Ç
\
*
BRUNTON'S STILT LOCOMOTIVE, 1813.
used on a railway from Middleton Collieries to Leeds, and could
haul as many as thirty loaded wagons at a speed of three and a
quarter miles an hour. What long kept the invention in this back-
ward state was the erroneous notion, that unless the locomotive had






l HISTORY OF THE STEAM-ENGINE.
wheels with cogs to pull against cogs in the railway, it would slip,
and not get forward; and it was not until this fanciful idea was got
rid of that much good was done with locomotive power. We find
on record the description of a steam-engine moved by stilts or
crutches which alternately pressed upon and lifted from the ground
like the legs of a horse; this machine was patented and exhibited
in 1813.
Finally, in 1813, Mr. Blackett, an engineer better advised than
his predecessors, demonstrated that the enormous weight Of
the adhesion between the smooth rails and the equally smooth
STEPHENSON's LocoMOTIVE, 1815.
wheels would always suffice to prevent the wheels from slipping,
and he established his theory by easy experiments. We may con-
ceive that for about twenty years subsequent to 1813, there were
many geniuses at work contriving improved locomotives, and among
these none thought more diligently or deeply than George Stephen-
son. After a variety of experiments, he was satisfied with Blackett's
theory that there would be sufficient adhesion in the wheels to over-
come any tendency to slip; teeth or cogs were accordingly dismissed.
In July, 1814, he was able to begin running his locomotive, called the
Plucher, on the Killingworth Railway. It was still only a coal-drag,
and at best a clumsy apparatus, but it hauled eight loaded wagons

HISTORY OF THE STEAM-ENGINE. 1i
weighing thirty tons, at about four miles an hour. This was un-
doubtedly a success; the thing could be done; yet, as the cost of
working was about as great as that by horses, little was gained.
There must be fresh trials. As by a flash of inspiration, Stephen-
son saw the leading defect and the method for curing it. The fur-
nace wanted draught, which he gave by sending the waste steam
into the chimney; and at once, by increased evolution of steam, the
power of the engine was doubled or tripled. In 1815 he had a new
locomotive at work, combining this and some minor improvements.
Still, there was much to be done to perfect the machine. The cost
of working was so considerable, that locomotive power did not meet
with general approval; the fact was, that railways at this period were
not so accurately finished as they now are, and smooth and easy
running ought not to have been expected. It was only step by step
that both rails and moving apparatus were brought to a compara-
tively perfect state.
At the Killingworth Colliery, Stephenson continued to plan his
improvements, and also to advance in general knowledge in the
society of his son, who, on leaving school in 1818, was placed as an
apprentice to learn practically, underground, the business of a
viewer of coal-mines; and in 1820 he went for a session of six
months to the University of Edinburgh. The cost of this piece of
education was £80, which the father could not well spare; but the
prize for skill in mathematics which his son brought home with him
at the end of the session was thought to be ample repayment.
Acquiring a knowledge of railways, Robert was appointed to pro-
ceed to Colombia, South America, to superintend some railway
operations. One day, previous to setting out, he dined with his
father, and a young man named Dixon was of the party. An anec-
dote is related to show the strong faith which George Stephenson
at this time entertained regarding railway progress. “Now, lads,”
said he to the two young men after dinner, “I will tell you that I
think you will live to see the day, though I may not live so long,
when railways will come to supersede almost all other methods of
conveyance in this country—when mail-coaches will go by railway,
and railways will become the great highway for the king and all his
subjects. The time is coming when it will be cheaper for a work-
ingman to travel on a railway than to walk on foot. I know there
are great and almost insurmountable difficulties that will have to be
lii HISTORY OF THE STEAM-ENGINE.
encountered; but what I have said will come to pass as sure as we live.
I only wish I may live to see the day, though that I can scarcely
hope for, as I know how slow all human progress is, and with what
difficulty I have been able to get the locomotive adopted, notwith-
standing my more than ten years' successful experiment at Killing-
worth.” * &
Stephenson's attention had frequently been drawn to the deplora-
ble destruction of life in coal-mines by the explosion of inflammable
air or fire-damp. As early as I 815 he devised a safety-lamp to
guard against those accidents. As it was about the same period
that Dr. Clanny and Sir Humphry Davy invented their respective
Safety-lamps for the like purpose, it is not quite clear to whom the
merit of the discovery should be assigned—though Stephenson's
claim has been strongly insisted on. As this is not the proper place
for debating the point, and, besides, as the matter is of inferior
importance, we pass on to what is of real moment—Stephenson's
perfecting of the locomotive; for on that his fame properly rests.
Pursuing schemes of this kind, after parting with his son, his
advancement was in no small degree owing to certain services in
which he was engaged on the Stockton and Darlington Railway, a
concern greatly promoted by Mr. Edward Pease, a man of property
and intelligence in the district. The engineering of this railway was
given up to Stephenson, and in some respects it became a model for
railway works—the gauge of four feet eight and a half inches, which
is now usually followed, having here been adopted in a regular
manner in imitation of the old tramways. Already a manufactory
of engines had been set up at Newcastle, in which George Stephen-
son was a partner, and from this establishment three locomotives
were ordered by the directors of the Stockton and Darlington Rail-
way Company; for in their act of Parliament they had taken power
to employ steam in the traction of goods and passengers. The
opening of this the first public railway took place on 27th Septem-
ber, 1825, in presence of an immense concourse of spectators. A
local newspaper records the event as follows: “The signal being
given, the engine started off with this immense train of carriages,
and such was its velocity, that in some parts the speed was fre-
quently twelve miles an hour; and at that time the number of pas-
sengers was counted to be 450, which, together with the coals, mer-
chandise, and carriages, would amount to near ninety tons. The
HISTORY OF THE STEAM-ENGINE. liii
engine, with its load, arrived at Darlington, a distance of eight and
three-quarter miles, in sixty-five minutes. The six wagons loaded
with coals, intended for Darlington, were then left behind; and
obtaining a fresh supply of water, and arranging the procession to
accommodate a band of music and numerous passengers from Dar-
lington, the engine set off again, and arrived at Stockton in three
hours and seven minutes, including stoppages, the distance being
nearly twelve miles.” The drawing of about 600 passengers, as
there appear to have been in the train, at the rate of four miles an
hour, was thought very marvellous. A month later a regular pas-
senger-coach, called the Experiment, was placed on the line; it was
drawn by a horse in two hours. The haulage of coal only was
effected by the locomotive. It was evident that the making of
engines was still in its infancy. Stephenson, at his manufactory,
continued to carry out improvements, in which he was assisted by
his son, on his return from South America in 1827.
When the project of the Manchester and Liverpool Railway was
before Parliament in 1825, George Stephenson, in the face of no
little browbeating from ignorant and interested opponents, gave
good evidence respecting the practicability and safety of drawing
passenger-trains with locomotives, though still speaking diffidently
as to a speed of more than from fifteen to twenty miles an hour.
Few things are more amusing than the real or affected incredulity
of members of the legislature at this time as to railway transit, not-
withstanding that the propulsion of coal-trains by locomotive power
had been satisfactorily demonstrated. It is always, however, easy to
find fault and to disbelieve; and the opposition which railways at
first encountered is no way singular. Stephenson's assertion during
his examination before a committee of the House, that it would not
be difficult to make a locomotive travel fifteen or twenty miles an
hour, provoked one of the members to reply that the engineer could
only be fit for a lunatic asylum.*
Parliamentary sanction once obtained, the Liverpool and Man-
chester Railway Company set to work upon their novel and im-
portant undertaking—novel, inasmuch as its scheme and magnitude
* It was on this occasion that Stephenson was asked by a member of the Parliamentary
Committee, “Mr. Stephenson, what would happen if a cow got on the track, with your
engine running at fifteen miles an hour?” To this Stephenson replied, “It would be
awkward for the coo.”
liv HISTORY OF THIE STEAM-ENGINE.
exceeded all that had been previously attempted of a similar nature.
Stephenson, who had already won a reputation, was appointed
engineer, at £ IOOO a year, and a chief point determined on was,
that the line should be as nearly as possible straight between the
two towns. In the carrying out of this design the series of “engi-
neering difficulties” was first encountered, the overcoming of which
has called forth an amount of scientific knowledge, of invention,
ingenuity, and mechanical hardihood unprecedented in the history
of human labor. Hills were to be pierced or cut through, embank-
ments raised, viaducts built, and four miles of watery and spongy
bog, called Chat Moss, converted into a hardened road—all which
was successfully effected.
The line being at length completed, the directors offered a prize
of £500 for the best locomotive that could be brought forward to
compete in running on a certain day. It was stipulated that the
engine should consume its own smoke; be not more than six tons
in weight; and be able to draw twenty tons, including tender and
water-tank, at ten miles an hour; be supported on springs, and rest
on six wheels; must have two safety-valves; the pressure of steam
should not exceed fifty pounds to the square inch; and the price of
the engine was not to be above £550. Stephenson determined to
compete, and built an engine called the Rocket for the purpose.
The day of trial was the 8th of October, 1829, when three engines
were brought forward. Stephenson was there with his Rocket,
Hackworth with the Sanspareil, and Braithwaite and Ericcson with
the Wovelty. The test assigned was to run a distance of thirty miles
at not less than ten miles an hour, backwards and forwards along a
two-mile level near Rainhill, with a load three times the weight of
the engine. The Novelty, after running twice along the level, was
disabled by failure of the boiler-plates, and withdrawn. The Sans-
parcil traversed eight times at a speed of nearly fifteen miles an
hour, when it was stopped by derangement of the machinery. The
Rocket was the only one to stand the test and satisfy the conditions.
This engine travelled over the stipulated thirty miles in two hours
and seven minutes nearly, with a speed at times of twenty-nine
miles an hour, and at the slowest nearly twelve; in the latter case
exceeding the advertised maximum; in the former, tripling it.
Here was a result! An achievement so surprising, so unexpected,
as to be almost incredible. Was it not a delusion ?—had it been
really accomplished?—and could it be done again?
HISTORY OF THE STEAM-ENGINE. lv.
The prize of £500 was at once awarded to the makers of the
Rocket. Their engine was not only remarkable for its speed, but
also for the contrivances by which that speed was attained. Most
important among them was the introduction of tubes passing from
end to end of the boiler, by means of which so great an additional
surface was exposed to the radiant heat of the fire, that steam was
generated much more rapidly, and a higher temperature maintained
at a smaller expenditure of fuel than usual. The tubular boiler was
indeed the grand fact of the experiment. Without tubes, steam
could never have been produced with the rapidity and heat essential
Ş
\º
§§§ § § § sº NN
§§§º
STEPHENSON's LocoMOTIVE ENGINE, THE “ROCKET,” 1829.”
to quick locomotion. In more senses than one, the trial of the
three locomotives in October, 1829, marks an epoch. By burning
coke instead of coal the stipulated suppression of smoke was
effected; the quantity consumed by the Rocket during the experi-
ment was half a ton. The coke and water were carried in a tender
attached to the engine.
On the 15th of September, 1830, the railway was opened. The
" * A, the boiler."6 feet long, 3 feet 4 inches in diameter. B, the fire-box enclosed in a
casing 3 inches wide, containing water. C, a water pipe communicating between the
casing and the boiler. D, a steam-pipe between the same. E, two pipes (one from
each cylinder) for throwing the exhaust steam into the chimney.







lvi HISTORY OF THE STEAM-ENGINE
two great towns, with due regard to the importance of the event,
made preparations for it with a spirit and liberality worthy of their
wealth and enterprise. Members of the government, and distin-
guished individuals from various quarters, were invited to be present
at the opening. On the memorable day a train was formed of eight
locomotives and twenty-eight carriages, in which were seated the
eminent visitors and other persons present on the occasion, to the
number of 600. The Worthumbrian, one of the most powerful of
the engines, took the lead, followed by the train, which, as it rolled
proudly onwards, impressed all beholders with a grand idea of the
energies of art, and of the power destined soon afterwards to effect
the greatest of civil revolutions. At Parkfield, seventeen miles from
Manchester, a halt was made to replenish the water-tanks, when the
accident occurred by which Mr. Huskisson lost his life, and tem-
pered the triumph by a general sentiment of regret. The proceed-
ings, however, though subdued, were carried out in accordance with
the arrangements prescribed.
Business began the next day. The Northumbrian drew a train
with I 30 passengers from Liverpool to Manchester in one hour and
fifty minutes; and before the close of the week six trains daily were
regularly running on the line. The surprise and excitement already
created were further increased when one of the locomotives by itself
travelled the thirty-one miles in less than an hour. Of the thirty
stage-coaches which had plied between the two towns, all but one
went off the road very soon after the opening, and their 500 passen-
gers multiplied at once into 1600. In December commenced the
transport of goods and merchandise, and afforded further cause of
astonishment; for a loaded train, weighing eighty tons, was drawn
by the Planet engine at from twelve to sixteen miles an hour. In
February, 1831, the Samson accomplished a greater feat, having
conveyed 164% tons from Liverpool to Manchester in two hours
and a half, including stoppages—as much work as could have been
performed by seventy horses.
There are some who will remember the wonder and excitement
created by these results in all parts of the kingdom. The facts
could not be disputed. Neither the laws of nature nor science
could be brought to accord with the views of those who saw in the
new agencies the elements of downfall and decay. Even the com-
pany had gone surprisingly astray in their calculations. Believing
HISTORY OF THE STEAM-ENGINE. lvii
that the greater part of their business and of their revenue would
be derived from the transport of heavy goods, they had set down
420,000 a year only as the estimated return from passenger traffic;
and scarcely a week had passed before they became aware of the
fact, as agreeable as it was unexpected, that passengers brought the
greatest return. The whole number conveyed from the time of
opening to the end of the year—three months and a half—was more
than 71,000. This line, as is well known, now forms part of that
vast system, the London and Northwestern Railway.
These successes placed George Stephenson in an eminent position
in the engineering world. He was sought after for various under-
takings; the business with which he was connected at Newcastle
increased; and, in short, he was, as far as worldly consideration and
circumstances are concerned, a “made man.” His steadiness, per-
severance, and skill had been acknowledged and rewarded. He
and his son further perfected the locomotive, which he lived to see
running at upwards of forty miles an hour. In 1837, he removed
to Tapton Hall, a residence near Chesterfield, and in 1840, he inti-
mated his design of retiring from his more active professional pur-
suits. He, however, did not subside into idleness or indifference;
but gave time to various railway matters, and took pleasure in
attending public meetings of mechanics' institutes. It was a great
day for him, the 18th of June, 1844, when the first train came with-
out break from London to Newcastle in the space of nine hours.
At the festival on that day at Newcastle, to signalize the event, all
eyes were turned on old George Stephenson, when, in reply to a
complimentary speech of Mr. Liddell, M.P., he gave the following
brief but interesting account of his career.
“As the honorable member has referred to the engineering efforts
of my early days, it may not be amiss if I say a few words to you
on that subject, more especially for the encouragement of my
younger friends. Mr. Liddell has told you that in my early days I
worked at an engine on a coal-pit. I had then to work early and
late, and my employment was a most laborious one. For about
twenty years I had often to rise to my labor at one and two o'clock
in the morning, and worked until late at night. Time rolled on,
and I had the happiness to make some improvements in engine-
work. The company will be gratified when I tell them that the first
locomotive that I made was at Killingworth Colliery. The owners
lviii HISTORY OF THE STEAM-ENGINE.
were pleased with what I had done in the collieries; and I then
proposed to make an engine to work upon the smooth rails. It was
with Lord Ravensworth's money that my first locomotive was built.
Yes, Lord Ravensworth and his partners were the first gentlemen
to intrust me with money to make a locomotive. That was more
than thirty years ago; and we first called it “My Lord.' I then
stated to some of my friends, now living, that those high velocities.
with which we are now so familiar would, sooner or later, be
attained, and that there was no limit to the speed of such an engine,
provided the works could be made to stand; but nobody would
believe me at that time. The engines could not perform the high
velocities now reached, when they were first invented; but, by their
superior construction, an immense speed is now capable of being
obtained. In what has been done under my management, the merit
is only in part my own. Throughout, I have been most ably
seconded and assisted by my son. In the early period of my career,
and when he was a little boy, I felt how deficient I was in education,
and made up my mind that I would put him to a good School. I
determined that he should have as liberal a training as I could
afford to give him. I was, however, a poor man; and how do you
think I managed P I betook myself to mending my neighbors'
clocks and watches at night, after my daily labor was done. By
this means I saved money, which I put by ; and, in course of time,
I was thus enabled to give my son a good education. While quite
a boy he assisted me, and became a companion to me. He got an
appointment as under-viewer at Killingworth; and at nights, when
we came home, we worked together at our engineering. I got leave
from my employers to go from Killingworth to lay down a railway
at Hetton, and next to Darlington for a like purpose; and I finished
both railways. After that I went to Liverpool to plan a line to
Manchester. The directors of that undertaking thought ten miles
an hour would be a maximum speed for the locomotive engine, and
I pledged myself to attain that speed. I said I had no doubt the
locomotive might be made to go much faster, but we had better be
moderate at the beginning. The directors said I was quite right;
for if, when they went to parliament, I talked of going at a greater
rate than ten miles an hour, I should put a cross on the concern
It was not an easy task for me to keep the engine down to ten
miles an hour; but it must be done, and I did my best. I had to
HISTORY OF THE STEAM-ENGINE. lix
place myself in the most unpleasant of all positions—the witness-
box of a parliamentary committee. I was not long in it, I assure
you, before I began to wish for a hole to creep out at. I could not
find words to satisfy either the committee or myself, or even to make
them understand my meaning. Some said: ‘He's a foreigner.'
‘No,' others replied; “he's mad.” But I put up with every rebuff
and went on with my plans, determined not to be put down. Assist-
ance gradually increased; great improvements were made in the
locomotive; until to-day, a train which started from London in the
morning has brought me in the afternoon to my native soil, and
enabled me to meet again many faces with which I am familiar, and
which I am exceedingly pleased to see once more.”
Besides planning several railways after this period, and giving
evidence respecting projects of this kind before parliamentary con-
mittees, Stephenson several times visited the continent to be con-
sulted respecting lines of railway; on one of which occasions he
had an interview, along with his friend Mr. Sopwith, with the king
of the Belgians. He likewise continued to be a prominent man at
public demonstrations connected with the opening of railways, one
of the latest of these festivities being at the opening of the Trent
Valley line in June 1847, when he was complimented by Sir Robert
Peel, and compared by him to Julius Agricola, the maker of Roman
roads in Britain. George was now accustomed to the language of
compliment from classes of men who formerly treated his theories
with derision. In replying to Sir Robert Peel's flattering remarks,
he could not refrain from noticing this change of sentiment.
“When,” he said, “I look back to the time when I first projected a
locomotive railway in this neighborhood, I cannot but feel aston-
ished at the opinions which then prevailed. We were told, even by
celebrated engineers, that it would be impossible ever to establish
railways. Judge, then, how proud must now be the feelings of one
who, foreseeing the results of railways, has risen from the lower
ranks on their success I may venture to make a reference to
what the Right Honorable Baronet said relative to Julius Agricola
and a direct line. If Julius Agricola laid down the most direct
lines, it must be recollected that he had no heavy goods-trains to
provide for, and gradients were of no consequence. The line that
general took was probably very good for his troops, where the hills
would serve to establish his watches; but such lines would be in no
5
lx HISTORY OF THE STEAM-ENGINE.
way applicable at the present day, where the road is covered with
long goods-trains propelled by the locomotive. What we require
now is a road with such gradients that locomotives shall be able to
carry the heaviest loads at the least expense. The Right Honor-
able Baronet will excuse me if I say that to have a line that is
direct is not the main thing. Had he studied the laws of practical
mechanics as I have done, he would doubtless have regarded good
gradients as one of the most important considerations in a railway.”
This last remark has been amply verified. Railways are now made
with gradients which would not formerly have been attempted; but
the heavy expense incurred on account of fuel and tear and wear
of machinery to overcome the ascents forms a serious deduction
from revenue.
At home, in the close of his days, George Stephenson occupied
himself with his birds and other animals, for which he had a great
fondness; nor did he take less pleasure in his garden and the rear-
ing of flowers and vegetables. Occasionally he visited the scenes
of his youth among the collieries about Newcastle, at all times
taking an interest in the welfare of the workmen, and never feeling
ashamed of recognizing old acquaintances. Though often invited
to the houses of persons of distinction, he acknowledged he had no
wish to figure in what he called fine company. It is said that he
was beset by projectors of all kinds for the sake of his advice; and
that the young likewise besought his counsel as to their proposed
professional career, which he gave always cheerfully, except when
these youthful aspirants were affectedly dressed, and put on airs
contrary to George's notions of propriety. To a young applicant
of this stamp his candor was probably not very agreeable, but may
have been salutary. “I hope you will excuse me; I am a plain-
spoken person, and I am sorry to see a nice-looking and rather
clever young man like you disfigured with that fine-patterned waist-
coat and all these chains and fang-dangs. If I, sir, had bothered
my head with such things when at your age, I should not have been
where I am now.”
With this love of simplicity, and universally respected, George
Stephenson closed his useful career. He died 12th August, 1848,
aged 67. In the preceding sketch we have touched merely on the
chief incidents in his biography, which we commend for perusal in
HISTORY OF THE STEAM-ENGINE. lxi
either of the admirable works composed by Mr. Smiles. The
mantle of George Stephenson fell on his son, Robert; and how he
added lustre to the family name is well known. Besides several
great railway, undertakings, of which he was engineer, he designed
the High Level Bridge across the Tyne at Newcastle, the Conway
and Britannia Tubular Bridges in North Wales, and that still more
magnificent work of art, the Tubular Bridge, nearly two miles in
length, across the St. Lawrence at Montreal—in all which works,
however, he was ably assisted by subordinates; nor should it be
omitted that to William Fairbairn, of Manchester, is generally im-
puted the invention of the tubular system of bridge-building. In
1844 he entered parliament as member for Whitby. This distin-
guished son survived his father only eleven years. He died in
1859, aged 56, and was honored with a public funeral and interment
in Westminster Abbey. If the traveller by railway wishes to see a
lasting monument to George and Robert Stephenson, he has only
to look around !
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TREVETHICK's CIRCULAR RAILWAY AT LONDON, 1808.

i
iº
--º-º:
*
__ROBERT FULTON) :
&= T F N.*:::)
THE SHARE AND CLAIMS OF AMERICANS AND
OTHERS IN THE DISCOVERY AND APPLICATION
OF STEAM.
The main story related above is from English records, and we
have deemed it necessary to glance at the share claimed for America
in this important introduction of steam for mechanical purposes. .
Reviewing the history of the discovery of steam, as described in
the two biographies given above, we have to conclude that, although
the fact of steam as a mighty power was known before the Christian
era,” yet for practical use it was worthless till Papin made his dis-
*The engineer, noting the curious things in bronze and in copper, exhumed at Pom-
peii and gathered together in the Museo Borbonica at Naples, will linger near a small
vessel for heating water, little more than a foot high, in which are combined nearly all
the principles involved in the modern vertical steam-boiler—fire-box, smoke-flue through
(lxii)

HISTORY OF THE STEAM-ENGINE. lxiii
covery as related at page xix, supra. Savary seems to have taken it
up where Papin left it, and Newcomen improved on Savary, till, as
we see at page xxiii, supra, Newcomen's engine fell into the hands of
Watt for repair, and it at once “became a living thing.” The
scramble for the application of Watt's discovery to locomotives and
navigation, whether from the improved experience of Savary or
Newcomen or the perfected discovery of Watt, numbers among the
scramblers such names as Murdoch, Symington, Miller, Fitch,
Rumsey, Fulton, Kingsley,Trevethick, Telford, Blenkensop, Blackett,
Ericsson, Hackwah, Bunstal, and several in France and Italy, and
the culminating success of the result of all these competitors was
A a dº a
yº-yº”
sº
FITCH's STEAMBOAT.
the Rocket locomotive at Rainhill, and Fulton's steamboat, the Cler-
mont, at New York. &
John FITCH, born at Windsor, Conn., 1743, was an original
genius. In 1787 he launched a steam-packet (it had paddles at the
side) at Philadelphia, which reached a speed of thirteen miles per
hour, and, having obtained by letters patent the exclusive right of
steam navigation in New Jersey, Pennsylvania and Delaware, he
built a boat to convey passengers on the Delaware river for hire,
which proved a commercial failure. He died 1798.
JAMES RUMSEY was born in Maryland, 1743, studied mechanics
and became an inventor. In 1784 (twenty-three years before Fulton
the top and fire-door at the side, all complete—and strange to say, this little thing has a
water-grate, made of small tubes crossing the fire-box at the bottom, an idea that has
been patented twenty times over, in one shape or another, within the period of the
history of the steam-engine.—joseph Harrison, jr.


lxiv, HISTORY OF THE STEAM-ENGINE.
built the Clermont) he exhibited on the Potomac, in the presence
of General Washington, a boat propelled by machinery. In 1786
he exhibited a boat in which a pump worked by steam-power drove
a stream of water from the stern and thus furnished the motive-
power. A society was formed to aid his project, of which Franklin
was a member. His death occurred in 1792, while he was making
further experiments.
APOLLOS KINGSLEY, a young man, of Hartford, Conn., about the
year 1798, made and propelled through the streets of that city a
steam locomotive, which he then said would in future be the means
of propelling the mail stages, etc. He was not credited, died soon
after, and all then went for nothing. .
ROBERT FULTON was born in Pennsylvania, 1765. He received
a good School education. When he was old enough his mother
apprenticed him to a jeweller in Philadelphia. In addition to his
labors at this trade he devoted himself to painting, and the sale of
his portraits and landscapes enabled him, in the space of four years,
to purchase a small farm, on which he placed his mother, his father
being dead. At the age of twenty-two he proceeded to London,
where he studied painting under West; but, after several years
spent thus, he felt that this was not his true vocation. Accordingly,
abandoning painting, he applied himself wholly to mechanics.
Some works he performed in Devonshire obtained him the patron-
age of the Duke of Bridgewater and likewise that of the Earl of
Stanhope. Accepting an invitation from the United States minister
at Paris, he proceeded to that city in 1796 and remained there for
seven years, devoting himself to new projects and inventions.
Amongst his inventions here was the nautilus, or sub-marine boat,
intended to be used in naval warfare, which he in vain sought the
French government to accept. Nor was he more successful with
the British government, which he next tried, though commissions
were appointed in both cases to test the value of his invention.
Having failed in this matter, he next turned his attention to a sub-
ject that had frequently occupied his mind before and about which
he had written a treatise in 1793, viz., the application of steam to
navigation. In 1803 he constructed a small steamboat, and his ex-
periments with it on the Seine were attended with great success,
He returned to New York in 1806 and pursued his experiments
there. In 1807 he launched a steam-vessel, the Clermont, upon the
HISTORY OF THE STEAM-ENGINE. lxv
Hudson, which made a successful start in the presence of thousands
of astonished spectators. From this period steamers (for the con-
struction of which Fulton received a patent from the Legislature)
came into pretty general use upon the rivers of the United States.
==
*#,
FULTON'S STEAMBOAT, I803.
Although Fulton was not the first to apply steam to navigation, as
a steam-vessel, Symington's, had been tried upon the Forth and
Clyde canal as early as 1789, and Miller, near Dumfries, 1790, yet
he was the first to apply it with any degree of success to STEAM
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NAVIGATION. His reputation was now firmly established, and he was
employed by the United States government in the execution of
various projects with reference to canals and other words. In 1814
he obtained the consent of the Legislature to construct a steam-







lxvi HISTORY OF THE STEAM-ENGINE.
frigate, which was launched in the following year. Though the
labors of Fulton were attended with such great success, various
lawsuits in which he was engaged in reference to the use of some
of his patents prevented him from ever becoming wealthy, and
anxiety, as well as excessive application, tended to shorten his days.
His death, in 1815, produced extraordinary demonstrations of
mourning throughout the United States.
* OLIVER Evans was born 1755 in the State of Delaware and was
educated in the common schools of Philadelphia, to which city his
parents had removed shortly after his birth. He was apprenticed
to a wheelwright, and when twenty-two years old he invented a
machine for card teeth, which superseded hand work. In his
thirty-first year, 1786, Evans petitioned the Legislature of Pennsyl-
vania for the exclusive right to use his improvements on flouring-
mills and steam-carriages in Pennsylvania. In the following year
he presented the same petition to the Legislature of Maryland. In
the former case he was only successful so far as to obtain the privi-
lege for the mill improvements, his representations respecting steam-
carriages savoring too much of insanity to deserve notice. .
He was more fortunate in Maryland, for although the steam pro-
ject was laughed at, yet one of his friends, a member, very judi-
ciously observed that the grant could injure no one, for he did not
think that any man in the world had ever thought of such a thing
before. He therefore wished the encouragement might be afforded, as
there was a prospect of its producing something useful. The exclu-
sive privilege was granted, and after this Mr. Evans considered him-
self bound in honor to the State of Maryland to produce a steam-
carriage as soon as his means would permit him.
To Oliver Evans must be awarded the credit of having built and
put in operation the first practically useful high-pressure steam-en-
gine, using steam at IOO pounds pressure to the square inch, or
more, and dispensing with the complicated condensing apparatus of
Watt. The high-pressure engine of Evans had advantages for us
in its greater simplicity and cheapness, and ever since his day it has
continued the standard steam-engine for land purposes in America.
* We are indebted for this notice of Oliver Evans to a valuable work, The Zocomotive
Engine and Philadelphia's Share in its Early Improvement, by Joseph Harrison, Jr.
# Watt's patent for the condensing apparatus was dated 1766. -
HISTORY OF THE STEAM ENGINE lxvii
English writers have tried to detract from the ſame of Oliver
Evans, but it is well known that early in his engineering life he sent
drawings and specifications of his engines, etc., to England by the
hands of Mr. Joseph Stacey Sampson, of Boston. It is well known
also that these drawings, etc., were shown to and copied by en-
gineers in England, and from this period dates the introduction
into Europe of the first really useful high-pressure steam-engine,
now so generally applied to locomotive and other purposes.
Basing his hopes of success on the use of the high-pressure en-
gine in his steam-carriage, Oliver Evans, notwithstanding the oppo-
sition and even the derision of his best friends, and of almost every
one, made earnest efforts in the beginning of this century to carry
out his design for building his favorite machine, but without suc-
cess. He had a good friend in Mr. Robert Patterson, the Professor
of Mathematics in the University of Pennsylvania, who recom-
mended the plan as highly worthy of notice and who wished to see
it tried. Evans' plan was shown to Mr. B. H. Latrobe, a scientific
gentleman of great eminence in his day, who publicly pronounced
them chimerical and who attempted to demonstrate their absurdity
in his report to the American Philosophical Society on Steam-En-
gines, in which he also undertook to show the impossibility of mak-
ing steamboats useful.
In Mr. Latrobe's report Mr. Evans was said to be seized with the
“steam mania,” which was no doubt most true. To the credit of
our then and now most learned society, the portion of Mr. Latrobe's
report which reflected so harshly upon Mr. Evans was rejected, the
members conceiving that they had no right to set up their opinions
as an obstacle in the way of an effort towards improvements that
might prove valuable for transport on land. The society did, how-
ever, admit in the report the strictures on steamboats.
Oliver Evans never succeeded in constructing a steam-carriage
such as he had contemplated. It was commenced, and unaided he
spent much time and money in fruitless efforts to complete it.
Finding himself likely to be impoverished if he persisted in the
scheme, he finally abandoned it, and devoted his time thereafter to
the manufacture of his high-pressure steam-engine and his improved
milling machinery. Previously, however, to the final abandonment
of his favorite project, Oliver Evans, on the 25th of September, 1804,
submitted to the Lancaster Turnpike Company a statement of the
lxviii HISTORY OF THE STEAM-ENGINE.
cost of and probable profits of a steam-carriage to carry one hundred
barrels of flour fifty miles in twenty-four hours, tending to show also
that one such carriage would make more net profit on a good turn-
pike road than ten wagons drawn by five horses each.
He offered to build a steam-carriage at a very low price. Evans'
statement to the turnpike company closed as follows: “It is too
much for an individual to put in operation every improvement which
he may invent. I have no doubt but that my engines will propel
boats against the currents of the Mississippi, and wagons on turnpike
roads with great profit. I now call upon those whose interest it is,
to carry this invention into effect.”
Oliver Evans, in the early part of 1804, came nearest to realizing
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OLIVER, EVANs’ “ORUCTOR AMPHIBOLIS.”
his favorite idea, in obtaining an order from the Board of Health of
Philadelphia to construct at his foundry (a mile and a half from the
water) a dredging machine for cleaning docks, the first one ever con-
trived for dredging by steam, now so common. .
To this machine Evans gave the name of “Oructor Amphibolis,”
or Amphibious Digger, and he determined, when it was completed,
to propel it from his work shop to the Schuylkill river, which was
successfully done, to the astonishment of a crowd of people gathered
together to see it fail. When launched, a paddle-wheel, previously
arranged, was put in motion at the stern, and again it was propelled
by steam to the Delaware, leaving all vessels half-way behind in the
trip, the wind being ahead.


































HISTORY OF THE STEAM-ENGINE. lxix
This result Evans hoped would have settled the minds of doubters
as to the value of steam as a motor on land and water. But his at-
tempt at moving so great a weight on land was ridiculed, no allow-
ance being made by the hinderers of that day for the disproportion
of power to load, rudeness in applying the force of steam for its
propulsion, or for the ill form of the boat. A rude cut of the
“Oructor Amphibolis” is still extant, which shows a common scow,
mounted on four wooden wheels, with power applied to the whole
number of the wheels by the use of leathern belts.
Evans, after this experiment, willing to meet the question in any
way, silenced the carpers around him by offering a wager, that for
$3,000 he would make a steam-carriage that would run on a level
road as swift as the fastest horse they could produce. His bet met
with no takers.
This movement by steam power of Oliver Evans' dredging ma-
chine on land was, without any doubt, the first application of steam
to a carriage in America, and in fact the first locomotive engine.*
It was a more important experiment than any that had preceded it,
anywhere in the same direction.
Oliver Evans' conceptions respecting the power of steam, many
of them practically exemplified by him, reflect great credit on his
Sagacity as an engineer, and many of his predictions in regard to its
great value, particularly for land transport, may well be termed
prophetic.
In the early part of this century he publicly stated that “The time
will come when people will travel in stages moved by steam-engines
from city to city, almost as fast as birds fly,–fifteen or twenty miles
an hour. Passing through the air with such velocity, changing the
scene in such rapid succession, will be the most exhilarating exer-
cise.” “A steam-carriage will set out from Washington in the morn-
ing, the passengers will breakfast in Baltimore, dine in Philadel-
phia, and sup in Wew York the same day.”f “To accomplish this,
two sets of railways will be required, laid so nearly level as not to
deviate more than two degrees from a horizontal line,—made of wood
or iron, on Smooth paths of broken stone or gravel, with a rail to
*"Du Cognot's carriage was made in 1770; see page xlviii. Mr. Harrison probably was
not aware of this.
† We now (1888) lunch at 2 o'clock in Washington, and dine at 8 o’clock the same
aſternoon in New York.
;
lxx HISTORY OF THE STEAM-ENGINE.
guide the carriages, so that they may pass each other in different
directions, and travel by night as well as day.”
Much stress is laid upon these early efforts of Oliver Fvans
towards the introduction of steam for land and water transporta-
tion, and much space has been given here to set them forth. With
no light to guide him (for it is fair to suppose that he knew nothing
of the little that had been done up to his day in Europe), how his
trumpet-tones ring out in the words above quoted (date 1804), com-
pared with the “uncertain sound” made by the English engineers
in 1829. They, with a quarter of a century of later experience,
during which period much had been done to improve and develop
the locomotive engine, then no new thing, nor was it barren of use-
ful practical results, hesitated and doubted in their course. He, with
no misgivings as to the future, and with no dimmed vision, saw with
prophetic eyes all that we now see. To him the present picture, in
all its grandeur and importance, glowed in broad sunlight. In the
history of these efforts of Oliver Evans it is noteworthy, and most
creditable to our sister State of Maryland, that that commonwealth
extended to him the first public encouragement in his steam-carriage
project.
Again our enterprising neighbor was first in the field, since be-
come so important, for we find that in March, 1827, the State of
Maryland chartered the first railway company in America, and in
1828 her citizens commenced the construction of the Baltimore and
Ohio Railway, aiming to cross the Alleghenies; certainly the greatest
railway scheme that had been thought of up to that date, and now,
in its completed state, a triumph of railway engineering. To this
first effort to make a great railway in the United States, and its in-
fluence upon the history of the locomotive, reference will be made
hereafter.
Oliver Evans died in 1819, and his plans for a steam-carriage died
with him, and although he produced nothing practically useful in
the great idea of his life, he has left behind him an enduring monu-
ment in his grain and flour machinery.
The materials for the history of the next attempt at making a
steam-carriage in America, eight or nine years after the death of
Oliver Evans, are not very full. At this period (1828) a steam-car-
riage to run on a common road was projected by some parties in
our city whose names cannot now be easily reached. This steam-
HISTORY OF THE STEAM-ENGINE. lxxi
carriage was built at the small engineering establishment of Nicho-
las and James Johnson, then doing business in Penn street, in the
old district of Kensington, just above Cohocksink creek, Phila-
delphia.
An eye-witness of its construction, and who saw it running under
steam on several of its trials, describes it as an oddly-arranged and
rudely-constructed machine. It is believed to have had but a single
cylinder, set horizontally, with connecting-rod attachment to a single
crank at the middle of the driving-axle. Its two driving-wheels
were made of wood, the same as an ordinary road-wagon, and were
of large diameter, certainly not less than eight feet. It had two
smaller wheels in front, arranged in the usual manner of a road-
wagon, for guiding the movement of the machine. It had an up-
right boiler hung on behind, shaped like a huge bottle; the smoke-
pipe, coming out through the centre at the top, formed the neck of
the bottle. Its safety-valve was held down by a weight and lever,
and it was somewhat amusing to see the puff, puff, puff of the
safety-valve as the machine jolted over the rough street. This was
before the days of spring-balances for holding down the safety-valves
of locomotives.
On its trials, made on the unpaved streets of the neighborhood
in which it was built, this steam-carriage showed an evident lack of
boiler as well as cylinder power. It would, however, run continu-
ously for some time and surmount considerable elevations in the
roads. It was sometimes a little unmanageable in the steering-
apparatus, and on one of its trials, in running over the High bridge
and turning up Brown street, its course could not be changed quick
enough, and before it could be stopped, it had mounted the curb-
stone, smashed the awning-posts, and had made a demonstration
against the bulk-window of a house at the southwest corner of
Brown and Oak streets.
After this mishap it was not seen on the streets again, nor is it
known what ultimately became of it. This last effort may be classed
in some respects no doubt with what Oliver Evans promised in his
mind to carry out, and it is very evident that up to its time no great
amount of knowledge, or of practical or theoretical skill, had been
brought to bear upon the construction of locomotives in Philadel-
phia. No books were as yet published in America describing the
locomotive, or telling what had been done in land transport by
lxxii HISTORY OF THE STEAM-ENGINE.
steam in Europe. The trials on the Liverpool and Manchester
Railway in 1829 had not been made, and a better result could have
hardly been expected than this recorded above.
With the wonderful success of the Rocket in October, 1829, the
attention of our engineers and capitalists was strongly turned
towards this new revelation in land transport, that had so suddenly
flashed upon the world. It was a matter of the greatest importance
to us, with our rich lands everywhere teeming with produce, the
producers meanwhile crying aloud for better means to get their
harvests to market, and for getting our people, too, more speedily
from point to point, that we should know more of this new thing,
and if it fulfilled its promise, to get the advantage of it as soon as
possible.
It is true that the river, the canal, and the turnpike road have done
good service in the past; but they did not keep pace with the grow-
ing wants of the country. The river, Nature's own free highway,
is, when navigable, often hindered by flood and frost, by currents
and by drought, nor does it run everywhere, or always where it
would best conduce to man's use and benefit. The slow, plodding
canal did its work cheaply, and with nothing better it must have
continued the favorite means for inland trade. But canals are only
possible where water can be had in abundance to keep them full,
and with winter's cold to interrupt their movement, they are prac-
tically useless for half the year. Their capacity, at best, is limited,
too, in many ways. The turnpike road, most useful in its place, had
a very narrow limit of usefulness, when the means to do the carry-
ing trade of a continent were to be attained. Man's restless nature
longed for and demanded something better than the river, the canal,
or the turnpike road, and this had been found in the RAILROAD and
the LocoMotive. It did not take long, therefore, to come to a
decision that railways” must be built, and the locomotive brought
into use, and that speedily.
* The first RAILROAD built in America was on Beacon Hill, near Boston, Mass., in
1807. It was built by Silas Whitney to haul gravel from the top of the hill to the bot-
tom, and consisted of two tracks. The next was from Thomas Leiper’s stone-quarries
on Crum creek, Delaware county, Pa., to his landing on Ridley creek, a distance of about
one mile, in 1809. The next railroad (five-foot gauge) was that from the granite-quar-
ries at Quincy to the Neponset river in Massachusetts, a distance of about three miles,
which was commenced in 1826 and finished in 1827. In January, 1826, was com-
HISTORY OF THE STEAM-ENGINE. lxxiii
It has been seen that Maryland took the lead, and she had her
great road well under way before other States looked the question
fairly in the face. South Carolina followed the lead of Maryland,
and granted a charter at an early period to the South Carolina
Railway, intending to cross the whole breadth of the State, and
ultimately aiming to reach the far west. 3.
Signs of railway movement were seen in Pennsylvania, Delaware
and New Jersey, and in New York and New England. The Colum-
bia Railroad (a State work) was projected in Pennsylvania at this
time, and the Philadelphia, Germantown and Norristown Railroad
was begun in Philadelphia. New Jersey had chartered and com-
menced her road from Camden to Amboy, and little Delaware,
ahead of all the States north and east of her, had two miles of the
Newcastle and Frenchtown Railroad ready for use on the 4th of
July, I831.
The South Carolina Railroad was amongst the first to encourage
the manufacture of American locomotives, and Mr. Horatio Allen,
one of the first engineers of the country, designed and had built,
in 1830–31, at the West Point foundry in New York, the first loco-
motives it is believed that were ever ordered and made in the
United States for regular railroad traffic.
Other engines subsequently built in New York after designs by
menced the novel “mule-road,” nine miles in length, connecting the Summit Hill coal-
mines, back of Mauch Chunk, with the Lehigh river. It was in operation May, 1827.
On August 8, 1829, the first locomotive that ever turned a driving-wheel on a railroad-
track in America was run at Honesdale, Pa., on the newly-finished road that connected
the Lackawanna coal-fields with tide water on the Hudson Canal. The road in question
was the first of any general commercial importance ever built in this country, and
inaugurated the economical system of inclined planes, since adopted by engineers
wherever practicable. It is claimed by some that at about the same time Peter Cooper,
of New York, built the first American locomotive—the Zom Thumb–in 1829, and
tried it on the Baltimore and Ohio Railroad, thirteen miles of which had then been
laid. It did not work quite so well as he desired, though it was capable of locomotion,
and he remodelled it. On August 28, 1830, it made a perfectly satisſactory trip, running
thirteen miles in an hour and a quarter. The 7om Thumb, however, was only an
experiment. The first American locomotive built for actual service was the Best
Friend of Charleston, ordered March 1, 1830, by the South Carolina Railroad Com-
pany, of the West Point Foundry, New York. It was completed in October, 1830, and
shipped to Charleston. It made its trial trip November 2, 1830, and worked satisfac-
torily. The second American engine ſor actual service was built by the same parties for
the same company, and was put on the railroad in March, 1831.—Arom Watson’s
Annals of Philadelphia.
lxxiv. HISTORY OF THE STEAM-ENGINE.
Mr. Allen, did good service on the South Carolina Railroad, and it
is curious to note that in these later engines was embodied every
valuable point of the Fairlie engine, now making so much noise
in England. These points being the use of a vibrating truck at
both ends with cylinders thereon, fire-box in the middle, with flues
from fire-box to each end of the boiler, double smoke-box and
double chimney, with fire-door at the side of fire-box, flexible
steam and exhaust pipe, etc.”
The directors of the Baltimore and Ohio Railroad in January,
I83 I, by advice of Mr. Jonathan Knight, of Pennsylvania, still tak-
ing the lead in the railroad movement, and with the desire to en-
courage American skill, adopted the same plan that had been so
successfully carried out at Liverpool in 1829 and offered a premium
of $4,000 for the best American locomotive.
At this period in this history more mind and more practical
knowledge had been brought out in Philadelphia aiming towards
the improvement of the locomotive engine. In March, 1830, Colonel
Stephen H. Long, of the United States Topographical Engineers, a
gentleman of high scientific culture and noted for his originality,
obtained a charter from the State of Pennsylvania, incorporating the
“American Steam-Carriage Company,” and soon thereafter com-
menced the construction of a locomotive in Philadelphia. This en-
gine was designed somewhat after the then recently improved loco-
motives made in England, but had several original points.
This first engine of Colonel Long was placed, when finished, upon
the Newcastle and Frenchtown Railroad, and the Hon. Wm. D.
Lewis has furnished the following account of its trial at various
times on that road, with which he at that period was connected in
an official capacity.
* The first locomotive ever run on a railroad in America was undoubtedly the
Lion, one of two engines built at Stourbridge, in England, under the direction of
Mr. Horatio Allen and imported into this country in the autumn of 1829 for the Dela-
ware and Hudson Railroad in the State of New York. Mr. Allen, in describing its
first movement, says that he was the only person upon the engine at the time, and he
certainly made the first trip by steam on an American railroad. The Zion, built
before the Rocket, had vertical cylinders, arranged somewhat after the manner of
the old style of Killingworth or Stockton and Darlington engines, with four driving-
wheels, all connected. The boiler of this engine approached closely to the locomotive
boiler of the present day, in having a fire-box with five flues leading to the Smoke-box,
this latter feature being, in fact, the first step towards the present multi-tubular boiler.
|
HISTORY OF THE STEAM-ENGINE. lxxv
COLONEL LONG's LOCOMOTIVE.
“On the 4th of July, 1831, two miles of rail being laid on the
Newcastle and Frenchtown Railroad, Colonel Long made trial on it of
his locomotive which weighed about three and one-half tons. The
first effort was not a success, the failure being attributed to lack of
capacity to furnish a sufficient supply of steam. It would go well
enough for a while, but the steam could not be kept up. The next
day the colonel had better luck, his engine then going to the end of
our rails and back, drawing two passenger cars packed with people
(say seventy or eighty) with apparent ease, and it had fifty pounds
of steam at the end of the experiment.
“The colonel, however, was not satisfied with it, and the machine
was brought to Philadelphia again and a new boiler was constructed
for it at Rush & Muhlenburgh's works at Bush Hill. This engine
was again taken to Newcastle and tried upon the road, but it again
failed. It would go very well for a time, but on the 31st of October,
1831, a pipe was burst and it became disabled. This being repaired,
two days thereafter another trial was made, but with equal want of
success, which was ascribed to lack of power as well as of specific
gravity. Alone this engine went very well and rapidly, say at the
rate of twenty-five miles an hour, but it would not draw a satisfac-
tory burden.
“Soon after the above date Colonel Long removed his engine from
the road and I do not know what became of it afterwards.” Mr.
Lewis adds: “The above memoranda I now enclose of the trials
of Colonel Long's locomotive in 1831 are made from a book in which
all the facts I give you were set down contemporaneously with their
occurrence.” This unsuccessful attempt of Colonel Long was, up to
its date, much the most important movement that had yet been
made in Philadelphia towards the improvement of the locomotive,
and as such it deserves special notice. It was furthermore not
without its value in inducing him thereafter to pursue the subject to
much better results. Had Colonel Long more faithfully copied the
English engine of his day he would have had better success in his
first effort; but he, as with all our Philadelphia engineers and me-
chanics at that time and in the succeeding years, aimed at making
an American locomotive.
Whilst Colonel Long was engaged in the construction of his engine
Matthias W. Baldwin, a name that has since become so famous in
6
lxxvi. HISTORY OF THE STEAM-ENGINE.
the history of the improvements and in the manufacture of the loco-
motive in Philadelphia, was engaged in making a model locomotive
for the Philadelphia Museum. In this work Mr. Baldwin was as-
sisted by that highly eminent practical mechanic and engineer,
Franklin Peale, then manager of the museum.
To gratify the curiosity of the public to know more of this new
thing, this little engine was placed upon a track laid around the
rooms of the museum, in what was then the Arcade, in Chest-
nut street, above Sixth, and where it was first put in operation on
April 25, 1831. It made the circuit of the museum rooms many
times during the day and evening for several months, drawing be-
hind it two miniature passenger cars, with seats in each for four
persons, but often carrying twice that number, in a manner highly
gratifying to the public, who attended in crowds to witness for the
first time in this city and State the effect of steam in railroad trans-
portation. This little engine was perhaps the first made expressly
to draw passengers that had ever been placed on a railroad in
America.”
With the knowledge of the success that had been achieved in
England, the desire to know more of, and the necessity to have as
speedily as possible, this new power soon became a paramount
question in the Middle, Northern, Southern and Eastern States of
the Union.
The reward of $4,OOO offered for the best American locomotive
by the directors of the Baltimore and Ohio Railroad, brought out
many competitors, and in after years several very curious specimens
of locomotive engineering might be seen in one of the shops of
*In rendering a just meed of credit to all who aided in the early development
of the locomotive in Philadelphia, it is not out of place here to introduce the following
extract from an obituary notice of Franklin Peale, read before the American Philo-
sophical Society at a meeting on December 16, 1870, by his friend, Robert Patterson, a
grandson of Robert Patterson, who had been Oliver Evans' firm friend in the latter's
efforts in the last century to introduce a steam-carriage. “It was while engaged at the
museum that Mr. Peale placed there a miniature locomotive, the first seen in this country
and manufactured by his friend, M. W. Baldwin, on a plan agreed upon between Mr.
Peale and his friend. It was put in operation on a track, making the circuit of the Ar-
cade, in which the museum then was, drawing two miniature cars with seats for four
passengers. The valuable aid of Mr. Peale was afterwards given to Mr. Baldwin in
the construction of the locomotive for the Philadelphia and Germantown Railroad, built
in 1832, the success of which led to the establishment of Mr. Baldwin in the great
business of his life—the foundation of the Baldwin Locomotive Works.”
à
HISTORY OF THE STEAM-ENGINE. lxxvii
this road. An eye-witness of these efforts in 1834 describes one
which sported two walking beams, precisely like some river steamers
of the present day. Mr. Phineas Davis, of York, Pennsylvania,
bore off the prize offered by the Baltimore and Ohio Railroad, and
his engine was the only one that survived the trial. With the Peter
Cooper upright tubular boiler adapted thereto, this locomotive of
Mr. Davis became for several years the type of engine for the road
upon which it won its fame, and to this day some of these Grass-
hopper or Crab engines, as they are sometimes called, may be seen
doing good service at the Camden Street station, in Baltimore.*
Philadelphia mechanics, following the lead of their predecessors
in the same field, entered with zeal into the Baltimore contest. An
engine was built by a Mr. Childs, who had invented a rotary engine
which in a small model promised good results, and an engine of
about fifty horse-power on this rotary plan was built and sent to
Baltimore for trial. A record of its performance cannot now be
easily reached, but it is known that it was never heard of as a
practically useful engine after this time.
The second locomotive built in Philadelphia, to compete at Bal-
timore, was designed by Mr. Stacey Costell, a man of great origi-
, nality as a mechanic, and the inventor of a novelty in the shape of
a vibrating cylinder steam-engine that had some reputation in its
day, and has come down to our time exactly in the little engine
now sold in the toy-shops for a dollar.
The Costell locomotive had four connected driving-wheels, of
about thirty-six inches in diameter, with two six-inch cylinders of
twelve-inch stroke. The cylinders were attached to right-angled
cranks on the ends of a counter shaft, from which shaft spur gear-
ing connected with one of the axles. The boiler was of the Cornish
type, with fire inside of an internal straight flue. Behind the bridge
wall of this boiler, and inside the flue, water tubes were placed at
intervals, crossing each other after the manner of the English Gal-
* Previous to the competition on the Baltimore Railroad, Mr. Peter Cooper, since de-
ceased, the well-known New York philanthropist, sent to Baltimore a small engine not
larger than an ordinary hand-car. This little locomotive had an upright tubular boiler
(no doubt the first of its kind), which developed such good steam-making qualities as
to induce Mr. Phineas Davis to purchase the Cooper patent right, and boilers of this
kind were used by Mr. Davis in the locomotives built by him subsequent to the com-
petitive trial on the Baltimore and Ohio Railroad.
Ixxviii HISTORY OF THE STEAM-ENGINE.
loway boiler of the present day. The peculiar arrangement of this
engine made it possible to use a very simple and efficient mode of
reversement by the use of a disc between the steam pipe and the
cylinders, arranged with certain openings which changed the direc-
tion of the steam and exhaust by the movement of this disc against
a face on the steam pipe near the cylinder, something after the
manner of a two-way cock.
It is not known whether this locomotive of Costell's went to Bal-
timore or not. It is known, however, to have been tried on the
Columbia road in 1833 or 1834, but its success was not very strik-
ing, and it was subsequently broken up. The boiler of the Costell
locomotive had very good steam-making qualities. It was used for
a long time as a stationary engine boiler.
The third engine begun in Philadelphia for the Baltimore trial in
1831 was after a design of Mr. Thomas Holloway, an engineer of
some reputation forty years ago as a builder of river steamboat
engines. This engine was put in hand, but was never completed.
Something was gained even by the ſailures that are here related,
and these early self-reliant efforts show with what tenacity Philadel-
phia engineers clung to the idea of building an original locomotive,
and it will be seen hereafter that a type of locomotive essentially
American was ultimately the result.
Whilst these movements towards the improvement of the loco-
motive were going on amongst us, the desire to have the railroad in
every section of the country became more and more fully confirmed.
The railway from Newcastle to Frenchtown, sixteen miles in length,
was finished in the winter of 1831 and 1832, and two locomotives
built by Robert Stephenson at Newcastle-upon-Tyne were imported
to be run upon this line, which made then an important link in the
chain of passenger travel between New York and Washington. In
this case, as in several others in the early history of the railroad in
the United States, this new element came in as an adjunct mainly
of the river steamboats, and was considered most useful in super-
seding the old stage coach in connecting river to river, and bay to
bay. -
That the railway would supersede the steamboat for passenger
travel, and the canal for heavy transport, was not dreamed of in the
early day of the new power.
When the English locomotives were landed at Newcastle, Del-
HISTORY OF THE STEAM-ENGINE. lxxix
aware, it became necessary to select a skilled mechanic to put them
together as speedily as possible. Through the agency of Mr. Wm.
D. Lewis, a most active director of the Newcastle and Frenchtown
Railroad Company, this task was assigned to Matthias W. Baldwin.
These engines were of the most improved English type, and were
greatly superior in design and workmanship to any that had then
been seen in this country. In putting these engines together, Mr.
Baldwin had all the advantage of handling their parts and studying
their proportions, and in making drawings therefrom. This proved
of great service to him when he received an order, in the Spring of
1832, to build a locomotive for the Philadelphia, Germantown and
THE “old IRONSIDEs,” 1832.
Norristown Railroad. This engine, called, when finished, the
Old Ironsides, was placed upon the above road in November,
1832, and proved a decided success. Mr. Franklin Peale, in an
obituary notice of M. W. Baldwin, writes: “that the experiments
made with the Ironsides were eminently successful, realizing the
sensation of a flight through the air of fifty or sixty miles an hour.”
The Old Ironsides, in its general arrangement, was a pretty close
copy of the English engines on the Newcastle and Frenchtown
Railroad, but with changes that were really improvements. The
reversing gear was a novelty in the locomotive, although the same
mode had been long used for steam ferryboats on the Delaware.
This arrangement consisted of a single eccentric with a double-
latch eccentric rod, gearing alternately on pins on the upper and

Ixxx HISTORY OF THE STEAM-ENGINE.
lower ends of the arms of a rock shaft. This mode of reversing
was used in the Baldwin locomotives for many years after the Old
Ironsides was built.
It is creditable to Mr. Baldwin as an engineer that the Old
Ironsides was the first and last of his imitations of the English
locomotives. He, following the bent of all the Philadelphia engi-
neers and mechanics that had entered the field, aimed, too, at mak-
ing an American locomotive; and his second engine, and those
succeeding it, were entirely different in design from the Old Ironsides.
Following the success of this first locomotive, other orders soon
flowed in upon Mr. Baldwin, and on these later engines many val-
uable improvements were introduced, of which mention will be
made hereafter.
Colonel Stephen H. Long, nothing daunted or discouraged by
the unsuccessful results of his first engine in 1831, renewed his
efforts, and under the firm of Long & Norris, the successors of the
American Steam Carriage Company, commenced building a loco-
motive in 1832, subsequently called the Black Hawk. This en-
gine, when finished, was run for some time on the Philadelphia and
Germantown Railroad, and did good service in the summer of 1833,
in competition with Baldwin's Ironsides. The Black Hawk
burnt anthracite coal with some success, using the natural draught
only, which was increased, for the first time in a locomotive, by the
use of a very high chimney, arranged to lower from an altitude of
at least twenty feet from the rails, to a height which enabled it to
go under the bridges crossing the railroad. In all of Colonel Long's
experiments he seems to have discarded the steam jet, or exhaust
for exciting the fire. The Black Hawk had several striking pe-
culiarities beside the one just mentioned. The boiler, a very good
and a very safe one, was unlike any that had preceded it, in having
the fire-box arranged without a roof, being merely formed of water
sides, and in being made in a detached piece from the waist or
cylindrical part. The cylinder portion of the boiler consisted of
two cylinders about twenty inches in diameter, and these, lying
close together, were bolted to the rear water side, and thus
covered the open top, and their lower half-diameters thereby
became the roof of the fire-box. A notch was cut half way
through these two cylinders on their lower half diameters, about
midway of the length of the fire-box, directly over the fire, and
HISTORY OF THE STEAM-ENGINE. lxxxi
from these notches flues of about two inches diameter passed
through the water space of each cylinder portion of the boiler to
the smoke-box. These flues were about seven feet in length. Be-
sides passing through the flues, the fire passed also under the lower
halves of the cylinder portions of the boiler, a double sheet-iron
casing, filled between with clay, forming the lower portion of the
flue and connecting it with the smoke-box.
The Black Hazelà rested on four wheels, the driving-wheels,
about four and a half feet diameter, being in front of the fire-box:
The guide-wheels were about three feet diameter. Inside cylinders
were used, and these required a double crank axle, and the latter,
forged solid, could not easily be had. Colonel Long overcame this
difficulty by making his driving axle in three pieces, with two bear-
ings on each, and with separate cranks keyed on to the ends of each
portion of the axle, with shackle or crank pins arranged after the
manner of the modern side-wheel steamer shafts.
Flanged tires of wrought iron could not then be had easily, and
this was overcome in the Black Hawk by making the tread for
the wheels of two narrow bands, shrunk side by side on the wooden
rim, with a flat ring, forming the flange, bolted on the side of the
wheel. Springs were only admissible over the front axle, and to
save shocks in the rear, the after or fire-box portion of the boiler
was suspended upon springs. The camb cut-off, then much in vogue
on the engines of the Mississippi steamers, was used in the Black
Hawk. Other locomotives, mainly after the design of the Black
Hazvá, were built by Long & Norris, and by William Norris & Co.,
in 1834, but they were not greatly successful.
With the firm of William Norris & Co., Colonel Long retired
from the manufacture of locomotives in Philadelphia, and his name
was not thereafter heard of in connection with its improvement. On
the retirement of Colonel Long, William Norris, a gentleman then
with no acknowledged pretensions as a mechanic or engineer,
brought other skill to his assistance, and after several not very suc-
cessful efforts with engines of a design more like those that had
succeeded of other makers, brought out an engine, in 1836, called
the George Washington, the success of which laid the foundation
of the large business done for thirty years thereafter at Bush Hill,
Philadelphia, by William Norris, and subsequently by his brother,
Richard Norris. - - - >
lxxxii HISTORY OF TIIE STEAM - ENGINE.
The George Washington was a six-wheel engine with outside
cylinders, having one pair of driving-wheels, four feet in diameter,
forward of the fire-box, with vibrating truck, for turning curves, in
front. This engine weighed somewhat over fourteen thousand
pounds, and a large proportion of the whole weight rested on the
single pair of driving wheels.
This locomotive, when put upon the Columbia road (now Penn-
sylvania Central), did apparently, the impossible feat of running up
the old inclined plane at Peter's Island, 2,800 feet long, with a rise
of one foot in fourteen, drawing a load of more than nineteen thou-
sand pounds above the weight of the engine, and this, too, at a speed
of fifteen miles per hour. This was no doubt impossible, if the
simple elements of the calculation are only considered. But there
was a point in this experiment, well known to experts at the time,
which did make it possible, even by calculation; and this point con-
sisted in the amount of extra weight that was thrown upon the
drivers by the action of the draft link connecting the tender with the
engine,—the result being that about all the weight of the locomotive
rested upon the drivers, less the weight of the truck frame and
wheels in front. This most extraordinary feat, a writer on the sub-
ject says, “took the engineering world by storm, and was hardly
credited.” er
The George Washington, an heir of the earlier efforts of Colonel
Long, was unquestionably a good and well-made engine, and greatly
superior to any that had preceded it from the Norris Works. The
fame this engine earned, led to large orders in the United States,
and several locomotives of like character were ordered for England
and for Germany.
Improvements were made from time to time in the Norris loco-
motives—the establishment fairly holding its own with its rivals
until the Norris Works ceased to exist about 1866 or ’67. Mr.
William Norris, who in connection with Colonel Long had founded
the works at Philadelphia, at one time commenced the building of
locomotives at Vienna, Austria, but with no very great success; and
after his return ceased his connection with the Norris Works. At
the epoch from 1833 to 1837, the Norris and Baldwin engines had
each their advantages and defects.
The AVorris engine, as it was at the commencement of 1837, may
be described as follows: The boiler was of the dome pattern, known
HIS TORY OF THE STEAM - ENGINE. lxxxiii
in England as Bury's, and used by that maker in 1830; the framing
was of wrought iron. The cylinders were placed outside of, and
were fastened to the smoke-box as well as to the frame. The engine
was supported on one pair of driving-wheels, placed forward of the
fire-box, and on a swivelling four-wheeled truck placed under the
smoke-box. The centre of the truck being so much in advance of
the point of bearing of the leading wheels in the English engines
of that day, there was considerably greater weight placed upon the
driving-wheels in proportion to the whole weight, while it was not
unusual to adjust the draw bar so as to throw a portion of the weight
of the tender upon the hinder end of the engine when drawing its
load. These engines used four excentrics with latches. Hand levers
were used for putting the valve rods into gear when standing. The
valve motion was efficient, as the performances of these engines fully
attested.
The Baldwin engine of the same period had a similar boiler, and
somewhat similar position of and fastening of the cylinders. The
driving-wheels were placed behind the fire-box, the usual truck
being placed under the smoke-box. These engines ran steadily,
Owing to their extended wheel-base, although they did not have the
weight on the drivers, and the consequent adhesive power of the
Norris engine. The framing was of wood covered with iron plates,
and was placed outside the wheels.
The driving-wheels had two outside bearings. The cylinders,
although outside of the smoke-box, were placed so as to give a con-
nection to the crank inside
of the driving-wheels. The
crank was formed in the driv- *:::=ºs
ing-axle, but instead of being (
made as a complete double
or full crank, the neck, to
which the connecting-rod #7
was attached, was extended Fºº-ºº.
through and fastened into a tº * * *
hole in the driving-wheel, &J
the distance from the centre BALDWIN ENGINE, I834.
being equal to the throw
of the crank. A simple straight pin, fitted to the centre of the
wheel, and extending outwards, formed an outside bearing for the

§
ºs-s-s
fiºs
º; :-
1xxxiv. HISTORY OF THE STEAM-ENGINE.
axles. This device of Mr. Baldwin's was most ingenious and
efficient. It simplified by more than one-half the making of a
crank-shaft, and increased its strength, and at the same time caused
the thrust of the cylinder to act close to the driving-wheel inside,
in the same manner as the outside crank-pin.
With the introduction of the outside cylinder, this mode of mak-
ing a crank-axle has gone into disuse. The guide-bar for the cross-
head, which had a double V top and bottom, was clasped by the
cross-head, and being hollow and with valve-chamber attached, was
made to serve the purpose of a force pump. The valve-gear,
already described, was placed under the foot-board, and although
efficient, was cramped for room, the excentric rods consequently
being rather too short.
In workmanship and proportion of parts the Baldwin engine was
the superior of the two classes of locomotives that had then become
in their manufacture an important feature in the trade of Phila-
delphia.
M. W. Baldwin, in 1834 and 1837, had greatly the advantage of
the Norris establishment, as he had had from the first, in being a
good practical machinist himself, and in having had some cxperience
in steam-engine building previous to the making of the Ironsides in
1832; whereas, William Norris, after Colonel Long retired, in
I833–34, having personally little engineering knowledge and no
practical skill in engine building, was left entirely dependent upon
hired assistance, which at that time, in the construction of the loco-
motive, was most difficult if not almost impossible to obtain.
Mr. Baldwin had also the great advantage of better workshops
and better tools than his early competitor at the commencement of
this new business; hence his success was at once more decided, and
the improvements in his locomotives, both in design and in work-
manship, were more important from the beginning. It is needless
to speak of the “Baldwin Locomotive Works,” Burnham, Parry,
Williams & Co., of to-day.
With a record of fifty years, during the early period of which it
passed successfully through many vicissitudes, it maintains its well-
earned character of the first locomotive manufactory, both in quan-
tity and quality, in this country; and it is doubtful whether it is not
now the equal to, if not the superior, in these particulars, of any
establishment doing similar work in the world.
HISTORY OF THE STEAM-ENGINE. lxxxv
The Baldwin engine of 1837, with its driving-axle behind the
fire-box, was steady at high-speeds, but with insufficient adhesion
to the rails.
The Norris engine, of the same date, having a great proportion
of the weight overhanging the driving-axle, and having adhesion
equal to its cylinder power, was unsteady on the rails. Improvement
rested between the two systems of Baldwin and of Norris.
In the spring of 1835 the firm of Garrett & Eastwick, then mak-
ing steam-engines and light machinery in Philadelphia, desiring to
engage in this new business, obtained an order for building a loco-
motive engine for the Beaver Meadow Railroad. This firm, having
no practical knowledge of locomotive engine building, had called
to their assistance, as foreman, Mr. Joseph Harrison, Jr., a young
man of twenty-five, with ten years' experience in the workshop, and
a good practical workman, who had been employed for nearly two
years as a journeyman in the Norris works, and who when there
had been schooled amidst the indifferent successes or real failures
of Long & Norris, and Wm. Norris & Co. The first locomotive
designed under the above auspices was called, when finished, the
Samuel D. Ingham, after the President of the road. It had outside
cylinder connections, then not much in vogue—running-gear after
the Baldwin type, with one pair of driving-wheels behind the fire-
box, and with four-wheel truck in front. It had the dome or
“Bury” boiler.
This engine had some points about it which differed from any
locomotive that had preceded it. Its most distinguishing feature
was an ingenious and entirely original mode of reversement, in-
vented and patented by Mr. Andrew M. Eastwick, the junior mem-
ber of the firm. It is scarcely possible to give a correct idea of
this device without a model or drawings, but its principle consisted
in the introduction of a movable block or slide, called a reversing
valve, between the usual slide valve and the opening through the
cylinder face. This reversing valve had an opening through it
vertically for the exhaust, and two sets of steam openings, cor-
responding, when placed opposite thereto, to the openings on the
cylinder face. One set, called direct openings, passed directly
through the valve, and when fixed for going forward made the usual
channels to the cylinder. The second set of openings through the
reversing valve, called indirect openings, coming into play when the
lxxxvi HISTORY OF THE STEAM-ENGINE.
engine, moved backwards, passed from the upper surface of this
valve but half way through it, and thence were diverted laterally to
the side of the valve, and thence along the side and again laterally,
came out of the under side where the reversing valve rested against
the valve face of the cylinder, directly opposite a second indirect
opening on the upper surface of this valve.
When the reversing valves were fixed for going forward the
direct openings were then exactly over the steam openings on the
cylinder, whilst the indirect openings came over the solid surface of
the cylinder face and were entirely out of use. The exhaust open-
ing through the reversing valve in this case came directly opposite
the exhaust opening on the cylinder. The slide valve, never de-
tached from the excentric, moved always over both sets of open-
ings in the usual way. Moving the reversing valve to the opposite
end of the steam chest ſrom where it had been placed in going for-
ward, and the case was different. Then steam entering the revers-
ing valve at the upper side, instead of going directly into the cylin-
der as before, was diverted in the manner just described and came
out at the cylinder face at the opposite end from which it had en-
tered on the slide valve face on the upper side of the reversing
valve, and thus the direction of the engine was changed from for-
wards to backwards, or vice versa, without detaching or reattaching
any of the moving parts of the valve gear.
The principle and action of Mr. Eastwick's invention may be
guessed at from what has been described, although its detail may
not be so easily made out.
This new arrangement, neat and efficient as it was, had its de-
fects, which no doubt interfered with its general use. It increased
by the thickness of the reversing block the length of the steam
openings in going forward, and further increased their length in
going backwards. It also prevented the use of a long lap on the
slide valve, for any lead of the excentric in going forward, causing
a corresponding delay in receiving steam in moving backward. In
reviewing these defects the beauty and originality of Mr. Eastwick's
device must not be overlooked.
Nothing for the same purpose so novel in its mode of action had
preceded or has succeeded this invention of a Philadelphia mechanic,
and it is doubtful whether any locomotive has since been made with
so few moving parts as this first engine of Garrett & Eastwick.
1HISTORY OF THE STEAM-ENGINE. lxxxvii
This engine had for the first time the rear platform covered with a
roof to protect the engineman and the fireman from the weather.
The success of the Samuel D. Ingham was quite equal to any
locomotive of its class that had been built up to that period in
Philadelphia, and orders came to the makers from several sources
for others of the same kind.
In 1836 Henry R. Campbell, of Philadelphia, “in order to dis-
tribute the weight of the engine upon the rails more completely,”
patented the duplication of the driving-wheels, placing one pair be-
hind and one pair in front of the fire-box, using the swivelling truck
in front of Baldwin and others.
Mr. Campbell subsequently made an engine after his patent,
which was tried on the Philadelphia and Germantown Railroad, and,
although not a decided success, it was a great step in the direction
in which improvement was most needed. Its principal defect con-
sisted in its having no good means of equalizing the weight on the
driving-wheels so as to meet the various undulations in the track.
To remedy the defects in the Baldwin, Campbell and Norris en-
gines Garrett & Eastwick (soon thereafter changing their ſ.rm to
Garrett, Eastwick & Co., Joseph Harrison, Jr., becoming the junior
| partner) commenced in the winter of 1836–7 a new style of locomo-
tive for the Beaver Meadow Railroad Company.
Adopting the Campbell plan of running gear, they aimed at
making a 1much heavier engine for freignt purposes than had yet
been used. This could be only rendered possible on the slight
roads of the country at that time by a better distribution of the
weight upon the rails.
In the first of the improved engines made by Garrett & Eastwick
for the Beaver Meadow Railroad Mr. Andrew M. Eastwick intro-
duced an important improvement in the Campbell eight-wheel en-
gine, for which he obtained a patent in 1836. This improvement
consisted in the introduction under the rear end of the main frame
of a separate frame in which the two axles were placed, one pair be-
fore and one pair behind the fire-box. This separate frame was
made rigid in the Hercules, the first engine in which it was used,
and vibrated upon its centre vertically, and being held together
firmly at the ends, both sides at all times moved in the same plane,
thus only accommodating the undulations in the track in a perfect
manner, when the irregularities were on both rails alike. The
lxxxviii IIISTORY OF THE STEAM-ENGINE.
weight of the engine rested upon the centre of the sides of this
separate frame through the intervention of a strong spring above the
main frame, the separate frame being held in place by a pedestal
bolted to the main frame, the centres of the separate frame vibrat-
ing upon a journal sliding vertically in this pedestal.
Mr. Eastwick's design was, however, somewhat imperfect in not
accommodating the weight of the four driving-wheels to the irregu-
lar undulations on both tracks. There were other minor improve-
ments in the Hercules, one of which was the introduction, for the
first time into steam machinery, of the bolted stub-end instead of
} āşīāsāk- İsº *O
Fºjëais
işăſălălțºgſæjj
CZ S-2
HENRY R. CAMPBELL’s FIRST DESIGN FOR AN EIGHT-
WHEELED LOCOMOTIVE, 1836.
the old-fashioned and unsafe mode of gib and key for holding the
strap on the connecting rods. This device, an idea of Mr. Harri-
son's, is now universally used in the connecting rods of the loco-
motive engine.
Doubts were expressed by some, and amongst them not a few
engine-builders, that the Hercules, weighing about fifteen tons, would
prove too heavy—that this engine would not turn curves or go
into switches without trouble, etc., etc., but Eastwick & Harrison
had good friends in Captain Matthew C. Jenkins, a director, and
Mr. A. Pardee, the chief-engineer of the Beaver Meadow Railroad.
They had committed, themselves to this new style of locomotive







HISTORY OF THE STEAM-ENGINE. lxxxix
and were not disposed to see it fail for lack of a fair trial. They
had no cause to regret their confidence in after years. At the time
the Hercules was placed upon the Beaver Meadow Railroad this road
had a flat rail, but five-eighths of an inch thick and two and a half
inches wide, laid upon continuous string-pieces of wood with mud-
sills underneath.
The Hercules, when put in operation on the Beaver Meadow Rail-
road, proved a great success and led to other orders for the same
class of engine. This division of the weight on more points of the
road, and its more perfect equalization thereon, seemed at the time,
as it has proved since, to have been the commencement of a new
era in the history of the locomotive. To remedy the defect incident
to Mr. Eastwick's plan, as before mentioned, in these early eight-
wheel engines, an improvement was patented in 1838 by Joseph
Harrison, Jr., the junior partner of the firm of Eastwick & Har-
rison. *
Mr. Harrison's patent showed many ways of carrying out the
principle of his improvement, but the one preferred consisted in
placing the driving axle bearings in pedestals, in the usual manner,
bolted to the main frame, and by the use of a compensating lever
above the main frame, vibrating on its centre, at the point of attach-
ment to the main frame, the ends of this lever resting on the axle-
boxes by means of pins passing through the frame. These levers
vibrated on each side of the engine separately, and thus met all the
unevenness in both rails within a certain prescribed limit, which was
governed by the play of the axle-boxes in the pedestals.
This arrangement of Mr. Harrison's was simpler, lighter and
cheaper than the one that had preceded it and was used in all the
eight-wheel engines built by Eastwick & Harrison after the second
Olle.
In all engines now built in this country or in Europe, with more
than six wheels, this device of Mr. Harrison is used in one or other
of the different ways indicated in his patent. Mr. Harrison's pat-
ent included an improvement in the forward truck, making it
flexible, so that it would accommodate itself to irregular undulations
on both rails.
The engineers and manufacturers of this period did not at once
fully understand the significance of the innovation so successfully
carried out by Eastwick & Harrison. They clung to the older idea
XC HISTORY OF THE STEAM-ENGINE.
that one pair of driving-wheels was quite sufficient whether placed
before the fire-box or behind, nor did they fairly adopt the new sys-
tem until after its value had been fully demonstrated by several
years of trial.
In the summer of 1839 Eastwick & Harrison received an order
from the Philadelphia and Reading Railroad Company, through
the chief-engineer, Mr. Moncure Robinson, for a freight engine that
had peculiar points. This engine was designed generally upon the
Płercules plan, but it was stipulated in the contract that the whole
weight should be eleven tons gross, with nine tons on the four
driving wheels. It was also stipulated that it should burn anthra-
cite coal in a horizontal tubular boiler.
“HERCULEs,”
Garrett & Eastwick’s first eight-wheeled Locomotive, 1837, as arranged with “IIarri-
son’’ equalizing levers.
To distribute the nine tons on the driving-wheels the rear axle
was placed under the fire-box and somewhat in advance of its cen-
tral line, instead of being behind the fire-box, as in the Hercules.
This arrangement of the rear axle permitted nine tons of the whole
weight of the engine to rest on the four driving-wheels. The boiler
was of the Bury type, and the fire-box had the then unprecedented
length, outside, of five feet. The tubes, two inches in diameter and
only five feet long, were more numerous than usual and filled the
cylinder part of the boiler almost to the top. Cylinders 12%
inches in diameter, 18-inch stroke, using no cut-off; driving-wheels

HISTORY OF THE STEAM-ENGINE. xci
42 inches. The Gurney draft-box was used with many exhaust
jets instead of one or two large ones.
It is believed, that in this engine was used, for the first time, the
steam-jet for exciting the fire when standing. The engine here
described, called, when finished, the Gozºan & Marx, after a Lon-
don banking firm, excited much attention in the railroad world by
its great tractive power, compared with its whole weight.
On one of its trips (February 20, 1840) it drew a train of one
hundred and one four-wheeled loaded cars from Reading to Phila-
FREIGHT ENGINE “GowAN & MARx,” 1839.
Designed and built by Eastwick & Harrison, Philadelphia, for the Philadelphia and
Reading Railroad, 1839. Slightly varied from the original.
delphia, at an average speed of 9.82+ miles per hour, nine miles
of the road being a continuous level. The gross load on this occa-
sion was 423 tons, not including the engine and tender, which, if
the weight of the tender is counted, equalled forty times the weight
of the engine.
. See ºurnal of Franklin Institute, 1840, vol. 25, page 99, Report
of G. N. Nicols, Superintendent Philadelphia and Reading Railroad,
which closes as follows: “The above performance of an eleven-ton
engine is believed to excel any on record in this or any other coun-
try.” It may be doubted whether it has been excelled since.

7
xcii HISTORY OF THE STEAM-ENGINE.
How strangely this feat of the Gowan & Mara compares with the
trials on the Liverpool and Manchester Railroad in October, 1829,
but ten years before, when all that was required of the competing
locomotives was that they should draw about three times their own
weight, tender included, on a level track, five miles long, especially
prepared for the trial. The great success of the Gozvan & Mara:
induced the Philadelphia and Reading Railroad Company to dupli-
cate the plan of this engine in ten engines subsequently built at
Lowell, Mass.
In 1840 the Gowan & Marx attracted the particular attention of
the Russian engineers, Colonels Melnikoff and Krafft, who had been
commissioned by the Emperor Nicholas to examine into and report
upon the various systems of railroads and railroad machinery then
in operation in this country and in Europe.
The result of their examination was favorable to the American
system, and when the engineers above named made their report on
the construction of a railroad from St. Petersburg to Moscow, an
engine upon the plan of the Gowan & Mara was recommended as
best adapted to the purposes of this first great line of railroad in
the Empire of Russia, and Eastwick & Harrison were requested
to visit St. Petersburg with the view of making a contract for build-
ing the locomotives and other machinery for the road. *
Mr. Harrison went to St. Petersburg in the spring of 1843, and in
connection with Mr. Thomas Winans, of Baltimore, a contract was
concluded with the government of Russia, at the close of the same
year, for building 162 locomotives, and iron trucks for 2500 freight-
cars. Mr. Eastwick joined Mr. Harrison and Mr. Winans at St.
Petersburg in 1844.
Eastwick & Harrison closed their establishment in Philadelphia
in 1844, removing a portion of their tools and instruments to St.
Petersburg, and there, under the firm of Harrison, Winans & East-
wick, completed, at the Alexandroffsky Head Mechanical Works,
the work for which they had contracted. When the work was
commenced under the contract of Harrison, Winans & Eastwick
with the Russian government, Joseph Harrison, Jr., designed and
had built under his own supervision, at St. Petersburg, the first
machine, it is believed, that was ever made for boring out the holes
for right-angled crank-pins in the driving-wheels of locomotive
engines. This right-angled boring-machine, on precisely the same
HISTORY OF THE STEAM-ENGINE. xciii
principle as devised by Mr. Harrison, has since become indis-
pensable in every locomotive establishment. The same idea was
partially put in use as early as 1838, when the second eight-wheel
engine Beaver was built by Garrett & Eastwick for the Beaver
Meadow Railroad.
The first contract with the Russian government was closed in
1851, at which time a second contract was entered into, by two
HARRISON, WINANS & EASTWICK's FREIGHT ENGINE.
Built at St. Petersburg, Russia, for the St. Petersburg & Moscow Railroad, 1844.
members of the firm, for the repairs to the rolling stock of the St.
Petersburg and Moscow Railroad, which continued until 1862.
Note.—We are indebted for the above lengthy and valuable extract to a work published
in Philadelphia, 1872 (Geo. Gebbie), written by Joseph Harrison, Jr.: “The Locomotive
and Philadelphia's Share in its Early Improvement.” Mr. Harrison was one of the ablest
and most successful mechanics that America has ever produced: he was a gentleman of
great good taste, eminent for his broad views and liberal patriotic aid in all good works.
He was born in Philadelphia in 1810 and died there 1875.

xciv HISTORY OF THE STEAM-ENGINE.
... [Having in a brief manner brought the history of the steam-engine in both Europe
and America forward to 1842, we find the subject suddenly expand beyond all hopes of
even keeping a fair report of the various establishments started for the manufacture of
boilers and steam-engines of every description. Not only every country has many pri-
vate shops and factories, but nearly every railroad company has its own machine-shops.
In order to bring the story of progress forward till near the present day, we will as
lºriefly as possible notice the progress of locomotive engine building at the Baldwin
Locomotive Works, Philadelphia, which, being the largest establishment of its kind ºn
the world, may be considered a representative establishment.]
In 1840 Mr. Baldwin received an order, through August Belmont,
Esq., of New York, for a locomotive for Austria, and had nearly
completed one which was calculated to do the work required when
lie learned that only sixty pounds pressure of steam was admissible,
whereas his engine was designed to use steam at one hundred
pounds and over. He accordingly constructed another, meeting
this requirement, and shipped it in the following year. This engine,
it may be noted, had a kind of link-motion, agreeably to the specifi-
cation received, and was the first of his make upon which the link
was introduced.
Mr. Baldwin's patent of December 31, 1840, covering his geared
engine, embraced several other devices, as follows:
I. A method of operating a fan, or blowing-wheel, for the purpose
of blowing the fire. The fan was to be placed under the footboard,
and driven by the friction of a grooved pulley in contact with the
flange of the driving-wheel.
2. The substitution of a metallic stuffing, consisting of wire, for
the hemp, wool, or other material which had been employed in
stuffing-boxes. -
3. The placing of the springs of the engine-truck so as to obviate
the evil of the locking of the wheels when the truck-frame vibrates
from the centre-pin vertically. Spiral as well as semi-elliptic springs,
placed at each end of the truck-frame, were specified. The spiral.
spring is described as received in two cups—one above and one
below. The cups were connected together at their centres by a
pin upon one and a socket in the other, so that the cups could
approach toward or recede from each other and still preserve their
parallelism.
4. An improvement in the manner of constructing the iron frames
of locomotives, by making the pedestals in one piece with, and con-
stituting part of, the frames.
HISTORY OF THE STEAM-ENGINE. xcv.
5. The employment of spiral springs in connection with cylin-
drical pedestals and boxes. A single spiral was at first used, but
not proving sufficiently strong, a combination or nest of spirals
curving alternately in opposite directions was afterward employed.
Each spiral had its bearing in a spiral recess in the pedestal.
In the specification of this patent a change in the method of
making cylindrical pedestals and boxes is noted. Instead of boring
and turning them in a lathe, they were cast to the required shape
in chills This method of construction was used for a time, but
eventually a return was made to the original plan, as giving a more
accurate job.
In 1842 Mr. Baldwin constructed, under an arrangement with Mr.
Ross Winans, three locomotives for the Western Railroad of Massa-
H
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M.
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All Cl kill #=
/*-īſīš . . . . .
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BALDw1N six-wheel S-CONNECTED ENGINE, I842.
chusetts, on a plan which had been designed by that gentleman for
freight traffic. These machines had upright boilers and horizontal
cylinders, which worked cranks on a shaft bearing cog-wheels en-
gaging with other cog-wheels on an intermediate shaft. This latter
shaft had cranks coupled to four driving-wheels on each side. These
engines were constructed to burn anthracite coal. Their peculiarly
uncouth appearance earned for them the name of “crabs,” and they
were but short-lived in service.
But to return to the progress of Mr. Baldwin's locomotive prac-
tice. The geared engine had not proved a success. It was unsat-
isfactory, as well to its designer as to the railroad community. The
problem of utilizing more or all of the weight of the engine for ad-
hesion remained, in Mr. Baldwin's view, yet to be solved. The plan
of coupling four or six wheels had long before been adopted in





xcvi HISTORY OF THE STEAM-ENGINE.
England, but on the short curves prevalent on American railroads
he felt that something more was necessary. The wheels must not
only be coupled, but at the same time must be free to adapt them-
selves to a curve. These two conditions were apparently incom-
patible, and to reconcile these inconsistencies was the task which
Mr. Baldwin set himself to accomplish. He undertook it, too, at a
time when his business had fallen off greatly and he was involved in
the most serious financial embarrassments. The problem was con-
stantly before him, and at length, during a sleepless night, its solu-
tion flashed across his mind. The plan so long sought for, and
– The ſlalº
HALF PLAN.
which, subsequently, more than any other of his improvements or
inventions, contributed to the foundation of his fortune, was his well-
known six-wheels-connected locomotive with the four front driving-
wheels combined in a flexible truck. For this machine Mr. Baldwin
secured a patent, August 25, 1842. Its principal characteristic
features are now matters of history, but they deserve here a brief
mention. The engine was on six wheels, all connected. The rear
wheels were placed rigidly in the frames, usually behind the fire-box
with inside bearings. The cylinders were inclined, and with outside
gonnections. The four remaining wheels had inside journals run-
ning in boxes held by two wide and deep wrought-iron beams, one

HISTORY OF THE STEAM-ENGINE. xcvii
on each side. These beams were unconnected, and entirely inde-
pendent of each other. The pedestals formed in them were bored
out cylindrically, and into them cylindrical boxes, as patented by
him in 1835, were fitted. The engine frame on each side was
directly over the beam, and a spherical pin, running down from the
frame, bore in a socket in the beam midway between the two axles.
It will thus be seen that each side-beam independently could turn
horizontally or vertically under the spherical pin, and the cylindrical
boxes could also turn in the pedestals. Hence, in passing a curve,
the middle pair of drivers could move laterally in one direction—say
to the right—while the front pair could move in the opposite direc-
tion, or to the left; the two axles all the while remaining parallel to
each other and to the rear driving-axle. The operation of these
beams was, therefore, like that of the parallel-ruler. On a straight
line the two beams and the two axles formed a rectangle; on curves
a parallelogram, the angles varying with the degree of curvature.
The coupling-rods were made with cylindrical brasses, thus forming
ball-and-socket joints, to enable them to accommodate themselves to
the lateral movements of the wheels.
The first engine of the new plan was finished early in December,
1842, being one of fourteen engines constructed in that year, and
was sent to the Georgia Railroad, on the order of Mr. J. Edgar
Thomson, then Chief Engineer and Superintendent of that line. It
weighed twelve tons, and drew, besides its own weight, two hundred
and fifty tons up a grade of thirty-six feet to the mile.
Other orders soon followed. The new machine was received
generally with great favor. The loads hauled by it exceeded any-
thing so far known in American railroad practice, and Sagacious
managers hailed it as a means of largely reducing operating ex-
penses. On the Central Railroad, of Georgia, one of these twelve-
ton engines drew nineteen eight-wheeled cars, with seven hundred
and fifty bales of cotton, each bale weighing four hundred and fifty
pounds, over maximum grades of thirty feet per mile, and the
manager of the road declared that it could readily take one thousand
bales. On the Philadelphia and Reading Railroad a similar engine
of eighteen tons weight drew one hundred and fifty loaded cars
(total weight of cars and lading one thousand one hundred and
thirty tons) from Schuylkill Haven to Philadelphia, at a speed of
seven miles per hour. The regular load was one hundred loaded
xcviii HISTORY OF THE STEAM-ENGINE.
cars, which were hauled at a speed of from twelve to fifteen miles
per hour on a level.
But the flexible-beam truck also enabled Mr. Baldwin to supply
an engine with four driving-wheels connected. Other builders were
making engines with four driving-wheels and a four-wheeled truck,
of the present American standard type. To compete with this de-
sign, Mr. Baldwin modified his six-wheels-connected engine by con-
necting only two out of the three pairs of wheels, making the
forward wheels of smaller diameter as leading wheels, but combin-
ing them with the front driving-wheels in a flexible-beam truck.
The first engine on this plan was sent to the Erie and Kalamazoo
Railroad, in October, 1843, and gave great satisfaction. The super-
intendent of the road was enthusiastic in its praise, and wrote to
Mr. Baldwin that he doubted “if anything could be got up which
would answer the business of the road so well.” One was also sent
to the Utica and Schenectady Railroad a few weeks later, of which
the superintendent remarked that “it worked beautifully, and there
were not wagons enough to give it a full load.” In this plan the
leading wheels were usually made thirty-six and the driving-wheels
fifty-four inches in diameter.
This machine of course came in competition with the eight-
wheeled engine having four driving-wheels, and Mr. Baldwin
claimed for his plan a decided superiority. In each case about
two-thirds of the total weight was carried on the four driving-
wheels, and Mr. Baldwin maintained that his engine, having only
six instead of eight wheels, was simpler and more effective.
At about this period Mr. Baldwin's attention was called by Mr.
Levi Bissell to an “Air Spring” which the latter had devised, and
which it was imagined was destined to be a cheap, effective, and
perpetual spring. The device consisted of a small cylinder placed
above the frame over the axle-box, and having a piston fitted air-
tight into it. The piston-rod was to bear on the axle-box, and the
proper quantity of air was to be pumped into the cylinder above the
piston, and the cylinder then hermetically closed. The piston had a
leather packing which was to be kept moist by some fluid (molasses
was proposed) previously introduced into the cylinder. Mr. Bald-
win at first proposed to equalize the weight between two pairs of
drivers by connecting two air-springs on each side by a pipe, the
use of an equalizing beam being covered by Messrs. Eastwick &
HISTORY OF THE STEAM-ENGINE. xcix
Harrison's patent. The air-springs were found, however, not to
work practically, and were never applied. It may be added that a
model of an equalizing air-spring was exhibited by Mr. Joseph Har-
rison, Jr., at the Franklin Institute, in 1838 or 1839.
With the introduction of the new machine, business began at once
to revive and the tide of prosperity turned once more in Mr. Bald-
win's favor. Twelve engines were constructed in 1843, all but four
of them of the new pattern; twenty-two engines in 1844, all of the
new pattern; and twenty-seven in 1845. Three of this number were
of the old type, with one pair of driving-wheels, but from that time
forward the old pattern with the single pair of driving-wheels dis-
appeared from the practice of the establishment, save occasionally
for exceptional purposes.
In 1842 the partnership with Mr. Vail was dissolved, and Mr.
Asa Whitney, who had been superintendent of the Mohawk and
Hudson Railroad, became a partner with Mr. Baldwin, and the firm
continued as Baldwin & Whitney until 1846, when the latter with-
drew to engage in the manufacture of car-wheels, establishing the
firm of A. Whitney & Sons, Philadelphia.
Mr. Whitney brought to the firm a railroad experience and
thorough business talent. He introduced a system in many details
of the management of the business, which Mr. Baldwin, whose mind
was devoted more exclusively to mechanical subjects, had failed to
establish or wholly ignored. The method at present in use in the
establishment, of giving to each class of locomotives a distinctive
designation, composed of a number and a letter, originated very
shortly after Mr. Whitney's connection with the business. For the
purpose of representing the different designs, sheets with engravings
of locomotives were employed. The sheet showing the engine with
one pair of driving-wheels was marked B; that with two pairs, C;
that with three, D; and that with four, E. Taking its rise from this
circumstance, it became customary to designate as B engines those
with one pair of driving-wheels; as C engines, those with two pairs;
as D engines, those with three pairs; and as E engines, those with
four pairs. Shortly afterwards a number, indicating the weight in
gross tons, was added. Thus, the 12 D engine was one with three
pairs of driving-wheels, and weighing twelve tons; the 12 C, an
engine of same weight, but with only four wheels connected. A
modification of this method of designating the several plans and
sizes is still in use, and is explained elsewhere.
C HISTORY OF THE STEAM-ENGINE.
It will be observed that the classification as thus established began
with the B engines. The letter A was reserved for an engine
intended to run at very high speeds, and so designed that the driv-
ing-wheels should make two revolutions for each reciprocation of
the pistons. This was to be accomplished by means of gearing.
The general plan of the engine was determined in Mr. Baldwin's
mind, but was never carried into execution.
The period under consideration was marked also by the introduc-
tion of the French & Baird stack, which proved at once to be one
of the most successful spark-arresters thus far employed, and which
was for years used almost exclusively wherever, as on the cotton-
carrying railroads of the South, a thoroughly effective spark-arrester
was required. This stack was introduced by Mr. Baird, then a fore-
man in the works, who purchased the patent-right of what had been
known as the Grimes stack, and combined with it some of the feat-
ures of the stack made by Mr. Richard French, then master
mechanic of the Germantown Railroad, together with certain im-
provements of his own. The cone over the straight inside pipe was
made with volute flanges on its under side, which gave a rotary
motion to the sparks. Around the cone was a casing about six
inches smaller in diameter than the outside stack. Apertures were
cut in the sides of this casing, through which the sparks in their
rotary motion were discharged, and thus fell to the bottom of the
space between the straight inside pipe and the outside stack. The
opening in the top of the stack was fitted with a series of V-shaped
iron circles perforated with numerous holes, thus presenting an
enlarged area, through which the smoke escaped. The patent-right
for this stack was subsequently sold to Messrs. Radley & Hunter,
and its essential principle is still used in the Radley & Hunter stack
as at present made.
In 1845 Mr. Baldwin built three locomotives for the Royal Rail-
road Committee of Würtemberg. They were of fifteen tons weight,
on six wheels, four of them being sixty inches in diameter and
coupled. The front driving-wheels were combined by the flexible
beams into a truck with the smaller leading wheels. The cylinders
were inclined and outside, and the connecting-rods took hold of a
half-crank axle back of the fire-box. It was specified that these
engines should have the link-motion which had shortly before been
introduced in England by the Stephensons. Mr. Baldwin accord-
HISTORY OF THE STEAM-ENGINE. ci
ingly applied a link of a peculiar character to suit his own ideas of
the device. The link was made solid, and of a truncated V-section,
and the block was grooved so as to fit and slide on the outside of
the link.
During the year 1845 another important feature in locomotive
construction—the cut-off valve—was added to Mr. Baldwin's prac-
tice. Up to that time the valve-motion had been the two eccentrics,
with the single flat hook for each cylinder. Since 1841 Mr. Baldwin
had contemplated the addition of some device allowing the steam
to be used expansively, and he now added the “half-stroke cut-off.”
In this device the steam-chest was separated by a horizontal plate
into an upper and a lower compartment. In the upper compartment
a valve, worked by a separate eccentric, and having a single opening,
admitted steam through a port in this plate to the lower steam-
chamber. The valve-rod of the upper valve terminated in a notch
or hook, which engaged with the upper arm of its rock-shaft.
When thus working, it acted as a cut-off at a fixed part of the
stroke, determined by the setting of the eccentric. This was usually
at half the stroke. When it was desired to dispense with the cut-off
and work steam for the full stroke, the hook of the valve-rod was
lifted from the pin on the upper arm of the rock-shaft by a lever
worked from the foot-board, and the valve-rod was held in a notched
rest fastened to the side of the boiler. This left the opening through
the upper valve and the port in the partition-plate open for the free
passage of steam throughout the whole stroke. The first application
of the half-stroke cut-off was made on the engine Champlain (20 D),
built for the Philadelphia and Reading Railroad Company, in 1845.
It at once became the practice to apply the cut-off on all passenger
engines, while the six- and eight-wheels-connected freight engines
were, with a few exceptions, built for a time longer with the single
valve admitting steam for the full stroke.
After building, during the years 1843, 1844, and 1845, ten four-
wheels-connected engines on the plan above described, viz., six
wheels in all, the leading wheels and the front driving-wheels being
combined into a truck by the flexible beams, Mr. Baldwin finally
adopted the present design of four driving-wheels and a four-
wheeled truck. Some of his customers who were favorable to the
latter plan had ordered such machines of other builders, and Colo-
nel Gadsden, President of the South Carolina Railroad Company,
cii HISTORY OF THE STEAM-ENGINE.
called on him in 1845 to build for that line some passenger engines
of this pattern. He accordingly bought the patent-right for this
plan of engine of Mr. H. R. Campbell, and for the equalizing beams
used between the driving-wheels, of Messrs. Eastwick & Harrison,
and delivered to the South Carolina Railroad Company, in Decem-
ber, 1845, his first eight-wheeled engine with four driving-wheels
and a four-wheeled truck. This machine had cylinders thirteen
and three-quarters by eighteen, and driving-wheels sixty inches in
diameter, with the springs between them arranged as equalizers.
Its weight was fifteen tons. It had the half-crank axle, the cylinders
being inside the frame but outside the smoke-box. The inside-con-
nected engine, counterweighting being as yet unknown, was admitted
to be steadier in running, and hence more suitable for passenger
H
I
BALDWIN EIGHT-WHEELS-CONNECTED “C” ENGINE, 1846.
service. With the completion of the first eight-wheeled “C” engine
Mr. Baldwin's feelings underwent a revulsion in favor of this plan,
and his partiality for it became as great as had been his antipathy
before. Commenting on the machine, he recorded himself as “more
pleased with its appearance and action than any engine he had
turned out.” In addition to the three engines of this description
for the South Carolina Railroad Company, a duplicate was sent to
the Camden and Amboy Railroad Company, and a similar but
lighter one to the Wilmington and Baltimore Railroad Company,
shortly afterwards. The engine for the Camden and Amboy Rail-
road Company, and perhaps the others, had the half-stroke cut-off.
From that time forward all of his four-wheels-connected machines
were built on this plan, and the six-wheeled “C” engine was aban-
doned, except in the case of one built for the Philadelphia, German-




HISTORY OF THE STEAM-ENGINE. ciii
town and Norristown Railroad Company in 1846, and this was
afterwards rebuilt into a six-wheels-connected machine. Three
methods of carrying out the general design were, however, subse-
quently followed. At first the half-crank was used; then hori-
zontal cylinders inclosed in the chimney-seat and working a full-
crank axle, which form of construction had been practiced at the
Lowell Works; and eventually, outside cylinders with outside con-
nections. -
Forty-two engines were completed in 1846, and thirty-nine in
1847. The only novelty to be noted among them was the engine
M. G. Bright, built ſor operating the inclined plane on the Madison
and Indianapolis Railroad. The rise of this incline was one in
seventeen, from the bank of the Ohio river at Madison. The engine
had eight wheels, forty-two inches in diameter, connected, and
worked in the usual manner by outside inclined cylinders, fifteen
and one-half inches diameter by twenty inches stroke. A second
pair of cylinders, seventeen inches in diameter with eighteen inches
stroke of piston, was placed vertically over the boiler, midway be- .
tween the furnace and smoke-arch. The connecting-rods worked by
these cylinders connected with cranks on a shaft under the boiler.
This shaft carried a single cog-wheel at its centre, and this cog-
wheel engaged with another of about twice its diameter on a second
shaft adjacent to it and in the same plane. The cog-wheel on this
latter shaft worked in a rack-rail placed in the centre of the track.
The shaft itself had its bearings in the lower ends of two vertical
rods, one on each side of the boiler, and these rods were united
over the boiler by a horizontal bar which was connected by means
of a bent lever and connecting-rod to the piston worked by a small
horizontal cylinder placed on top of the boiler. By means of this
cylinder, the yoke carrying the shaft and cog-wheel could be de-
pressed and held down so as to engage the cogs with the rack-rail,
or raised out of the way when only the ordinary driving-wheels
were required. This device was designed by Mr. Andrew Cathcart,
Master Mechanic of the Madison and Indianapolis Railroad. A
similar machine, the John Brough, for the same plane, was built by
Mr. Baldwin in 1850. The incline was worked with a rack-rail and
these engines until it was finally abandoned and a line with easier
gradients substituted.
The use of iron tubes in freight engines grew in favor, and in
civ HISTORY OF THE STEAM-ENGINE.
October, 1847, Mr. Baldwin noted that he was fitting his flues with
copper ends, “for riveting to the boiler.” -
The subject of burning coal continued to engage much attention,
but the use of anthracite had not as yet been generally successful.
In October, 1847, the Baltimore and Ohio Railroad Company adver-
tised for proposals for four engines to burn Cumberland coal, and
the order was taken and filled by Mr. Baldwin with four of his
eight-wheels-connected machines. These engines had a heater on
top of the boiler for heating the feed-water, and a grate with a
rocking-bar in the centre, having fingers on each side which inter-
locked with projections on fixed bars, one in front and one behind.
The rocking-bar was operated from the foot-board. This appears to
have been the first instance of the use of a rocking-grate in the
practice of these works.
The year 1848 showed a falling off in business, and only twenty
engines were turned out. In the following year, however, there was
a rapid recovery, and the production of the works increased to
thirty, followed by thirty-seven in 1850, and fifty in 1851. These
engines, with a few exceptions, were confined to three patterns, the
eight-wheeled four-coupled engine, from twelve to nineteen tons in
weight, for passengers and freight, and the six- and eight-wheels-
connected engine, for freight exclusively, the six-wheeled machine
weighing from twelve to seventeen tons, and the eight-wheeled from
eighteen to twenty-seven tons. The wheels of these six- and eight-
wheels-connected machines were made generally forty-two, with
occasional variations up to forty-eight, inches in diameter.
The exceptions referred to in the practice of these years were the
fast passenger engines built by Mr. Baldwin during this period.
Early in 1848 the Vermont Central Railroad was approaching com-
pletion, and Governor Paine, the President of the company, con-
ceived the idea that the passenger service on the road required
locomotives capable of running at very high velocities. Mr. Bald-
win at once undertook to construct for that company a locomotive
which could run with a passenger train at a speed of sixty miles per
hour. The work was begun early in 1848, and in March of that
year Mr. Baldwin filed a caveat for his design. The engine was
completed in 1849, and was named the Governor Paine. It had one
pair of driving-wheels, six and a half feet in diameter, placed back
of the fire-box. Another pair of wheels, but cinaller and uncon-
HISTORY OF THE STEAM-ENGINE. CV
*
nected, was placed directly in front of the fire-box, and a four-
wheeled truck carried the front of the engine. The cylinders were
seventeen and a quarter inches diameter and twenty inches stroke,
and were placed horizontally between the frames and the boiler, at
about the middle of the waist. The connecting-rods took hold of
“half-cranks” inside of the driving-wheels. The object of placing
the cylinders at the middle of the boiler was to lessen or obviate the
lateral motion of the engine, produced when the cylinders were
attached to the smoke-arch. The bearings on the two rear axles
were so contrived that, by means of a lever, a part of the weight of
the engine usually carried on the wheels in front of the fire-box
could be transferred to the driving-axle. The Governor Paine was
used for several years on the Vermont Central Railroad, and then
[[II] f
# || || ||
BALDWIN FAST PASSENGER ENGINE, 1848.
Z
rebuilt into a four-coupled machine. During its career it was stated
by the officers of the road that it could be started from a state of
rest and run a mile in forty-three seconds. Three engines on the
same plan, but with cylinders fourteen by twenty, and six-feet
driving-wheels, the Mifflin, Blair, and Indiana, were also built
for the Pennsylvania Railroad Company in 1849. They weighed
each about forty-seven thousand pounds, distributed as follows:
eighteen thousand on driving-wheels, fourteen thousand on the pair
of wheels in front of the fire-box, and fifteen thousand on the truck.
By applying the lever, the weight on the driving-wheels could be
increased to about twenty-four thousand pounds, the weight on the
wheels in front of the fire-box being correspondingly reduced. A
speed of four miles in three minutes is recorded for them, and upon


cvi HISTORY OF THE STEAM-ENGINE.
one occasion President Taylor was taken in a special train over the
road by one of these machines at a speed of sixty miles an hour.
One other engine of this pattern, the Susquehanna, was built for
the Hudson River Railroad Company in 1850. Its cylinders were
fifteen inches diameter by twenty inches stroke, and driving-wheels
six feet in diameter. All these engines, however, were short-lived,
and died young, of insufficient adhesion.
Eight engines with four driving-wheels connected and half-crank
axles were built for the New York and Erie Railroad Company in
1849, with seventeen by twenty-inch cylinders; one-half of the
number with six-feet and the rest with five-feet driving-wheels.
These machines were among the last on which the half-crank axle
was used. Thereafter, outside-connected engines were constructed
almost exclusively. sº
In May, 1848, Mr. Baldwin filed a caveat for a four-cylinder loco-
motive, but never carried the design into execution. The first
instance of the use of steel axles in the practice of the establishment
occurred during the same year—a set being placed as an experiment
under an engine constructed for the Pennsylvania Railroad Company.
In 1850 the old form of dome boiler, which had characterized the
Baldwin engine since 1834, was abandoned, and the wagon-top form
substituted.
The business in 1851 had reached the full capacity of the shop,
and the next year marked the completion of about an equal number
of engines (forty-nine). Contracts for work extended a year ahead,
and, to meet the demand, the facilities in the various departments
were increased, and resulted in the construction of sixty engines in
I853, and sixty-two in 1854.
At the beginning of the latter year, Mr. Matthew Baird, who had
been connected with the works since 1836 as one of its foremen,
entered into partnership with Mr. Baldwin, and the style of the firm
was made M. W. Baldwin & Co.
The only novelty in the general plan of engines during this period
was the addition of the ten-wheeled engine to the patterns of the
establishment. The success of Mr. Baldwin's engines with all six
or eight wheels connected, and the two front pairs combined by the
parallel beams into a flexible truck, had been so marked that it was
natural that he should oppose any other plan for freight service.
The ten-wheeled engine, with six driving-wheels connected, had,
HISTORY OF THE STEAM-ENGINE. cvii
however, now become a competitor. This plan of engine was first
patented by Septimus Norris, of Philadelphia, in 1846, and the
original design was apparently to produce an engine which should
have equal tractive power with the Baldwin six-wheels-connected
machine. This the Norris patent sought to accomplish by proposing
an engine with six driving-wheels connected, and so disposed as to
carry substantially the whole weight, the forward driving-wheels
being in advance of the centre of gravity of the engine, and the truck
only serving as a guide, the front of the engine being connected
with it by a pivot-pin, but without a bearing on the centre-plate.
Mr. Norris's first engine on this plan was tried in April, 1847, and
was found not to pass curves so readily as was expected. As the
truck carried little or no weight, it would not keep the track. The
New York and Erie Railroad Company, of which John Brandt
was then Master Mechanic, shortly afterwards adopted the ten-
wheeled engine, modified in plan so as to carry a part of the weight
on the truck. Mr. Baldwin filled an order for this company, in
1850, of four eight-wheels-connected engines, and in making the
contract he agreed to substitute a truck for the front pair of wheels
... if desired after trial. This, however, he was not called upon to do.
In February, 1852, Mr. J. Edgar Thomson, President of the Penn-
sylvania Railroad Company, invited proposals for a number of
freight locomotives of fifty-six thousand pounds weight each. They
were to be adapted to burn bituminous coal, and to have six wheels
connected and a truck in front, which might be either of two or four
wheels. Mr. Baldwin secured the contract, and built twelve engines
of the prescribed dimensions, viz., cylinders eighteen by twenty-two;
driving-wheels forty-four inches in diameter, with chilled tires.
Several of these engines were constructed with a single pair of truck-
wheels in front of the driving-wheels, but back of the cylinders. It
was found, however, after the engines were put in service, that the
two truck-wheels carried eighteen thousand or nineteen thousand
pounds, and this was objected to by the company as too great a
weight to be carried on a single pair of wheels. On the rest of the
engines of the order, therefore, a four-wheeled truck in front was
employed.
The ten-wheeled engine thereafter assumed a place in the Baldwin
classification. In 1855–56, two of twenty-seven tons weight, nine-
teen by twenty-two cylinders, forty-eight inches driving-wheels,
8
cviii HISTORY OF THE STEAM-ENGINE.
were built for the Portage Railroad, and three for the Pennsylvania
Railroad. In 1855, '56, and '57, fourteen of the same dimensions
were built for the Cleveland and Pittsburg Railroad; four for the
Pittsburg, Fort Wayne and Chicago Railroad; and one for the
Marietta and Cincinnati Railroad. In 1858 and '59, one was con-,
structed for the South Carolina Railroad, of the same size, and six
lighter ten wheelers, with cylinders fifteen and a half by twenty-two,
and four-feet driving-wheels, and two with cylinders sixteen by
twenty-two, and four-feet driving-wheels, were sent out to railroads
in Cuba.
It was some years—not until after 1860, however—before this
pattern of engine wholly superseded in Mr. Baldwin's practice the
old plan of freight engine on six or eight wheels, all connected.
On three locomotives—the Clinton, Athens, and Sparta—
completed for the Central Railroad of Georgia in July, 1852, the
driving-boxes were made with a slot or cavity in the line of the
vertical bearing on the journal. The object was to produce a more
uniform distribution of the wear over the entire surface of the bear-
ing. This was the first instance in which this device, which has
since come into general use, was employed in the Works, and the
boxes were so made by direction of Mr. Charles Whiting, then
Master Mechanic of the Central Railroad of Georgia. He subse-
quently informed Mr. Baldwin that this method of fitting up driving-
boxes had been in use on the road for several years previous to his
connection with the company. As this device was subsequently
made the subject of a patent by Mr. David Matthew, these facts may
not be without interest.
In 1853, Mr. Charles Ellet, Chief Engineer of the Virginia Central
Railroad, laid a temporary track across the Blue Ridge, at Rock
Fish Gap, for use during the construction of a tunnel through the
mountain. This track was twelve thousand five hundred feet in
length on the eastern slope, ascending in that distance six hundred
and ten feet, or at the average rate of one in twenty and a half feet.
The maximum grade was calculated for two hundred and ninety-six
feet per mile, and prevailed for half a mile. It was found, however,
in fact, that the grade in places exceeded three hundred feet per
mile. The shortest radius of curvature was two hundred and thirty-
eight feet. On the western slope, which was ten thousand six hun-
dred and fifty feet in length, the maximum grade was two hundred
HISTORY OF THE STEAM-ENGINE. cix
and eighty feet per mile, and the ruling radius of curvature three hun-
dred feet. This track was worked by two of the Baldwin six-wheels-
connected flexible-beam truck locomotives constructed in 1853–54.
But the period now under consideration was marked by another,
and a most important, step in the progress of American locomotive
practice. We refer to the introduction of the link-motion. Al-
though this device was first employed by William T. James, of New
York, in 1832, and eleven years later by the Stephensons, in Eng-
land, and was by them applied thenceforward on their engines, it
was not until 1849 that it was adopted in this country. In that year
Mr. Thomas Rogers, of the Rogers Locomotive and Machine Com-
pany, introduced it in his practice. Other builders, however, strenu-
ously resisted the innovation, and none more so than Mr. Baldwin.
The theoretical objections which confessedly apply to the device,
but which practically have been proved to be unimportant, were
urged from the first by Mr. Baldwin as arguments against its use.
The strong claim of the advocates of the link-motion, that it gave a
means of cutting off steam at any point of the stroke, could not be
gainsaid, and this was admitted to be a consideration of the first
importance. This very circumstance undoubtedly turned Mr. Bald-
win's attention to the subject of methods for cutting off steam, and
one of the first results was his “Variable Cut-off,” patented April
27, 1852. This device consisted of two valves, the upper sliding
upon the lower, and worked by an eccentric and rock-shaft in the
usual manner. The lower valve fitted steam-tight to the sides of the
steam-chest and the under surface of the upper valve. When the
piston reached each end of its stroke, the full pressure of steam from
the boiler was admitted around the upper valve, and transferred the
lower valve instantaneously from one end of the steam-chest to the
other. The openings through the two valves were so arranged that
steam was admitted to the cylinder only for a part of the stroke.
The effect was, therefore, to cut off steam at a given point, and to
open the induction and exhaust ports substantially at the same
instant and to their full extent. The exhaust port, in addition,
remained fully open while the induction port was gradually closing,
and after it had entirely closed. Although this device was never put
in use, it may be noted in passing that it contained substantially the
principle of the steam-pump, as since patented and constructed.
Early in 1853 Mr. Baldwin abandoned the half-stroke cut-off.
CX HISTORY OF THE STEAM-ENGINE.
previously described, and which he had been using since 1845, and
adopted the variable cut-off, which was already employed by other
builders. One of his letters, written in January, 1853, states his
position, as follows:
“I shall put on an improvement in the shape of a variable cut-off, which can be
operated by the engineer while the machine is running, and which will cut off anywhere
from six to twelve inches, according to the load and amount of steam wanted, and this
without the link-motion, which I could never be entirely satisfied with. I still have the
independent cut-off, and the additional machinery to make it variable will be simple and
not liable to be deranged.”
This form of cut-off was a separate valve, sliding on a partition
plate between it and the main steam-valve, and worked by an inde-
pendent eccentric and rock-shaft. The upper arm of the rock-shaft
was curved so as to form a radius-arm, on which a sliding-block,
forming the termination of the upper valve-rod, could be adjusted
and held at varying distances from the axis, thus producing a vari-
able travel of the upper valve. This device did not give an abso-
lutely perfect cut-off, as it was not operative in backward gear, but
when running forward it would cut off with great accuracy at any
point of the stroke, was quick in its movement, and economical in
the consumption of fuel.
After a short experience with this arrangement of the cut-off, the
partition plate was omitted, and the upper valve was made to slide
directly on the lower. This was eventually found objectionable,
however, as the lower valve would soon cut a hollow in the valve-
face. Several unsuccessful attempts were made to remedy this defect
by making the lower valve of brass, with long bearings, and making
the valve-face of the cylinder of hardened steel; finally, however,
the plan of one valve on the other was abandoned and a recourse
was again had to an interposed partition plate, as in the original
half-stroke cut-off.
Mr. Baldwin did not adopt this form of cut-off without some
modification of his own, and the modification in this instance con-
sisted of a peculiar device, patented September 13, 1853, for raising
and lowering the block on the radius-arm. A quadrant was placed
so that its circumference bore nearly against a curved arm projecting
down from the sliding-block, and which curved in the reverse direc-
tion from the quadrant. Two steel straps side by side were inter-
posed between the quadrant and this curved arm. One of the straps
HISTORY OF THE STEAM-ENGINE. cxi
was connected to the lower end of the quadrant and the upper end
of the curved arm; the other to the upper end of the quadrant and
the lower end of the curved arm. The effect was the same as if the
quadrant and arm geared into each other in any position by teeth,
and theoretically the block was kept steady in whatever position
Sº -
& R
:=E.
§::::::::::55.
sº zºzaza
º
VARIABLE CUT-OFF ADJUSTMENT.
placed on the radius-arm of the rock-shaft. This was the object
sought to be accomplished, and was stated in the specification of the
patent as follows:
“The principle of varying the cut-off by means of a vibrating arm and sliding pivot-
block has long been known, but the contrivances for changing the position of the block
upon the arm have been very defective. The radius of motion of the link by which the
sliding-block is changed on the arm, and the radius of motion of that part of the vibrating
arm on which the block is placed, have, in this kind of valve-gear, as heretofore con-
structed, been different, which produced a continual, rubbing of the sliding-block upon
the arm while the arm is vibrating; and as the block for the greater part of the time
occupies one position on the arm, and only has to be moved toward either extremity
occasionally, that part of the arm on which the block is most used soon becomes so worn
that the block is loose, and jars.”
This method of varying the cut-off was first applied on the
engine Belle, delivered to the Pennsylvania Railroad Company,
December 6, 1854, and thereafter was ſor some time employed by
Mr. Baldwin. It was found, however, in practice that the steel
straps would stretch sufficiently to allow them to buckle and break,
and hence they were soon abandoned, and chains substituted be-
tween the quadrant and curved arm of the sliding-block. These
chains in turn proved little better, as they lengthened, allowing lost
motion, or broke altogether, so that eventually the quadrant was
wholly abandoned, and recourse was finally had to the lever and
link for raising and lowering the sliding-block. As thus arranged,
the cut-off was substantially what was known as the “Cuyahoga Cut-



cxii HISTORY OF THE STEAM-ENGINE.
off,” as introduced by Mr. Ethan Rogers, of the Cuyahoga Works,
Cleveland, Ohio, except that Mr. Baldwin used a partition plate be-
tween the upper and the lower valve.
But while Mr. Baldwin, in common with many other builders,
was thus resolutely opposing the link-motion, it was nevertheless
rapidly gaining favor with railroad managers. Engineers and mas-
ter mechanics were everywhere learning to admire its simplicity,
and were manifesting an enthusiastic preference for engines so con-
structed. At length, therefore, he was forced to succumb : and the
link was applied to the Pennsylvania, one of two engines completed
for the Central Railroad of Georgia, in February, 1854. The other
engine of the order, the Wew Hampshire, had the variable cut-off,
and Mr. Baldwin, while yielding to the demand in the former en-
gine, was undoubtedly sanguine that the working of the latter would
demonstrate the inferiority of the new device. In this, however, he
was disappointed, for in the following year the same company
ordered three more engines, on which they specified the link-motion.
In 1856 seventeen engines for nine different companies had this
form of valve gear, and its use was thus incorporated in his practice.
It was not, however, until 1857 that he was induced to adopt it
exclusively. *
February 14, 1854, Mr. Baldwin and Mr. David Clark, Master
Mechanic of the Mine Hill Railroad, took out conjointly a patent
for a feed-water heater, placed at the base of a locomotive chimney,
and consisting of one large vertical flue, surrounded by a number
of smaller ones. The exhaust steam was discharged from the noz-
zles through the large central flue, creating a draft of the products
of combustion through the smaller surrounding flues. The pumps
forced the feed-water into the chamber around these flues, whence
it passed to the boiler by a pipe from the back of the stack. This
heater was applied on several engines for the Mine Hill Railroad,
and on a few for other roads; but its use was exceptional, and
lasted only for a year or two.
In December of the same year Mr. Baldwin filed a caveat for a
variable exhaust, operated automatically, by the pressure of steam,
so as to close when the pressure was lowest in the boiler, and open
with the increase of pressure. The device was never put in service.
The use of coal, both bituminous and anthracite, as a fuel for
locomotives, had by this time become a practical success. The
HISTORY OF THE STEAM-ENGINE. cxiii
economical combustion of bituminous coal, however, engaged con-
siderable attention. It was felt that much remained to be accom-
plished in consuming the smoke and deriving the maximum of useful
effect from the fuel. Mr. Baird, who was now associated with Mr.
Baldwin in the management of the business, made this matter a sub-
ject of careful study and investigation. An experiment was con-
ducted under his direction, by placing a sheet-iron deflector in the
fire-box of an engine on the Germantown and Norristown Railroad. .
The success of the trial was such as to show conclusively that a
more complete combustion resulted. As, however, a deflector
formed by a single plate of iron would soon be destroyed by the
action of the fire, Mr. Baird proposed to use a water-leg projecting
upward and backward from the front of the fire-box under the flues.
Drawings and a model of the device were prepared, with a view of
patenting it, but subsequently the intention was abandoned, Mr.
Baird concluding that a fire-brick arch as a deflector to accomplish
the same object was preferable. This was accordingly tried on two
locomotives built for the Pennsylvania Railroad Company in 1854,
and was found so valuable an appliance that its use was at once
established, and it was put on a number of engines built for railroads
in Cuba and elsewhere. For several years the fire-bricks were sup-
ported on side plugs; but in 1858, in the Media, built for the West
Chester and Philadelphia Railroad Company, water-pipes extending
from the crown obliquely downward and curving to the sides of the
fire-box at the bottom were successfully used for the purpose.
The adoption of the link-motion may be regarded as the dividing
line between the present and the early and transitional stage of
locomotive practice. Changes since that event have been principally
in matters of detail, but it is the gradual perfection of these details
which has made the locomotive the symmetrical, efficient, and wonder-
fully complete piece of mechanism it is to-day. In perfecting these
minutiae, the Baldwin Locomotive works has borne its part, and it
only remains to state briefly its contributions in this direction.
The production of the establishment during the six years from
1855 to 1860, inclusive, was as follows; forty-seven engines in
1855; fifty-nine in 1856; sixty-six in 1857; thirty-three in 1858;
seventy in 1859; and eighty-three in 1860. The greater number
of these were of the ordinary type, four wheels coupled, and a four-
wheeled truck, and varying in weight from fifteen ton engines, with
cxiv HISTORY OF THE STEAM-ENGINE.’
cylinders twelve by twenty-two, to twenty-seven ton engines, with
cylinders sixteen by twenty-four. A few ten-wheeled engines were
built, as has been previously noted, and the remainder were the
Baldwin flexible-truck six- and eight-wheels-connected engines.
The demand for these, however, was now rapidly falling off, the
ten-wheeled and heavy “C” engines taking their place, and by 1859
they ceased to be built, save in exceptional cases, as for some foreign
roads, from which orders for this pattern were still occasionally
received.
A few novelties characterizing the engines of this period may be
mentioned. Several engines built in 1855 had cross-flues placed in
the fire-box, under the crown, in order to increase the heating sur-
face. This feature, however, was found impracticable, and was soon
abandoned. The intense heat to which the flues were exposed con-
verted the water contained in them into highly super-heated steam,
which would force its way out through the water around the fire box
with violent ebullitions. Four engines were built for the Pennsyl-
vania Railroad Company, in 1856–57, with straight boilers and two
domes. The Delano grate, by means of which the coal was forced
into the fire-box from below, was applied on four ten-wheeled en-
gines for the Cleveland and Pittsburg Railroad in 1857. In 1859
several engines were built with the form of boiler introduced on the
Cumberland Valley Railroad in 1851 by Mr. A. F. Smith, and which
consisted of a combustion-chamber in the waist of the boiler, next
the fire-box. This form of boiler was for some years thereafter
largely used in engines for soft coal. It was at first constructed
with the “water-leg,” which was a vertical water-space, connecting
the top and bottom sheets of the combustion-chamber, but even-
tually this feature was omitted, and an unobstructed combustion-
chamber employed. Several engines were built for the Philadelphia,
Wilmington and Baltimore Railroad Company in 1859, and there-
after, with the Dimpfel boiler, in which the tubes contain water, and
starting downward from the crown-sheet, are curved to the horizontal,
and terminate in a narrow water-space next the smoke-box. The
whole waist of the boiler, therefore, forms a combustion chamber,
and the heat and gases, after passing for their whole length along and
around the tubes, emerge into the lower part of the smoke-box.
In 1860 an engine was built for the Mine Hill Railroad, with a
boiler of a peculiar form. The top sheets sloped upward from both
HISTORY OF THE STEAM ENGINE. CXV
ends towards the centre, thus making a raised part or hump in the
centre. The engine was designed to work on heavy grades, and
the object sought by Mr. Wilder, the Superintendent of the Mine
Hill Railroad, was to have the water always at the same height in
the space from which steam was drawn, whether going up or down
grade.
All these experiments are indicative of the interest then prevail-
ing upon the subject of coal-burning. The result of experience and
study had meantime satisfied Mr. Baldwin that to burn soft coal
successfully required no peculiar devices; that the ordinary form of
boiler, with plain fire-box, was right, with perhaps the addition of a
fire-brick deflector; and that the secret of the economical and suc-
cessful use of coal was in the mode of firing, rather than in a differ-
ent form of furnace.
The year 1861 witnessed a marked falling off in the production.
The breaking out of the civil war at first unsettled business, and by
many it was thought that railroad traffic would be so largely re-
duced that the demand for locomotives must cease altogether. A
large number of hands were discharged from the works, and only
forty locomotives were turned out during the year. It was even
seriously contemplated to turn the resources of the establishment to
the manufacture of shot and shell, and other munitions of war, the
belief being entertained that the building of locomotives would have
to be altogether suspended. So far, however, was this from being
the case, that, after the first excitement had subsided, it was found
that the demand for transportation by the general government, and
by the branches of trade and production stimulated by the war, was
likely to tax the carrying capacity of the principal Northern railroads
to the fullest extent. The government itself became a large pur-
chaser of locomotives, and it is noticeable, as indicating the increase
of travel and freight transportation, that heavier machines than had
ever before been built became the rule. Seventy-five engines were
sent from the works in 1862; ninety-six in 1863; one hundred and
thirty in 1864; and one hundred and fifteen in 1865. During two
years of this period, from May, 1862, to June, 1864, thirty-three en-
gines were built for the United States Military Railroads. The de-
mand from the various coal-carrying roads in Pennsylvania and
vicinity was particularly active, and large numbers of ten-wheeled
engines, and of the heaviest eight-wheeled four-coupled engines,
cxvi HISTORY OF THE STEAM-ENGINE.
were built. Of the latter class, the majority were with fifteen- and
sixteen-inch cylinders, and of the former, seventeen- and eighteen-
inch cylinders. Q
The introduction of several important features in construction
marks this period. Early in 1861, four eighteen-inch cylinder
freight locomotives, with six coupled wheels, fifty-two inches in di-
ameter, and a Bissell pony-truck with radius-bar in front, were sent
to the Louisville and Nashville Railroad Company. This was the
first instance of the use of the Bissell truck in the Baldwin Works.
These engines, however, were not of the regular Mogul type, as
they were only modifications of the ten-wheeler, the drivers retaining
the same position, well back, and a pair of pony-wheels on the Bis-
sell plan taking the place of the ordinary four-wheeled truck. Other
engines of the same pattern, but with eighteen and one-half inch
cylinders, were built in 1862–63, for the same company, and for the
Dom Pedro II. Railway of Brazil.
The introduction of steel in locomotive-construction was a dis-
tinguishing feature of the period. Steel tires were first used in the
works in 1862, on some engines for the Dom Pedro II. Railway of
South America. Their general adoption on American Railroads
followed slowly. No tires of this material were then made in this
country, and it was objected to their use that, as it took from sixty
to ninety days to import them, an engine, in case of a breakage of
one of its tires, might be laid up useless for several months. To
obviate this objection M. W. Baldwin & Co. imported five hundred
steel tires, most of which were kept in stock, from which to fill
orders. The steel tires as first used in 1862 on the locomotives
for the Dom Pedro Segundo Railway were made with a “shoulder”
at one edge of the internal periphery, and were shrunk on the wheel-
Centres.
Steel fire-boxes were first built for some engines for the Pennsyl-
vania Railroad Company in 1861. English steel of a high temper
was used, and at the first attempt the fire-boxes cracked in fitting
them in the boilers, and it became necessary to take them out and
substitute copper. American homogeneous cast-steel was then
tried on engines 23 I and 232, completed for the Pennsylvania Rail-
road in January, 1862, and it was found to work successfully. The
fire-boxes of nearly all engines thereafter built for that road were
of this material, and in 1866 its use for the purpose became general.
H:STORY OF THE STEAM-ENGINE. cxvii
It may be added that while all steel sheets for fire-boxes or boilers
are required to be thoroughly annealed before delivery, those which
are flanged or worked in the process of boiler construction are a
second time annealed before riveting.
Another feature of construction gradually adopted was the placing
of the cylinders horizontally. This was first done in the case of an
outside-connected engine, the Ocmulgee, which was sent to the
Southwestern Railroad Company "of
Georgia, in January, 1858. This engine
had a square smoke-box, and the cylin-
ders were bolted horizontally to its sides.
The plan of casting the cylinder and half-
saddle in one piece and fitting it to the
round smoke-box was introduced by Mr.
Baldwin, and grew naturally out of his
original method of construction. Mr.
Baldwin was the first American builder
to use an outside cylinder, and he made
it for his early engines with a circular
flange cast to it, by which it could be
bolted to the boiler. The cylinders were
gradually brought lower, and at a less
angle, and the flanges prolonged and en- Horizontal cylinDERs.
larged. In 1852 three six-wheels-con-
nected engines, for the Mine Hill Railroad Company, were built with
the cylinder flanges brought around under the smoke-box until they
nearly met, the space between them being filled with a spark-box.
This was practically equivalent to making the cylinder and half-
saddle in one casting. Subsequently, on other engines on which the
spark-box was not used, the half-saddles were cast so as almost to
meet under the smoke-box, and, after the cylinders were adjusted in
position, wedges were fitted in the interstices and the saddles bolted
together. It was finally discovered that the faces of the two half-
saddles might be planed and finished so that they could be bolted
together and bring the cylinders accurately in position, thus avoiding
the troublesome and tedious job of adjusting them by chipping and
fitting to the boiler and frames. With this method of construction
the cylinders were placed at a less and less angle, until at length the
truck-wheels were spread sufficiently, on all new or modified classes

cxviii HISTORY OF THE STEAM-ENGINE.
of locomotives in the Baldwin list, to admit of the cylinders being
hung horizontally, as is the present almost universal American prac-
tice. By the year 1865 horizontal cylinders were made in all cases
where the patterns would allow it. The advantages of this arrange-
ment are manifestly in the interest of simplicity and economy, as the
cylinders are thus rights or lefts, indiscriminately, and a single pat-
tern answers for either side.
A distinguishing feature in the method of construction which
characterizes these works is the extensive use of a system of standard
gauges and templets, to which all work admitting of this process is
required to be made. The importance of this arrangement, in se-
curing absolute uniformity of essential parts in all engines of the
same class, is manifest, and with the increased production since 1861
it became a necessity as well as a decided advantage.
Thus had been developed and perfected the various essential
details of existing locomotive practice when Mr. Baldwin died, Sep-
tember 7, 1866. He had been permitted, in a life of unusual activity
and energy, to witness the rise and wonderful increase of a material
interest which had become the distinguishing feature of the century.
He had done much, by his own mechanical skill and inventive genius,
to contribute to the development of that interest. His name was as
“familiar as household words” wherever on the American continent
the locomotive had penetrated.
To do right, absolutely and unreservedly, in all his relations
with men, was an instinctive rule of his nature. His heroic struggle
to meet every dollar of his liabilities, principal and interest, after his
failure, consequent upon the general financial crash in 1837, con-
stitutes a chapter of personal self-denial and determined effort which
is seldom paralleled in the annals of commercial experience. When
most men would have felt that an equitable compromise with credi-
tors was all that could be demanded in view of the general financial
embarrassment, Mr. Baldwin insisted upon paying all claims in full,
and succeeded in doing so only after nearly five years of unremitting
industry, close economy, and absolute personal sacrifices. As a
philanthropist and a sincere and earnest Christian, zealous in every
good work, his memory is cherished by many to whom his contri-
butions to locomotive improvement are comparatively unknown.
From the earliest years of his business life the practice of systematic
benevolence was made a duty and a pleasure. His liberality con-
, HISTORY OF THE STEAM-ENGINE. cxix
stantly increased with his means. Indeed, he would unhesitatingly
give his notes, in large sums, for charitable purposes when money
was absolutely wanted to carry on his business. Apart from the
thousands which he expended in private charities, and of which, of
course, little can be known, Philadelphia contains many monuments
of his munificence.
After the death of Mr. Baldwin the business was reorganized, in
1867, under the title of “The Baldwin Locomotive Works,” M.
Baird & Co., Proprietors. Messrs. George Burnham and Charles T.
Parry, who had been connected with the establishment from an early
period, the former in charge of the finances, and the latter as General
Superintendent, were associated with Mr. Baird in the copartnership.
Three years later, Messrs. Edward H. Williams, William P. Henszey,
and Edward Longstreth became members of the firm. Mr. Williams
had been connected with railway management on various lines since
1850. Mr. Henszey had been Mechanical Engineer, and Mr. Long-
streth the General Superintendent of the works for several years
previously.
The production of the Baldwin Locomotive Works from 1866 to
1871, both years inclusive, was as follows:
\
1866, one hundred and eighteen locomotives.
1867, one hundred and twenty-seven “
1868, one hundred and twenty-four “
1869, two hundred and thirty-five & 4
1870, two hundred and eighty & 4
1871, three hundred and thirty-one “
In July, 1866, the engine Consolidation was built for the
Lehigh Valley Railroad, on the plan and specification furnished by
Mr. Alexander Mitchell, Master Mechanic of the Mahanoy Division
of that railroad. This engine was intended for working the Mahanoy
plane, which rises at the rate of one hundred and thirty-three feet
per mile. The Consolidation had cylinders twenty by twenty-
four, four pairs of wheels connected, forty-eight inches in diameter,
and a Bissell pony-truck in front, equalized with the front driving-
wheels. The weight of the engine, in working order, was ninety
thousand pounds, of which all but about ten thousand pounds was
on the driving-wheels. This engine has constituted the first of a
cxx * IIISTORY OF THE STEAM-ENGINE.
class to which it has given its name, and Consolidation engines
have since been constructed for a large number of railways, not only
in the United States, but in Mexico, Brazil, and Australia.
A class of engines known as Moguls, with three pairs of
wheels connected and a swinging pony-truck in front equalized
with the forward driving-wheels, took its rise in the practice of this
establishment from the E. A. Douglas, built for the Thomas Iron
Company, in 1867. Several sizes of Moguls have been built,
but principally with cylinders sixteen to nineteen inches in di-
ameter, and twenty-two or twenty-four inches stroke, and with driv-
ing-wheels from forty-four to fifty-seven inches in diameter. This
plan of engine has rapidly grown in favor for freight service on
heavy grades or where maximum loads are to be moved, and
has been adopted by several leading lines. Utilizing, as it does,
nearly the entire weight of the engine for adhesion, the main and
back pairs of driving-wheels being equalized together, as also
the front driving-wheels and the pony–wheels, and the construc-
tion of the engine with swing-truck and one pair of driving-wheels
without flanges allowing it to pass short curves without difficulty,
the Mogul is generally accepted as a type of engine especially
adapted to the economical working of heavy freight traffic.
In 1867, on a number of eight-wheeled four-coupled engines for
the Pennsylvania Railroad, the four-wheeled swing-bolster-truck was
first applied, and thereafter a large number of engines have been so
constructed. The two-wheeled or “pony-truck" has been built
both on the Bissell plan, with double inclined slides, and with the
ordinary swing-bolster, and in both cases with the radius-bar pivot-
ing from a point about four feet back from the centre of the truck.
The four-wheeled truck has been made with swinging or sliding
bolster, and both with and without the radius-bar. Of the engines
above referred to as the first on which the swing-bolster-truck was
applied, four were for express passenger service, with driving-wheels
sixty-seven inches in diameter, and cylinders seventeen by twenty-
four. One of them, placed on the road September 9, 1867, was in
constant service until May 14, 1871, without ever being off its
wheels for repairs, making a total mileage of one hundred and fifty-
three thousand two hundred and eighty miles. All of these engines
have their driving-wheels spread eight and one-half feet between
CentreS.
HISTORY OF THE STEAM-ENGINE. cxxi
f
Steel flues were first used in three ten-wheeled freight engines,
Numbers 21 1, 338, and 368, completed for the Pennsylvania Rail-
road in August, 1868. Flues of the same material have also been
used in a number of engines for South American railroads. Expe-
rience with tubes of this metal, however, has not yet been sufficiently
extended to show whether they give any advantages commensurate
with their increased cost over iron.
Steel boilers were first made in 1868 for locomotives for the Penn-
sylvania Railroad Company, and the use of this material for the
barrels of boilers as well as for the fire-boxes has continued to some
extent. Steel plates somewhat thinner than if of iron have been
generally used, but at the same time giving an equal or greater
tensile strength. The thoroughly homogeneous character of the
steel boiler-plate made in this country recommends it strongly for
the purpose.
In 1854 four engines for the Pennsylvania Railroad Company,
the Tiger, Leopard, Hornet and Wasp, were built with straight
boilers and two domes each, and in 1866 this method of con-
struction was revived. Since that date the practice of the estab-
lishment has included both the wagon-top boiler with single dome,
and the straight boiler with one or two domes. When the straight
boiler is used the waist is made about two inches larger in diameter
than that of the wagon-top form. About equal space for water and
steam is thus given in either case, and, as the number of flues is the
same in both forms, more room for the circulation of water between
the flues is afforded in the straight boiler, on account of its larger
diameter, than in the wagon-top shape. Where the straight boiler
is used with two domes the throttle-valve is placed in the forward
dome. - -
In 1868, a locomotive of three and a half feet gauge was con-
structed for the Averill Coal and Oil Company, of West Virginia.
This was the first narrow-gauge locomotive in the practice of the
works.
In 1869 three locomotives of the same gauge were constructed for
the Uniao Valenciana Railway of Brazil, and were the first narrow-
gauge locomotives constructed at these works for general passenger
and freight traffic. In the following year the Denver and Rio
Grande Railway, of Colorado, was projected on the three-feet gauge,
and the first locomotives for the line were designed and built in
cxxii HISTORY OF THE STEAM. ENGINE.
1871. Two classes, for passenger and freight respectively, were
constructed. The former were six-wheeled, four wheels coupled
forty inches in diameter, nine by sixteen cylinders, and weighed
each, loaded, about twenty-five thousand pounds. The latter were
eight-wheeled, six wheels coupled thirty-six inches in diameter,
eleven by sixteen cylinders, and weighed each, loaded, about thirty-
five thousand pounds. Each had a swinging-truck of a single pair
of wheels in front of the cylinders. The latter type has been main-
tained for freight service on most narrow-gauge lines, but principally
of larger sizes, engines as heavy as fifty thousand pounds having
been turned out. The former type for passenger service was found
to be too small and to be unsteady on the track, owing to its com-
paratively short wheel-base. It was therefore abandoned, and the
stºº
*—H–1–H–
FREIGHT LocoMotive, “CONSOLIDATION’ TYPE.
ordinary “American" pattern, eight-wheeled, four-coupled, substi-
tuted. Following the engines for the Denver and Rio Grande
Railway, others for other narrow-gauge lines were called for, and
the manufacture of this description of rolling stock soon assumed
importance. From 1868 to 1870, inclusive, eleven narrow-gauge
locomotives were included in the product. The number of narrow-
gauge locomotives built in succeeding years has been as follows:
1871, thirty-two; 1872, nineteen; 1873, twenty-nine; 1874, forty-
four; 1875, thirty-six; 1876, fifty one; 1877, sixty-five; 1878, sev-
enty-five; 1879, seventy-eight.
The Consolidation type, as first introduced for the four feet
eight and one-half inches gauge in 1866, was adapted to the three-
feet gauge in 1873. In 1877 a locomotive on this plan, weighing in
working order about sixty thousand pounds, with cylinders fifteen

HISTORY OF THE STEAM-ENGINE. cxxiii
by twenty, was built for working the Garland extension of the
Denver and Rio Grande Railway, which crosses the Rocky Moun-
tains with maximum grades of two hundred and eleven feet per mile,
and minimum curves of thirty degrees. The performance of this
locomotive, the Alamosa, is given in the following extract from a
letter from the then General Superintendent of that railway:
“DENVER, CoL., Aug. 31, 1877.
“On the 29th inst. I telegraphed you from Veta Pass–Sangre de Cristo Mountains—
that engine Alamosa had just hauled from Garland to the Summit one baggage car
and seven coaches, containing one hundred and sixty passengers. Yesterday I received
your reply asking for particulars, etc.
“My estimate of the weight was eighty-five net tons, stretched over a distance of three
hundred and sixty feet, or including the engine, of four hundred and five feet.
“The occasion of this sized train was an excursion from Denver to Garland and
return. The night before, in going over from La Veta, we had over two hundred pas-
sengers, but it was 8 P. M., and, fearing a slippery rail, I put on engine No. 19 as a
pusher, although the engineer of the Alamosa said he could haul the train, and I
believe he could have done so. The engine and train took up a few feet more than the
half circle at “ Muke Shore,” where the radius is one hundred and ninety-three feet. The
engine worked splendidly, and moved up the two hundred and eleven feet grades and
around the thirty degree curves seemingly with as much ease as our passenger engines
on seventy-five feet grades with three coaches and baggage cars.
“The Alamosa hauls regularly eight loaded cars and caboose, about one hundred
net tons; length of train about two hundred and thirty feet.
“The distance from Garland to Veta Pass is fourteen and one-quarter miles, and the
time is one hour and twenty minutes. Respectfully yours,
(Signed) “W. W. Borst, Sup't.”
In addition to narrow-gauge locomotives for the United States, -
this branch of the product has included a large number of one-metre
gauge locomotives for Brazil, three-feet gauge locomotives for Cuba,
Mexico, and Peru, and three and one-half feet gauge stock for Costa
Rica, Nicaragua, Canada, and Australia.
Locomotives for single-rail railroads were built in 1878 and early
in 1879, adapted respectively to the systems of General Roy Stone
and Mr. W. W. Riley.
In 1870, in some locomotives for the Kansas Pacific Railway, the
steel tires were shrunk on without being secured by bolts or rivets
in any form, and since that time this method of putting on tires has
been the rule.
In 1871 forty locomotives were constructed for the Ohio and Mis-
sissippi Railway the gauge of which was changed from five feet six
cxxiv. HISTORY OF THE STEAM-ENGINE.
inches to four feet eight and one-half inches. The entire lot of forty
locomotives was completed and delivered in about twelve weeks.
The gauge of the road was changed on July 4th, and the forty
locomotives went at once into service in operating the line on the
standard gauge.
The product of the works, which had been steadily increasing for
some years in sympathy with the requirements of the numerous
new railroads which were constructing, reached three hundred and
thirty-one locomotives in 1871, and four hundred and twenty-two in
1872. Orders for ninety locomotives for the Northern Pacific Rail-
road were entered during 1870–71, and for one hundred and twenty-
four for the Pennsylvania Railroad during 1872–73, and mostly
executed during those years. A contract was also made during
1872 with the Veronej-Rostoff Railway of Russia for ten locomo-
tives to burn Russian anthracite coal. Six were Moguls, with
cylinders nineteen by twenty-four, and driving-wheels four and one-
half feet diameter; and four were passenger locomotives, “American”
pattern, with cylinders seventeen by twenty-four, and driving-wheels
five and one-half feet diameter. Nine “American” pattern locomo-
tives, fifteen by twenty-four cylinders, and five-feet driving-wheels,
were also constructed in 1872–73 for the Hango-Hyvinge Railway
of Finland.
Early in 1873 Mr. Baird sold his interest in the works to his five
partners, and a new firm was formed under the style of Burnham,
Parry, Williams & Co., dating from January 1st of that year. Mr.
John H. Converse, who had been connected with the works since
1870, became a member of the new firm. The product of this year
was four hundred and thirty-seven locomotives, the greatest in the
history of the business. During a part of the year ten locomotives
per week were turned out. Nearly three thousand men were
employed. Forty-five locomotives for the Grand Trunk Railway
of Canada were built in August, September, and October, 1873, and
all were delivered in five weeks after shipment of the first. As in
the case of the Ohio and Mississippi Railway, previously noted,
these were to meet the requirements of a change of gauge from five
and one-half feet to four feet eight and one-half inches. Two
Consolidation locomotives were sent in September, 1873, to the
Mexican Railway. These had cylinders twenty by twenty-four;
driving-wheels forty-nine inches in diameter; and weighed, loaded,
HISTORY OF THE STEAM-ENGINE. CXXV
about 95,000 pounds each, of which about 82,000 pounds were on
the driving-wheels. These engines hauled in their trial trips, with-
out working to their full capacity, five loaded cars up the four per
cent. grades of the Mexican Railway. In November, 1873, under
circumstances of especial urgency, a small locomotive for the Meier
Iron Company of St. Louis was wholly made from the raw material
in sixteen working days.
The financial difficulties which prevailed throughout the United
States, beginning in September, 1873, and affecting chiefly the rail-
road interests and all branches of manufacture connected therewith,
have operated of course to curtail the production of locomotives
since that period. Hence, only two hundred and five locomotives
were built in 1874, and one hundred and thirty in 1875. Among
these may be enumerated two sample locomotives for burning
anthracite coal (one passenger, sixteen by twenty-four cylinders, and
one Mogul freight, eighteen by twenty-four cylinders) for the
Technical Department of the Russian Government; also, twelve
Mogul freight locomotives, nineteen by twenty-four cylinders, for
the Charkoff Nicolaieff Railroad of Russia. A small locomotive to
work by compressed air, for drawing street cars, was constructed
during 1874 for the Compressed Air Locomotive and Street Car
Company of Louisville, Ky. It had cylinders seven by twelve, and
four wheels coupled, thirty inches in diameter. Another and smaller
locomotive to work by compressed air was constructed three years
later for the Plymouth Cordage Company of Massachusetts, for
service on a track in and about their works. It had cylinders five
by ten, four wheels coupled twenty-four inches diameter, weight,
seven thousand pounds, and has been successfully employed for
the work required.
The year 1876, noted as the year of the Centennial International
Exhibition in Philadelphia, brought some increase of business, and
two hundred and thirty-two locomotives were constructed. An
exhibit consisting of eight locomotives was prepared for this occa-
sion. With the view of illustrating not only different types of
American locomotives, but the practice of different railroads, the
exhibit consisted chiefly of locomotives constructed to fill orders
from various railroad companies of the United States and from the
Imperial Government of Brazil. A Consolidation locomotive fo
burning anthracite coal, for the Lehigh Valley Railroad, for which
cxxvi HISTORY OF THE STEAM-ENGINE.
line the first locomotive of this type was designed and built in 1866;
a similar locomotive, to burn bituminous coal, and a passenger
locomotive for the same fuel for the Pennsylvania Railroad; a
Mogul freight locomotive, the Principe do Grao Para, for the D.
Pedro Segundo Railway of Brazil; and a passenger locomotive
(anthracite burner) for the Central Railroad of New Jersey, com-
prised the larger locomotives contributed by these works to the
Exhibition of 1876. To these were added a mine locomotive and
two narrow (three feet) gauge locomotives, which were among those
used in working the Centennial Narrow-Gauge Railway.
Steel fire-boxes with vertical corrugations in the side sheets were
first made by these Works early in 1876, in locomotives for the
Central Railroad of New Jersey, and for the Delaware, Lackawanna
and Western Railway.
The first American locomotives of New South Wales and Queens-
land were constructed by the Baldwin Locomotive Works in 1877,
and were succeeded by additional orders in 1878 and 1879. Six
locomotives of the Consolidation type for three and one-half feet
gauge were also constructed in the latter year for the Government
Railways of New Zealand, and two freight locomotives, six-wheels-
connected with forward truck, for the Government of Victoria.
Four similar locomotives (ten-wheeled, six-coupled, with sixteen
by twenty-four cylinders) were also built during the same year for
the Norwegian State Railways.
Forty heavy Mogul locomotives (nineteen by twenty-four cylin-
ders, driving-wheels four and one-half feet in diameter) were con-
structed early in 1878 for two Russian Railways (the Koursk
Charkof Azof, and the Orel Griazi). The definite order for these
locomotives was only received on the sixteenth of December, 1877,
and as all were required to be delivered in Russia by the following
May, especial despatch was necessary. The working force was in-
creased from eleven hundred to twenty-three hundred men in about
two weeks. The first of the forty engines was erected and tried
under steam on January 5th, three weeks after receipt of order, and
was finished, ready to dismantle and pack for shipment, one week
later. The last engine of this order was completed February 13th.
The forty engines were thus constructed in about eight weeks, be-,
sides twenty-eight additional engines on other orders, which were
constructed wholly or partially and shipped during the same period.
HISTORY OF THE STEAM-ENGINE. cxxvii
In December, 1878, the heaviest locomotive ever built at these
Works was completed for the New Mexico and Southern Pacific
Railroad (four feet eight and one-half inches gauge), an extension
of the Atchison, Topeka and Santa Fé Railway. It was of the
Consolidation type, was named Uncle Dick, and was of the following
general dimensions: Cylinders, twenty by twenty-six inches; driv-
ing-wheels, forty-two inches diameter, four pairs connected; truck-
wheels, thirty inches diameter, one pair; total wheel-base, twenty-
two feet ten inches; wheel-base of flanged driving-wheels, nine
feet; capacity of water-tank on boiler, twelve hundred gallons;
capacity of water-tank of separate tender, twenty-five hundred
gallons; weight of engine in working-order, including water in
tank, one hundred and fifteen thousand pounds; weight on driving-
wheels, one hundred thousand pounds.
This locomotive was built for working a temporary switchback
track (used during the construction of a tunnel) crossing the Rocky
Mountains, with maximum grades of six in one hundred. Over
these grades the engine hauled its loaded tender (forty-four thou-
sand pounds) and nine loaded cars (each forty-three thousand
pounds): total load, exclusive of its own weight, four hundred and
thirty-one thousand pounds. On a grade of two per cent, it hauled
a train weighing nine hundred and sixty-five thousand pounds, and
on one of three and a half per cent, five hundred and seventeen
thousand pounds. Curves of sixteen degrees occurred on the
switchback track, but not in combination with the six per cent.
grades.
The production during the sixteen years from 1872 to 1888 inclu-
sive was as follows: º
1872 gº sº dº 422 locomotives.
I873 . . . 437 4 &
I874 º de dº 2O5 &&.
1875 * > sº sº I 30 &
1876 gº º © 232 6&
1877 * ſº sº 185 <&
1878 & •º sº 292 46
1879 e ſº gº 398 &&.
I88O gº sº e 5 I 7 £6
I88.I . . . 555 44
cxxviii HISTORY OF THE STEAM-ENGINE.
I882 e g © 563 locomotives.
1883 & © te 557 4&
1884 & tº e 429 6&
1885 tº Ç 242 &&
I886 wº © e. 550 6&
1887 tº e º 653 & 4
I888 e tº ſº 700+ “ (partly estimated.)
res- r * r *.
FREIGHT LOCOMOTIVE, “MOGUL * TYPE.
The year 1888 is marked by the largest production in the his-
tory of the Works, and the character of the product reflects the
growing demand for larger and more powerful locomotives.
* Compare this with the following: In 1838 the United States Government made a
request for statistics of steamboats, locomotive, and stationary engines, with the following
result:
8oo e * tº Steamboats,
35O tº © tº Locomotives, and
I861 º * e Stationary Engines.
Of the latter 383 were in Pennsylvania, and Louisiana came second on the list, 274,
which were used chiefly on the sugar plantations. Massachusetts came next with 165;
New York, 87; Ohio, 83; the rest distributed among the States. The 8oo steamboats
were either all coasters or river boats, and although the Savannah, built in New York in
1819, had been the first to cross the Atlantic, there was not one classed as an ocean
steamer. The largest was a government vessel, The AWatchez, 860 tons measurement,
300 horse-power. There were 350 locomotives reported, 90 of which were in Pennsyl-
vania; Massachusetts, 37; Virginia, 34; New Jersey, 32; Maryland, 31; New York,
28; South Carolina, 27. No other State had more than Io owned within its limits.

HIGHEST SPEED ATTAINED BY LOCOMOTIVES.
ENGLAND–THE HIGHEST RAILROAD SPEED TILL AUGUST 6, 1888.
An Edinburgh despatch to the New York Times says: Flying
Scotchman has been beaten by the West Coast Flyer. When
the London and Northwestern, or West Coast Express, ran into
Edinburgh Station at 5.52 this evening, it broke all previous records
of high railroad speed, not only for England, but in the railway
world in general. This was the first day of the great 400-mile race
between two of the biggest English Companies, and the faster train
of the two traversed the greater part of that distance at a speed of a
mile a minute.
Competition between the Great Northern and West Coast Com-
panies began to grow lively a year ago, when the former, by adding
third-class compartments to its Edinburgh limited express, took
away the third-class passengers which the Northwestern had
hitherto carried on trains going at a somewhat slower speed. Since
that time the contest for Edinburgh travel has been active.
For the summer traffic, which is always very large, the Great
Northern in June reduced its schedule time to 8% hours. The
West Coast Line met this figure July 1. Competition in England
always cuts time and never cuts rates. Two weeks ago the Great
Northern made a further cut to 8 hours and its rival followed suit.
Great Northern trains began running in on the new schedule last
Wednesday, but the West Coast did not begin until to-day. As the
Flying Scotchman on the old 9-hour schedule was the fastest
train in the world, the interest taken in to-day's race between the
two trains, when both were sent through in 8 hours, was naturally
great in railway circles and everywhere else.
In company with Assistant Superintendent Turnbull, of the West
Coast Line, and William Acworth, railway expert of the London
Times, I entered a first-class compartment at Euston this morning
just before Io o'clock. The West Coast was the better line to go
by. It only had to get through in the same time to win, as its
longer route compels it to make I mile per hour more than the
*, (cxxix)
CXXX HISTORY OF THE STEAM-ENGINE.
Scotchman. The 2 trains pulled out at the same moment, the
Scotchman from Kings Cross and the West Coast from Euston.
Everybody in our compartment flourished a watch. We could not
time the rival train, but we were sufficiently interested in keeping
view of our own iron horse, as that capable animal probably
travelled faster than any locomotive ever did before for a continuous
run. The engine had a single pair of driving-wheels, 7 feet 6 inches
in diameter, and weighed 27 tons. It burned 24 pounds of coal
per mile during the run. The tender, loaded, weighed 25 tons.
Behind it were 4 coaches filled with passengers, making a weight
of 20 tons each, or 80 tons in all. We started slowly. The run to
Tring was up-grade, the steepest portion being a rise of I foot in
70. This distance, 31% miles, was covered in 40 minutes. Once
over the hill, the engineer woke up and began to show his mettle.
The speed was increased steadily until our hair began to stand on
end. Telegraph poles began to seem like fence posts and the road-
side a medley of objects hard to distinguish. We knew we were
going over 60 miles an hour, but were not prepared for the an-
nouncement that the speed was 72 miles. Mile-post after mile-post
was registered at 50 seconds, by our watches, and the 15 miles from
Tring to Bletchley took exactly 12 minutes and 30 seconds. With
a speed varying between 72 miles and that, we flew over the flat
land, the spirits of the party naturally heightened by the novel expe-
rience after the first tendency to hang on to something wore off.
Fears now began to be entertained that we were going to stop at
Rugby, as is usual with this train. The general desire was to keep
straight on to Crewe, 158 miles, without halt, according to schedule,
and the fears of a stop at Rugby arose only from the fact that we
were several minutes ahead of time. Rugby was passed without
halt, however, the 82% miles from Euston having been done in 92
minutes. The same speed was kept up and Tamworth, IOO miles,
was reached in two hours. The run of 95 miles from Tring to Tam-
worth was made in IOO minutes, which was considered pretty good.
From Tamworth to Crewe took 58 minutes for 48 miles, and we
ran into the latter station at I 2.58, two minutes ahead of the schedule
time. This run of 158 miles, without a halt, in 2 hours and 58
minutes, is the longest known to any schedule, being I 2 miles
longer than the Fort Wayne and Chicago run. Water was, of
course, taken in from the track.
HISTORY OF THE STEAM-ENGINE. cxxxi
At Crewe we spent five minutes, exchanging our single-wheel
driver for a 32-ton engine, with two pairs of driving-wheels. The
moment we pulled out of the station it became evident that the en-
gineer proposed to show what he could do. The landscape began
to fly by us at an unprecedented rate, and watches began to regis-
ter from 48% to 48 seconds for the following miles. This meant'
from 73% to 75 miles per hour. This speed was kept up for 8 or
IO miles, when the engineer, contented with his spurt, eased down
to 60 miles an hour. From Hartford to Warrington we ran I2%
miles in I 194 minutes. Warrington to Wigan, 12 miles, we did in
II minutes. The engineer was allowed 58 minutes to make the run
of 51 miles from Crewe to Preston, but he cut under the schedule
and ran into Preston in exactly 51 minutes, an average of a mile a
minute from platform to platform.
We spent 20 minutes at Preston for luncheon, leaving there at
2. I 8. Once out of town we clapped spurs to our animals and rose
to 73 miles per hour. The run from Preston to Oxenholme, 4o
miles, was made in 42 minutes, the last ten miles being up grade.
A heavy grade of 75 feet was met at Teebay Junction, but we did
the 5% miles to Sharp Summit in 8% minutes, this being at the
altogether miserable run of 37% miles per hour. Once over Sharp,
however, we began to do 72 miles an hour again, and flew along
down grade at this rate for IO miles, when we slowed down and
lounged along at the comfortable pace of 60 miles. A little rise
caused further diminution, but the 31 miles, from Sharp to Carlisle,
was done in 31 minutes. At Carlisle IO minutes were spent and
the engine changed for another with one pair of large drivers. As
before, this was an engine specially constructed and which was ex-
hibited in the Edinburgh Exhibition of 1886. With this we went
to Beattock, 39% miles, in 39 minutes, now having rain against us
and a wet track. From Battock the IO-mile climb to Summit, on a
grade one in eighty, was done at the rate of 44% miles per hour.
Over the Summit the speed rose to 67% miles, and the next 13%
miles took only 12 minutes. The 24 miles from the Summit to
Carstairs was done in 22 minutes, and at a slightly less rate than
a mile a minute we finished the 27% miles to Edinburgh. We ran
into the station at 5.52 o'clock, 8 minutes under the schedule. The
IOI miles from Carlisle had been covered in IO4 minutes, over a
pass I,015 feet high, and this run is simply unprecedented in rail-
way annals.
cxxxii HISTORY OF THE STEAM-ENGINE.
The entire distance covered was 400 miles, and the actual time,
including stops, was 7 hours and 25 minutes, an average of 53;
miles per hour. This has never been approached before for so long
a run. The fastest continuous record in England hitherto was that
of the special train which took the Prince of Wales from Liverpool
to London, 200 miles, in 3 hours and 59 minutes, an average slightly
over 57 miles.
After we arrived the Flying Scotchman thundered into the Wav-
erly station. We had beaten it, however, not only 7 minutes in
time, but 8 miles in distance, and this 8 miles superiority on the
West Coast will continue as long as present schedule holds, which
will be for several months at least. It is now said that Great North-
ern will cut to 7% hours. I do not think it likely, however, as
there is a large conservative party among the directors opposed to
any faster speed. Consequently the West Coast train will bear off
the palm henceforth.
Despite the fearful speed, the journey was not at all unpleasant.
The jostling and lateral motion seemed no greater than when going
at an ordinary speed. The sight from the windows was very un-
usual, however. Trains coming at full speed from the opposite di-
rection went by with a crash like a volley of musketry and were
indistinguishable brown-colored masses seen only for a moment.
A short tunnel was like a gas jet, suddenly extinguished and sud-
denly relighted, the eye not having time to accustom itself to the
darkness. Long tunnels were passed through with a booming roar
and a continuous shower of sparks. Against the blackness it was
quite like an effect in fireworks. There was no more danger in the
trip than in one at the ordinary speed, and the only noticeable dif-
ference was a slight shakiness of the legs upon getting out. All
the passengers bore the trip well except one lady, and the eight-
hour express, which will continue through the summer months, will
undoubtedly be a popular train.
[From the Philadelphia Evening Telegraph, August 8, 1888.]
AMERICA’s SPEED RECORD.
- The liveliest interest was manifested yesterday by railroad men in
the cable account of the race between the Flying Scotchman and the
West Coast Flyer from London to Edinburgh, in which 400 miles
were covered by the winner in 7 hours and 25 minutes. This was
HISTORY OF THE STEAM-ENGINE. cxxxiii
an average of something over 53% miles an hour. There was a
general jogging of memories and overhauling of the records of fast
railroad trains on American lines. And much comfort was found
by many in going over those records. For they show that, although
the British and French roads admitted make much better time
habitually than is made on any of the American lines, some aston-
ishing and sustained rates of speed have been attained here, when
special efforts were expended with that end in view.
The best run on record in this country which can be fairly com-
pared with the English run was made over the West Shore Road
from Buffalo to New York on July 9, 1885, when 426 miles were
covered in 7 hours and 27 minutes. Quite a large number of rail-
road men, including officials of the Baltimore and Ohio, Wabash,
Grand Trunk, and West Shore Roads happened at Buffalo together
en route for New York. It was decided to see how quickly they
could move over the new road. At the start the railroad men had
their watches out, and soon the mile-posts were flying past every 43
seconds. That speed was held so steadily that the greater part of
the run was made at the rate of 45 seconds to the mile, or from 7o
to 83 miles an hour. From East Buffalo to Genesee Junction, 61
miles, took 56 minutes; from East Buffalo to Newark, 93.4 miles,
97 minutes; from Alabama to Genesee Junction, 36.3 miles, 3o
minutes. The 97 minutes to Newark included stops of 9 minutes,
making the actual running time for the 93.4 miles 88 minutes.
From Newark to Frankfort, where the conditions for running were
not so good as before, the run of IO8.3 miles was made in 134
minutes, including 17 minutes for stops. From East Buffalo to
Frankfort, 202 miles, the time was 240 minutes, of which 35
minutes were consumed in stops.
On the New York Central Road a newspaper train with two cars
weighing sixty tons hauled into Syracuse Sunday morning, August
8, 1886, at IO o'clock, an hour late. The train was booked to go
from New York to Buffalo in nine and one-half hours. Orders
came to try and make up for the time on the further run of 148.7
miles to Buffalo. John W. Cool, ane of the best engineers on the
road, mounted his cab bound to obey the order. He started out at
54% miles an hour. At the end of three miles his speed increased
to 66 miles an hour, and then to 74%. He stopped at Rochester
for water and slowed up after passing Crittenden. His average
cxxxiv. HISTORY OF THE STEAM-ENGINE.
speed from Syracuse to Rochester was 67% miles per hour; from
Rochester to Buffalo, 63.72 miles per hour, and from Syracuse to
Buffalo, 65.6 miles an hour. The run of 148.7 miles was made in
I36 minutes.
The most remarkable long-distance run on record was when the
Jarrett-Palmer combination went from New York to San Francisco
in half time, or three and one-half days. Their train left the Penn-
Sylvania station in Jersey City at 12.53 on the morning of June 1,
I876. They were not to make a stop until they reached Pittsburg.
An engine and baggage-car, on the approach of the special to Har-
risburg, got up a speed of about 50 miles and passed mails to the
special by running along an adjoining track for several miles while
the mail-bags were thrown from train to train. The run to Pitts-
burg, 438% miles, took IO hours and 5 minutes, an average of 43%
miles an hour, notwithstanding the Alleghenies. From Pittsburg to
Chicago, 458.3 miles, took I I hours and 6 minutes, an average of
42. I miles, including twenty-five stops and four changes of engines.
From Chicago to Council Bluffs, 491 miles, took I 194 hours, an
average of 42.6 miles, although there was a record for part of this
journey of 62.2 miles. Over the Union Pacific the run of 1032.8
miles from Omaha to Ogden was made in 24 hours and 14 minutes,
at an average of 41 miles and a maximum of 72 miles an hour.
The brakes became worn at Ogden and hand-brakes had to be used,
retarding the onward journey somewhat, as the men feared that
they might lose control of the train. San Francisco was safely
reached at 12.57 on June 4th, quite in time for the dinner that had
been ordered for the company for that day. The last stage of the
journey was run at an average of 37 miles. During the entire run
20 engines were used, there were 72 stops, and the running time for
33.13% miles was 84 hours and 17 minutes, an average of 40 miles
an hour.
"On the Pennsylvania Road forty-five miles an hour is not uncom-
mon, and there are level stretches where a speed of a mile a minute
is attained. Samuel Carpenter, the General Agent of the road,
said yesterday that if there was any need of making time to com-
pare with the new English schedule, it could be done. On the New
York Central Road the run of eighty miles from Rochester to
Syracuse has been made in eighty minutes when it was necessary to
make up lost time. Assistant Superintendent Voorhees, of the New
HISTORY OF THE STEAM-ENGINE. CXXXV
York Central, said that he stood ready any day to send a party from
New York to Buffalo, 440 miles over that road, in the same time
made by the English racer for 400 miles, if the party would pay
two dollars per mile to get there in seven hours and twenty-five
minutes.
| Professor Arthur T. Hadley, of Yale, when interviewed upon the
subject, said that he had been at work during a portion of the day
in order to go over some of the best American railroad records.
The result of his examination, he says, shows that the claim made
by the Englishmen that the run made August 6th between Edin-
burgh and London broke all previous records for high railroad
speed in England and the railroad world cannot be supported by
fact. -
LINES TO A LOCOMOTIVE.
[Written by Hon. WILLIAM D. Lewis, of Philadelphia, about 1840.]
Sublimest courser of the plain,
Whom toil can neither daunt, nor tire,
Onward thou bear'st thy lengthened train,
With iron nerves and lungs of Fire.
Boldest exploit of daring man,
Whose restless and impatient mind
Infringes Mature's general plan,
And leaves with thee the Winds behind.
No match for thee in airy race,
The Eagle born on sounding wings—
Starfled, he views thy Lightning pace,
Most wondrous of Earth's wondrous things.
As some bright Meteor of the sky,
Or some unsphered and shooting star,
Thou, Locomotive, seems to fly,
Beheld by dazzled eyes afar.
Science and skill their aid impart;
Trained, hills to level, valleys rear;
Thy pathway smoothed by laboring art,
To urge thee in thy swift career.
cxxxvi HISTORY OF THE STEAM-ENGINE,
Ot, then, Majestic, Mighty Steed,
Speed thy fast flight from clime to clime;
To thee the glorious task decreed,
To cancel Space, to vanquish Time.
THE SONG OF STEAM.
[G. W. CUTTER. Born in Cincinnati, in 1818. A captain in the United States army
during the invasion of Mexico.]
Harness me down with your iron bands,
Be sure of your curb and rein ;
For I scorn the power of your puny hands,
As the tempest scorns a chain
How I laughed as I lay concealed from sight
For many a countless hour,
At the childish boast of human might,
And the pride of human power!
When I saw an army upon the land,
A navy upon the seas,
Creeping along, a snail-like band,
Or waiting the wayward breeze;
When I marked the peasant fairly reel
With the toil which he faintly bore,
As he feebly turned the tardy wheel,
Or tugged at the weary oar—
When I measured the panting courser's speed,
The flight of the courier-dove,
As they bore the law a king decreed,
Or the lines of impatient love,
I could not but think how the world would feel
As these were outstripped afar,
When I should be bound to the rushing keel,
Or chained to the flying car !
Ha! haſ haſ they found me at last ;
They invited me forth at length;
And I rushed to my throne with a thunder-blast,
And laughed in my iron strength !
HISTORY OF THE STEAM-ENGINE. cxxxvii
Oh! then ye saw a wondrous change
On the earth and ocean wide;
Where now my fiery armies range,
Nor wait for wind or tide.
Hurrah! hurrah! the waters o'er
The mountain's steep decline;
Time—space—have yielded to my power;
The world—the world is mine !
The rivers the sun hath earliest blest,
Or those where his beams decline,
The giant streams of the queenly West,
And the Orient floods divine.
The ocean pales where’er I sweep,
To hear my strength rejoicel
And the monsters of the briny deep
Cower, trembling at my voice.
I carry the wealth to the lord of earh,
The thoughts of his god-like mind;
The wind lags after my flying forth,
The lightning is left behind.
In the darksome depths of the fathomless mine,
My tireless arm doth play;
Where the rocks never saw the sun's decline,
Or the dawn of the glorious day.
I bring earth's glittering jewels up
From the hidden cave below,
And I make the fountain's granite cup
With a crystal gush o'erflow.
I blow the bellows, I forge the steel,
In all the shops of trade;
I hammer the ore and turn the wheel,
Where my arms of strength are made.
I manage the furnace, the mill, the mint;
I carry, I spin, I weave;
And all my doings I put into print
On every Saturday eve.
cxxxviii HISTORY OF THE STEAM-ENGINE.
I've no muscles to weary, no breast to decay,
No bones to be laid on the “shelf;”
And soon I intend you may “go and play,”
While I manage this world myself.
But harness me down with your iron bands,
Be sure of your curb and rein; -
For I scorn the strength of your puny hands,
As the tempest scorns a chain
STEAM—YACHT ATALANTA, constructED BY MESSRS, WM. CRAMP &
SONS, SHIP AND ENGINE BUILDERS, PHILADELPHIA.

MODERN STEAM PRACTICE
AND ENGINEERING.
COAL AND CO AL - M IN IN G.
COAL is the primary source of our commerce and manufactures,
by enabling steam-power and machinery to be produced at the
most economical rate. The economical importance of the coal
deposits in England and Scotland is much enhanced by the rich
beds of iron ore found in their associated shales, as well as in the
contiguity of the carboniferous limestone which is required to assist
in reducing the ore to a metallic state, not to speak of the lesser
advantage of the proximity of the fire-clay, which furnishes the
only material for building blast-furnaces capable of resisting the
heat of the smelting process. The varieties of coal usually met
with are anthracite, caking-coal, Cherry-coal, splint-Coal, and
cannel-coal.
För manufacturing purposes coals are generally considered to
consist of two parts—a volatile or bituminous portion, and a sub-
stance comparatively fixed, and usually known by the name of coke.
This latter form of coal is extensively used in locomotive engines
on railways, in consequence of its yielding no smoke, the volatile
matter, or that which forms the smoke of coal, being removed by
ignition. As the bituminous or volatile part of coal yields the gas
used for lighting, it has been found that the heating power of the
coal resides in the coke, and no heat is lost by first extracting the
gas from coal by the usual methods of burning, or rather distilling
coal.
Coal is deposited in beds more or less horizontal, although some-
times by movements of the earth's crust their position has become
much inclined. The great coal-field of Britain, which is composed
of numerous subordinate coal-fields, Crosses the island in a diagonal
direction, the south boundary line extending from near the mouth
of the river Humber, upon the east coast of England, to the south
l
2 MODERN STEAMI PRACTICE.
part of the Bristol Channel on the west coast; and the north boun-
dary line extending from the south side of the river Tay in Scot-
land, westward by the south side of the Ochil Hills, to near
Dumbarton upon the river Clyde; within these boundary lines
North and South Wales are included. This area is about 260 miles
in length, and on an average about 150 miles in breadth. Coal
also occurs in other formations of later geological age; but none of
these later deposits equal in economical importance the rich stores
of the carboniferous system in our island. Beds of coal are found
in most European countries, as also in China, India, Australia,
Japan, and Borneo; but the coal-fields of the United States of
America are by far the most extensive and richest in the world.
Boring in search of coal is an important branch of mining. In
ordinary practice the boring plant consists of shearlegs, windlass,
brake, brace-head, bore-rods, cutting tools, &c. Steam-engines
specially adapted for boring have also been devised. A very simple
method with hollow rods combined with a force-pump was intro-
duced by M. Fauvelle in 1846.
The “troubles” met with in working coal are various:–for
example, a “want” or “nip” is, as its name suggests, a part of the
field where no coal exists, or only in a very thin streak; if this
streak is followed, however, the coal seam will again be found.
“Dykes” are generally of whin, projecting from below. It rarcly
happens that the coal is either elevated or depressed by this
“trouble,” but it is much burned and rendered useless for some
yards on either side. A “step ’’ or “fault” is a dislocation, some-
times of considerable magnitude, by which the strata are elevated
or depressed many fathoms. A “hitch" is of the same nature as
a “step,” but on a smaller scale. A whin bed is perhaps the worst
kind of “trouble" to be met with, as, when found near to and
parallel with a coal-seam, it renders the entire bed useless. When
a miner mects with a “step" or a “hitch" he at once knows
whether it is an “up throw" or a “down throw.” If a “hitch" lies
off at the top, by following the rise upwards he will find the coal;
if off at the bottom, he must follow the dip downwards. Although
it is both annoying and expensive to meet with these “troubles,”
they often serve useful purposes: “steps,” for instance, sometimes
elevate the coal from a depth that would be difficult to reach by
ordinary means to a depth of comparatively easy working. Again,
when a coal-seam is nearly cropping out, a “step" is met with
COAL AND COAL-MINING. 3
#
that throws it down, in this way extending the field. Again, whin
dykes serve the purpose of dams, and prevent water passing from
one “waste” or worked-out space to another.
It is also of importance to fix on the best position and form for
the pits. Where much water may be expected, the best form for
the pit-shaft is circular, so that the water met with in sinking may
be kept back by tubbing; that is, lining the shaft with suitable
material, such as stone, timber, or cast-iron, the latter being pre-
ferred. When the pressure of water is great, sometimes the tub-
bing is formed of half rings, so as to fit the shaft; but where pumps
and brattices interfere, segments of cast-iron are used, about 4 feet
in length and 2 feet in height, and from 3% of an inch to I inch in
thickness. The segments are made to form a smooth surface in
the shaft, and they are fitted to each other by means of flanges,
3 to 4 inches at each end, and the spaces between the segments
are filled up with thin deal. Stone tubbing is merely common
walling, with the foundation made tight by means of grooves cut
in the stone, the joints and backing being filled up with cement,
which, if carefully executed, will answer for light purposes; but the
success of this method of tubbing is of too precarious a nature to
meet with general application for important works, and wood or
iron is preferred. It sometimes happens in sinking pits that all the
wells and springs in the neighbourhood are drained off, but this evil
may be prevented by tubbing the shaft.
Some pits are sunk at great expense, owing to the nature of the
strata which have to be passed through, and other difficulties, as,
for example, a heavy flow of water. Such instances occur in the
north of England, as at Pemberton's Pit, Monkwearmouth, near
Sunderland, and a pit at Seaham near Durham, which is 3OO
fathoms deep and cost the enormous sum of £ IOO,OOO. Before the
steam-engine was introduced, the coal-pits capable of drainage with
hydraulic machinery or water-engines were Comparatively few in
number; and when drained by wind-mills, as was sometimes the
case, the pits were drowned in calm weather. The driving of day
levels was thus a primary object with the early miner; and this
system of draining is the cheapest where circumstances allow of its
adoption. The day levels were often of sufficient dimensions to
admit of roads, and even in some cases of canals, being formed in
them, so that machinery was not required. In modern times, how-
ever, the water is pumped from great depths by steam power, the
4. MOLERN STEAM PRACTICE.
single-acting Cornish pumping engine, having a beam with the
steam cylinder at one end and plunger or force pumps at the other,
being extensively used. Sometimes lift or bucket pumps are
introduced, while in other cases both plunger and lift are combined
in a single barrel. Some of these engines work direct, the pump
rods being attached at once to the piston-rod over the pit.
The deleterious air met with in mines is of two kinds, the one
being heavier and the other lighter than atmospheric air;--the
natural consequence of which is that the heavier gas rests in the
lower parts of the mine, while the lighter ascends to the higher
parts. The heavier is carbonic acid gas, known to the miners by
the names of “choke-damp,” “black-damp,” and “stythe,” the
lighter gas is carburetted hydrogen, commonly called “fire-damp,”
or inflammable gas. Where the former gas has been allowed to
accumulate there is great difficulty in getting it expelled. In coal
mines it is seldom present except as “after-damp,” and is the
result of a preceding explosion. No light will burn in this gas.
We have seen a fire-lamp, with about 3 cwt. of coal in full blaze,
burning in a pit where choke-damp filled the bottom, as completely
extinguished as if it had been plunged in water. At times, though
seldom, the coal has been known to catch fire in mines, and burn
for years; in such cases carbonic acid gas has been successfully
applied in extinguishing these fires.
Carburetted hydrogen or “fire-damp,” the lighter gas, is not
explosive until mixed with atmospheric air. According to experi-
ment, the mixture most explosive is I of gas to 6 of atmospheric
air; when it is I to 14 a candle burns in it, but with a flame much
elongated. Many of the fearful explosions and attendant loss
of life occasioned by this gas arise from carelessness. Some
obstruction in the air course is allowed to take place, a door has
been left open all night, or a miner enters his room with a safety-
lamp in his hand, but has neglected to remove the open lamp from
his cap; even some of the miners are so fool-hardy as to light their
tobacco-pipes by drawing the flame through the wire gauze, thus
igniting the gas. We need not impress upon all workmen the great
danger arising from such carelessness.
The electric light is being experimented with at present as an
illuminating medium for coal workings. The great difficulty in
fiery mines being the risk of explosion arising from lights, it
becomes an important matter to devise methods to meet this danger.
COAL AND COAL-MINING. 5
The Davy lamp does not emit a strong light; hence if it can be
proved that the electric light will not set fire to the inflammable
gases of the mines in the event of accidental breakage of the
protecting glass globes, its intense light should prove very valuable
to the miner.
It has been found by experiment that the presence of coal
dust in the workings contributes much to the risk of explosions;
and it seems certain that if 3 per cent. of gas exists in the air
of a mine which is thoroughly mixed with coal dust, an explosive
mixture is formed. Mines should have at least two shafts, one
of which serves to admit the pure air, while the foul gases escape
by the other. The ascent of these gases is facilitated by creating
a draught by means of a furnace at the bottom of one of the shafts
or by fans driven at a high speed placed at top. This shaft
is called the upcast shaft; the downcast shaft, which may be within
a few yards of the other, allows the fresh air to pass down to the
workings, to the faces of which it is directed by partitions of wood
or canvas called “brattices.” The air in its circuit below will
travel several miles.
The Coal lies in parallel layers, between which the gas exists in
a highly compressed state. In order to detach these layers with
the least possible danger, it is usual to cut through them endways,
by which means the gas is allowed to make its escape at once from
a considerable portion of the coal. From observation of some
mines it is seen that discharge of fire-damp, though governed by
atmospheric pressure, takes place before being indicated by the
barometer, so that, as an indicator, that instrument cannot be relied
on. As before said, the explosion of “fire-damp” in a mine results
in an accumulation of the dangerous “after-damp,” and more lives
are lost by it than by the explosion itself. . It has the appearance
of a dense misty vapour, and resists the application of ventilation
in an extraordinary manner. It benumbs the faculties and deprives
the miner of all presence of mind, so that, instead of rushing at
once to the pit bottom, if he has escaped the fire, he gets bewild-
ered, and a deadly lethargy comes over him, ending in sleep from
which he never awakes. It is rare to find choke-damp and fire-
damp in the same workings, or if they do occur it is only in small
quantities.
* A mixture of carbonic acid and other products of the combustion of the carburetted
hydrogen.
MODERN STEAM PRACTICE,
viz. pump and centrifugal.
Waddle, and Schielé.
The only effectual means of preventing accidents from these
gases is a complete system of ventilation by air-courses through
the mine. This ventilation is maintained either by the natural heat
of the mine; by mechanical appliances, as pumps, fans, or pneu-
matic screws—either forcing air into the downcast shaft or exhaust-
ing it from the upcast shaft, by water falling constantly down the
downcast, or by furnaces placed at the bottom of the upcast.
For-
merly furnace ventilation was considered to be the most efficient
and reliable mode of ventilating very deep pits.
The distance of
the furnace from the bottom of the upcast shaft is a point of impor-
tance, 30 to 40 yards being a common distance.
The fans used for ventilation may be divided into two kinds,
º
|
%
%
§
\
j
N
&-
- s
NºN W
Fig. 1.-Side Elevation of Guibal Fan.
A A, Rotating Fan. B, Discharge Orifice. C, Outlet.
In the first class are the Struvé, Nixon,
Lemielle, and Roots; and in the second class the Guibal, Rammell,
Mechanical ventilators of the fan descrip-
tion appear in Some cases to effect a saving of about 50 per cent.

COAL AND COAL-MINING. 7
over the furnace system, and the useful effect of a good fan seems
to be from 40 to 60 per cent of the power employed. The quan-
tity of air discharged varies with the size of the fan and the speed
of rotation. In some of the centrifugal fans of about 16 feet
diameter, the quantity of air in cubic feet per minute passed
amounts to from 40,000 to 50,000, and in larger fans of 30 to 50
feet diameter, 100,000 to 200,000 cubic feet per minute may be
discharged. In the Schielé fan the speed is very high, I 50 to 300
revolutions per minute, the diameter being smaller than some of
the other forms, such as the Guibal, which is generally of a larger
diameter with a less velocity of rotation, say about 90 revolutions
per minute. An engraving of the Guibal fan, which is now largely
used, is shown in Fig. I.
As a general rule no mine should have a ventilating power of
less than IOO cubic feet per minute for each man and boy employed
in the underground passages, and in mines making large quantities
of fire-damp a ventilation equal to from 200 to 600 cubic feet per
minute per man should be attained.
The common methods of working coal in this country are “long-
wall” and “stall and pillars,” with a modification of the latter called
“rances.” By the “long-wall ” system all the coal is excavated,
and it is the most profitable way of working. Before starting any
coal “long-wall,” however, there are several circumstances to be
considered, such as the nature of the roof, the property that might
be injured by the subsidence of the superincumbent strata, and so
on. In the “stall and pillar” system there is a great sacrifice of
coal, generally about one-third, but often nearly one-half; this plan,
therefore, should never be adopted if the coal can be worked “long-
wall.” Pillars are often left large or worked in “rances,” with the
intention of being afterwards removed; but this plan does not
always succeed. Large as the pillars may be, they often sink into
the pavement if it is soft, and cause a “creep,” which shatters the
coal, besides forcing the soft pavement up to the roof in the roads and
rooms or stalls, and the contemplated removal of the pillars is thus
frustrated. The edge seams of coal are worked “long-wall” in some
cases, and “stall and pillar” in others. Instead of the pits being
sunk straight down, inclined shafts are driven through the bed of
coal, with rooms branching Uff from either side of the incline, and
to work these the men stand on the coal as a floor, having the coal
also as the roof. In the shaft, instead of a cage and slides, there is
8 MODERN STEAM PRACTICE.
a tramway, with trucks capable of holding two hutches or small
waggons in each, the tramways being laid double in order to
balance the engine, one truck ascending and the other descending,
as in ordinary vertical shafts. These trucks have likewise boxes
fitted for drawing the water, the mechanism for doing so being
self-acting.
The method now universally adopted for bringing the coal to the
Surface is by a steam-engine having a drum on which the wire ropes
are wound, the drum being sheathed with wood; the cages or frames
for holding the hutches or small waggons being attached to the
other end of the wire ropcs, which are so arranged that one cage is
descending with an empty hutch, and the other ascending with a
hutch full of coal, the men descending and ascending in like manner.
The shaft has a central division all the way down, formed of timber,
to which are attached balks of the same material; balks are also
fixed to each side of the shaft, to form a guide for the cages, the
cage or iron frame having guiding pieces fitted to it. Many ingeni-
ous devices have been adopted to disconnect the cage from the rope
in case of over-winding, or to prevent the cage from being dashed
to the bottom should the rope Snap. All these plans consist of
mechanical contrivances, such as wedges, clips, eccentrics, serrated
and arranged with springs and levers, so as instantly to grip the
guides in the pit, and thus sustain the cage until the defects are
made good. On the engine shaft is fitted a worm wheel and pinion,
with an index, so that the engine tenter—who should always be on
the look out, as this index is intended to point out the approach of
the cage either way—knows when to stop the engine at the top or
bottom. All modern engines are fitted with the link motion for
actuating the slide valve; thus the man in charge of the engine
can stop and reverse instantly, and so prevent accidents from Over-
winding.
A variety of machines have been introduced for cutting and
breaking down the coal, saving the practical miner much hard
labour. These consist chiefly in an arrangement of a series of
cutters, which are made to revolve by the action of compressed air
or steam; and they answer in certain localities where the seams of
coal are of great thickness, but in many cases the miner has to lie
on his side and use the pick in that position. Machines do not
answer well in thin seams, where, after the coal is broken down, the
men have to push it out of their rooms with their feet.
COAL AND COAL-MINING. 9
The utilization of coal for raising steam has now been adopted
for many years, and the steam-engine may be called a machine
whereby the power stored in the coal may be rendered available
for the performing of mechanical work.
The history of the steam-engine, like that of other important
inventions, shows a slow and gradual development from compara-
tively simple and rude appliances to the highly finished and complex
machine of the present day.
The earliest notice which we have of the use of steam is in the
writings of Hero of Alexandria (B.C. I2O), where a rotatory steam-
engine is mentioned. In 1663 the Marquis of Worcester devised a
steam-engine for pumping water, and in 1697 Savery applied steam
to pump water out of mines. Papin in 1690 improved the earlier
rude machine, and introduced the cylinder and piston. Newcomen
in 1705 introduced the separate boiler, and through the alternate
pressure and condensation of the steam produced the atmospheric
pumping engine.
To James Watt, however, we must look as the inventor who
brought the steam-engine to be a really serviceable machine for
commercial purposes, and this mainly through his invention of the
separate condenser, whereby the steam, instead of being condensed
in the cylinder, as in Newcomen's engine, was conveyed to a
separate vessel, where, by means of a jet of water, it became Con-
densed and afterwards pumped out to be used as feed-water to the
boiler.
Attempts were made from time to time to use the steam-engine
as a propelling power for boats, and both in Europe and in America
various experiments were made. To Fulton in America and Bell
in this country, however, the credit of successfully introducing
passenger steamers must be given.
The application of steam to locomotives was attempted by vari-
ous engineers, but the successful introduction of the railway loco-
motive is mainly due to George Stephenson; the main elements of
success being the adoption of the tubular boiler and forced blast.
Steam has also been applied to road locomotive traction engines
and agricultural machinery, and, of course, in the many forms of
land engines it is still Supreme.
DOILERS FOR STATIONARY ENGINES.
DISTINCTIVE FORMS OF BOILERS.
The common cylindrical boiler with hemispherical ends is exten-
sively used for colliery engines and other places where space is no
object, and the consumption of fuel but little thought of For such
purposes it is the simplest, and, as no stays are required, the
strongest of its kind. It rests on a structure of brickwork, having
the furnace underneath, with a return flue all round; the parts ex-
posed to the action of the flame are lined with fire-brick. As there
are usually no internal flues, it is obvious that it is a very safe
boiler, having always a good, body of water over the furnace, or
fire-grate; but still it is not free from the rapid corrosion that sets in
with all boilers resting on a substructure of brickwork. Sometimes
boilers of this form have the front end quite flat, for the conveni-
ence of attaching the water gauge glass, steam-pressure gauge, &c.
Fig. 2.-Cornish Boiler with Single Furnace. Longitudinal and Transverse Sections.
A, Shell. B, Furnace, c, Fire-brick bridge. D, Flue. E, Steam dome.
The Cornish boiler differs materially from the plain cylindrical form:
both the ends are quite flat, with one internal flue running through
and through, and having the fire-grate at one end; or with one in-
ternal flue, and having the furnace underneath the boiler, with return
flues in the usual manner. Another form has two internal furnaces,
meeting in a combustion chamber. This plan of construction is
well suited for the prevention of smoke; but to attain this end the
furnaces should be fired alternately, so that one fire is quite bright,
while the other one is green, or in the act of firing. To assist com-
bustion, small tubes are introduced from the front end, passing
through the water space into the combustion chamber. Thus a

BOILERS FOR STATIONARY ENGINES. II
current of heated air mixes with the flame and heated gases, and
prevents smoke to a great extent. The simplicity of this arrange-
ment cannot be excelled, as careful firing of itself will, in a great
measure, prevent smoke, while the current of hot air, mixing with
the heated gases in the furnace, largely contributes to the same
result. The top parts of the ends are stayed with gusset pieces, con-
nected to the top and ends of the boiler, and the combustion chamber
is strengthened at the back of the furnace with one or more conical
Fig. 3.-Boiler with Double Furnaces. Horizontal and Transverse Sections.
A. Shell B B, Furnaces. C, Combustion chamber. D D, Stay tubes. E e, Flues. F, Steam dome.
tubes, with the water freely passing through them. As large flues
are weak, sometimes they are strengthened with conical tubes at
intervals; the back flue, in some cases, is divided into two smaller
ones, and the conical tubes omitted, thus leaving the flues quite
clear, so that they can be easily cleaned out. Another kind of
Fig. 4.—Combined Cornish and Multitubular Boiler. Horizontal and Transverse Sections.
A, Shell. B B, Furnaces. C, Combustion chamber. D, Small tubes. E, Stay tube. F, Steam dome.
cylindrical boiler has a number of small tubes set at the back of
the combustion chamber, thus combining, in some respects, the
Cornish with the multitubular arrangement. For low pressure
steam, and where space is an object, and when deposits from
the water are rapidly formed over the heating surface, a self-con-
tained boiler, designed by the author, has done good service. It
is fitted with one round furnace, carrying the flame and heated
gases to the back, returning to the front end through large tubes,
8 inches in diameter, and then repassing to the back through other


I2 MODERN STEAM PRACTICE.
tubes of the same diameter; then down at the back, and along the
sides and bottom, through suitable flues of brickwork, so that,
A, Shell. D D, Tubes. internally and externally, a large
B, Furnace. . - E. Smoke-box. - & {. &
C, Combustion chamber. F, Flue. amount of heating surface is ob-
A tained, and this great desideratum
is secured that all the tubes are
easily got at for repairs and scaling
off the deposits.
Thus we have noticed arrange-
ments partly self-contained, but
having external flues of brickwork,
such as are in general use. Next
comes that class which is wholly
% self-contained, the heated gases,
Fig. 5–Return Tubular Boiler. Longi after doing duty in the boiler, sim-
tudinal Section. ply going up the chimney. There
are several arrangements having all the same object in view,
namely, to economize space. By one of them an ordinary round
shell has a square furnace fitted; the flame, after doing its best duty
in the fire-box, passes through one or two large flues, crossed with
a series of conical tube stays, and the flame interlacing, as it were,
2%,
Fig. 6.—Self-contained Flue Boiler. Longitudinal and Transverse Sections.
A, Shell. B, Fire-box. cc, Flues. D, Stay tubes. E, Steam dome. F, Fire-door.
amongst them, makes a very effective arrangement, and in cases where
the water, from its impure state, rapidly forms deposit, all the parts
can easily be reached. Instead of the large flues, small tubes are
sometimes arranged, as in the locomotive boiler, so that the useful
caloric is extracted by honeycombing the water, as it were, with
hundreds of square feet of heated surface; but when very small tubes
are used, they should be of a different material from the boiler—
brass, or composition tubes, are to be preferred—thus the incrusta-
tion is in a great measure prevented. Sometimes the fire-box is
made cylindrical, having a hemispherical outside dome; by this


BoILERs For STATIONARY ENGINES. I 3
plan very few stays are required; the tube-plate, however, must be
made flat, with the back of the outside fire-box to correspond, or as it
were part of the cylindri- A.
cal portion of the fire-box,
cut away in the plan, that
part having screwed stays
in the usual manner. This
arrangement has now be-
Fig. 7.-Self-contained Tubular Boiler.
COIſle obsolete. A, Shell, B, Fire-box. C, Tubes. D, Smoke-box.
Another form exten- E, Fire-door.
sively used for general purposes is the vertical type. Such boilers
are made entirely cylindrical; some are constructed with an internal
barrel, with the smoke-pipe passing through the steam space; while
A, Shell. c, Smoke-pipe, e
B, Fire-box. D, Fire-door. Fig. 9.
A, Shell. A
B, Fire-box.
c, Tubes. #############
D, Smoke-pipe. ::
E, Fire-door.
Fig. Io. # Hº:
A, Shelf. # #####º:
B, Fire-box. : É
cc, Flues. É
D, Fire-door. B #C#
C
/
%z” '//777777.
* Fig. 8. ºf Fig. 9. Fig. Io.
Vertical Dome Boiler. Vertical Tubular Boiler. Vertical Return Boiler.
some steam generators of this kind are made very lofty, fitted with
an internal cone fire-box, and arranged in communication with the
waste heat from puddling and other furnaces, &c., and others for
general purposes have small tubes placed vertically, arranged with
the smoke-box underneath the water, and the smoke-pipe passing
through the steam space. Other arrangements have the tubes
passing to the top of the boiler, with a dry uptake; thus the tubes
can easily be inspected without disturbing the steam-tight portions
of the boiler; and the tubes are easily cleaned by simply taking off
the dry uptake, or lower portion of the funnel. The boiler-tubes


I4. MODERN' STEAM PRACTICE.
of a steam carriage for common roads having become foul with .
soot, thus impeding the draught, gunpowder was wrapped up tightly
in a piece of paper and thrown on the fire, and the fire-box door
immediately shut; a slight explosion took place, sending a cloud of
soot up the chimney, effectually clearing the tubes without stopping
the machine. Of course, it would be somewhat dangerous to carry
an explosive mixture about for such a purpose; but, in most cases,
this means of clearing the tubes can be cheaply and most effectu-
ally carried out, and there is no danger whatever, provided too
much gunpowder is not used at once. All vertical self-contained
boilers should have air tubes 34 inch in diameter, and spaced about
6 inches apart, all round the fire-box, dipping downwards, so that
a current of air may mix with the flame and heated gases at about
the level of the top of the fuel, thus tending to the prevention of
smoke; these tubes are screwed into the outside shell and the
inside fire-box, and then rivetted over.
There is one objection common to all vertical boilers, namely, that
a great portion of the heat passes directly up the chimney without
doing duty; to obviate this defect the flame and heated gases are
directed downwards with suitable flues; this plan must have separate
flues of fire-brick, with a chimney, and is not so compact an arrange-
ment as the multitubular one. The feed-water pipe passes through
the bottom flues, thus heating the water in its passage to the boiler,
and all the flues are easily reached for scaling and cleaning out.
The pot boiler derives its name from the
peculiar pot-like vessel, fitted to, and hanging
from the top of the fire-box; this spherical
generator is introduced so that the lower part,
made of copper, receives the full benefit of the
flame; the annular space between the pot and
the fire-box is made narrow, thus the flame and
łcatcd gases impinge against the sides of the
fire-box, and then pass through the small tubes
; into the chimney. The ebullition of the water in
the pot is very violent, ejecting the sediment and
3. # preventing incrustation; the deposit finds its way
# # to the bottom of the boiler, and is cleaned out by
*:::::::::::::::::... suitable sludge doors. The dry uptake can be
* Fire-door. F. Smoke Pipe easily removed, and the inside of the boiler in-
spected through the man-hole, placed exactly Over the pot, in the

BOILERS FOR STATIONARY ENGINES. I5
centre of the boiler, there being no tubes at the centre, but merely
all round the opening in the top of the pot, which is bolted to the
tube-plate by means of projecting flanges on the pot and tube-
plate.
In some cases, such as in the Fire-engine, it is a desideratum
to have a rapid steam-producing boiler; a good example is simply
an ordinary vertical boiler, having the tubes suspended inside of
the fire-box, arranged with an internal tube in each, loosely sup-
ported from the tube-plate, these small inside tubes leaving annular
spaces between them and the larger tubes, so that only a thin film
of water is exposed to the heating surface. By this means steam is
raised rapidly; but it must be borne in mind that, as the evapora-
tion of the water is very great, care must be
taken that a sufficient quantity of water is kept
up in the boiler, which would otherwise soon
boil dry. The circulation is very rapid in the
tubes. The bottoms of the tubes are hermeti- § { }
cally sealed; and as the steam is generated, ###| || =
it ascends, displacing the water in the annular
space between the inner and outer tubes, and
the water from the top circulates down the
inner tubes and fills up the cavity. The smoke-
pipe is connected to the top of the fire-box,
passing through the steam space, and is rivetted
to an angle-iron ring on the top of the boiler;
and there is an open part left in the centre of j
the fire-box where there are no tubes, this Fºllºwith sº
opening being blocked up with a lump of fire- tºº, **ś.
brick suspended by a rod from the top of the F. Fire-door
boiler, thus the flame is prevented from going directly up the
chimney, as it impinges against the fire-clay lump, and by this
means it is distributed beneficially amongst the small tubes.
Instead of a number of annular tubes, one large tube has been suc-
cessfully adopted, the arrangement consisting of an internal fire-box,
having an annular" water space all round. On the outside of this
water space there is an annular flue, and the whole is contained in
an ordinary vertical boiler, having a hemispherical top; the flame
and the gases, after doing duty in the fire-box, find their way
==-:
==
º
º:
5:
---
---
t
f
RS:
* The space between a small inner and large outer tube is called annular.




I6 MODERN STEAM PRACTICE.
through an opening into the annular flue, and then escape all round
into a flue of brickwork; thus a large heating surface is obtained.
As in the pot boiler, there is great
—n ebullition in the annular space around
- the inside fire-box, the steam escaping
into the boiler proper through a tube
É: at the top, the circulation of the water
ºr being effected by a series of small
tubes, connecting the inside and the
outside water spaces at the bottom of
the boiler. !
What are termed “water-tube”
boilers show examples consisting
N merely of large tubes, so connected
§ GN c s as to form a series of boilers, the whole
§SS being encased in brickwork. This
*...*.*.*.*.*, *... species of steam generator is capable
* * * * *** * * of sustaining great pressure, the whole
of the steam pipes and the connections being tested to about 500 lbs.
per square inch; and as they are constructed so that all the joints :
are protected from the action of the flame, they ought to be very
durable. Where space is no object they are well suited for small
powers, but for large power it is doubtful if they are so well adapted
as the ordinary Cornish arrangements, fitted with conical water
tubes in the flues. -
One arrangement of the water-tube boiler consists of a series of
tubes 4 feet 6inches long and 7 inches in diameter, closed at the upper
ends, having plates 34 inch in thickness welded in, and round

Z
G)
|S
S$
§
|
§
*
the bottom ends heavy cast-iron rings with lugs are fixed. The
ends of the tubes are roughened, and the rings are cast on, thus the
contraction of the cast-iron, as well as a partial uniting of the two
metals, render this mode of ſastening on the rings a very secure one;
the tubes are arranged in transverse rows in an oven, between the
furnace and the chimney. The lower ends of the tubes for each row
are united to a pipe IO inches in diameter, and of suitable thickness,
which is strengthened by diaphragm plates cast in, and perforated
with small holes. On this pipe short branch pieces are cast, which
are turned and recessed, for the reception of the ends of the other
tubes, to which they are strongly united by means of bolts and gun-
metal nuts, recessed into the lugs, the rings on the tubes having
BoILERS FOR STATIONARY ENGINEs. 17
corresponding lugs. The joint is made with a composition ring, of
lead and tin, dropped into the recess, and then the screws are
tightened; this joint is capable of sustaining as great a pressure as
the tubes, and can be made and re-made at any time without injury.
5-
- N
I. -
! N S
s N
mº º
* * * * ~ *. ---
Fig. 14.—Water-tube Boiler. A, Furnace. B, Tubes, c, Flue. D, Division plate. E, Damper.
F, Steam receiver. G, Stop valve. H, Safety valve.
The upper ends of the tubes have short pieces of wrought-iron
welded gas pipe, tapped into the end plates, for taking away the
steam to the main pipe, which is placed horizontally. Upon t.e
main steam pipe smaller pipes are fitted, and connected to the small
gas pipes from each generator; thus the steam flows along them into
the large pipe, to which is fixed the safety-valve and the pipe to
the steam cylinder. All the parts are so arranged that they can
expand freely, without disturbing the joints. The oven has a
division plate strongly ribbed; by this means the flame impinges
on the bottom halves of the generators, and passing along the top
half goes to the chimney.
Another arrangement of water-tube generators has simply
wrought-iron tubes, with cast-iron ends, secured with long bolts
inside of the tubes, having the feed pipes joining together at the
bottom; similar pipes are situated at the top of the tubes for the
steam, these lead into one main steam pipe, the whole being
encased in suitable brickwork. All the parts in this arrangerment
are well protected, only the plain parts of the tubes being ºposed

I8 MODERN STEAM PRACTICE.
to the action of the flame; the bottom joints are embedded in
the brickwork, and each of the tubes exposes an area of 16 feet,
NTN
F E N
A 2. N
N §
º G N
Ø
: C N
ºss N
2 N
*N N
R §
2.
º N
§ N
__N
SN § A, Shell. B, Fire-box, c, Smoke-
§§§§§ pipe. D, Circulating water
§§ space. E, Comical tubes. F, Fire-
- door. G, Sludge cap
Fig. 15.-Water-tube Boiler. A, Furnace. B, Tubes, c, Flue.
D D, Division plates. E, Damper. F, Stop valve. G, Chimney.
equal to one horse-power. This arrange-
ment is certainly very simple, and is to
be commended, provided the expansion
of the long bolts does not affect the caps
at the ends, causing steam to blow at the
joints. These water-tube boilers must be Fig. 16.-Self-contained Water-
So manufactured that no destructive ex- tube Boiler.
pansion may be allowed to take place, and all the joints should be
metal to metal where practicable.
Water-tube boilers, sometimes called tubulous, may be of various
forms. . The water tubes can be arranged in a variety of ways,
so that the furnaces, the tubes, and the shell are self-contained.
Thus to an ordinary vertical boiler an inside fire-box is fitted, as
likewise a pot-shaped vessel connected by circulating pipes with the
shell, as shown by Figs. I5 and 16. A current of water is continually
descending between the fire-box and the outside shell, and finds its
way into the pot through the circulating pipes at the bottom. These
boilers keep free from deposit, owing to the rapid circulation, and
for some purposes are recommended to be arranged with conical or
common tubes.



BOILERS FOR STATIONARY ENGINES. I9
In the Perkins system of boiler a large number of water tubes are
enclosed in a double shell of plate iron, the space being filied with a
non-conducting medium. The tubes are 2% inches inside diameter
and 3% inch thick. About one half of the tubes are used for generat-
ing steam, the other half being used for superheating. The boiler is
supplied with distilled water, and the furnace is placed beneath the
tubes which run vertically above. Tubulous boilers have been tried
at sea in the Propontis and other vessels on Rowan's system, and
again recently in the steam yacht Anthracite, which lately made
a voyage across the Atlantic and back, carrying a pressure of from
3OO to 500 lbs. of steam per square inch. This vessel was fitted
with the Perkins boiler.
ON BOILERS, BY FAIRBAIRN.
We propose under this head to consider the steam-boiler in its
construction, management, security, and economy.
As regards the construction, it is absolutely necessary to study
carefully the shapes which give maximum strength, and require
minimum of material. In boilers this is most important, as any
increase in the thickness of the plate obstructs the transmission
of heat, and exposes them as well as the rivets to injury on the side
exposed to the action of the flame. It has been generally supposed
that the rolling of boiler plates gives to the sheets greater tenacity
in the direction of their length than in that of their breadth. This is,
however, not always the case, as experiments show that the tensile
strain across the fibre of boiler plates is in some samples greater than
their tensile strength when torn asunder in the direction of the fibre.
We consider this may be owing to the way the iron is piled before
putting it through the rolls; more recent experiments plainly show
that the tensile strength of boiler plates is slightly greater in the
direction of the fibre, and from this it would appear that although
it is more convenient to construct circular boilers, with plates rolled
in the direction of the fibre, still we think that boilers diagonally
plated are the strongest.
Next to the tenacity of the plates comes the question of rivet-
ting. On this point we have been widely astray, and it required
some skill, and no inconsiderable attention in conducting the ex-
periments, to convince even some practical men that the rivetted
joints were not stronger than the plate itself. In punching holes
along the edge of a plate, it is obvious that the plates must be
2O MODERN STEAM PRACTICE.
weakened to the extent of the sectional area punched out; and
it is found also that the metal between the holes is deteriorated
by the process of punching." This deteriorating result was clearly
demonstrated by a series of experiments which took place some
years ago, and in which the strength of almost every descrip-
tion of rivetted joints was determined by tearing each directly
asunder. The results obtained from these experiments were con-
clusive as regards the relative strength of rivetted joints and the
solid plates. In two different kinds of joints, double and single
rivetted, the strength was found to be in the ratio of Ioo for the solid
plate, 70 was the strength of a double-rivetted joint after allowing
for the adhesion of the surfaces of the plates, and 56 was the strength
of a single-rivetted joint. These proportions of relative strength of
plates and joints may therefore in practice be safely taken as the
standard value in the construction of vessels required to be steam
and water tight, and subjected to pressure varying from Io lbs. to
IOO lbs. on the square inch.
The following is the rule for proportions as given by Professor
Rankine:*—
“Let r denote the radius of a thin hollow cylinder, such as the
shell of a high-pressure boiler; t, the thickness of the shell; f, the
tenacity of the material in lbs. per square inch; ?, the intensity
of the pressure in lbs. per square inch required to burst the shell.
This ought to be taken at SIX TIMES the effective working pressure,
then p = 4, and the proper proportion of thickness to radius is given
– 2"
–2.
“The following formula gives approximately the collapsing pressure
p in lbs. on the square inch of a plate iron flue, whose length l,
diameter d, and thickness t, are all expressed in the same units of
z” , ,
measure: A = 9,672,000 ºz.
by the formula :
7-
“Tenacity of wrought-iron plates = 51,000 lbs. per square inch.
Tenacity of wrought-iron joints, double rivetted = 35,700 lbs, per square inch.
Tenacity of wrought-iron joints, single rivetted = 28,600 lbs. per square inch.”
In the construction of boilers exposed to severe internal pressure,
it is desirable to adopt such forms, and so to dispose the material,
as to apply the greatest strength in the direction of the greatest
* In the best modern practice, therefore, all rivet holes are drilled where practicable.
* See Manual of the Steam &ngine.
BOILERS FOR STATIONARY ENGINES. 2 I
strain. Professor W. R. Johnson, of the Franklin Institute of
America, whose inquiries into the strength of cylindrical boilers
are of great value, may be quoted as an authority:-
“Ist. To know the force which tends to burst a cylindrical boiler
in the longitudinal direction, or, in other words, to separate the head
from the curved sides, we have only to consider the actual area of
the head, and to multiply the units of surface by the number of
units of force, applied to each superficial unit, this will give the total
divellent. To counteract this, we have, or may be conceived to have,
the tenacity of as many longitudinal bars as there are units in the
circumference of the cylinder. The united strength of these bars
constitutes the total retaining or quiescent force, and at the moment
when rupture is about to take place the divellent and quiescent
forces must obviously be equal.
“2d. To ascertain the amount of force which tends to rupture the
cylinder along the curved side, or rather along the opposite sides, we
may consider the pressure as applied through the whole breadth of the
cylinder upon each lineal unit of diameter. Hence the total amount
of force which would tend to divide the cylinder in halves, by sepa-
rating it along two lines of opposite sides, would be represented by
multiplying the diameter by the force exerted on each unit of surface,
and this product by the length of the cylinder. But even without
regarding the length, we may consider the force requisite to rupture
a single band in the direction now supposed, and of one lineal foot
in breadth, since it obviously makes no difference whether the cylinder
be long or short, in respect to the ease or difficulty of separating the
sides. When the diameter of a boiler is increased, it must be borne
in mind that the area of the ends is also increased, not in the ratio
of the diameter, but in the ratio of the square of the diameter; and
it will be seen, that instead of the force being doubled, as in the case
of the direction of the diameter and circumference, it is quadrupled
upon the ends, or, what is the same thing, a cylinder double the
diameter of another cylinder, has four times the pressure in the
longitudinal direction. The retaining force, or the thickness of metal
of a cylindrical boiler, does not, however, increase in the same ratio
as the area of the circle, but simply in the ratio of the diameter,
consequently the thickness of the metal will require to be increased
in the same ratio as the diameter is increased. From this it appears
that the tendency to rupture, by blowing out the ends of a cylindri-
cal boiler, will not be greater in this direction than it is in any other
22 MODERN STEAM PRACTICE.
direction; we may therefore safely conclude, since we have seen
that the tendency to rupture increases in both directions in the
ratio of the diameter, that any deviation from that law, as regards
the thickness of the plates, would not increase the strength of the
boiler.”
We have been led to the following inquiries from the circumstance
that Mr. Johnson appears to reason on the supposition that there
are no joints in the plates, and that the tenacity of the iron is equal
to 60,000 lbs., rather more than 26 tons, to the square inch. Now the
result of experiment has shown that ordinary boiler plates will not
bear more than 23 tons to the square inch; and as nearly one-third
of the material is punched out for the reception of the rivets, we must
still further reduce the strength, and take I5 tons, or about 34,OOO lbs.,
on the square inch, as the tenacity of the boiler plates, or the pres-
sure at which the boiler would burst. By experiment it has been
found that the strength of the single-rivetted joints of boilers is little
more than half the strength of the plate itself; but taking into
consideration the crossing of the joints, 34,000 lbs. may reasonably
be taken as the tenacity of the rivetted plates, or the bursting
pressure of a cylindrical boiler.
It has been stated that the strength of cylindrical boilers, when
taken in the direction of their circumference, is in the ratio of their
diameters, and when taken in the direction of the ends, as the Squares
of the diameters; a proposition which it will be difficult to demonstrate
as applicable to every description of boiler of the cylindrical form.
It will be seen, however, that the strain is not exactly the same in
every direction, and that there is actually less upon the material in
the longitudinal direction than there is upon the circumference. For
example, let us take two boilers, one 3 feet in diameter and the other
6 feet in diameter, and suppose each to be subjected to a pressure
of 40 lbs. to the square inch. In this condition, it is evident that
the area, or number of square inches, in the end of the 3 feet boiler
is to that of the area of the 6 feet boiler as I to 4; and, by a common
process of arithmetic, it is found that the edges of the plates forming
the cylindrical part of the 3 feet boiler is subject, at 40 lbs. on the
square inch, to a pressure of 40,714 lbs., or upwards of 18 tons;
whereas the plates of a 6 feet boiler have to sustain a pressure of
162,856 lbs., or 72 tons, which is quadruple the force to which the
boiler only one-half of the diameter is exposed; and the circumfer-
ence being only as 2 to I, there is necessarily double the strain upon
BOILERS FOR STATIONARY ENGINES. 23
the cylindrical plates of the large boiler. Now this is not the case
with the other parts of the boiler, as the circumference of a cylinder
increases only in the ratio of the diameter, consequently the pressure
instead of being increased in the ratio of the squares of the diameter,
as shown in the ends, is only doubled, the circumference of the
6 feet boiler being twice that of the 3 feet boiler.
Let us, for the sake of illustration, suppose the two cylindrical
boilers such as we have described to be divided into a series of hoops
of I inch width, and taking one of these hoops in the 3 feet boiler, we
shall find it exposed at a pressure of 40 lbs. on the Square inch to a
force of 1440 acting on each side of a line drawn through the axis of
a cylinder 36 inches diameter and I inch in depth, and which line forms
the diameter of the circle. Now this force causes a strain tending to
burst the hoops in the 3 feet circle of 720 lbs., and assuming the pres-
sure to be increased until the force becomes equal to the tenacity or
retaining power of the material, it is evident, in this state of the equi-
librium of the two forces, that the preponderance on the side of the
internal pressure would insure fracture; and supposing we take the
plates of which the boiler is composed, of one quarter of an inch thick,
and the ultimate strength at 34,000 lbs. on the square inch, we shall
34OOO
have ;: , =472 lbs. per square inch, as the bursting pressure of the
boiler. Again, as the forces in this direction are not as the squares,
but simply as the diameters, it is clear that at 40 lbs. on the square
inch we have in a hoop an inch in depth, or that portion of a cylinder
whose diameter is 6 feet, exactly double the force applied to rend
the iron asunder, as in the 3 feet boiler. Now, assuming the plates
to be quarter of an inch thick, as in the 3 feet boiler, it follows, if
the forces at the same pressure be doubled in the large cylinder, that
the thickness of the plates must also be doubled, in order to sustain
the same pressure with equal security; or, what is the same thing,
the 6 feet boiler must be worked at half the pressure, in order to
secure the same degree of safety as attained in the 3 feet boiler at the
given pressure. From these facts it may be useful to know that
boilers having increased dimensions, should also have increased
strength in the ratio of their diameters; or, in other words, the plates
of a 6 feet boiler should be double the thickness of the plates of a
3 feet boiler, and so on as the diameter increases.
The relative powers of force applied to cylinders of different dia-
meters become more strikingly apparent when we reduce them to
their equivalents of strain per square inch, as applied to the ends
24. MODERN STEAM PRACTICE.
and circumference of the boiler respectively. In the 3 feet boiler,
working at 40 lbs. pressure, we have a force equal to 720 lbs. upon an
inch width of plates, and one quarter of an inch thick, or 720 × 4 =
2880 lbs., the force per square inch upon every point of the circum-
ference of the boiler. Let us now compare this with the actual
strength of the rivetted plates themselves, which, taken as before at
34,OOO lbs. on the square inch, gives the ratio of the pressure as
applied to the strength of the circumference as 2880 to 34,000,
nearly as I to 12, or 472 lbs. per square inch as the ultimate strength
of the rivetted plates,
These deductions appear to be true in every case as regards the
resisting powers of cylindrical boilers to a force radiating in every
direction from its axis towards the circumference; but the same
reasoning is, however, not maintained when applied to the ends, or,
to speak technically, to the angle-iron, and rivetting, when the ends
are attached to the circumference. Now, to prove this, let us take
the 3 feet boiler, where we have I I 3 inches in the circumference,
and upon this circular line of connection we have, at 40 lbs. to the
square inch, to sustain a pressure of 18 tons, which is equal to a
strain of 360 lbs. acting longitudinally upon every inch of the cir-
cumference. Apply the same force to the 6 feet boiler, with a
circumference or line of connection equal to 226 inches, and we
shall find it exposed to exactly four times the force, or 72 tons;
but in this case it must be borne in mind that the circumference is
doubled, and consequently the strain, instead of being quadrupled,
is only doubled on a force equal to 720 lbs., acting longitudinally
as before upon every square inch of the circumference of the boiler.
From these facts we come to the conclusion that the strength of
cylindrical boilers is in the ratio of their diameters, if taken in the
line of curvature, and as the Squares of the diameters as applied
to the ends or their sectional area; and that all descriptions of
cylindrical tubes, to bear the same pressure, must be increased in
strength in the direction of their circumferences, simply as their
diameters, and in the direction of the ends as the squares of the
diameters.
Again, if we refer to the comparative merits of the plates com-
posing cylindrical vessels, subjected to internal pressure, they will
be found in the anomalous condition, that the strength in their
longitudinal direction is twice that of the plates in the curvilinear
direction. This appears by a comparison of the two forces, wherein
13OILERS FOR STATIONARY ENGINES. 25
we have shown that the ends of the 3 fect boiler, at 40 lbs. internal
pressure, sustain 360 lbs. of longitudinal strain upon each inch of a
plate a quarter of an inch thick; whereas the same thickness of plates
have to bear, in the curvilinear direction, a strain of 720 lbs. This
difference of strain is a difficulty not easily overcome; and all that
we can accomplish in this case will be to exercise a sound judgment
in crossing the joints, in the quality of the workmanship, and in the
distribution of the material. For the attainment of these objects,
the following table, which exhibits the proportionate strength of
cylindrical boilers from 3 to 8 feet, may be useful:—

º Bursting Pressure equivalent to the ultimate strength Thickness of the
Pºlº of of the Rivetted Joints, as deduced from experiment. | Plates in decimal
© 34,000 lbs. to the square inch. parts of an inch.
Feet. Inches.
3 O ‘25o
J 6 "29 I
4 O "333
4 6 "3 ſ:
5 O * * “4 I
Ö O ‘500
6 6 541
7 O ‘583
7 6 625
8 O "666
Boilers of the simple form, and without internal flues, are subjected
only to one species of strain; but those constructed with internal
flues are exposed to the same tensile force which pervades the
simple form; and farther, to the force of compression, which tends
to collapse or crush the material of the internal flues.
From the existing state of our knowledge we must rest satisfied
that the flues of ordinary boilers can be materially strengthened by
the introduction of iron hoops, but we are of opinion they should
never be introduced where deposits rapidly form, such as in marine
boilers, &c.; for it must be borne in mind that there are two thick-
nesses of material at the parts hooped, and the incrustation that
forms proves highly detrimental to the furnaces. In many cases
where deposits have formed at the hoops the furnace-plates have
bulged out very much.
Fairbairn gives a table of internal flues fitted with T-iron or angle-
iron hoops. The length of the flues must be measured between the
rigid supports; in an unsupported flue, as ordinarily constructed,
26 MODERN STEAM PRACTICE.
the length is measured between the end plates of the boiler. In
the flues as proposed, between the T-iron ribs, the dimensions given
are for a collapsing pressure of 450 lbs. per square inch; the safe
working pressure should be 75 lbs. per square inch.


THIckness of PLATES.
Diameter of "
Flues in inches.
Io Feet Long. 20 Feet Long. 30 Feet Long.
I 2 ‘291 *399 '48o
18 "350 '48o ‘578
24. *399 '548 '659
3O 450 lbs. "442 ‘607 '730
36 '48o '659 '794
42 '516 ‘707 ‘851
48 '548 ‘752 ‘905
The above are founded on the supposition that the 20-feet and
30-feet long flues have T-iron or angle-iron hoops at the necessary
joints, the hoops to be placed IO feet
= ſ \ = apart. Some makers prefer placing the
T-iron hoops at each joint, the plates
Fig. 17. –Rolled Hoop. butting on one another, and at the
longitudinal joints likewise." When the joints are planed, and
the butt strips properly fitted, the strain is entirely taken off the
rivets, the compressive strain being taken on the ends of the plates
directly.
In the cylindrical boiler, with round flues, the forces are diverging
from the central axis as regards the outer shell, and converging
as applied to every separate flue which the boiler contains. To
show the amount of strain upon a high-pressure boiler 30 feet
long and 6 feet in diameter, having two centre flues, each 2 feet
3 inches diameter, working at a pressure of 50 lbs. on the Square
inch, we have only to multiply the number of square feet of Sur-
face—IO3O exposed to pressure—by 3:21, and we have the force
of 3306 tons which a boiler of these dimensions has to sustain. We
mention this to show that the statistics of pressure, when worked
out, are not only curious in themselves, but instructive as regards a
knowledge of the retaining powers of vessels so extensively used.

* These T-hoops are now almost superseded by rings shaped as above (Fig. 17), and
rolled specially for the purpose. The latter answer admirably, and also allow of ex-
pansion and contraction.
BOILERS FOR STATIONARY ENGINES. 27
To pursue the subject a little further, let us suppose the pressure to
be 450 lbs. on the square inch, which a well-constructed boiler of this
description will bear before it bursts, and we have the enormous force
of 29,754 tons, or nearly 30,000 tons, compressed within a cylinder
30 feet long and 6 feet diameter. This is, however, inconsiderable
when compared with the locomotive and some marine boilers, which,
from the number of tubes they contain, present a much larger surface
to pressure. Locomotive boiler engines are usually worked at
120 lbs. on the square inch; and taking one of the usual construction
we shall find that it rushes forward on the rail with a pent-up
force within its interior of nearly 60,000 tons, which is rather
increased than diminished at an accelerated speed. In a station-
ary boiler, charged with steam at a given pressure, it is evident
that the forces are in equilibrium, and the strain being the same
in all directions, there will be no tendency to motion. Supposing,
however, this equilibrium to be destroyed, by accumulative pressure,
till rupture ensues, it follows that the forces in one direction
having ceased, the others in an opposite direction, being active,
would project the boiler from its seat with a force equal to that
which is discharged through the orifice of rupture. The direction
of motion would depend upon the position of the ruptured part: if
in the line of the centre of gravity, motion would ensue in that direc-
tion; if out of that line, an oblique or rotatory motion round the
centre of gravity would be the result. (An explosion of a plain
vertical boiler may be taken as an example: it gave way at the
bottom of the fire-box or bottom of the boiler, and by the reactive force
of the steam it was lifted about IOO feet in the air like a sky-rocket,
and when the force was spent, and the water and the steam expelled,
it descended, landing on the identical spot where it had rested pre-
vious to the explosion.) The momentum or quantity of motion pro-
duced in one direction would be equal to the intensity or quantity
lost; and the velocity with which the body would move would be
in the ratio of the impulsive force, or the quantity lost. Therefore,
the quantity of motion gained by an exploded boiler in one direction
will be as the weight and quantity lost in that direction. These
definitions, however, belong more to the province of the mathemati-
cian, and may be easily computed from well-known formulae on the
laws of motion.
The following table shows the bursting pressure of boilers, as
likewise the safe working pressure, as deduced from experiment,
28
MODERN STEAM PRACTICE.
with a strain of 34,000 lbs. on the square inch as the ultimate strength
of rivetted joints:—

e Worki Burstin Workin Burstin
Diº. of p.". Pº £r Pressure #or Pressure %r
Oller, %-inch Plates. 36-inch Plates. || 4-inch Plates. |}%-inch Plates.
ft. in.
3 O IIS 708% I57% 944%
3 3 IO9 653% I45% 87.1%
3 6 IOI 607 I34% 809%
3 9 94% 566% I25% 755%
4 O 98% 53 I I 18 . 708%
4 3 83% 500 I II 666%
4 6 78% 472 IO4% 62.9%
4 9 74% 447% 99% 596%
5 O 70% 425 94% 566%
5 3 67% 4O4% 83% 515
5 6 64% 386% 82 49.2%
5 9 61% 369% 78% 472
6 o 59 354 75% 453%
6 3 56% 340 72% 435%
6 6 54% 3.26% 69% 4.19%
6 9 52% 3.14% 67% 4O4%
7 o 52% 3O3% 65 396%
7 3 48% 293 62% 377%
7 6 47 283% 60% 365%
7 9 45% 274 59 354
8 O 44 265% 57 343%
8 3 42% 25.7% 55% 333%
8 6 41% 25O
Rule for 36-inch Plates.—Divide 4250 by the diameter of the
boiler in inches; the quotient is the working pressure, being one-
sixth of the strength of the joints.
Rule for W4-inch Plates.—Divide 56666 by the diameter of the
boiler, and the quotient will be the greatest pressure that the boiler
should work to while new ; that is, one-sixth of the punched plates.
We now come to the rectangular forms, or flat surfaces, which are
not so well calculated to resist pressure. Of these we have many
instances: the fire-box of the locomotive boiler, the sides and flues
of marine boilers, and the flat ends of cylindrical boilers, and other
boilers of weaker construction. The locomotive boiler is generally
worked up to a pressure of I2O lbs. On the Square inch, and at times,
when ascending steep inclines, we have known the Steam nearly as
high as 200 lbs. on the square inch. In a locomotive boiler subject
to such enormous working pressure, it requires the utmost care and
attention on the part of the engineer to satisfy himself that the flat
surfaces of the fire-box are capable of resisting that pressure, and
that every part of the boiler is so nearly balanced in its powers of
BOILERS FOR STATIONARY ENGINES. 29
resistance, as that when one part is at the point of rupture, every
other part is on the point of yielding to the same uniform force.
This appears to be an important consideration in mechanical con-
structions of every kind, as any material applied for the security of
one part of a vessel subject to uniform pressure, whilst another part
is left weak, is so much material thrown away; and in stationary
boilers, or in moving bodies such as locomotive engines and steam
vessels, they are absolutely injurious, at least so far as the parts are
disproportionate to each other, because when maintained in motion
they become an expensive and unwieldy encumbrance. The greater
portion of the fire-boxes in locomotive boilers have the rectangular
form, and in order to economize heat, and give space for the ſurnace,
it becomes necessary to have an exterior and interior shell. That
which contains the furnace is generally made of copper, firmly united
by rivets, and the exterior shell, which covers the fire-box, is made
of iron, and united by rivets in the same way as the copper fire-box.
Now these plates would of themselves, unless supported by rivetted
stays, be totally inadequate to sustain the pressure. In fact, with one-
tenth of the pressure, the copper fire-box would be forced inwards
upon the furnace, and the external shell bulged outwards, and with
every change of force these two flat surfaces would move backwards
and forwards, like the sides of an inflated bladder, at the point of
rupture. To prevent this, and give the large flat surfaces an
approximate degree of strength with the other parts of the boiler,
wrought-iron or copper stays, I inch in diameter, are introduced.
They are first screwed into the iron and copper on both sides to
prevent leakage, and then firmly rivetted to the exterior and interior
plates. These stays are from 6 inches to 434 inches asunder, form-
ing a series of Squares, and each of these will resist a strain of about
I5 tons before it breaks. Let us suppose the greatest pressure con-
tained in the boiler to be 200 lbs. on the square inch, and we have
6 × 6 × 200–72OO lbs., or 3% tons, the force applied to a square
containing 36 Square inches. Now as these squares are supported
by four stays, each capable of sustaining 15 tons, we have 4 × 15 =
60 tons as the resisting powers of the stays; but the pressure is not
divided amongst all the four, but each stay has to sustain that pres-
sure, consequently the ratio of strength to the pressure will be 4%
to I nearly, which is a very fair proportion for the resisting power
of that part.
We have treated of the sides, but the top of the fire-box and
3O MODERN STEAM PRACTICE.
the ends have also to be protected, and there being no other part
but the circular top of the boiler to which to attach stays, it has
been found more convenient and equally advantageous to Secure
these parts with a series of wrought-iron bars, from which the roof
of the fire-box is suspended, and which effectually prevents it being
forced down upon the fire. It will not be necessary here to go into
the calculation of those parts. They are, when rivetted to the dome
or roof, of sufficient strength to resist a pressure of 3OO to 400 lbs. on
the square inch. This is, however, generally speaking, the weakest
part of the boiler, with the exception probably of the flat ends above
the tubes in the smoke-box, where they are carefully stayed. In
the flat ends of cylindrical boilers, and those for marine purposes,
the same rule applies as regards construction, and the due propor-
tion of the parts, as in those of the locomotive boiler, must be closely
adhered to.
Every description of boiler used in manufactories, and also on
board ship, should be constructed to stand at least six times the
working pressure, or a pressure of about 500 lbs. on the square incli;
and locomotive-engine boilers, which are subjected to a much
severer duty, to about 800 lbs. per square inch. Internal flues, such
as contain the furnaces in the interior of the boiler, should be kept
as nearly as possible to the cylindrical form; and as wrought-iron
will yield to a force tending to crush it of about one-half of what
would tear it asunder, the flues should in no case exceed one-half of
the diameter of the boiler; and, with the same thickness of plates,
it may be considered equally safe to the other parts. In fact, we
should advise the diameter of the internal flues to be in the ratio of
I to 2%, instead of I to 2 of the diameter of the boiler. Corrugated
flues as now made of iron or steel give increased strength.
THE STRENGTH OF ROUND BOILERS WITH DIFFERENT
QUALITIES OF PLATES.
When the tensile stress of each boiler-plate is not known per
square inch, or the strain that it will bear before breaking, to find
the thickness for a certain diameter, multiply the diameter in inches
by the steam pressure, dividing the product by one-sixth of the
ultimate mean strength of the plate per Square inch, and the
quotient is the thickness. When the boiler rests on brickwork, add
tº inch more. The tensile strain of the best boiler-plate is about
BOILERS FOR STATIONARY ENGINES. 3I
62,544 lbs., and the worst 34,000 lbs. per square inch. Taking one-
sixth of the mean, or 8045 lbs.-(this is presuming the best plates
are used; if the plates are of inferior quality, it is obvious the con-
stant is too high proportionally, although it may answer in practice
with a parcel of the best plates untested)—we have, for a boiler
6 feet 6 inches in diameter, and with 60 lbs. steam per square inch,
the following result (the seams being single-rivetted):—
78 x 60 e * >
-ād-- 58, Say H* inch,
as the thickness, or when set in brickwork say 5% of an inch. This
is allowed on account of the corrosion that takes place with all boilers
resting on a brickwork foundation. The ends should be at least
% inch more than the calculated thickness.
In another form it may be taken thus—
P. Pressure per square inch.
D. Diameter of boiler in inches.
T. Thickness of plates in inches.
C. Constants for varying qualities of plates.
Double Rivetted. Single Rivetted.
C=For Yorkshire plates of best quality,............. 78oo 62oo
C= For Staffordshire plates of best quality,.......... 62OO 5000
C=For ordinary plates,................ .................. 3700 33OO
_ P D
2 C
It will be seen that this formula gives a thickness of the plates
somewhat less than the previous rule, using the best quality, a result
not at all to be desired; yet when the quality of the plates is tested
by a strip cut off each plate, one-sixth of the strength of the rivetted
joints, as per following table, may be safely taken as the constant,
The Strongest Form and Proportion of Rivetted joints, as deduced from Experiment
and Practice.
Thickness of Diameters of Length of Rivets Distance of Rivets | Quantity of Lap
Plates in Parts Ičivets in from Head from Centre to in Single Joints
of an Inch. Inches. in Inches. Centre in Inches. in Inches.
‘18=#s '38 -88 I'25 l 6 I ‘25
‘25=} 59 2 I I 3 I '50 ) I 50 Å 6
‘3 I = Hºs '63 1:38 I 63 | 5 I SS
'37 = } ‘75 I 63 - 4.5 I '75 2 'OO 5'5
‘50 = } •8 I 2°25 2 *OO 2°25
62–; '94 X 1 '5 2.75 2 *SO X 4 2’75 × 4'5
"75 =# I ‘I 3 3:25 J 3’OO 3'25
32. MODERN STEAM PRACTICE.
For double-rivetted joints, add two-thirds of the depth of the
single lap. Where great strength is desirable this form of joint
should always be adopted. It will be seen from the following table
that the double-rivetted joints retain their resisting power, while the
single-rivetted joints lose about one-fifth of the actual strength of
the plates.
The figures 2, I'5, 4-5, 6, 5, &c., given in the preceding table are
multipliers. These multipliers are considered as proportionals of
the plates; thus, supposing we take 3% of an inch as the thickness
of plates, we have simply to multiply the thickness by the number
to find the proportionate quantities to form the strongest joint:-
Inches.
'375 x 2 = 750 diameter of rivet.
'375 x 4'5= I-687 length of rivet.
*375 x 5 = I '875 distance between rivets.
'375 x 5'5=2'o62 quantity of lap, single rivetted.
'375 x 9"I =3°412 quantity of lap, double rivetted.
It will be seen that the dimensions thus found nearly agree with
the dimensions in the preceding table, which are practically correct.
Boilers are now being made of steel: as made by the Siemens or
Bessemer process, the tensile strength is about 29 tons per square
inch, and the elastic strength appears to lie within I I to 16 tons
per square inch. Test pieces, IO inches long, give an elongation of
28 per cent, with a contraction of area of about 49 per cent.
Punching the rivet holes weakens the metal by about 30 per cent.;
the strength can, however, be restored by annealing. Drilling the
holes does not seem to affect the strength. By the use of steel
the weight of boilers has been reduced about IO per cent. For
further reference to manufacture and strength of steel see section on
Shipbuilding, p. 96O.
Mean Strength of Plates in the direction of and across the Fibre (Fairbairn).

Breaking Weight Breaking Weight
in the direction of across the Fibre,
the Fibre, in tons in tons per square
per square inch. inch.
Yorkshire Plates......... 25'720 27°490
Do. do. ......... 22 760 26'o67
Derbyshire do. ......... 2I 68O 18:650
Shropshire do. ......... 22°826 22 *OOO
Staffordshire do. ......... I9'563 2 I ‘OIO
Mean................ 22°509 23'O37
BOILERS FOR STATIONARY ENGINES. 33
Tensile Strength of Single and Double Rivetted Plates.

Area of boiler stays =
f y
Cohesive Strength of Strength of Single Rivetted | Strength of Double Rivetted
Plates. Joints, of equal Section Joints, of equal Section
Breaking Stress in Lbs. to the Plates, taken through to the Plates, taken through
per Square Inch. the Line of Rivets. the Line of Rivets.
57,724 45,743 52,352
6 1,579 36,606 48,821
58,322 43, I4 I 58,286
50,983 43, 5 I5 54,594
5 I, I 30 40,249 53,879
49.281 44, 7 I5 53,869
43,805 37, 161 tº º is
47,062 tº € 9.
Mean, 52,485 4I, 59C 53,633
A x £
where A=area of surface of plate
held by one stay, and p and t being the pressure and tenacity re-
spectively.
The following value of plates may be fairly assumed with those
of joints:—
s g º e º 'º a ſe e º ºs e a tº gº & e g º º e º 'º º ſº e º º gº tº 4 & 9
Double Rivetting..................
Single Rivetting...................
In a series of experiments by Napier the tensile strength of iron
plates averaged from 56,735 to 41,743 lbs. per square inch.
Weight of a Square Foot of Wrought-iron Plate from gº to 1 inch in 7%ickness.


º: Yºigº Thickness. Weight.
#: 'I 25 # + ºr 2I-25
+'s 2°5 | Tº: 22°5
I's Fºr 3°75 * as 23°75
# & # 25°
* + š, 6-25 || 3 + ..” 26:25
, is , 3.5 , , is , 2.5
Tº + ºr 8.75 ## * * 28:75
# IO* # 3O'
# + ºr II 25 ###'s 3I ‘25
5 *s 1 2.5. I .# l 32.5
* : * 13.75 # , º, 3375
s ºf 1 5. • * , 33.
# + ºr 16:25 # -H 5's 36°25
, #, ...; .# , 37.5
Tº -H ºr 1875 # 3 + sy 38°75
# 2O * I 4O'
Weight of Angle Iron, in Zös, per Lineal Foot.
Breadth in inches..............
Weight per foot in lbs........
I}4, I}%, 1%, 2, 2% 2%, 2%, 3, 3%, 3%.
I 8, 27, 33, 3’9, 5, 6'5, 83, Io'4, II '7, 14.
34 MODERN STEAM PRACTICE.
Weight of a Zineal Foot of Square and Round Bar Iron, in Zbs.

size sº | * | size. sº | Fººd || size sº | Rºº
# ‘209 “I64 I}{ 5’25 4."O9 || 3 3oro'ſ 23:60
# '326 ‘256 || 13% 6°35 | 4'96 || 3% | 35-28 || 27-70
# ‘47O 369 I}% 7' 51 5'90 || 3% 4O’9 I 32 3
* *64O '502 I 5% 8-82 6'92 || 3% 46-97 || 36'89
# ‘835 '656 I}{ | IO-29 | 8'03 || 4 53'44 || 4 || '97
+% I ‘O57 '831 I 7% II '74 9-22 || 4% 60'32 || 47.38
; 1.325 225 *. 3.3% 1949 4% 67.63 53.43
# 579 || 34. 2% I5 OS II '84 || 434 || 75°35 | 59° 18
# I '879 I 476 || 2% 16'91 || 13-27 || 5 83’51 65-58
## 2°2O5 I '732 || 2% | 1884 || 14-79 || 5% 92°46 | 72°30
§ 2-556 || 2:OI I 2% 2O'87 | 1639 || 5% IOI 63 || 79°35
## 2.936 || 2:306 25 23 II 18:07 || 5% I 14:43 86-73
I 3'34 2-62 234 25-26 1984 || 6 I2O’24 || 94'43
I# 4'22 3'32 2% 27-61 21 '68
Surface of Tubes per Zineal Foot, in Square Feet.

Diameter inch| 5
Surface...... ..... 'I
% 7% I I}% I}{ | 1.3% I}%
6 || '1963 229I 2618 2945 '3270 3599 || 3927
Diameter inch| 15% I34 I 7% 2 2% 2% 2% 3
Surface............ '4253 || 458o 4906 || 5233 '5890 || 6544 || 7199 || 7854
º
A
Weight per Foot in Zös. and Decimal Parts of Iron, Brass, and Copper Tubes.




Inches | Birming- Inches | Birming-
External ham Wire Iron. Brass. Copper.|| External ham Wire Iron. Brass. Copper.
Diameter. Gauge. Diameter. Gauge.
I}% I3 I 402 I-529 I ‘627 || 3% 9 5'64O | 6’I48 || 9°500
I3% I3 I 528 I '665 I '772 || 4 $ 8 6-652 7.25o 7-7 16
I34 I3 I '653 I ‘Son | I '917 4% 8 7:087 || 7'724 8:220
I 7% I 2 2 O24 || 2:2O6 || 2:347 || 4% 8 7'497 8-171 8-696
2 I 2 2 168 || 2:363 || 2:514 4% 8 7 '953 8-668 9'225
2% I2 2-3 II | 2:513 2-680 5 7 9. I2O | 9-94O IO'579
2% I I 2’687 2 '928 || 3: I 16 5% 7 9°596 |IO'459 |II ‘I31
2% I I 3'OO2 || 3 272 3'482 5% 7 |IO-089 |Io:997 |II 603
2% IO 3.685 4'OI6 || 4-274 5% 7 |IO-539 |II 487 |I2'225
3 IO 4 O38 4'4OI 4'684 6 6 |I2°371 || 3:484 |I4'350
3% 9 || 4 S26 5°26o 5'598 || 7 6 |I4°168|I5'444 16'435
3% 9 || 5’215 5'684 || 6’O49
PROPORTIONS FOR PLAIN LAND BOILERS.
Shell.—Having pointed out the principles to be observed in con-
struction, we will proceed to give the proportions generally adopted
in steam boilers. For each nominal horse-power make an allow-
ance of I cubic yard, or 27 cubic feet capacity; this is simply the
BOILERS FOR STATIONARY ENGINES 35
cubical contents of the shell, with or without inside flues. Sup-
posing, for the sake of illustration, a Cornish boiler of 40 nominal
horse-power was required, multiply the horse-power by 27 cubic
feet, and the result will be the cubical contents, thus—
40 × 27 = 1080 cubic feet.
Zength and Diameter.—The length of the boiler should be about
three and one-half times the diameter for moderate power, or up to
about 20 horse-power inclusive; above that size five times the
diameter can be adopted—a little more or less can do no harm. To
find the diameter, multiply IOSO, the cubical contents required, by
the constant I-28, dividing the result by the proportion of the dia-
meter to the length, say five times, and the cube root of the quotient
will be the diameter, which, multiplied by 5, gives the length of the
boiler nearly.
Io8o × I 28
5
The length of the boiler, in round numbers, is 325 feet, and
6.5 feet in diameter. To check the calculation, the area of 6.5 feet
in diameter is 33 18 square feet x 32°5 = IO7835 cubic feet, within
a trifle of what is required.
Pſeating Surface, Fire-grafe, and Flue Area.—The heating surface
should not be less than I Square yard, or 9 Square feet, per nominal
horse-power; but in ordinary boilers it will be found that more than
this can be conveniently got. The area of the fire-grate, when the fur-
nace is underneath the boiler, should be I square foot, and when the
furnace is in a flue, forming part of the boiler, 75 of a square foot will
be sufficient, per nominal horse-power. The length of the fire-grate
should never exceed 7 feet. When the furnaces are placed inside of
the boiler, for small diameters, the inside flues should be 2 feet 6 inches
in diameter, and certainly not less than 2 feet 3 inches. When smaller
than this, the fires do not burn well, and they are troublesome to
fire; for large diameters of boilers, the furnace flues can be 3 feet
3 inches in diameter. The area of the furnace flues should be
about 28 square inches per nominal horse-power, a little more doing
no harm; thus for 40 horse-power, we have for two furnaces—
= %276'48 = say 6.5 x 5 = 32°5.
40 × 28 = I I 20 + 2 = 560 square inches,
equal say 2 feet 3 inches diameter for each flue in the boiler, and
4 feet 6 inches as the sum of the width for both; thus, for the
36 MODERN STEAM PRACTICE.
length of the grate, making an allowance of 75 of a square foot per
nominal horse-power, we have—
*:::: = 6.6 feet in length.
The area over the bridge is generally about 18 square inches per
nominal horse-power.
Water and Steam Room.—For boilers with hemispherical ends,
the water should fill the boiler two-thirds of its diameter, thus leav-
ing one-third as steam-room. For Cornish arrangement with two
furnaces (otherwise known as the Butterly boiler) the water generally
fills the boiler three-fourths of its diameter, the remainder being the
steam-room. One foot height of water over the furnaces is allowed;
when one furnace is adopted the steam-room in the boiler can be in-
creased, and it is always advisable to have steam domes fitted to
the top.
RELATIVE VALUE OF HEATING SURFACE.
Horizontal surface above the flame, .............................. = I 'O
Vertical 39 5 3 © tº º te e º 'º º 'º e = O'5
Horizontal surface below the flame,.............................. O "O
Tubes and flues................................. = IX of their diameter.
BOILER FOUNDATIONS.
With the foregoing proportions we may now commence to lay out
the boiler foundations. The boilers are generally ordered in dupli-
cate, so that no stoppage may occur in the event of one of them
requiring repairs; indeed, when deposits rapidly form from impurities
in the water, frequent inspection is necessary, periodical scaling and
cleaning out being required. After the ground is excavated, a bed
of concrete is laid all over, on which is built the superstructure for
carrying and bedding the boiler thereon. The Cornish or London
boiler, with inside furnaces, rests on a mid wall, having cast-iron
supports imbedded in the middle wall, and should be of sufficient
height to leave about 3 feet 4 inches from the stoking-floor to the
dead plates on the furnace front. The boiler is surrounded with
what is technically termed a wheel-flue, that is to say, the flame and
the heated gases pass through the internal furnaces and the back
flues contained in the boiler, then wheel round at the end, and return
to the front—along one side, and pass along the other side nearest
the chimney, an opening being left in the mid wall at the bottom
BOILERS FOR STATIONARY ENGINES. 37
for the flame and the gases to cross from one side of the boiler
to the other side nearest the chimney, and they escape into a flue
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F, Steam receiver.
GG, Stop valves.
H, Manhole.
I 1, Dampers.
K, Safety valve,
Fig. 18.—Foundations for Cornish or London Boilers. A, End view.
B, Section showing direction of the Flues. C, Longitudinal section.
common to both boilers, and thence find their way into the chimney
placed at the end of this main terminal flue. The flues round the
boiler should have the necessary area, and sufficient room left at












38 MODERN STEAM PRACTICE.
the bottom for the convenience of executing repairs and cleaning out
the flues. To resist the action of the flame the flues are lined with
fire-brick, and at the front of the building openings are left, which
are fitted with cast-iron doors for the convenience of periodical
inspection of the boiler.
Damper-plates are fitted to each boiler. They are simply cast-
iron plates, sliding in suitable frames of cast-iron imbedded in the
building. The damper-plate has a “snug” cast on for attaching a
chain provided with a back balance weight, the chain passing over
a pulley, carried up by means of a cast-iron pedestal, securely fast-
ened down to a large stone imbedded in the top courses of the brick-
work. Sometimes the revolving pulley can be carried up from a
plate and pin secured to the wall of the boiler-house. To protect
the top of the boiler from radiation, it is arched over with fire-bricks,
the space between the boiler and the brick arch being filled in with
ashes, and sometimes sand is used.
The walls of the boiler-house are covered over with a suitable
wrought-iron roof, having a ventilator at the top for carrying away
any waste steam that may blow off. The arrangement of the flues
just described will suit all boilers having internal furnaces; but when
the boiler is constructed with one internal small flue, it is preferable
to form the furnace underneath.
Now for cylindrical arrangements, having hemispherical ends, this
class of steam-generators is usually longer in proportion to the dia-
meter than the Cornish type; in some instances six and three-quarter
times the diameter has been adopted. The buildings are very differ-
ent from the foregoing example. The same height from the stoking-
floor to the dead-plate is allowed, namely, 3 feet 4 inches. This
plate is made long, so that the coal may cake before being pushed
amongst the incandescent fuel, this effecting a considerable economy
when properly attended to. A height of about 2 feet 4 inches is
allowed in large boilers, from the top of the fire-bars to the under-
side of the boiler; and the flues are arranged on the wheel principle,
as in the Cornish type, with this difference, that the flame passes
underneath the boiler, and then ascends at the back, all round, and
thence up the chimney. There is a combustion chamber formed at
the back of the bridge, at the end of the fire-bars furthest from the
front, the flame as it were hanging at the hollow left in the bottom
flue, thus making the bottom surface of the boiler very effective as
heating surface. This recess likewise serves the purpose of collecting
BOILERS FOR STATIONARY ENGINES. 39
both the ashes and the soot that may be drawn over by the draught,
and which are raked out through a hole, fitted with a movable door,
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B, Section showing direction of the Flues. C, Longitudinal section.
placed at the bottom of the bridge. The boiler is usually set with
a dip towards the back of 36 inch to the foot, so that the sludge












4O MODERN STEAM PRACTICE.
may collect at the part farthest from the fire. A plug-valve is
fitted to the underside of the boiler, to which is attached a pipe
leading into a drain left in the building; by this means the water
flows away when the boilers are blown off. The buildings are
generally hollowed out to lighten the structure, and the boiler is
fitted with brackets, bolted to the top, so as partly to take the
weight; but the main support is at the sides of the furnace, the
furnace walls being carried up from the bed; but at times when the
sides of the furnace are undergoing repair, the top brackets take the
weight. All the flues must have sufficient area, as likewise doors
must be left in the brickwork for cleaning them out; the height
from the top of the bridge to the under side of the boiler is gener-
ally about 18 inches. The fittings are just the same as for the
Cornish boiler, having a wrought-iron steam-chest connecting all
the boilers, provided with a stop-valve to each boiler, with the
addition of a stone float and back-balance for indicating the height
of the water inside of the boiler. No float is required for the
Cornish class, as the ordinary water-gauge is fitted to the front
end; hemispherical-ended boilers, however, can have a gauge-glass
in front, with suitable pipe Connections passing through the brick-
work. The safety-valve is placed on the top, at the fire-end,
then the stop-valves, next the float of stone with weight, then the
manhole, and the feed-pipes at the back of the boiler, all placed on
the centre line. &
We will now notice the arrangements for one small internal flue.
The furnace is placed underneath the boiler, the flame acting on the
bottom, and then through the small tube, which carries it to the
front, the flame splitting as it were at the front end, passing down
each side, and meeting at the back in one central flue, in the same
line as the centre of the boiler; this is required so that the draught
may be equalized in the side flues, as the heated gases have always
a tendency to take the shortest passage into the chimney. Some
boilers of the cylindrical type, with hemispherical ends, are hung
from the top with brackets, having no support underneath, the
flame acting on the bottom and the sides, and then passing directly
into the chimney; this is not so good an arrangement as the return
flues, as the flame and the heated gases have no time to act on the
surfaces, unless boilers of inconvenient length are adopted. The
furnace bars should be made in suitable lengths, having a thick-
ness of 76 inch at the top, and 3% inch at the bottom, with
BOILERS FOR STATIONARY ENGINES. 4. I
projections at the ends, and the middle of the top, the open-
ings between the bars varying from 3% to 5% inch, to suit soft
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Chimney.
F, Steam receiver.
GG, Stop valves.
H, Manhole.
I I, Dampers.
K, Safety valve.
L., Float.
M, Feed pipe.
direction of Flue. C, Longitudinal section.
and hard coal, the depth of the bars at the middle being from
3% to 4 inches.
AREA AND DIMENSIONS OF CHIMNEY.
• To determine the area of the top of the chimney for a given con-
sumption of coal per hour, the average for Cornish boilers being
Io lbs. per nominal horse-power, multiply the number of lbs. Con-
sumed per hour by I2, and divide the product by the square root
of the height of the chimney in feet (the usual height for factory


















42 MODERN STEAM PRACTICE.
chimneys being 80 feet), and the quotient is the area at the top of the
chimney, thus for 40 nominal horse-power—
tº = 539, say 26 inches diameter,
or 23 inches square at the top. It is always preſerable to make an
allowance over and above this for the convenience of leading other
flues into it. For a chimney 80 feet in height the brickwork should
be divided into three courses: for 30 feet height from the bottom two
bricks in thickness, the next course one and a half brick in thick-
ness, and the remainder one brick thick. For each 25 feet added
in height the brickwork at the bottom should be increased one-
half brick in thickness. The batter or the slope of the side is usually
o:3 of an inch to the foot. Thus, with 26 inches inside diameter at
the top, the bottom of the chimney would be 92 inches external
diameter, while that of the top would be 44 inches. Should the
internal diameter at the top require to be 54 inches and upwards,
the top course should be one and a half brick in thickness, and the
bottom courses in proportion. The inside at the bottom is lined
with fire-bricks, leaving a space of one inch between the inner lining
and the main building, and is carried up to a height of I5 feet from
the bottom. For a chimney 80 feet in height the foundation should
be at least 5 feet in depth, laid on a bed of concrete 2 feet in thick-
ness, but this will depend on the soil; on sand or gravel this bed will
be quite sufficient, but of course some soils require the foundation
to be carried down to a firm bed. In marsh land, and even for the
Colonies, wrought-iron chimneys may be used with advantage, but
brick chimneys are to be preferred. The best temperature for an
efficient chimney draught is about 600°Fahr.
SMORE PREVENTION.
Although the distance between the fire-bars varies from 3% to
% inch, allowing a good volume of air underneath the grate, so
essential for perfect combustion, other means must be taken to con-
sume the gaseous constituents thrown off from coal when in the semi-
incandescent state; the simplest and most effectual way of doing
this is by admitting a current of air through a series of small holes
drilled through the furnace door, thus supplying the common oxygen
contained in the atmosphere, and of which we have an unlimited
command. Many schemes have been brought forward from time
to time to consume the gases evolved before a dense mass of smoke
BOILERS FOR STATIONARY ENGINES. 43
is formed in the flues, for if the gases are not consumed before reach-
ing the flues, it is impossible to burn the smoke with the ordinary
arrangements; but those who are under the impression that smoke,
or at least what we term smoke, cannot be burned when once formed,
labour under a sad mistake, for the densest volume passing through
a regenerative furnace is effectually consumed.
We will take the Butterly boiler, having two internal flues or fur-
naces meeting in one combustion chamber at the back of the bridge:
fire both of these furnaces at one and the same time, and dense
volumes of smoke will be seen issuing from the top of the chimney;
the smoke is formed in the furnace, and passes over the bridge.
Now this arrangement, with careful firing, in a great measure prevents
smoke issuing from the chimney. One fire should be bright while
the other one is dull, or in the act of firing, and what is the conse-
quence? the combustion chamber is in a perfect glow, from the bright
fire; and the smoke evolved by the dull one is effectually consumed
by the other. This simple fact is half of the battle; careful firing
is the best and most economical means for the prevention of smoke;
so by alternately firing little or no smoke is seen issuing from the
top of the chimney. Such practice every good fireman is perfectly
conversant with.
As hydrogen is the main element in the gases evolved, and by
the admixture of the oxygen of the atmosphere flame is produced;
and as neither hydrogen nor oxygen can burn of itself, it remains for
us to Supply a current of air, so as to obtain the most economical
result from the fuel. With the common blow-pipe an intense heat
is obtained by simply blowing a current of air through a flame of
gas, or rushes, as used by the gasfitter. And in the smelting fur-
nace air is forcibly blown through a coil of pipes, surrounded and
inclosed in a furnace, the air is thus intensely heated, and, indeed,
will melt a bar of lead before it is admitted into the smelting fur-
nace; this is termed the “hot blast,” and is familiar to all metallur-
gists. Were it not for the complication entailed, this method would
be by far the best plan that could be adopted for steam boilers, but
such an intense heat is not at all desirable, for should the water in
the boiler fall below the working level, the plates would get intensely
hot, and an explosion would be the inevitable result; so a moderate
measure of heated air is all that is required.
A very simple plan for introducing heated air is by arranging
Small pipes, fixed to the front plate of the boiler, as in the double
44 MODERN STEAM PRACTICE,
furnace Lancashire class, the pipes passing through the water space
to the combustion chamber plate, through which they are securely
rivetted, or clenched over. Thus a current of hot air passes through
the tubes, mixing with the flame and gases in the combustion
chamber, so that when the fires are properly attended to, as with all
arrangements introduced for the prevention of this nuisance they
must be, little or no smoke will appear at the top of the chimney.
The introduction of heated air into the combustion chamber after
the smoke or gases have passed the bridge, seems mainly to keep up
the temperature of the flues, by the admixture of the oxygen of the
atmosphere with the flame in the combustion chamber; this plan,
where it can be conveniently applied, should always be adopted.
As before stated, vertical boilers are so fitted with a series of Small
air-tubes all round the fire-box, inclining downwards, thus the air
freely mixes with the live coal. In former years some persons
scouted the idea of consuming the smoke after passing the bridge;
the fact of our now being able to do so speaks for itself. Some
may term it gas before it has passed the bridge; but what we
plainly see in the furnace we denominate Smoke.
For single furnaces a very different arrangement is adopted,
the smoke being consumed in the furnace: the fire-door is perfor-
ated with a number of small holes 36 inch in diameter, drilled
closely together. It seems impossible to give the exact number of
holes to suit all furnaces, as the same furnace, with different kinds
of coal, requires more or less openings, as the case may be, and even
the same furnace often requires more or less air with the same kind
of coal; this may be owing to the temperature of the atmosphere, or
which way the wind is blowing; if blowing in such a direction as to
fan the fire, as in the forward boilers for marine purposes, less air
will do at the furnace door. Thus it is imperative to have a great
number of holes, say 5 to 6 square inches for every foot of fire-grate
surface; they should be covered with a regulator, or movable disc-
plate, with corresponding holes for regulating the supply; some
adopt slits instead of round holes, but the latter, or jet system, is by
far the best, as it distributes the air equally amongst the gases in
the furnace. This plan necessitates regulation by the damper.
Should no steam be required, or the engine not working, or even
when the fireman is trimming the fire, the damper can be shut, check-
ing the draught for a time; the smoke remains in the furnace, or is
slowly consumed there, thus preventing it issuing at the chimney top.
BOILERS FOR STATIONARY ENGINES. 45
Another plan for consuming the smoke is attained by blowing
superheated steam through a number of minute apertures placed
at the front of the furnace; with high-pressure steam in the boilers;
this plan works well, so long as the apparatus remains in good
order. The steam requires to be dry before it is sprayed into the
furnace in minute jets above the grate. The steam from the boiler
is made to flow through a coil of pipes placed in the fire-brick bridge,
and then passes through a pipe laid across the furnace front, fitted
with nozzles having holes ºr inch in diameter; the pipe is fitted
with a plug-valve to regulate the supply to the nozzles, the furnace
door being provided with a number of air holes, the Superheated
steam is turned on, causing a powerful current of air to pass through
the fire door, and before mixing with the gases in the furnace is
distributed with the steam jets into minute atoms, and we may
say the mere forcing of the atoms driving the oxygen through
and between the live coal, produces complete combustion, with
great economy in fuel. This is much better than any plan we
know of, from the fact that fuel will burn with this arrangement
that would be entirely worthless in ordinary furnaces. By the use
of the jets of superheated steam all the waste cinders from the
smithy can be utilized, and dross or small coals effectually burned,
without the smoke nuisance; but we unhesitatingly give as our
opinion, that unless the attendant sees that the furnace is kept in
proper trim, firing with the least quantity of coal, oft times replen-
ished, that all the refinements for the prevention of smoke will not
attain the desired object, for careful firing is the main secret to
arrive at.
SYSTEMS OF TUBING.
The triangular and square systems of tubing have certain advan-
tages as well as disadvantages. With the former, almost used
exclusively for locomotive boilers, a greater number of tubes can be
got into less space, the water being honey-combed as it were with
a large amount of heating surface. The tubes for locomotive boilers
are generally made of composition metal; this is absolutely required
where deposits form from impurities in the water. When iron or
steel tubes are used, the small water spaces, in some instances only
half an inch, soon get choked up, and the steam does not rise freely;
and as the arrangement will not allow of much scraping and clean-
46 MODERN STEAM PRACTICE.
ing, were deposits forming to any great extent, it would soon prove
fatal to the boiler. To partially remedy this evil the boiler should
Fig. 21.-Systems of Tubing.
be emptied every day, while for other boilers the water must be
blown off frequently. With the triangular system of tubing the
steam generated from the bottom row of tubes must take many a
zigzag course before reaching the top, or the
Steam space. To obviate the difficulties at-
tending the triangular system the square plan
is adopted, more especially for marine boilers,
So that when iron or steel tubes are used there
is Some possibility of Scraping and cleaning
them occasionally; and even where composi-
tion tubes are adopted the square system finds
favour, as the globules of steam generated
from the tubes pass up in parallel rows be-
tween the tubes, instead of following the zig-
Zag Course as in the triangular system.
DRY STEAM.
In order to provide as dry steam as pos-
sible, without using a Superheater, there should
be steam-chests of ample capacity fitted to
all land boilers, in fact we may say to every
class of boiler where they can be convenient-
Fig. 22.-Separator. A, Steam- *
Pipe B, *, *, *P. ly applied; but as the steam still contains
watery particles, a separator may be fitted to the steam-pipe. The
action of this contrivance is very simple, and consists in abruptly


BOILERS FOR STATIONARY ENGINES. 47
changing the flow or current of the steam. To a vertical chamber
a right-angled pipe is suspended, passing down into the chamber
a little below the exit pipe; the steam flowing through the pipe
from the boiler impinges against the elbow, causing the moisture
contained in the steam to trickle down the pipe, thus the water is
‘collected at the bottom of the receiver, and is drawn off at pleasure
with a tap; this plan is very simple, and it can be made self-acting
by means of a float and valve. We consider these separators for
drying the steam, or rather separating the moisture contained in the
steam, should be fitted to all steam-pipes.
Taking Low-pressure Steam from a High-pressure Boiler.—Some-
times it is desirable to reduce the pressure of the steam, so as to work a
low-pressure engine from a high-pressure boiler. There are a variety
of plans for doing so; we have an equilibrium valve, actuated by the
pressure of the steam acting on a piston open to the atmosphere,
and regulated by a lever and spring-balance, similar to the safety-
valve on the locomotive engine boiler. The valve is formed of five
rings cast together, with four vertical arms, or ribs, having a boss
for securing the valve-spindle; this annu- -*- C
lar tube moves in a corresponding seat,
cast together, with vertical pieces between
the openings; there is an annular passage
all round the seat, with a branch pipe
communicating with the steam-boiler. On
the lower part of the valve-chest a branch
pipe is cast in communication with the
cylinder of the valve-casing of the engine,
and on the top of the chest a short cylin-
der and piston are arranged, the piston Eig. 23. — Steam-reducing Valve.
being connected to the valve by a screwed ºº sº.
rod and nuts. The combined circumfer- boiler. E. Branch to cylinder.
ential openings in the valve are equal in area to that of the pipe
from the boiler, and the pipe for the engine must be of sufficient
area according to the usual rules for steam-pipes. By this contriv-
ance the steam can be regulated to the greatest nicety. The action
is as follows:—After being properly set with the nuts on the valve-
spindle, and the thumb-screw on the balance at the end of the lever,
should there be an accumulation of steam in the chest, after passing
the valve, the steam acts on the piston in connection with the valve,
and by its pressure lifts it partially, shutting the apertures until the
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48 MODERN STEAM PRACTICE.
balance is restored, thus keeping up constant low pressure, regu-
lated at pleasure by the thumb-screw pressing down or releasing
the piston and the valve. One of these valves can be fitted to the
main steam-pipe, or a separate one for each cylinder when required.
THE DETERIORATION OF LAND BOILERS.
After a time the plates of all boilers deteriorate, the iron becomes
brittle, and although the plates have a sound-looking exterior, with-
out the slightest symptoms of corrosion, yet such a boiler should
not be worked beyond a certain number of years, and certainly not
at So high pressure as it was originally designed for; in fact, the
steam pressure should decrease year by year, so as to work it with
any degree of safety. It must be understood, however, that unless
a new boiler is properly managed, it is quite as unsafe as a much
older one well managed. To determine the number of years a
boiler ought to last, with fair treatment, we must have recourse to
experiment. When it is thought a boiler has done enough duty
test it to destruction. Such experiments are very easily carried out,
and it is the interest of steam users to do so, that correct data may
be arrived at by a careful experimentalist.
We place before our readers the results of a series of experiments,
testing two boilers to destruction, instituted by Mr. Peter Carmichael,
and which forms a useful contribution on the subject of steam-
boilers. The boilers were cylindrical, with double flues, and were
used at the Dens Works, Dundee, for nineteen years. They were
precisely alike, and of the following dimensions:–Length, 25 feet;
diameter, 7 feet; diameter of furnaces and end flues, 2 feet 9 inches;
diameter of back end of flues, 2 feet 6 inches. The shell was made
of 3% inch “Glasgow best iron;” the flues of Glasgow best scrap iron,
3% inch thick, the end plates being ſº inch in thickness. The boilers
were kept in work until the beginning of November, 1869, when it
was resolved to take one out, and test it to destruction by water
pressure. In the case of the above boilers the pressure has never
been so great as 60 lbs., and as reported they were not wasted,
having always been kept in good repair, and have stood the peri-
odical water test of 60 lbs.; therefore we may presume they could
have been worked for a year or two longer. The fact of the iron
getting hard and brittle after being in use for a length of time had
* See Złºans. Inst. Engineers and Shipbuilders in Scotland, vol. xiii.
BOILERS FOR STATIONARY ENGINES. \ 49
been often pointed out, and in consequence the pressure ought to
be lowered, or new boilers introduced, after they have been working
for sixteen or seventeen years. Before testing, all the brick flues
were taken down, so that easy access could be got to all parts of
the boiler, but it was left sitting on its natural seat. The boilers
were filled with water of about 120° temperature, and a force-pump
was then attached. To check off the pressure no fewer than five
pressure-gauges were used, four of which nearly indicated the same
pressure and tallied with the safety valves. At 80 lbs. pressure per
square inch an examination was made, and all appeared to be right;
but as soon as the pump was started again the joint of the safety
valve was blown out, and this stopped proceedings for a time.
After this joint had been made good the pressure was again brought
up, and at 85 lbs. the joint of the feed-pump pipe, at the front end
of the boiler, began to leak, owing to the bulging out of the end.
At IOO lbs. a number of the longitudinal seams of the shell began
to exude water badly. The pressure was then removed, and the
ends gauged above and below the flues, and on the pressure being
again put on the following was the result:-Front end below flues
bulged out in centre fºr inch at 35 lbs. pressure; 3% inch at IOO lbs.
pressure; front end above flues bulged out in centre sº inch at
35 lbs. pressure, sº inch at IOO lbs. pressure; back end below flues
bulged out at centre #3 inch at 35 lbs. pressure, sº inch at IOO lbs.
pressure. The pressure was then brought up to IO5 lbs., when the
ring seam at the back of the taper of the left-hand flue began to
crack, and the pump became unable to keep up the pressure, owing
to the great leakage. This joint or seam when gauged, before
testing, measured 2 feet 3% inches horizontally, by 2 feet 5 inches
vertically; and it gave way by crushing inwards on the flat or hori-
zontal side, and remained flattened after the pressure was taken
off. This boiler was then removed, and sent to the foundry for
breaking up.
Mr. Carmichael proceeded to clear away the brick flues from
the sister boiler. On the 15th December, 1869, it was tested in the
same way, having been in use for rather more than nineteen years.
. The flues were gauged, and were found, with one exception, similar
to the other boiler. The exceptional one being I }% inch oval, it
was attempted to support this flat part by fixing a batten in the
line of the shortest axis of the ellipse, but this was not found to
be of any use, as the plate bulged, oozed out below at one end of
4.
5O MODERN STEAM PRACTICE.
the batten and above at the other end, and loosened it when the
strain came on. The pressure was noted as before; at 60 lbs. pres-
sure the feed-pipe began to leak, the end bulging out ſº inch. At
80 lbs. the feed valve joint leaked very much, and the longitudinal
seams of the shell began to exude water; at 90 lbs. the south or right-
hand flue began to crack, as if giving way; at 95 lbs. one of the joints
of the shell, and the first rings on the crown of the boiler, commenced
to Spout water, and the pressure could not be kept up, the leakage
being equal to the supply of the force-pump. The joints of the feed-
valve were then tightened, and also some parts of the shell caulked,
the right-hand flue being found to be very much flattened. The
pressure was again put on, but it could not be got higher than
80 lbs., as the flues had given way so much as to allow the water to
escape by the fracture as fast as it was pumped in ; so that the
highest pressure attained was 95 lbs., and this pressure had so injured
the joints and flattened the flues as to render further experiment
impossible. According to Fairbairn's rules the bursting pressure of
these boilers was about 300 lbs. on the square inch, yet they failed
with one-third of this pressure. When the boilers were broken up
the plates were very brittle; indeed, so much so that it was a diffi-
cult matter to get strips for testing. The rivets had likewise deteri-
orated, and the heads flew off when the plates were struck with a
hammer. The test strips gave the following results:–Shell in the
direction of the fibre, 197 tons; across the fibre, 192 tons; while
Glasgow best plates is 24'O4 tons in the direction of the fibre, and
2 I-8 tons across the fibre. Furnace plates, direction of fibre, 17. I
tons; ditto across, I 5-3 tons. It will thus be seen that the mean of
the shell plates is 19:45 tons, and that of the furnace 16-2 tons.
Thus the furnace plates had deteriorated or weakened from 22:7
tons to 162 tons, while the shell had weakened from 22:92 tons to
1945 tons. Now this is after the boilers had done duty for nineteen
years; so we are of opinion that sixteen years is quite long enough
for boilers similarly constructed to be in use: and we trust other
firms will follow Mr. Carmichael, so that this all-important question
of the deterioration of boiler plates that have not shown the slightest
symptom of corrosion, as in these boilers, may be finally deter-
mined, with different qualities of plates.
In recording the testing of another old steam boiler, Mr. Car-
michael states,” “The result of the test so nearly coincides with that
* See Trans. Inst. of Engineers and Shipbuilders in Scotland, vol. xxii.
BOILERS FOR MARINE PURPOSES. 5 I
of the two former boilers—namely, 95, IoS, and I I2 lbs. pressure,
that it may be accepted as the ultimate strain that boilers of this
construction can bear after being twenty years in use. It is much
less than that due to the formula usually given for a new boiler.”
This boiler was twenty-five years old. Some of the plates and
rivets showed little or no change, but brittleness appeared in the
angle-iron.
BOILERS FOR MARINE PURPOSES.
It is not our intention to treat upon the old flue-boiler, with its
multitudinous arrangements, as that class has now become nearly
obsolete, though there is still a demand for them in particular cases,
such as for dredgers. The arrangement of this type of boiler
should be as simple as possible, and all the flues ought to run in
the same direction, and be of uniform width, commencing at the
part where the flame and gases meet from the furnace. When
Fig. 25. Fig. 24.
AA, Furnaces. A A, Furnaces.
B, Combustion chamber. B, Flue.
c, Tubes. C, Uptake.
D, Smoke-box.
E, Uptake.
A.
Fig. 24.—Flue Boiler for Dredger. Fig. 25.-Tubular Boiler for Dredger.
Longitudinal and Horizontal Sections.
more than one furnace is adopted all flues from the furnaces which
join into one large flue should taper from the furnace farthest from
the large main flue. This is obvious, as the flame and gases from
that furnace mix with the next, and so on; care ought to be taken





52 MODERN STEAM PRACTICE.
that the main flue is large enough, and that the flame and heated
gases do not meet in opposite directions. As dredgers generally
work in harbours, where the water is very muddy, the mud being
stirred up from the bottom by the action of the buckets, small
tubular boilers should be avoided; the tubes should be at least
8 inches in diameter, with ample water space between them. The
tubes in such cases are joined to the tube-plates, with a flange of
angle-iron rivetted to the tube. In this example there are two fur-
naces, one at each side of the boiler meeting in a back flue, with
return tubes at the same level as the furnaces. By this means ample
water above the tubes, and a large steam space, are obtained. As
it is an object to keep the weights low down, and as dredging
vessels are generally shallow, a low boiler should be adopted, placed
well below the deck, to give free passage fore and aft for the moor-
ing chains, &c.
For ocean steam ships the multitubular boiler is decidedly the
best, although some very good examples of flat flue overhead arrange-
ments find favour. The tubes vary from 2% inches to 4 inches in
diameter; and in the merchant service they are placed over the
furnaces on the return principle. When for moderate power, and
w
| || ||
Longitudinal Section. Front Elevation and Transverse Section.
Fig. 26.-Ordinary Tubular Boiler.
AA, Furnace. B, Combustion chamber. C, Tubes. D, Smoke-box. E., Uptake.
arranged fore and aft, the boiler is generally made in one piece,
Some of these boilers have no bottoms, but are simply fitted with
a dry plate; while others, made in the usual manner, have dry plates
ſaid on the bottom of the furnaces, thus preserving the rivet heads



BOILERS FOR MARINE PURPOSES. 53
from getting rubbed away by the mere friction of the tools for
raking out the ashes.
Some boilers are constructed, as it were, back to back, in one
large boiler. By this means two ends are saved, but the great
weight of the mass deters many from adopting this plan; but where
large power is required in small space, the arrangement has certain
advantages. The stoke holes must be “fore and aft;” and in general
the fore part of the boiler is the best steam producer, owing to the
\
I
C
lº
º
º
Fig. 27.--Double Boilers. Longitudinal Section and Front Elevation.
A A, Furnaces. B B, Combustion chambers. C C, Tubes. D D, Smoke-boxes. E E, Uptakes.
air getting better circulated in the stoke hole, but, with suitable
air funnels from the deck, the aft furnaces of the boiler can be pro-
vided with the plentiful supply of air so necessary for combustion,
and for keeping the stoke hole cool. There is a passage left be-
tween the two boilers, forming a communication between the fore
and aft stoking-rooms; two funnels are fitted, and the general
arrangement is best suited for paddle-wheel ships.
Another modification differs materially from the former example,
having one combustion chamber common to both sets of furnaces.
This will tend, in a great measure, to effect complete combustion,
and the prevention of smoke; that is to say, if the furnaces are
properly constructed and fired—the fore and aft furnaces being
fired alternately, so that one fire is bright while the other is receiv-
ing fresh fuel. To assist combustion, air is admitted through the
bridge, thus getting partially heated before mixing with the flame
in the combustion chamber. These boilers are made high to insure
ample steam room, while the large area of the uptakes inside of
the boiler dries the steam. Indeed, some think this is by far the

54. MODERN STEAM PRACTICE.
best plan for superheating the steam; far before the complicated
arrangements of separate superheating boxes, with the extra stop-
valves, &c. In fact, dry superheaters soon get out of order, more
especially when there is no steam in the boilers, as must be the case
- F-
Longitudinal Section. Front Elevation and Transverse Section.
. Fig. 28. High Double Boiler.
AA, Furnaces. B, Combustion chamber. cc, Tubes. D D, Smoke-boxes. E. E., Uptakes.
for a considerable time when the fires are first kindled. Any one
can fancy the flame acting on a thin tube, roasting, as it were, the
steam, which subsequently dries up the lubricants, and soon plays
havoc with the slide-valves, pistons, and cylinder faces of the engine.
Steam is only partially dried in the best modern practice, and can
be done in the boiler itself. It will be understood, in the boiler
described, that two ends and two furnace backs are saved, the
material being better disposed in the uptakes.
As we are dealing at present with low-pressure steam-boilers
suited for the merchant service, we will draw attention to overhead
flue arrangements. All boilers of this class should be so designed
that every part is easily accessible for repairs; and, when properly
constructed, we do not see why the flues should not last as long as
any other part, and certainly boilers can be designed so that the
flame and heated gases will pass up and down over a greater length
of surface than in the plain tubular boilers. The flues in this ex-
ample are the entire width of the boiler, leaving 6 inches of water
space at the sides; the flame passes to the top of the combustion
chamber at the back of furnaces, then dips downwards, and so on,

BOILERS FOR MARINE PURPOSES. 55
the flues being divided with suitable water spaces, and are strength-
ened at the top and bottom with conical tube stays, through which
the steam rises and the circulation is effected. The water in the
boiler is thus freely circulated, with the advantage of having a mode-
Fig. 29.—Overhead Flue Boilers. Longitudinal and Transverse Sections.
AA, Furnaces. B, Combustion chamber. C, Flues. D D, Circulating tubes. E, Uptake.
rate body of water, which, under certain circumstances, conduces to
rapid evaporation. There are side doors at the bottoms of the flues
for the convenience of cleaning them out, which can be done in
some instances while the vessel is under way. Another form of flue
l
s
Fig. 30.—Overhead Flue Boilers. Longitudinal and Transverse Sections.
AA, Furnaces. B, Combustion chamber. C, Flues. D, Smoke-box. E., Uptake.
boiler in extensive use materially differs from the foregoing example.
The flues are quite narrow, and are arranged overhead, similar to
tubular arrangements. The flues are 3 feet 9 inches deep, 6 feet in



56 MODERN STEAM PRACTICE.
length, with 2 inches of space for the flame to pass through, and the
pitch of the flues is 434 inches. They are formed of two parallel
plates for the sides, with U-shaped pieces at the top and bottom;
the side plates are flanged at the ends, as well as are the U-pieces at
the top and bottom, for uniting them to the tube plates. The method
of rivetting the top, bottom, and the sides together is as follows: the
rivets are put through the holes, then wedging bars are placed in
at the top and the bottom, and means taken to secure them in their
places. Thus the rivets are firmly held in position, and are clenched
quite cold; and when each section of the tubes are rivetted together
they are placed between the tube plates, and firmly rivetted thereto.
This kind of work requires to be carefully executed; for, should
great leakage occur at sea, the tubes are not easily repaired. The
flues are well stayed every 9 inches apart either way; these stays
also act, to some extent, as heat conductors. When the work in
this class of boiler is well executed it gives very little trouble at sea,
which is essential in all marine steam generators.
The arrangement of low-pressure boilers for ships of war differs
A A, Furnaces.
B, Combustion chamber.
cc, Tubes.
D, Smoke-box.
E, Uptake.
F, Chimney.
Fig. 31. –High Boilers, as arranged for the Royal Navy. Longitudinal and Transverse Sections.
from the tubular class adapted for the merchant service. There
are two classes, namely, high and low, the former having the tubes


BOILERS FOR MARINE PURPOSES. 57
over the furnaces on the return principle, while the latter have
generally the furnaces fore and aft, with the tubes athwart ship,
the tubes reaching no higher than the tops of the furnaces. The
best arrangement for the high class are furnaces athwart ship, with
the stoke-hole between the boilers on the centre line of the vessel—
the distance apart from front to front of the boilers being IO feet;
this is considered ample room for the firemen. As the top of the
boilers requires to be at least I foot below the water line, the ordinary
steam-chest is dispensed with, sufficient height being left between
the top and the water in the boiler. To give free circulation fore
and aft, the uptake or dry smoke pipe is shaped thus, /\, flat at
the bottom sides, but rounded at the top, to take the main funnel.
This is a very good plan.
We have also seen many arrangements formed with the steam-
chest over the firemen's heads; a plan that should never be attempted,
as such require an artificial blast to keep free circulation in the Stoke-
hole, the usual plan being a fan driven by a separate engine; but
in some classes of war ships, such as “Monitors,” even this fan is
necessary, the “free-board” in such ships being so low that in rough
weather the hatches require battening down, and then ventilation
must be kept up by mechanical appliances.
The low class boiler is
admirably suited for fine
midship sections, firing
fore and aft. They are
placed closely together at
the centre line of the ves-
sel, leaving only a space
of 2 inches between the
lagging, or the wood cover-
ing which is placed over
the boilers to prevent ra-
diation. The furnaces, say
three in number, join in
one “athwart-ship flue,”
widening from the furnace
at the centre of the vessel Fººgºº, ſº
to those at the sides, and bustion chamber. C, Tubes. D, Smoke-box, E, Uptake.
then passing into the combustion chamber, which runs fore and aft,
this chamber tapering from the furnaces to the extreme end. This

58 MODERN STEAM PRACTICE.
is necessary, as the flame has always a natural tendency to take the
nearest cut to the funnel: thus, when the combustion chamber is
made wide at the furnaces and narrow at the extreme end the flame
and gases are more equally distributed through the tubes. The tube
plates are placed at an angle, for the convenience of getting out
the tubes for repairs; and at the back, under the funnel, there is
space left for cleaning out the tubes.
When the boiler space is rather limited, as in narrow vessels
such as despatch boats, the fur-
naces are arranged fore and aft,
with two furnaces at the centre
of the ship, with separate Com-
bustion chambers for each fur-
nace. This arrangement will
suit best when the stoke-hole
is forward, so that a current of
air freely passes through, the
air supply being greatly im-
C A A C proved by the forward motion
of the ship. The tubes are
arranged at the sides on the
e return principle, but they are
Fig. 33.--Low Boiler for Despatch Boats. Transverse e
and Horizontal Sections. A A, Furnaces. B B. Combus- placed 1) O higher than OI) a. level
tion chambers. cc, Tubes. DD, Smoke-boxes. E, Uptake. with the top of the furnaces.
The high and low pressure combined engines necessitate a stronger
form of steam-generator, for which circular boilers are decidedly the
strongest. One arrangement of double boiler has three furnaces
at each end, the middle one being placed much lower than the two
side ones; this is done to fill up the dead water space at the bottom.
The furnaces are fore and aft, with one combustion chamber com-
mon to both ; they are provided with dry uptakes fitted to the fronts.
When four uptakes are arranged for one funnel, each boiler has a
separate tubular uptake with a flue running through it. All the
uptakes converge to the centre of the vessel; these uptakes serve
the purpose of superheaters, and the inner tube, or flue, is strength-
ened with rings of angle-iron. For 3OO horse-power nominal, the
boilers being I 3 feet 6 inches in diameter, the heating surface in each
is as follows: 2308.88 Square feet in tubes, IOO square feet in fire-
box, 248-22 Square feet in furnaces, making a total for two double
boilers, 53I42 Square feet, or 1771 Square feet per nominal horse-
ID ID

BOILERS FOR MARINE PURPOSES. 59
So it will be seen that circular arrangements can be placed
in almost as little space as ordinary marine boilers.
power.
A. A
Fig. 34.—High-pressure Double Boilers. Transverse and Longitudinal Sections.
AA, Furnaces, B, Combustion chamber. cc, Tubes. D D, Smoke-boxes. E. E., Uptakes. F, Separate uptake.
Some are arranged for only two furnaces in each single boiler,
with tubes overhead as in the previous example, and having one
combustion chamber common to both furnaces; this chamber at
Fig. 35.-High-pressure Boilers. Transverse and Longitudinal Sections.
AA, Furnaces. B, Combustion chamber.
C, Tubes. D, Smoke-box. E., Separate uptake.
the back of the furnaces is made large; indeed, in all boilers hav-
ing tubes on the return principle the combustion chambers should




6O MODERN STEAM PRACTICE,
have ample capacity, so that the flame hangs, as it were, before
passing through the small tubes, giving more time to abstract the
heat from the gases before they pass up the chimney. This is more
required when the uptakes in front of the furnaces are made dry,
or separate from the body of the boiler, so as to keep the stoking-
room as cool as possible. For moderate power, say 300 horse-
power nominal, four boilers are adopted, with uptakes arranged
for two funnels; and should the section of the vessel be very fine,
with a great rise of floor, the back end can be bevelled or cut away
at the bottom to suit the form of the ship. All the flat parts are
stayed in the usual manner. For ships of war, when the stoke-
hole is fore and aft, on the centre line of the vessel, the uptakes
should form part of the boiler, as dry uptakes would make it intoler-
A A, Furnaces. B, Combustion chamber. CC, Tubes. D, Smoke-box. E. E., sºme F, Chimney.
ably warm for the firemen. The uptakes, or “lumleg,” should be
made double; they can be made slightly oval, and be strengthened
with conical tubes, so that the steam freely passes through them;
and when great steam pressure is demanded the insides and the
outsides of the uptakes should be well secured with screwed stays;
this arrangement will make a very effective superheater. The top
of the uptakes must be below the water line. When one funnel is
required for six boilers, it is placed centrally between the four front
boilers, and the aft boilers have dry pipes, thus joining the three
boilers on a side; the back of the boilers at the bottom are cut
away to suit the form of the ship, but when this is not required
they should be straight, thus simplifying the construction. The up-
takes must be fitted with the usual outer casings, for taking away
the vitiated atmosphere from the stoking-rooms.




BOILERS FOR MARINE PURPOSES. 6 I
For small power for great steam pressure, one furnace is fitted
with return tubes at the side; while other boilers have the furnace
central with the boiler, with return tubes overhead and at each side.
The lower tubes in such an arrangement should be larger; thus the
flame is drawn down, as it were, and the bottom tubes by this plan
are kept free from soot deposit. Another arrangement has two
furnaces in each boiler, with the combustion chamber at the back
of the furnaces, and then the tubes placed direct through the boiler,
thus entailing a long boiler; and this plan is good when there is
Figs 37,38, ºsman High pressure Boilers.
A, Furnace. B, Combustion chamber. C, Tubes. D, Dry uptake. E, Steam dome.
sufficient room in the vessel. When a steam-chest can be fitted,
it is preferable to do so; and it is found a great advantage in such
small boilers to line the combustion chamber with fire-bricks, having
apertures for the smoke to freely pass. The steam pressure usually
adopted is from 40 to 60 lbs. per square inch, and such boilers are
best suited for river navigation, where good fresh water is obtained.
As some river boats are made very shallow, and constructed of
very light scantling, it is desirable to have the boiler, and all the
machinery, designed to spread over a large surface; and when

62 MODERN STEAM PRACTICE.
IOO lbs. steam pressure is used, boilers of the locomotive type are
decidedly the best, and they can be made of steel, thus tending
materially to increase the carrying power for cargo by lightening the
boiler. The same class is largely used for steam-launches, having
the whole of the machinery fitted thereto.
Torpedo boats are now fitted with the locomotive type of boiler,
carrying a working pressure of about 120 lbs. per square inch. The
draught is forced by a fan blast. The evaporation in these boilers
per lb. of coal seems to be about 7 lbs., and the evaporation per hour
per square foot of heating surface varies from II to 18 lbs. The coal
consumed per hour per square foot of grate varies from 50 to IOO lbs.
The haystack boiler, originally introduced in Clyde river practice,
is well suited for vessels of light draft. The shell is cylindrical
with a dome-shaped top. The tubes are placed vertically, with the
furnaces beneath and around the sides.
PROPORTIONS FOR MARINE BOILERS.
When a number of boilers are to be designed of various sizes, it
will facilitate the designer if he fixes on the scale to be universally
adopted, and get the drawing-paper prepared with light lines, ruled
in 2-inch squares, according to the scale determined on, these Squares
corresponding to the pitch of the rivets, or 2 inches between centre
and centre. It is by far the cheapest and best arrangement where
the front and the sides are worked square at the corners, the back
at the top and the bottom being rounded, as in many instances
this requires to be done to fit the midship sections of the vessel.
Boilers so designed, and drawn on ruled paper, greatly assist the
draughtsman in getting up the working drawings for the work-
shop.
After making a rough sketch of a boiler, we know about the
length, breadth, and the height required, and commencing on the
side of a square, we lay off the length, breadth, and the height per
scale; thus the configuration of the boiler is represented by so many
squares; the length, breadth, and the height should always be even
dimensions, and there is nothing to prevent all boilers being so
constructed. We may now set out the plating, taking the centre of
the squares as the edges of the plates, wherever we arrange the joints,
breaking bond where required. It is evident that the plates must be
always of even dimensions. Each plate will contain as many rivets,
of the universal pitch of 2 inches, as there are squares; thus by
**-*.
BOILERS FOR MARINE PURPOSES. 63
counting the number of squares in each line of plating in the length
and the breadth we arrive at the true length and breadth of each
plate without using a scale, the ruled paper being the universal
scale for all flat surfaces; all the other parts of the boiler where
practicable should be set out in like manner, and after they are
marked on the drawing No. 1, No. 2, &c., these are the marks
that must be numbered on each plate as delivered from the rolling-
mills. No. I plate will contain so many rivets in the length and
breadth, thus the machinemen need never apply a foot-rule, but
simply adjust them on the travelling table of the drilling or punching
machine, and the machine itself will do the work of drilling or
punching the plates with mathematical precision, the plates being
previously planed on the edges to the correct size.
In all Government contracts the top of the boiler must be at
least I foot below the water line. To insure ample steam room
3 feet 6 inches is allowed from the top of the boiler to the top of
the flucs. For boilers intended to run out about four times the
nominal horse-power make an allowance of '68 to 7 of a square
foot of fire-grate surface, per nominal horse-power, and from 18:8
to Ig Square feet of heating surface, taking the whole circumference
of the Small tubes that in multitubular arrangements is available,
including the flues, sides, and the tops of the furnaces above the
fire-grate, and one half of the back tube-plate may be included in
the total heating surface. Composition tubes are usually adopted,
having an external diameter of 2% to 3% inches, and the pitch of
the tubes 3% to 4% inches. The length of the tubes may vary
from 5 feet 6 inches to 7 feet, but should never exceed that length.
Fire Grate and Heating Surface for Indicated Horse-power—For
every indicated horse-power the engine is intended to work at, make
an allowance of about 3 to 3% square feet of heating surface, and
one-eighth of a square foot, or 18 square inches, of fire-grate for
every horse-power indicated. The consumption of coal per square
foot of grate is about 20 lbs. per hour, and the water evaporated
about 9 lbs. per 1b. of coal.
Writing on this subject, Professor Rankine gives as follows:– “The
greatest available heat, or the rate of expenditure of heat upon the
steam, is to be compared in units of work, by dividing the greatest
indicated power required in units of work, per unit of time (say in
foot-pounds per hour), by the probable efficiency of the engine; or,
otherwise, multiply the pressure equivalent to the rate of expendi-
64 MODERN STEAM PRACTICE.
ture of heat by the total cylinder capacity, and by twice the number
of revolutions per minute.
FIRST METHOD,
Probable indicated power,.......................................................... 743
x foot-pounds per hour (in indicated horse-power),......................... 1,980, OOO
I,47 I, I4O,OOO
The above divided by the probable efficiency of the steam, o' 12, gives
the available heat required in foot-pounds per hour,......................... = I2,259,500,000
SECOND METHOD.
Estimated pressure equivalent to rate of expenditure of heat in steam
(lbs. on the square inch) 108% x estimated total cylinder capacity in
prism of 1 foot x I inch x inch by twice the number of revolutions per
hour,........................................................................................ 39,033
4,228,575
28,992
I2,259,484,650
“Available Heat required in foot-founds per hour—The available
heat of combustion of 1 lb. of fuel (or rather coal) is to be estimated
by multiplying the total heat of combustion of 1 lb. of fuel by the
efficiency of the furnace.
“The total heat of combustion of 1 lb. of coal of a good quality for
marine purposes may be estimated at from 9,000,000 to IO,OOO,OOO
foot-pounds, and that of the very best at 12,OOO,OOO foot-pounds.
Inferior qualities about two-thirds of the above estimates.
“The efficiency of the furnaces may be roughly estimated as fol-
lows—Divide the intended number of square feet of heating surface
per lb. of fuel per hour, by the same number + o-5, eleven-twelfths
of the quotient will be the probable efficiency nearly. The following
are examples:— *

| vailable Heat
Hàº. Emºney º
per Lb. of Fuel Furnace of Total Heat,
per Hour. º IO,OOO,OOO.
Small Value for Marine Boilers...... o'50 o'46 4,600 OOO
O'75 O'55 5, SOO,OOO
I ‘OO O'6I 6, IOO, COO
Ordinary Values in Marine Boilers I ‘25 o 65 6,500, OOO
I '50 o:69 6,900,000
2 “OO o'73 7,300, OOO
- 3’OO O'79 7,900, OOO
Water Tube and Cellular Boilers, Ó ‘OO O'84 8,400,000
“The most common values of the available heat of a pound of good
BOILERS FOR MARINE PURPOSES. 65
steam coal in marine boilers are 5,000,000 to 6,000,000 foot-pounds,
making an allowance of 20 to 50 per cent, for waste, &c.
“To find the probable greatest rate of consumption of fuel, divide
the available heat per hour by the available heat of combustion of
1 lb. of fuel (example) available heat per hour, I2,26O,OOO,OOO +
available heat of combustion per lb. coal, say 5,500,000 = 2229 lbs.,
probable consumption of fuel per hour.
“To find the proper area of heating surface, multiply the rate of
consumption of fuel in pounds per hour by the intended area of
heating surface to each pound of fuel per hour, that is usually from
34 to I}% square foot.
“To find the proper area of fire-grate, divide the rate of consump-
tion of fuel in pounds per hour by the weight of fuel in pounds to
be burned per hour on each square foot of grate, the quantity ranges
in ordinary boilers from 16 to I2 lbs., and the latter limit may be
considered a suitable rate for the most rapid combustion at high
speed, provided air is admitted above the fuel to burn its gaseous
constituents. In some grates the combustion is as low as from 6
to I2 lbs.
“The total sectional area of flues (or tubes) is from one-fifth to one-
seventh of that of grate, the area of the chimney one-tenth of that
of the grate.
“The capacity of marine boilers is equal to the heating surface
multiplied by about I foot for flue boilers, or o:625 of a foot for
tubular ones (exclusive of furnace room), including all internal parts;
the contents may be estimated as nearly equal to the area of fire-
grate multiplied by from 6 to 8 cubic feet, one-fifth being steam-
room, and the rest partly water space, &c.” *
The following are some of the relations which exist in recent
marine practice:—
Grate Surface in square feet = Nominal Horse-power × 3.
Heating Surface in square feet = 25 to 28 times the Grate Surface.
And ºths of the total Heating Surface = Tube Surface.
Indicated Horse-power.
8 3.
And Heating Surface in square feet = Indicated Horse-power x 3%.
Or Grate Surface in square feet =
Staying.—Flat surfaces, such as for low-pressure marine boilers,
must be strengthened with a suitable number of stays. The dis-
tance between the stays may be 18 inches for pressures below 20 lbs.
per square inch, but for pressures above 20 lbs. per square inch, the
5
66 MODERN STEAM PRACTICE.
distance between should be 16 inches, in the parts that require
periodical inspection, but in confined places where it is not easy of
access I4 inches between the stays may be adopted. As corrosion
rapidly sets in, the stays must be made of greater strength, in the
first instance, than what is actually required; and it is advisable
that all the stays should be rivetted to angle-iron secured to the
boiler, palms or flat pieces being forged on the stays for taking the
rivets. By this plan the angle-iron materially stiffens the sides of
the boiler. When the sides of the boiler are stayed with round bar-
iron, screws are formed at each end, the diameter at the bottom of
the thread being the same as the main body of the bar; thus the
ends being larger than the bar, are more easily passed through
and through. These stays have nuts on the outside and inside of
the plates, with washers for screwing the nuts against: by this means
the plates can neither bulge out nor collapse. The sides of the
furnaces and water spaces all round the combustion chamber at the
back of the boiler have screwed stays similar to a locomotive boiler.
These stays are simply short bars of iron, screwed from end to end,
the plates being tapped to receive them, so that when they are
screwed into the two plates, each bar forms a secure stay to resist
bulging and collapsing; and as they require to be at times removed
they are not rivetted as in the locomotive boiler, but merely fitted with
nuts on each plate. The stays for the sides of the furnaces should
be well kept out of the fire; they can generally be so arranged that
the top rows are above the live coal, as high up as convenient, and
the bottom rows entirely below the fire-bars. The tube-plates should
be properly stayed. Some makers prefer using tube-stays, well
screwed at the ends and fitted with outside and inside nuts. Some-
times collars are formed on the stay-tubes for the inside, and nuts
on the outside. This is not a very good plan, for should anything
happen to a tube, there is a difficulty in taking it out, and it is evident
that it cannot be replaced. The best method of staying the tube-
plates together is by sacrificing some of the tubes as heating surface,
and staying with plain round bars screwed at the ends, with nuts inside
and outside of the plates. Although for the working parts of marine
engines, and all parts subjected to tension, 4000 lbs. per square inch
is allowed for wrought-iron, it is advisable for the stays only to
allow about 3OOO lbs, per square inch. We will now run out the
number and diameter required in a flat-sided boiler, Supposing the
side is IO feet by I I feet, and say 56 stays can be conveniently got
BOILERS FOR MARINE PURPOSES. 67
in. Find the number of square inches in the surface, multiply by
the pressure per square inch, say 20 lbs.; thus, IO × I I × I44= I5,840
x 20=316,800 lbs., equal pressure on the whole surface, which,
divided by 3000, gives the total area of the stays; and again by 56,
gives the area in square inches for each stay at the bottom of the
thread: *:::= IOS 6––56= I-8 square inch area for each stay, say
I #4 inch in diameter. For the screwed stays in the furnace side-
plates the diameter is generally I 34 inch, with spaces to suit; and the
stays which secure the sides and bind the top and bottom together—
i.e. the stays passing through the water spaces between the Small tubes
—are made of flat bar-iron, with screwed ends and nuts inside and out.
Fire-bars.-Wrought-iron fire-bars have a breadth of 13% inch
at the top and 9% inch at the bottom, and are 3 inches deep.
Weight of Wrought-iron Bars,............ 3 ft. 3 in. long = 30 lbs.
Weight of Cast-iron Bars,.................. 2 O , , = I9
Weight of do. .................. 2 6 , , = 24
Weight of do. .................. 3 O , , = 27.5
Weight of do. .................. 3 6 , = 32 to
Weight of do. .................. 4 O , , = 36'5
Cast-iron bars have a breadth of full 76 inch at the top and full
% inch at the bottom, the depth ranges from 3 to 4% inches, and
the distance between bars from 3% to 9% inch.
Tube A7ea, Furnaces, &c.—The calorimeter of the boiler or sec-
tional area of the tubes is a subject no one need trouble himself
about, as the combined area of the tubes is greatly in excess of
what is required, and in which we have no choice, as it depends on
the length of the tubes that can be introduced. The ordinary size
of tubes for the merchant service varies from 3 to 4 inches external
diameter, and from 6 feet to 7 feet in length; while for the Royal
Navy the tubes are 2% to 3% inches external diameter, and 5 feet
6 inches to 7 feet in length, consequently it will be seen that the longer
the tubes are the greater the heating surface, while the combined area
through them may be the same. The only thing to be considered
is to arrange them so as to get the greatest effect from the fuel. For
the Royal Navy composition tubes are usually adopted, as their con-
ductive power is greater, and the water spaces are not so liable to
choke up with deposit; but for the mercantile marine iron and steel
tubes are extensively used. The tubes in either case are driven hard
into the holes in the tube-plates, and, after they are all in their places,
are widened out with a suitable tool, and the edges neatly laid over.
68 MODERN STEAM PRACTICE.
Sometimes ferrules are fitted and driven into the tubes nearest the
furnaces, but at the smoke-box end they are simply expanded, and a
slight countersink left in the holes on the outside, thus forming a collar
when the ends of the tubes are laid over. The flues and combus-
tion chamber at the back of the boiler are of great importance, more
especially with short tubes arranged and worked on the return prin-
ciple. In many boilers of this class the flame and heated gases pass
too rapidly through the boiler into the chimney, and if not fitted with
a high uptake causes great waste in fuel, the flame and gases having
little time to act on the heating surface. The combustion chamber
should be made large, so as to make the flame hang in the flues
before passing through the small tubes. The usual size at the top
of the combustion chamber is 18 inches, and at the bottom 22 inches,
from the tube-plate to the back of the chamber, this being actually
required in all cases to properly expand and lay over the ends of
the tubes. It is advisable, however, not to increase this space to any
great extent, more especially for high pressure, as large flat surfaces
are not to be desired. But for moderate pressure, 22 inches at the top
and 26 inches at the bottom will tend to retard the flame and gases in
the combustion chamber. The area over the bridges is from 18 to
I9 square inches per nominal horse-power; thus it will be seen that
the calorimeter of the tubes is greatly in excess of this. It must be
acknowledged by all that marine boilers should have as many fur-
naccs as possible, bearing in mind that there is a certain size of
furnace very convenient to manage, and other sizes, above or below,
that are not so convenient. A good medium is a width of 2 feet
9 inches, and certainly not less than 2 feet 6 inches, or greater than
3 feet 3 inches, and from 6 feet to 7 feet in length, but should not
exceed the latter, as a 7-feet furnace is quite long enough to manage
properly. But in some instances the boiler room is so limited that
length must be substituted instead of breadth. Some makers have
even gone to the extreme as regards the width, considering if they
make the furnace circular, a diameter of 3 feet 6 inches could be
used with impunity; but experience proves the contrary, as with
ordinary Sea water Scale will form, and accumulating to any great
thickness, the furnace plates become heated and the tops come
down, even although there is a plentiful supply of water in the boiler.
So as many furnaces of a medium width as can be conveniently
arranged are far better than a less number of a great width, con-
sidering the more furnaces we have there will be more side surface
BOILERS FOR MARINE PURPOSES. 69
exposed to the action of the fire; for undoubtedly at the tops and
sides of the furnaces the water is most rapidly evaporated, and
consequently a better steam-producing boiler will be obtained,—a
result that all should strive to reach, even although it may be at
considerably more cost in manufacturing.
Thickness of Plates for Round Boilers.-As these boilers, for the
compound marine engine, are made large in diameter, carrying high
steam pressure, the best quality of iron must be used, or B, B, equal
to Yorkshire plates, the breaking strain being 57, I2O lbs. per Square
inch; and taking one-fifth of the breaking strain of the plate or
rivetted seams as the constant for this quality of iron, we have—
D P
I I424
= thickness of the shell.
Thus, supposing we have a boiler I42 inches in diameter, and the
steam pressure 70 lbs. per Square inch—
I42 × 7O © º
T 11424 TT .87 or 7% inch thick.
The seams should be double-rivetted, which are nearly equal in
strength to the solid plates. For the thickness of the plates for the
other parts of boilers we give two examples by English and Scotch
firms, the steam pressure being 70 lbs. per square inch in each
CaSC —
London Made. Leith Made.
inches. inches.
Diameter of Boiler...........................I42 .............. I2O
Thickness of Shell........................... § ............... #
Do. End Plate..................... + ............... #
Do. Tube Plate................... # ............... #
Do. Furnace Plate ............... I's ........ & e º e º e e +g
Do. Back of Furnace Plate...... ¥s ............... i's
Strength of Flue Tubes to resist crushing. Example:—
.43° inch thickness of plate x constant 7ooooo -:
7.25 feet length of tube x 36 inches, diameter of tube T
ult. strength 495 -- 6th = 82 lbs. working pressure.
In a paper on the Strength of Boilers, by Mr. J. Milton, surveyor
to Lloyd's," the question of factors of safety is considered; and it
is shown that the ordinary cylindrical boiler is the only really reli-
able marine boiler at present in use, and that as the shell plates had
reached up to a thickness of I }4 inch, the weight of such a boiler
became an important item in the load carried by the ship. Hence,
* See Zºrans. Inst. Mazal Architects, session xviii.
70 MODERN STEAM PRACTICE.
any method whereby the boiler could be lightened, and yet kept
efficient, would be of great value for mercantile purposes. It is
shown that Prof. Rankine and others estimate that a factor of safety
of eight is necessary for such a live load as steam. The author
however, states, “Now experiments show conclusively that up to a
temperature considerably exceeding that at which it is practicable
to use Steam, wrought-iron does not lose strength; and as no part
of a properly designed boiler is subjected to a temperature much
greater than that of the steam within it, without being specially
strengthened, there does not appear to be any reason for this great
difference of factor of safety. The Manchester Steam Users' Asso-
ciation, founded by Fairbairn for the prevention of boiler explosions,
consider that where boilers are well built and carefully examined
periodically a factor of safety of four is sufficient, and the correctness
of these views is shown by the freedom from accidents in boilers
guaranteed by them; but of course we are not warranted in con-
cluding from this that the same factor would be sufficient for marine
boilers, which often cannot be subject to the same careful and
systematic examinations as land boilers. The old-fashioned box
boiler working at from IO to 30 pounds had only a factor of about
four, and yet the accidents which have happened with this low factor
of safety were quite as few in proportion to the number of boilers
in use as with the higher factor of six, which is about the present
practice of the country, although at the same time improved appli-
ances have enabled boiler-makers to make better and more reliable
work than formerly. But although the present factor of safety is
nominally sit in many boilers which are at present at work, there
are parts which, either from oversight or want of knowledge on the
part of their designers, are very much weaker than the other parts,
and which considerably reduce the actual factor of safety. Yet we
find that these specially weak parts are often quite strong enough
for their work, for even after many years' service they do not show
any signs of weakness. If these parts are strong enough, then un-
doubtedly the extra strength of the remainder of the boiler has becn
so much useless weight.”
On the question of proportioning the strength of boiler, the effect
of expansion is pointed out as an important agent in the tear and
wear of a boiler. “There are certain strains which boilers are sub-
ject to which are, under certain conditions, much greater than any
which the working pressure can bring upon them, and which are
BOILERS FOR MARINE PURPOSES. 71
altogether independent of the factor of safety employed. I mean
the strains brought upon the boiler by the unequal expansion of its
different parts. Ordinary wrought-iron plates, if left free from
stress, expand OOOOO64 of their linear dimensions for each degree
Fahr, increase of temperature. Also if the plates are subjected to
stress they alter in length a certain amount according to the quality
of the iron; the more ductile irons altering more for the same
amount of stress. Taking as the mean value of E, 29,000,000 (the
value given by Rankine) we find that a stress of 186 lbs. per Square
inch will give the same alteration in length as I* Fahr. If, now,
the ends of a plate are rigidly fixed so that it is incapable of altering
its length, an increase of 1°Fahr. will subject it to a compressive stress
of 186 lbs. per square inch, and a decrease of 1° to a tensile stress
of equal intensity; and it is to be observed that these stresses are
totally independent of the sectional area of the plate. Now, in the
case of a furnace, the portion above the fire, especially when coated
with even the thin enamel or scale which is necessary to preserve it
from corrosion, must be considerably hotter than the portion below
the bars. Hence the top of the furnace tends to get longer than
the bottom. If the end fastenings of the furnace were so rigid as
to maintain the top and bottom of same length, the top would have
to be compressed and the bottom stretched, and every difference of
a degree Fahr. in the temperature would produce a compressive
stress in top and a tensile stress in bottom of 93 lbs. per square inch.
But actually the end fastenings are not so rigid, and the strains
caused by the unequal expansion are not distributed from top to
bottom by the ends only, but also in a great measure by the resist-
ance to shear of the plate, and hence the greatest stresses come at
the middle of the length of the furnace. Also, it is evident that
these strains are not uniformly distributed, and hence their maximum
must be greater than their mean, and with a great difference of
temperature the stresses reach a high figure. The only way to
strengthen furnaces from such strains is either to prevent the differ-
ence of temperature, or else to allow the crown freedom to expand.”
The question of reduction of strength of plates by punching or
drilling has had much attention, and experiments go to prove the
greater strength of drilled plates. Steel plates should always be
drilled; if punched, they must be annealed afterwards to reduce the
local strains set up by the action of the punch.
The corrosion of boilers is an important matter, and recently since
72 MODERN STEAM PRACTICE.
the introduction of steel the question has been raised as to the rela-
tive resistance of the iron and steel plates to this action. So far as
experiment or experience has gone, the action seems to be pretty
much the same in both materials. The influence of scale upon the
steel plates is prejudicial, as a galvanic action is set up between the
part covered with scale and any parts not so covered, which causes
pitting of the latter. This scale of black oxide can be removed by
exposure to acid, and in ships building at present for H. M. Navy
the plates are immersed in a solution of sulphuric acid and water so
as to clear away any scale which may adhere to them.
Where certain kinds of peaty water is used for feeding, the boiler
seems to be quite unaffected by corrosive action. This is notably
the case in the boilers of the Loch Lomond steamers, some of which
after very many years' service are unaffected by corrosive action.
It appears that a kind of coating, of a dark or brownish Colour, is
deposited on the iron, which protects it, and does not appear to
affect the conducting power of the plate.
One method of bringing about the much to be desired lightening
of boilers is to adopt the locomotive type of boiler with forced com-
bustion. This method is now tried in steam launches, or torpedo
boats, where as much as I 50 lbs. of fuel appears to have been
burned per foot of grate per hour.
In reference to this question of economy of weight, The Engineer,
in a leading article, July 8, 1881, says—“The modern high-pressure
marine boiler is by no means all that a boiler should be. We may take
as a type a three-furnaced boiler to carry 70 lbs. Such a boiler will be
about 12 feet in diameter by Io:6 feet long. It will contain three
furnaces, each three feet in diameter, and a little more than 7 feet
long, and each furnace will have a separate back uptake, and sixty
3-inch tubes 7 feet long. A boiler of this kind, if fitted with a large
steam dome, will steam well, and may be depended upon, with fair
coal, to work a pair of compound engines up to 500 indicated horse-
power. Its shell plates will be nearly I inch thick, and its total
weight without water will be roughly 28 tons, and it will hold 14
tons of water. Its gross weight therefore will be, under steam and
allowing for grate-bars, &c., not far short of 45 tons. It will have
a grate surface of about 57 square feet, a tube surface of 900 feet,
the crowns of the furnaces will amount to about 100 square feet,
and the uptakes may be taken as 120 feet more. The total heating
surface will be therefore a little over I IOO square feet.
BOILERS FOR MARINE PURPOSES, 73
“If we contrast this with a locomotive boiler, we find that the
latter will not weigh, complete with water and in working order,
more than 12 or 13 tons. It will have I IOO feet of heating surface,
and 18 to 20 square feet of grate, and it may be depended upon to
develop 600 horse-power in a non-condensing engine.
“The cubical space occupied by the locomotive boiler will not be
more than one-fourth of that taken up by the marine boiler, and it
will be on the whole quite as economical, if not more economical.”
In referring to objections to the use of the locomotive type of boiler
at sea, it is pointed out that a fair trial has not yet been made of
such boilers at sea for mercantile purposes, and that it has proved
serviceable in torpedo boats.
Attempts are being made at present to give practical effect to
this question of decreased dead weight by reducing the diameter of
the shells, and giving increased draught so as to consume more fuel
per foot of grate surface.
As to the question of the relative economy of chimney draught
and forced draught, it has to be borne in mind that although power
has to be expended in driving fans or blowers to produce a forced
draught, still in the chimney draught a large proportion of the heat
of the furnace is spent to produce and keep up such draught,
reaching, according to some authorities, to one-fourth of the avail-
able heat of combustion.
It has been proposed to carry out forced draught by jets of steam
in funnel or air in ashpit, or by fans blowing air into ashpit direct,
or into the stoke-hole, the latter in this case requiring to be air-
tight.
Funnel, Damper, &c. — The ordinary height of funnels for
steamships of the merchant service is about 32 feet 6 inches
from the top of the steam-chest, and about 48 feet height from
the top of the fire-bars, the area = #th of fire-grate. Where
more than one funnel is required the arrangement of the boilers
will determine the number and positions of the funnels. It is
very usual now in large Ocean-going ships to have two funnels,
and in some cases even three funnels, as the City of Rome, Zivadia,
and other vessels. In the first-named ship the funnels are arranged
fore-and-aft, in the Livadia athwart-ships. The plates are gener-
ally arranged in four lengths, the three lengths towards the bottom
9 feet each, and the top plates 5 feet 6 inches. The joints are butted,
with strips inside of the chimney, and the circumferential joints are
74. MODERN STEAM PRACTICE.
made with a flat ring and iron moulding. At the top horizontal
joint, or 27 feet from the bottom of the funnel, lugs are forged on
the ring, on which to fix links for the funnel shrouds, which are
Secured below to the side of the ship.
Thickness of Bottom Plates, .......................... ... ** inch.
Do. of Top Plates, .................................. § 2,
Joint Straps,................................ • * g e º º is is a s e 4; x is ,
Flat Rounded Moulding, .................................. 3 inches.
The bottom of the funnel is fitted to a cast-iron ring secured to the
top of the steam-chest. Where four boilers are used this ring is
divided into four parts, with cross bars of cast-iron, cast in one piece,
to which is fitted a damper for each boiler, having an uptake from
each, independently of the others, that the draught of each boiler
may be regulated separately. One of the cross bars is cast hollow,
forming a pipe from the side to the centre of the ring, or centre
of the funnel; this is termed the blow-pipe, and is fitted with a
plug-valve in connection with the steam-room in the boiler. The
engineer by this means can urge on the fires by blowing the steam
up the chimney, and thereby causing a partial displacement of the
air, which is filled up by the atmospheric air rushing under the fire-
bars and through the holes left in the furnace doors, providing the
large supply of oxygen so necessary for combustion. With high-
pressure engines the waste steam from the cylinders is blown up
the chimney in a manner similar to the blast-pipe of the locomotive
engine.
Funnels of large diameter are usually stayed internally with
round bar iron, to prevent them from getting out of shape in the
workshop or on carriage to the ship. For ships of war the funnel
is made telescopic, the top part sliding into the lower part. The
outside part, or lower portion, is formed conical at top, with a cor-
responding cone for the internal or top portion, fitted at the bottom.
Thus, when the top part is hoisted up, the inside cone fits into the
outer one, and the funnel is screwed hard up with set screws, swivel-
ling in boxes recessed in the funnel. The points of the screws bear
on an angle-iron, fitted round the outer portion. The top part has
likewise the shrouds for securing the funnel to the ship's side. The
mechanism for hoisting up the funnel is a worm-wheel and pinion,
with the necessary barrels, chains, and guide blocks. This gear
should, when possible, be fastened down to the top of the boilers,
or strongly bolted to the side plates of the bunkers, as the worm-
BOILERS FOR MARINE PURPOSES. 75
wheel is apt to jam in the pinion if the frame for it is not rigidly
secured. An outside air-casing must be carried up from the top of
the boiler, or dry uptake if so fitted, to about 8 feet above the deck,
for taking away the vitiated air from the stoke-hole, and protecting
the woodwork of the combings around the funnel from the great heat
radiated from the uptake. On the deck thcre is another casing, so as
effectually to keep the passage round the funnel cool. There are holes
all round at the tops of the casings, and likewise at the bottom, for
the thorough ventilation of the stoke-hole. The waste steam-pipe is
likewise made telescopic, the bottom part having a suitable stuffing-
box, through which the top part slides steam tight, the top part
having a stay, with collars on the waste-pipe, the stay being attached
to the top or sliding part of the main funnel.
The smoke-doors should be hinged to flat bars, fastened vertically
to the Smoke-box. The doors should have an inside plate and an
outer one, kept apart from the door itself, but secured to it by
ferrules and rivets: the inner plate is to protect the door from the
fire, and the outer one to keep the Stoke-hole cool. By this arrange-
ment a current of air passes freely between both the inside and the
outside plates. There are handles, fitted with a means of keeping the
door shut, so constructed that the Sneck or Snib presses the door for-
cibly against the hinge plates. The furnace doors are hinged so as
to cover the apertures formed in the front plates, thus doing away with
cast-iron frames, and are pierced with air holes, having the means of
regulating the Supply of air to the furnaces. The ashpits are fitted
with dampers at front, hinged on a pin, having ratchet wheels and
pawls, for regulating the supply of air underneath the bars, or, by
shutting them, damping the fires. The manhole on the top of the
boiler should be cut in the most convenient place, and the door
secured on the outside with a bridge piece, strongly bolted. The size
of the manhole is usually 18 inches by 14 inches, which is sufficient
to allow a man of ordinary size to pass through for inspecting and
cleaning the inside of the boiler. Smaller doors are left in the
front plate of the boiler, between the furnaces at the top, of sufficient
size to allow a boy to pass through for Scaling the furnace tops. All
the necessary doors must be fitted at the bottom of the boiler, for
raking out the sludge, the bolts for Securing them being made so as
to draw up the door against the inside of the front plate of the boiler;
one large bolt, having a cross bar over the hole, is by far the best
plan for securing them.
-6 MODERN STEAM PRACTICE.
Of late years many improvements have been made in connection
with steam boilers, with the view of increasing the economy of the
fuel, and thereby rendering the boiler a more efficient steam-gener-
ator. The loss due to emission of smoke may in many cases be
met by careful firing. Appliances known as mechanical stokers
have been introduced, whereby the fuel is gradually fed to the fur-
nace through a hopper arrangement in front, means being adopted
to work the coal to back of furnace. Another method of fuel feeding
has been recently tried, in which the coal is charged upon a mov-
able truck, which by gearing is pushed inside the grate and below
the fire-bars, the fresh coal is then lifted or pushed up below the
burning fuel, and thus partially cokes before being consumed.
Feed-water heaters are also used, by which it appears a consider-
able saving in fuel is effected. The covering of the boiler and
steam-pipes has also had much consideration, various non-conduct-
ing compositions being used; one of those recently tried is slag
wool or silicate cotton, partly made from blast-furnace slag; it is
applied either as a composition or in slabs curved to suit the surface.
Figs. 39A and 39B illustrate the most modern type of marine
boilers for compound engines, as supplied to the S.S. Parisian, built
by R. Napier & Sons, Glasgow, for the “Allan Line” of ocean steamers.
There are four boilers, each I 5 feet in diameter, and carrying a
working pressure of 75 lbs. per square inch, a hydraulic test having
been applied, as is usual in such cases to double the working pres-
sure, viz. I 50 lbs. per square inch. The shell plates are treble
rivetted in the longitudinal seams, and double rivetted in the cir-
cumferential seams. The furnaccs are double butt strapped (see
A, A in Fig. 39A on opposite page), and welded for a length of IO inches
at each end. The stays B, B are 236" diameter, and are spaced
I4%" apart. The tubes are 3%" diameter and 7 feet long, arranged
vertically one over the other as shown in the figure. The total
heating surface of the four boilers is 15, 176 Square feet, and the
total grate surface is 540 Square feet.
It will be seen from the dimensions on Fig. 39 B that the
thickness of the plates, which are of iron, vary, the thickest part of
the shell being 1%", and the end plates from 56" at the tubes
to Hº" above these and where the stay rods are affixed.
These boilers supply steam to three-cylinder compound inverted
engines working up to 6OOO indicated horse-power, which are
illustrated and described under Marine Engines.
BOILERS FOR MARINE PURPOSES.
OOOOOOO
Fig. 39A.—Vertical Section of one of the Boilers of the S.S. Parisian.
* * * * * sº 3rº--
Fig. 39B,-Longitudinal Section of one of the Boilers of the S.S. Parisian,


78 MODERN STEAM PRACTICE
TIIICKNESS OF PLATES, &c., FOR COAL BOXLS.
Thickness of Side Plates,................................... }% inch.
Do. Bottom,........................................ ." .
Do. Corner Angle-iron,........... I }% x 1% x % ,
Do. Stay Angle-iron,.... ............... 2 × 2 × # , ,
Stayed every 3 feet apart.
For Coal Stowage allow 46 cubic feet per ton.
PRIMING.
Impurities in the water used is fio doubt the chief cause of
priming, and the evil is much increased by the want of proper
circulation. We are apt to crush into small space a number
of tubes, without ever considering how the water is to circulate
around them. A continual ebullition goes on in all directions, the
globules of steam are hurried through and between the water spaces
in their passage upwards, and the water is allowed to fill up the
cavity as best it can. A simple experiment on a kitchen fire will
clearly point out how this frothing of impure water occurs. Take a
vessel partially filled with pure water, place it on the fire, and the
water will boil without flowing over; but fill the vessel half full of
potatoes, with just sufficient water to cover them, when the water
has boiled for some time a slight scum will be raised, and the water
having thus become impure from matter extracted, will eventually
overflow. This process is greatly accelerated by the small water
spaces between the potatoes, the water having little or no circulation
downwards. The tubes in a boiler fill up the water space in a
similar way, and when the globules of steam are shooting in all
directions there is no time for the water to circulate freely. It is a
good plan to confine the great ebullition to those parts where the
steam is more rapidly raised, by simply fitting circulating plates
between the tubes and the side of the boiler and other parts, thus the
space left between the circulating plates would be comparatively
free from ebullition, and the surface water in the boiler would flow
down and circulate upwards amongst the tubes. Were such plates
fitted loosely over the furnace crowns, allowing the steam to escape
freely at the top, the ebullition would be very great, the water circu-
lating rapidly between the plates and the furnaces would tend in
a great measure to prevent scale forming. The part mostly affected
by the want of good circulation is the bottom of the tube-plate at
TREATMENT OF STEAM. 79
the back of the boiler, and the great heat at this part soon cracks the
plate, if the scale that rapidly forms is not frequently removed. Of
course, where water from a surface-condenser is used, little or no
deposit is formed over the heating surfaces; but even with surface-
condenser water, it is found necessary to allow a slight film of
deposit to form, otherwise the corrosion that rapidly sets in would
corrode the plates very quickly. As we cannot prevent the water
frothing up when it is taken into the boiler in an impure state,
we must simply consider the best means to prevent the water priming
over into the cylinders. With a good height of steam-chest, and
with the steam taken from the highest point, the bubbles of water
will be broken up before reaching the top of the inside steam-pipe
in the boiler, and when a slotted pipe is carried along the top of
the boiler, perforated with a number of slits fºr inch wide, should the
globules of steam and water reach that height, as they cannot pass
through the slits, they are broken up, liberating the steam, which
finds its way through the slits into the pipe, while the water con-
tained in the spheres falls down amongst the water in the boiler,
with the additional advantage that the steam is taken away directly
from over the surfaces where it is generated. However, when no
priming takes place, a certain amount of water will be carried along
with the steam; and when the steam-pipe is at one point, the atoms
are all converging to that point, and the mere mechanical friction
of the atoms of stcam rubbing against one another tends to carry
water through the steam-pipe into the cylinders, therefore the steam
should be partially dried by an apparatus we will now explain.
TREATMENT OF STEAM FROM THE BOILER TO
THE CYLINDER.
Steam generated from ordinary boilers is far from being a pure
gas, properly speaking, it is quite dry and invisible. The vapour
blowing off from the safety-valve shows a transparent ring near the
orifice of the valve; this ring, however, soon widens, and mixing
with the cold atmosphere, takes the form of a misty vapour, highly
charged with watery particles; this vapour is soon dispelled, and
8O MODERN STEAM PRACTICE.
nothing but pure water falls to the ground in a gentle shower. Thus,
wherever the steam comes in contact with cold surfaces in its passage
to the cylinder, condensation takes place, and it is robbed of an
amount of heat, and consequently pressure, thus wasting much valu-
able fuel.
The saturation of steam with watery particles, however, is not
entirely due to condensation, as there are various other causes at
work; for instance, when the steam-room in a boiler is not of
sufficient height above the water in the boiler, the violent ebullition
that goes on has a tendency to surcharge the steam with water.
Again, if the steam is taken away from one end of the boiler, instead
of from immediately over the parts where it is generated, the same
result takes place, the atoms rubbing, too, against one another, in
flowing towards one point, has a great tendency to charge the steam
with water. Violent priming, whether from the want of circulation
of the water in the boiler, owing to defective construction, or by a
sudden change of water injected into the boiler, surcharges steam
with water to an aggravated degree. When the boilers, steam-pipes,
and cylinders are not properly clothed, condensation takes place, and
watery particles will be mixed with the steam to a large extent, thus
reducing its pressure.
Many schemes have been devised to superheat the steam in
marine boilers by the waste heat in the smoke-box, or uptake, with
the view of delivering it into the cylinder in a dry state. Many
of these superheaters have been fitted to boilers defective in con-
struction. Some authorities are of opinion that the best place for
drying the steam is in the boiler itself, drawing it from high steam-
chests and uptakes, thus the steam is taken away at a greater height
from the level of the water in the boiler, while the heated gases from
the tubes have time to act on the lofty uptake contained in the
steam-chest, and drying the steam sufficiently for all practical pur-
poses. In many cases it is not convenient to form lofty steam-
chests, and then other means must be adopted for drying the steam,
separate vessels, termed Superheaters, being used for that purpose.
The steam dried by such contrivances generally receives 80° of
Superheat above the temperature of the steam in the boiler, this is
considered, with fine lubricants, a good working temperature, that is
to say, Steam of 60 lbs. pressure has 295° Fahr., thus the total tem-
perature will be 295° + 80° = 375° Fahr.; but it should be borne in
mind that the best oil or grease must be used as the lubricant, other-
TREATMENT OF STEAM. 81
wise the dry steam hardens the oil, to the detriment of the piston
and slide-valve rubbing surfaces.
Some engineers consider that when the steam is Superheated,
it should be mixed with the steam in the boiler; little advantage
exists, however, in this arrangement, for it appears a very doubtful
proceeding to heat up the steam, and then rob it of a portion of
the heat by mixing it again with steam from the boiler. The main
thing to be studied is to give the steam a sufficient degree of super-
heat, so that in its passage to the cylinder it may not be cooled
down below the temperature existing in its primary state in the
boiler; thus steam in a dry state is passing
into the cylinders, whereas without some
contrivance for drying the steam in the
boiler, or in the superheater, an admixture
of steam and water presses on the piston,
tending to diminish the power and increase
the consumption of fuel.
The various forms of superheaters may
be classed just as are steam-boilers. The Fig. 40–cylindical superheater.
plain cylindrical form has an outer shell,
containing a single large tube, the inner tube being stayed with rings
of angle-iron; where double round boilers are used, firing fore and
aft, the part fitting on to the boiler is bevelled, while Hºri
the other end that joins on to the funnel is quite ;
Square; these superheaters, four in number, converge | : H
to one point, to which a single funnel is fitted, the !
bottom part of the funnel or the uptake being
bevelled to suit; this form of superheater is simply
effective, and easily constructed, while the scale can
be readily cleaned out, and as it lies at a consider-
able angle the heat acts better on the surfaces.
Some superheaters of this class, however, are placed
vertically, and it is an object with the designer to
arrange passages so that the steam travels up and F
down within the superheater, time being required
to dry the steam thoroughly. The passages are ... * - -
te * º - Fig. 41.-Cylindrical
formed with plating rivetted vertically between the jelji,
inner and outer shells, one of these plates is rivetted *P*
to the bottom and sides, another to the top and sides, and so
on alternately; but at the top and bottom alternately the vertical


|
L=A_

6
82 MODERN STEAM PRACTICE.
plates are not carried to the ends of the superheaters, an opening
being left at these points; thus between the inner and outer
shells cellular compartments are formed, the steam
coming in at the bottom of one cell travels upwards,
and then descends into another compartment, and SO
on according to the number of compartments, until it
is finally carried away by the steam-pipe, the heated
gases in this arrangement acting on the inside tube,
the outside shell, and the lower end-plate, all of which
are contained within the bottom part of the funnel.
Again, we have a vertical superheater of the cylindri-
cal class, but instead of one large tube passing through
º it, a series of small tubes are securely rivetted to the
Fig. e-tubular end-plates, thus forming a multitubular superheater;
Superheater again, time is required, so it is necessary to place
division plates, rivetted to the sides and one end, having an open-
ing at the other end, thus the steam being admitted at the top
passes downwards, flowing all round the small tubes, and then
upwards in the other compartments according to the number of
division plates fitted, until it passes into the steam-pipe to the
cylinder. Sometimes the multitubular type has the tubes lying
horizontally, and division plates so disposed that the steam from
the boiler enters at the bottom, passing through the small tubes,
then returning, and finally passing through the top rows, thus the
steam goes three times through, from the point where it enters
the superheater, at the bottom, to that point at the top on the
opposite side where it is taken away by the steam-pipe. In plan
this arrangement has the tubes at the central part, the tube-plates
being inclosed with a circular shell, and the tubes arranged in
vertical rows. At the middle and sides there is space left so that
the heated gases are not so much obstructed as when passing
between the tubes; this makes a very effective arrangement, and
may be reckoned a good example where time is required. -
Many examples of tubular superheaters have been fitted directly
on the tube-plate, Some arrangements having the tubes merely a con-
tinuation of the tubes in the boiler, the pitch of the tubes in the super-
heater being identical. With this plan time is sacrificed and surface
adopted; however, in some cases the tubcs are laid the long way of
the smoke-box, having boxes at each end, one end in communi-
cation with the steam-space in the boiler, and the other with that of
i

TREATMENT OF STEAM. 83
the steam-pipe to the cylinder. In some instances three boxes have
been fitted to the superheaters, involving four tube-plates, the tubes
running right and left from the central box; the steam from the
boiler enters this centre compartment, passes right and left through
the tubes, and is taken away with separate steam-pipes at each end.
Sometimes the superheater forms part of the boiler; and for low
boilers for marine purposes this plan has certain advantages, the
tubes are arranged vertically, and are secured into tube-plates, run-
ning the entire length of the smoke-box, the lower tube-plate being
a few inches above the tubes in the boiler, while the top tube-plate is
placed a few inches from the top of the shell of the boiler. The steam
from the boiler enters the superheater through a number of small
apertures, these take a downward course; a division plate being
fitted, the Steam passing this plate ascends, and is taken away by
the main steam-pipe; there are certain advantages connected with
this arrangement, though the main one simply consists in doing
away with a good deal of piping, as the steam from the boiler enters
the superheater directly. The great desideratum to attend to in
tubular superheaters is provision for cleansing them from the soot
in the Smoke passages, whether arranged internally or externally;
some mode of access must also be provided to the steam space for
cleansing away the Scale that rapidly forms.
To employ a large flat surface, giving time to the steam to be
thoroughly dried, is certainly the correct principle to be studied,
when superheaters require to be placed in small space, though the
complication entailed renders many arrangements of flat flue super-
heaters not at all to be commended in practice. Vertical flat flues,
similar in construction to the overhead flue boiler with U-shaped end-
pieces, and the plates flanged at the ends, for uniting them to the tube-
plates, all of which are inclosed in a suitable casing, properly and
securely stayed, with stay-bolts and ferrules, is an effective arrange-
ment of the kind; the heated gases pass through the elongated tubes,
while the steam is admitted at one end of the casing, and passes
between the spaces left betwixt the flues, and is taken away by the
steam-pipe placed on the opposite end of the casing. This plan of
superheater is expensive in first cost, and complicated in its many
parts in the event of repairing it and keeping the apparatus in
thorough working order. In all cases where separate superheaters
are used for marine purposes, a stop-valve and pipe must be fitted
for each boiler, for shutting off, or allowing the steam free access to
84 MODERN STEAM PRACTICE.
the superheater. One stop-valve is fitted to the superheater for
regulating the steam to the cylinders, while in connection with this
stop-valve and pipe there is fitted a stop-valve on each boiler,
having a pipe connected to the main steam-pipe, thus in the event
of anything going wrong with the superheating apparatus, all the
stop-valves connected to the superheater can be closed, and the
steam taken from the boiler in the usual manner. This will show
how much more preferable it is to form high steam-chests and up-
takes; thus complication is reduced to the minimum, while at the
same time the steam is effectively dried. Superheaters, in all cases
when made separate vessels from the boiler, should be fitted with a
safety-valve, of ample size; this is to prevent rupture, as, in case all
the stop-valves are shut, a certain amount of moisture, or even
steam, is in the superheater when the valves are closed, and this
would generate a highly-explosive dry gas, or steam proper, were the
safety-valve not relieving the superheater from the accumulating
pressure. In the absence of steam in the Superheating vessels, the
injurious effect of the waste heat passing up the chimney acting
upon the dry plates and small tubes need scarcely be pointed out.
In concluding this brief sketch of superheaters, that have all been
practically tried more or less, it may be stated that for pressures of
60 lbs. per square inch in the boilers the simplest arrangement that
is found in practice to suit all requirements is a circular shell fitted
with an internal flue. The surface exposed, or total surface of the
internal flues, in this system is I 3 Square foot for every nominal
horse-power the engine is calculated for; but for low-pressure steam
the surface is generally I square foot for every indicated horse-power
the engine works to; or otherwise from 3 to 4 feet Square per nominal
horse-power is reckoned amply sufficient for the superheating sur-
face, as usually arranged, for pressures varying from 20 lbs. to 30 lbs.
steam in the boiler.
We will now consider the different points to be attended to in the
arrangement for conveying the steam from the boiler to the cylinder.
With the view of keeping the steam as free as possible from watery
particles, as has already been discussed in the section on priming,
a pipe is fixed to the interior of the boiler, perforated throughout
its length with a number of holes, by which the steam is removed
from over the parts where it is rapidly generated. This pipe should
be fitted to all boilers, whether using superheaters or fitted with
ordinary arrangements. The use of the separator has also been
MANUFACTURE OF BOILERS. 85
explained, fitted to the steam-pipes, for retaining any moisture that
is carried along with the steam, more especially steam that has not
received a sufficient degree of Superheat. The reader on turning back
to page 46 will find the use of the separator fully explained. As the
pipes are made of copper, which is a very good conductor of heat, it
is necessary to clothe them with felt, and then cover them over with
canvas, securely sewn together; the whole is then painted, to pre-
sent a neat and smooth surface. The steam is still further treated
in the cylinder by the use of a steam jacket encircling the cylinder
in all parts where radiation takes place; even the ends and the covers
of the 'cylinders are steam-jacketed, and are still further protected
with felt, covered with “lagging,” the technical term for narrow
strips of wood that are firmly secured to rings of wood bolted to the
cylinder, ribs being cast on for that purpose. Thus it becomes
imperative that pipes and surfaces, exposed to external cold, should
be thoroughly protected to prevent condensation or reduction of
steam pressure. The boilers are likewise covered with felt and wood
lagging, and sheet-lead overall, to prevent radiation
MANUFACTURE OF BOILERS.
In all branches of industry there are certain methods better
adapted for carrying on work than others, and although one maker
may adopt a very different method from another, they may be
equally successful in turning out as good work, although the one
may have expended more money than the other in doing so. Some,
for instance, adopt modern improvements, and their plant is of
modern make; the punching machine, for example, being Superseded
by the multiple drilling machine, and no one can doubt for a mo-
ment that drilling the holes for the rivets is done without straining
the plates so much as with the multiple punching machine forcing
through three holes at once, even although the drilling machine may
be doing twenty holes at one time. The plating for boilers and
other work is now done with mathematical exactness; the distance
between the rivets for ordinary boilers, having 34 inch rivets for
securing the plates, is 2 inches between centre and centre, and
from the edges I inch to the centres of the holes; consequently
the plates should be ordered with even dimensions.
86 MODERN STEAM PRACTICE.
Some may say this cannot always be done, so as to give a boiler
of a certain diameter. We will only remark that if the plates will
not run evenly, an inch more or less does not affect the diameter
very much, as likewise the length of the boiler is not generally so
confined. The object of even dimensions is simply that when the
plates arrive they are at once taken to the planing machine to have
the edges planed, and then they are punched or drilled, as the case
may be, the punching machine being provided with a travelling
table, moved along by hand, the table having suitable stops, thus
the machine templates or sets out the holes and punches at one and
the same time. Now this could not be done if the plates were
ordered of uneven dimensions. Those who have not adopted this
plan for plating for all kinds of boilers cannot be aware of the
great saving effected. We have known working drawings going
into the workshop, and the boilers have been plated haplazard,
stock plates being kept for that purpose. We may at once note
this plan a complete barbarism. Plates should be ordered for
each boiler separately, and properly marked both on the drawing
and on the plates as delivered from the rolling mills, when they
should be assorted, and the workman then knows where to lay his
hand on No. 1 or No. 13 plate, as the case may be. By this rule
being duly attended to much saving is effected. Indeed, a prac-
tised eye can at once detect when boilers are plated haphazard
or regularly; and certainly it is not very pleasant to be told that
this or that boiler has not the same appearance, owing to the
irregularity of the plating as taken from stock; and great waste
occurs when plates require to be cut down to suit a particular boiler.
For all difficult boilers block models should be made, and all the
plates set out and marked, so that the workmen can see at a glance
what the work consists of, the model giving a better idea than a
drawing, and also standing more rough handling;-the drawing, in
some cases, never being required in the workshop.
All the plates should be ordered for planing the edges; % of an
inch is the regular allowance for doing so, not that so much is required
to be planed off, but at times the plates are not so square at the
corners as can be desired. This method of planing the edges saves
a great deal of chipping, and the joints are more easily caulked.
In plating the boiler care must be taken so that the flame does not
act on the edges of the plates. All joints should be so laid that the
flame passes over, and does not impinge against the end of the
MANUFACTURE OF BOILERS. 87
plate, and all the outside edges should be placed downwards; thus
the moisture freely runs down, and is not allowed to collect at these
parts, preventing the rapid corrosion that would otherwise set in.
The drawing should plainly show all the laps, to prevent the work-
men from plating the boiler incorrectly. The plates exposed to the
immediate action of the flame should be of the best description,
more especially in the crowns of the furnaces, where they must run
lengthways, and all the joints kept well
out of the fire. Sometimes the furnaces
are plated with butt joints and strips;
this is a good plan for boilers intended
to carry high-pressure steam. The end-
plates of rounded boilers are usually
attached and stayed to the shell with
angle-iron at the corners, having three
or more flat plate-stays, rivetted be-
tween two angle-irons at the ends
and top, dividing the surface to be
stayed equally. When the furnaces
are inside of the boiler the angle-iron
for joining the furnace with the end-
plate is placed inside, at the furnace
end, and outside of the flue-plates at the
extreme end; but should the furnace be underneath the boiler the
flues must be joined to the end-plates with angle-iron outside of
the flues, or, in other words, inside of the shell. The water space
underneath the boiler in this case will be more than in the former
arrangement, with 2% inches breadth of angle-iron, not less than
5 inches between the flue-plates and the outside shell; and where
two furnaces or flues are adopted, the same space should be between
them: when stronger angle-iron is used the distance may be the
same, but the angle-iron will require to be flattened or cut away
at that point.
Sometimes boilers are ordered to be flanged in all the corner plates.
When so specified, all the flanges should have a bold radius at the
corners, not less than 2 inches: this makes a neat piece of work, and
the strength of the boiler is materially increased. Water spaces,
having flat sides, should be stayed together with 34 inch screwed
stays, tapped into both plates, and rivetted or fitted with nuts and
washers outside, as occasion may require, the distance between
Fig. 43.-Plate-stays.

88 MODERN STEAM PRACTICE.
the stays being regulated by the steam pressure used. For strength-
ening the flues when they are of extra size sometimes angle-iron
and manufactured hoops are introduced at the joints
NZN •
º (see sketch on page 26). This plan answers well
sºs where deposits do not form rapidly; and although
*†.” large flucs, whether oval or circular, are not at all
desirable, they can be strongly stayed with conical
tubes, having the water inside of the tubes, which are most efficient
stays, and give extra heating surface, and no boiler having large or
flat flues should be without such a means of support. The tube-
Fig. 45.-Comical Water Tube-stays.
stays are so made that the bottom parts with flanges can go through
the top holes; thus they can be fitted to existing boilers cheaply.
Such a system of staying must tend to decrease the number of
Ž dº
} @@ () () (90 (5 69
© (E) ()(3)
Fig. 46.-Flat Fire-box.
boiler explosions; but on no account should a boiler so fitted be
tampered with. For staying the end-plates of round boilers
T-irons are sometimes introduced, having long rods of round iron
passing from end to end of the boiler, and jointed with pins and


MAN UFACTURE OF BOILERS. 89
cotters to the T-irons. With boilers having hemispherical ends it is
quite evident that no stays are required. Flat fire-boxes (see page 88)
for general purposes, and similar in construction to the locomotive
type, should be well stayed; the inside fire-box can be made circular
at the top, and for moderate pressure the flat sides are only stayed
to the inside fire-box, with 34 inch screwed stays, rivetted on the out-
side, the distance between the squares being 6% inches for 50 lbs.
per square inch, to 4% inches for IOO lbs. Steam pressure per Square
inch. The plates are all flanged at the corners, but the fire-box is
sometimes united to the outer casing, with angle-iron at the bottom.
The short flange pipe, to form the furnace-door case, strongly stays
the fire-box at that part.
As we consider that this subject closely affects the interests of
steam users, we append the following from a report presented to
the National Boiler Insurance Company:-“A large number of
the boilers proposed for insurance are so weak in construction
that some general remarks, based on the extensive experience of
the construction and working of all kinds of steam boilers, will
doubtless be found useful to many owners and makers. Of the
numerous varieties none are more generally used than the Lanca-
shire, or the cylindrical two-flued, and the Cornish one-flued boilers,
and where these are well constructed, properly fitted up, and care-
fully attended to, their performance is generally satisfactory. There
are various modifications of these forms, some of which are valuable.
In designing such boilers excessive length, as compared with the dia-
meter, should be avoided. Long boilers strain considerably, and
frequently give great trouble by leakage at the rivetted seams. A fair
proportion is when the length is about three-and-a-half times the dia-
meter. The staying of the end-plates, and the attachment of the flue-
tubes to the ends, should be so arranged that the tube may expand
freely, unless there be some special arrangement in the form of the
flue-tubes to attain the same object. Many boilers, otherwise well
made, have given considerable trouble by leakage and fracture, owing
to the severe strains of unequal expansion to which their rigid con-
struction exposed them. In some of the boilers inspected the ends
were so heavily stayed, and so rigid, that considerable leakage and
occasional fracture at the ring seams of the lower part resulted. In
others the staying was so slight that the ends were bulged outwards,
and serious risk of explosion thus occurred. Flue-tubes should never
be stayed to the shell, but be attached at the ends only. Many boilers
90 MODERN STEAM PRACTICE.
have given serious trouble through being thus stayed. The shell
should be made quite circular, and the longitudinal seams, which
should break joint, be so arranged that when the boiler is set all
those below the water-line may be accessible for examination in the
flues, and be clear of the brick seatings. Many makers now double-
rivet these seams, thus materially increasing their strength, and, when
the work is well performed, reducing liability to leakage. Flue-
tubes are now constructed in various ways, some makers preferring
to use thick plates not strengthened in any way, whilst others prefer
Comparatively thin plates, but flanging them at the ring Seams, or
by welding each ring of plates and connecting them by Solid T-iron
hoops, form a much stronger and more reliable flue-tube. The
liability to leakage, fracture, and excessive expansion is thus much
reduced, as the heat is more freely transmitted through the thin
plates. The cross-tubes and water-pockets introduced by some
makers in that part of the flue-tubes beyond the furnace bridge are
of great value, chiefly from the manner in which they improve the
efficiency of the heating surface by the diversion and breaking up
of the current of gases, whilst they much increase the strength of
the tubes to resist collapse. All large tubes exposed to high pres-
sure should be strengthened by some of the means described. Where
the tubes are formed with the ordinary lap-joints the longitudinal
seams should break joint, as a tube thus made is much stronger than
where those seams are in a line; and at the furnace end all longitu-
dinal seams should be below the fire-grate level. The plan of form-
ing tubes with the plates longitudinally in narrow strips is very
objectionable, as the tubes cannot be made so circular, and the
seams above the bars are injured by the action of the fire, whilst
such tubes are much weaker than those made in the Ordinary man-
ner Multitubular boilers should, as far as practicable, be so con-
structed that every part of the interior may be accessible for cleaning
and examination; and it would be a great improvement if those of
portable and locomotive engines were so constructed that the tubes
could be drawn out without difficulty, So as to allow occasional
inspection of the internal surface of the plates. External flues are
necessary to stationary cylindrical boilers of this class, otherwise
the lower seams are strained, and become leaky through excessive
unequal expansion of the boiler. Plain cylindrical externally fired
boilers, with egg or saucer shaped ends, are preferred by some
owners, chiefly on account of their simple form. Such boilers can
MANUFACTURE OF BOILERS. 9I
never work so safely as a properly constructed internally-fired boiler,
as they are so liable to fracture at the seams over the furnaces,
through the excessive alternate expansion and contraction to which
they are exposed. The application of stout longitudinal stays would
add materially to the safety of such boilers. A variety of cylindrical
vertical boilers are used in various iron-works. These boilers are
generally heated from the puddling or similar furnaces, the heat
first entering the external flues, and passing thence by an internal
descending flue-tube to the chimney. They are especially liable to
starting and fracture of the rivetted seams opposite the furnace
necks, owing to the intense heat at that point; and where the feed
water deposits much sediment the solid plate is sometimes fractured.
To avoid this liability the part referred to should be protected by a
Screen of brickwork, or the boiler set at a higher level; the brick-
work may be so arranged as to spread the heat before it reaches the
boiler. The bottoms of these boilers are frequently quite inaccessible
for examination, and serious corrosion may go on unknown to those
in charge. If the boilers were supported by brackets at the side, or
by wrought-iron plate standards rivetted to the bottom, so that a
thin wall of brickwork would suffice to form the flues, the condition
of the plates could be occasionally ascertained without much diffi-
Culty. -
“As the safety of boilers depends so much on the sufficiency and
condition of their fittings, a few remarks thereon will be useful. It
is well to have two safety-valves to each boiler, as a check upon each
other; one of them should be a dead-weight valve, loaded externally,
and the other a lever-weight valve, or a compound valve, which
would allow the steam to escape, if the water were allowed to fall
below the proper level. Safety-valves are frequently met with, the
levers of which are of such length, that the usual working pressure
for which the boiler was made would be much exceeded if the weight
were fixed at the end of the lever. The weight should always be
calculated and adjusted to hang at the end of the lever. All boilers
should be provided with correct pressure-gauges for the guidance of
the attendants. The glass-gauge is undoubtedly the best and most
reliable water-gauge, and it is a good plan to attach two gauges to
each boiler. Where floats are used there should be two, one of
them fitted with an alarm whistle. Boilers with internal tubes should
always be fitted with glass-gauges. Fusible plugs should be inserted
in the furnace crowns of all internally-fired boilers. The feed regu-
92 MODERN STEAM PRACTICE.
lating valve, which may be constructed to act also as a back-pressure
valve, should always be placed at the front end of the boiler, within
the reach of the attendant, and where boilers work in connection,
each should have a back-pressure valve attached. The feed water
should be delivered a few inches below the surface of the water in
the boiler, and above the level of the tube crowns, and in a horizontal
direction, or by means of a horizontal perforated pipe. Where the
feed water is delivered near or at the bottom of the boiler, it cools
and contracts the lower plates, whilst those of the upper part are
heated and expanded by the steam, frequently causing fracture at
the ring seams at the lower part of the shell. The feed water should
always be heated before it is forced into the boiler. The blow-out
tap at the bottom of the boiler should be so placed that it may be
examined at any time, So that any leakage occurring, it should be at
Once noted; valves should never be used, double-gland taps made
altogether of brass are far preferable. Stout seatings with planed
joint faces, suitable for each fitting, should be rivetted to the boiler.
All manholes should be strengthened by a faced mouthpiece, rivetted
to the boiler, so that the joint may be easily and well made, and
leakage and corrosion avoided. Steam domes are unnecessary in
stationary boilers; a perforated pipe placed in the upper part of the
steam-space is quite as efficient to prevent priming, and the boiler
is not weakened. Where domes are preferable, they should never
be of large diameter, and the shell plates inside them should not be
all cut away, that is to say, the hole should be strengthened with
strips left in the plate. The setting of stationary boilers should
always be intrusted to a man of experience. When boilers are
about to be set, special care should be taken to thoroughly drain the
ground, that no dampness may exist in the flues to cause corrosion
of the plates. All the flues should be quite large enough to allow
a man to pass through, so that every part may be accessible for
repairs and examination. Midfeather seatings are very objection-
able, and no boiler should be so set, except those of very small dia-
meter, and in such cases, thick but narrow iron plates should be
placed on the top of the brickwork to protect the boiler. Cylindri-
cal boilers internally fired should be set on side walls, the boiler
resting on fireclay blocks made for the purpose, and so shaped that
when built in place the bottom of the side flues may be much lower
than the point where the boiler rests on the blocks. If the blocks
be properly fitted to the plates, that the bearing thereon may be
MANUFACTURE OF BOILERS. 93
equalized, the total breadth of both side walls, where in contact with
the plates, need not exceed I inch for every foot of diameter of the
boiler. The top of the side flues should be level with the crown of
the flue tube. All boilers should be roofed over to protect them
from external moisture, otherwise the sides in contact with the flue
brickwork will be weakened by corrosion. Where flues are properly
arranged as described, no serious corrosion could exist in the seatings
undetected by a skilled inspector. The laws for the prevention of
smoke are now being enforced in many districts, but boiler-owners
should be cautioned against too readily adopting any form of appar-
atus which may be pressed upon their notice, as many are unneces-
sarily complicated and expensive.
“It frequently happens that good boilers are injured and serious
risk is incurred through neglect and carelessness. Where the feed
water contains much sediment, and no cleaning apparatus is in use,
frequent internal cleaning is indispensable, or the plates may become
overheated and injured, whilst the efficiency of the boiler is reduced.
The external flues are in many cases allowed to become almost
choked before being cleaned, and the boiler plates so thickly coated
with soot, that a wasteful consumption of fuel is the result. Some firms,
on the other hand, clean their boilers thoroughly about once a month,
and are thereby considerable gainers, as the efficiency of the heating
surface is retained, whilst any defects are at once discovered and
made good, which, if neglected, might entail expensive repairs, or
even lead to serious disaster. When boilers are being restarted after
stoppage, they should be heated very gradually, so as to avoid, as
much as practicable, the severe strains of unequal expansion, and
when at work the feed supply and the firing should be as steady and
regular as possible. Frequent and extreme alterations of pressure,
especially with high-pressure boilers, or irregularity of any kind, is
most objectionable, and sometimes really dangerous.”
We consider the foregoing remarks are well worthy the consider-
ation of steam users, although we do not entirely agree with the
writer in limiting the length of land-boilers to three and one half
times the diameter; and we do not advocate too thin plates for
flues, even though stayed with hoops, although the flues are thereby
strengthened; but entirely agree with him that conical water tube-
stays are invaluable for staying the flues, as deposit is not liable to
form, as is the case with the hoops. We have known many instances
where deposits have rapidly formed at the roots of the hoops,
94. MODERN STEAM PRACTICE.
thereby tending to injure the plates, by a thick coating, through
which the heat cannot effectually act on the water, or, as it were, the
water cannot keep the plates sufficiently cool and in proper working
condition. This heating of the plates, whether from violent priming,
or from carelessness in the attendant allowing the water to fall below
the crowns of the furnaces, is the main cause why efficient steam-
boilers at times explode. As already stated at page 32, steel plates
are now being used for boilers, a reduction in thickness being
thereby effected of about 20 per cent, and on the whole weight of
the boiler about IO per cent.
THE REGULATION OF STEAM BY THE SLIDE-VALVE,
AS APPLIED TO LAND, LOCOMOTIVE, AND MARINE ENGINES.
The reciprocating motion imparted to the piston of the steam-
engine is caused by the steam acting alternately on the top and
bottom of the piston; passages, or ports, as they are technically
termed, being formed in the cylinder to admit the steam: these ports
having a valve so arranged as to admit the steam above and below
the piston alternately, with means of allowing it afterwards to escape
into the atmosphere, or into the condenser, as the case may be. The
valve in its original form was simply an oblong box of cast-iron,
open on the front or face, having a flange all round, this face sliding
on a corresponding part on the cylinder, both being accurately faced
up, and made perfectly steam-tight, reciprocating motion being im-
parted to the valve by a simple arrangement similar to the crank
and connecting-rod for the piston. This valve, from its peculiar
sliding action, rubbing against a corresponding face on the cylinder,
is termed the slide-valve. The older valve arrangements admitted
the steam during the entire travel or stroke of the piston; there were
three ports, two in the cylinder, one at the top and bottom to admit
the steam into the cylinder, and a central one outside the cylinder
for the exhaust or waste steam from it to escape into the atmosphere,
or into the condenser, if so fitted. When the valve was at half
stroke, the steam-ports were covered, the valve face for doing so
being the exact width of the ports, that is to say, the steam ones.
It is quite evident that at this position the piston must be either at
the top or the bottom of the cylinder, and as the crank-pin for the
piston rotates round a fixed point, similar to the crank centre for the
REGULATION OF STEAM. 95.
slide-valve, the former drives the shaft that gives motion to all the
minor details, and as the slide-valve must be opened and shut as the
crank-pin travels from one end of its path, in a line with the cylinder,
to the other end, it is quite evident that the centre, or pin, for the
slide-valve must be at right angles to that of the crank centre for the
piston; or, more correctly writing, with the length of the eccentric
rod as the radius, taken from the centre of the engine shaft, on a
horizontal line, sweep the path of the centre of the eccentric, and the
point intersected on the circle is the position of the eccentric centre
when the crank-pin is at the commencement of the IN stroke. Or
when the crank is moving towards the cylinder, at this position the
centre will be above the horizontal line; but should the crank be
moving on the OUT stroke, the centre of the eccentric will be below
the centre line of the engine. -
It is quite apparent from the foregoing that when the crank-pin
has travelled one half of its stroke that the valve will be full open;
\
& Path
Fig. 47.-Original form of Valve without Lap.
A, Commencement of the IN stroke. B, The point on crank path at half stroke. C, Centre of
eccentric at the commencement of the IN stroke. D, Centre of eccentric at half stroke of
piston. CE, Length of the eccentric rod. F, Commencement of the OUT stroke.
and that when the crank-pin has travelled to the end of its path,
or one half of the circle delineated by the crank centre, that the
valve has returned, and covers the steam-ports exactly. At this
position the crank-pin centre commences describing the other half
of the circle or path, the piston is returning, and the slide-valve opens
the steam-port for it to do so, at the same time the exhaust is
becoming free, the steam which has acted on one side of the piston
is escaping into the atmosphere as for non-condensing engines, or
into the condenser, as with the low-pressure type; thus the steam
acts alternately on the top and the bottom of the piston. It will
be observed that the full pressure of the steam from the boiler was
admitted into the cylinder the entire length of the stroke of the
piston; this was wasteful, so it became expedient to admit the steam

96 - MODERN STEAM PRACTICE,
for only a portion of the travel of the piston, or, in modern phrase-
ology, “cutting off” the supply, the “cut off" being one fourth, one
half, and so on, as might be determined on, the remainder of the
stroke of the piston being actuated by the expansive force of the
steam in the cylinder. So it was found that by adding a little more
width to the slide-face, keeping the opening in ports by valve the
same area, and making a new eccentric
to suit the required amount of cut off,
that the economical duty of an engine
- was greatly improved. This addition to
Fig. 48–Valve with Lap. Vertical lines the face of the slide-valve is termed the
show the outside lap. & *
/aft of the valve, or outside cover. Again,
in high-speed engines it is found advisable to give the valve an amount
of lead or opening before the piston reaches the end of the stroke;
this is required to check the piston at the termination of each stroke
by cushioning the moving mass gradually; thus the piston is brought
to a momentary stand-still by the steam acting upon it directly from
the boiler. It will thus be obvious that a piston of great weight and
high velocity will require more lead or opening by valve than a
piston of less weight, travelling at the same velocity; or, on the other
hand, a much less piston, having a greater speed, may require the
same lead as the heavy piston moving slowly. Were very little
lead adopted in such cases, the moving mass being suddenly stopped
at the termination of each stroke, a succession of blows would be
imparted that eventually would damage the machine, and the lead
is simply introduced to prevent this occurring, and to secure the
earliest possible admission of steam, so as to obtain a large port area
early in the stroke. The inside edge of the valve face should just
cover or be in a line with the port, so that the exhaust is open at
the commencement of each stroke a linear distance equalling the
extent of the outside lap plus the lead; by this means the opposite
end of the cylinder, or rather the piston, is relieved from the steam
pressure, and the condensation fully established before the steam is
admitted into the other end of the cylinder.
In proportioning the slide-valve of the steam-engine, the lead of
the valve must be duly considered, a little more opening of port by
valve greatly affecting the lap or outside cover, as likewise the
length of the eccentric rod must be taken into account; as a rule,
with a proper length of eccentric rod of not less than six times the
throw of the eccentric, the versed sine of the chord contained by
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REGULATION OF STEAM. 97
the arc, or travel of the eccentric centre, equals the opening of valve
minus one half of the lead. This may be taken in all cases to be
practically correct when the valve is worked by direct means from
the eccentric, but when levers and rocking-shafts are interposed
between the eccentric and the valve, the versed sine will be more
or less, as the case may be; thus supposing the eccentric rod lever
is longer than the one on the rocking-shaft for the valve, the versed
sine must be greater than for a direct motion, and vice versa, but
in all cases the throw of the eccentric, or the circle described by
the eccentric centre or pin, the lap of the valve, &c., must be found
in the first place to suit the cut off in the cylinder, as for direct
motion, and the levers proportioned accordingly.
Sometimes the valves for land-engines are made double-ported;
this class of valve is simply adopted to reduce the “throw” of the
eccentric, and secure rapid admission and cut off for the steam ;
thus with ports of the same length as for single-ported arrange-
ments, we can, by having double or more ports, increase the area
for the entrance and exit of the steam, a matter of importance
when a high rate of piston-speed is adopted.
When the valve is made large, it is necessary to relieve it from
the steam-pressure that tends to force it against the cylinder face.
There are a variety of plans for doing so: Some engineers introduce
a piston working in a short cylinder, placed in the valve-casing
cover, connecting the piston to the valve by means of a vibrating
link; by this plan it is lifted as it were off the face, thereby reduc-
ing the friction, as the valve is partly suspended, and consequently
more easily moved. Others have introduced a flexible plate, con-
necting it to the valve in like manner, the spring of the plate acting
in a similar way as the piston arrangement; both are acted on by
the steam in the valve-casing, pulling the valve from the face, of
course, according to the amount of area exposed. However, such
arrangements are not to be relied on, and the end in view is attained
by simpler contrivances. The usual method, now in extensive use,
is by recessing two rings in the valve-casing cover, and pressing
them against a planed face, on the back of the slide-valve, by a
number of set screws, placed around, central with the recess; these
set bolts press against a ring of iron in the first place, then a plaited
gasket is interposed between this ring and the brass ring, which
presses on the back of the slide-valve, thus making the area covered
by the ring perfectly free from steam; the valve is by this means
7
98 MODERN STEAM PRACTICE.
relieved of much of the steam-pressure. A small pipe is introduced
through the valve-casing cover, in connection with the eduction-pipe
on the cylinder, thus any slight leakage of steam between the ring
in the recess and the valve is taken over into the condenser when
so fitted.
Other engineers have constructed the valve as a hollow frame,
having merely sides; the back in this arrangement being fitted
with a narrow piston-ring edge, having springs to keep the valve
to the face on the cylinder, and also to press the piston-ring against
the back of the valve-casing or the cover. This is certainly a
refinement, and so long as the rubbing surfaces remain steam-tight,
the plan is to be commended, as it is impossible such a valve, under
any circumstances, can have any more back-pressure than merely
the rubbing surface that is not covered by the piston-ring; but in
the event of leakage between the rubbing surfaces, the plan is not at
all to be desired, as the vacuum would be impaired, and great waste
of steam occur. Therefore, when it can be conveniently applied,
the plain ring system appears best, screwing the ring against the
back of the valve, as such a plan can be adjusted at any time with-
out breaking a joint, the set bolts being simply screwed into tapped
holes in the valve-casing cover; it must be borne in mind, however,
that the valve-gear must be proportioned to meet the full pressure
on the valve, as at times the best arrangements will get out of
order. When cast-iron surfaces are adopted, one-sixth of the total
pressure on the valve may be taken for calculating the strength of
the valve-rod and adjuncts, that is to say, if the faces are in good
working order, and the lubrication properly attended to.
The position of the valve next claims attention. In all cases
where practicable, it should be placed on its edge, so as to drain
or run off moisture or water that may collect when the engine is not
working, a small valve being fitted to the casing for running it off;
thus the faces are kept as dry as possible, preventing the corrosion
that would otherwise set in.
The reciprocating motion imparted to the valve is usually obtained
by means of a simple eccentric, although cam arrangements at times
find favour. The eccentric wheel or sheave has both a rotatory and
reciprocating motion, its action is somewhat the same as a pin re-
volving around a fixed centre, such as the main crank-pin of the
steam-engine; in fact, a plain crank and pin is often used instead of
an eccentric; but when the line of eccentric or valve-rod cuts across
REGULATION OF STEAM. 99
the engine-shaft, it becomes imperative to use an eccentric sheave,
over which is placed a loose strap, to which is attached the eccentric
rod; thus the eccentric sheave revolves inside of the strap, and the
former being firmly attached to the <
main engine-shaft, communicates
reciprocating motion to the valve
and its adjuncts; the jointed end
of the valve having suitable guides,
so that the valve-rod moves in a
straight line. To set out the ec-
centric, we will suppose the dia-
meter of the engine-shaft is given,
and Consequently its centre, which
we will term A; draw a straight
line through the centre of circle
delineating the engine-shaft, and A, Centre of engine-shaft, B, Centre of eccentric.
on this line set off A B; this we will E F, Thickness of metal round shaft.
name the crank of the eccentric, the C D equals A B, multiplied by 2.
point B denoting the centre from which the eccentric sheave is
described; the distance from A to B equals the outside cover, or lap,
plus the full opening of the port by valve; then set off a proper
thickness of metal for the eccentric sheave, around the shaft, and
from the point B describe a circle touching the periphery of the
circumscribed thickness around the shaft, and the circle described
is the full size of the eccentric sheave; thus the basis is given for
constructing the eccentric motion.
The eccentric is certainly not the best method of imparting motion
to the slide-valve, as cams give a better cut off; but considering the
great number of revolutions per minute many engine-shafts revolve
at, it is the only motion that gives satisfaction, being regular and
easy; whereas with high speeds the cams impart a succession of
blows that would soon shatter the machine, and the noise would be-
come intolerable. However, some steam-engines of the fire-engine
class have neither eccentric nor cam motion, but simply an arm
keyed on the piston-rod, having an oblong eye, working on a twisted
flat bar of iron, thus imparting motion to the slide-valve; an arm is
fixed on the end of the twisted bar for taking the valve-spindle,
a short link being interposed between, with the necessary pins,
guides, &c.
Having now considered some of the leading features demanding
Fig. 49.—Eccentric Sheave.
:
;
e
©
:
i

loo MODERN STEAM PRACTICE.
thought in designing the slide-valve gear, attention must be drawn
to the beautiful link-motion, as first applied to the locomotive,
in its general application to land-engines, more especially to that
**
*
**-----~~
- Fig. 50.—Link-motion.
A. Centre of crank-pin at the commencement of the IN stroke. B, Centre of forward eccentric.
C, Centre of backward eccentric. D, Centre of suspension in link. E, Lifting arm. F, Slide-
rod block.
class of engine requiring skilled men as drivers, or those techni-
cally termed engine-tenters. In days long gone past we have often
handled colliery winding-engines, and it required a great amount
of patience and skill to do it properly; but now it is done in an
easy and satisfactory manner by the double eccentrics and link-
motion, so that with an attentive man there is no fear of drawing
the cage, with probably a living load, over the pulleys on the pit-
head frame, as he can reverse or stop the engine with a single
movement. Indeed, the numerous small engines handled in this
manner every day lifting heavy weights quickly and under perfect
control, lead many inquirers to consider that the double eccentrics
and link-motion is the greatest improvement yet contrived in the
mechanism for actuating the slide-valve.
There has always been an amount of mystery in explaining the
action of the double eccentrics and link, while all allow that the
common eccentric, or crank movement, is very easily comprehended.
The latter is set to give a movement of the main crank of the engine
in the particular way required; the eccentric centre being fixed, the
crank-pin could by no means travel in the contrary direction per se,
but by placing a twin-eccentric on the engine-shaft alongside of the
other one, with the centre directly opposite, in relation to the main
crank, the backward movement is obtained; then by connecting
the extreme ends of the eccentric rods to a slotted link, so that
this link can be moved up or down at pleasure, bringing the forward


REGULATION OF STEAM. IOI
or backward eccentric rod in a line with the valve-spindle, we have
the power of moving the crank IN or OUT, as while one eccentric
is in gear the other is simply doing nothing; they have joined
hands, and are ready at a moment's notice for either going forwards
or backwards, or by lifting the rods, and placing the link at mid-
way between the centre of the eccentric rods, on a line with the
valve-spindle; thus no motion is imparted to the valve, or but a
trifle, and in this position the steam is shut off from the cylinder.
In fact, the motion of the one eccentric is identically opposed to
that of the other, and they can only move in contrary directions
to open the ports as required; and being linked together, it is im-
possible that the one can do the duty of the other, or that both
combined can ever fail in making the main crank of the engine
travel in the direction required. When the link is down, the top
eccentric may be named the driver (as in the locomotive) for the
forward motion; but when the link is raised, the bottom eccentric
rod becomes the driver, while the top rod simply moves to and fro
along with the link which oscillates on the pin and block on the
centre line of the valve-rod, reciprocating motion being imparted to
the valve by the forward or backward eccentric, as the case may be.
The radius of the link is found by placing the valve and adjuncts
at half stroke, and the distance from the centre of the pin, for taking
the valve-block, to the centre of the crank-shaft is the radius of the
link, all the other dimensions or lengths being calculated accordingly;
the point of suspension of the link is generally on this arc, described
by the radius of the link, placed midway between the eccentric-rod
ends, the distance between the eccentric-rod ends being usually
three times the throw of the eccentric. . When the link is drawn
half up, the lifting arm being level, the suspending link should be
nearly vertical, so as to equalize the motion; there are various
methods of holding the link in position, which will be treated in
detail further on.
The slide-valves for compound engines are so arranged, that two
valves, fitted to one casing, is sufficient, one at the top and another
at the bottom of the high-pressure cylinder, the port at the top and
bottom admits the steam into the high-pressure cylinder, the next
port is in communication with the passages for the low-pressure
cylinder, while the third, or middle ports, are in communication
with the condenser; thus there are three ports at the top, and the
same number for the bottom, of the high-pressure cylinder.
I O2 MODERN STEAM PRACTICE.
The cylinders are arranged side by side on the centre line of the
engine; the steam, after doing duty on the top of the small or
high-pressure piston, expands to the bottom of
the low-pressure piston, and then passes into
the condenser; steam is also admitted to the
under side of the small piston, from there to the
top of the large piston, and then into the con-
denser; two long ports or passages are cast in
the low-pressure cylinder, and there is a belt
cast around the high-pressure cylinder, fitted
with a pipe leading to the condenser. Such an
arrangement, designed by the author, was fitted
to a pair of engines for driving the machinery
at the Royal Gun Factory, Woolwich. The
valve gear was simply a crank-pin fitted to a
cast-iron disc-plate; on the pin was secured a
three-cornered cam, described from the centre
of the disc-plate, one cross shaft driven by
bevel wheels and shaft off the crank
shaft, suited for both engines. This
Jis. class of engine requires no cover on
l, the valves, consequently the length
from the centre of the disc-plate to
the pin or centre of the cam is ex-
actly the width of the exhaust-port
Fig. 51.-Valves for High and Low Pressure into the low-pressure cylinder.
- Combined Engines. This cam-motion opens the ports
a B, Throw of the cam. C, Passage to condenser. e * &
Hijºs. i., Lºrºsiºns. Quickly, while the valve hangs, as it
- were, at the top and bottom of the
stroke. With coupled engines the cams are of course set at right
angles to each other, and as the weight of the valves is considerable,
they are balanced with a weight, having a lever and links connected
to the valve-spindle. There was no hand-gear, as factory-engines
rarely require to be moved by hand, more especially when set at
right angles to each other. -
The slide-valve for the locomotive-engine differs very little from
land-engines; but certainly the locomotive type has arrived at a
higher state of perfection than what is usually seen in engines for
ordinary work. The various schemes for working the slide-valve
of the locomotive, Land many arrangements have been tried,—have
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REGULATION OF STEAM. IO3
resulted, at this date, in the universal application of the link-motion,
with double eccentrics, as first practically introduced by the Stephen-
sons.
However, there are a variety of link-motions; with some the links
are curved, while others have them quite straight. Referring to
those most in use, namely, those with the curved link, attention
must be drawn to the various plans adopted for connecting the
eccentric rods to the link. Some arrangements have lugs forged on
Fig. 52.-Locomotive Link-motion.
w, Weigh-shaft.
the link, within, and others without, the centre line of the link for con-
necting the eccentric rods (Fig. 52); other arrangements have no lugs
whatever, but merely a plain link, having the eccentric rods connected
to the ends, on the radius line of the link (Fig. 53), this plan neces-
sitating the eccentrics to have a greater throw than in either of the
two former arrangements. Some links are constructed of two side
plates, with distance pieces, the eccentric rods being placed between
them; while in other arrangements the link is a solid bar of iron,
Fig. 53. –Locomotive Link-motion.
w, Weigh-shaft.
with the eccentric rods at the top and bottom on the centre line of arc,
described by the link. Then, again, the mode of lifting and suspend-
ing the link is by a lever and rod, the point of suspension on the
link is on the arc described by the radius line, and placed half way
between the centres of the pins for the eccentric rods; thus the link
and eccentric rods are raised or lowered simultaneously. With other
arrangements the link is not lifted, but merely oscillates to and fro


IO4. MODERN STEAM PRACTICE.
§
on a pin and suspending-rod, having a fixed centre at end on which
the arm oscillates; this arrangement is complicated, as a movable
Fig. 54.—Locomotive Link-motion.
w, Weigh-shaft.
rod must be interposed between the link and the valve-rod, with the
necessary lifting lever and rod to raise or lower it as required to suit
the forward and backward motion of the engine (Fig. 54).
Again, some link-motions differ entirely from the foregoing, the
link oscillating on centres, on the guide-bar for the valve-rod, Sup-
T
Ö
ſ
iT
|
l'ig. 55.-Locomotive Link.
ported close to the link, while the eccentric rods are connected to
the sliding-block; this arrangement admits of the boiler being placed
lower down, as the link requires less head room; the link-block is
of increased length to insure steadiness; and as the reversing lever
supports only the eccentric rods and link-block, the slide-valves are
more easily handled, although all can be so arranged with counter-
weights to ease the labour in reversing (Fig. 55).
The great value of the link-motion not only consists in ena-
bling us to control the movements of the engine, but it is like-
wise admirably adapted for cutting off the steam at any portion
of the piston's stroke, thus working expansively without the aid
of an additional valve and mechanism, and also simplifying the

REGULATION OF STEAM. IO5
machine, for undoubtedly all motors, especially those travelling
at such high speed as the locomotive-engine, should be as simple
as possible.
The means adopted for keeping the link in position, to suit the
grade of expansion that is required, is effected by placing a lifting arm
on the weigh-shaft that crosses the engine, having a rod attached, pass-
ing along to the starting platform, to which is fitted a quadrant and
reversing lever for taking the long rod, connected to the lifting arms,
on the weigh-shaft. The reversing handle has a catch and quad-
rant having a number of notches cut on its periphery, so by pulling
the reversing handle the link is raised; the catch is then released,
and being fitted with a spring, instantly drops into any one of the
notches, thus holding up the link. As the weight of the links and
rods is considerable, they are balanced with a weight fitted to an
arm on the weigh-shaft; thus the power required to move the links
and rods is equalized very nearly.
Many well-designed link-motions, from imperfections in the mode
of suspension, have failed to give all the requisites necessary for a
perfect motion, a free admission and release of the steam being of
the first importance. The lead or opening of the port by valve at
the commencement of the stroke should be equal, or nearly So, for
all grades of expansion, both for the forward and backward move-
ment; this being the case, the release must follow as a matter of
course. It is often necessary, when designing a new arrangement,
to make a skeleton model, to practically test the best position for
suspending the link, as the latter becomes very sensitive should this
point not be duly attended to. However, by carefully laying out
the valve-gear on paper, drawing it accurately to Scale, testing by
delineation the various positions, the proper point of suspension can
be arrived at without the aid of the model. The point of suspension
of the link itself is midway between the eccentric-rod ends, on the
arc described by the radius line, or nearly so, and on which the
suspension-rod should vibrate equally forward and backward. Some
links are suspended from the bottom, on the pin, for the backgoing
eccentric-rod; and instead of the valve-rod being guided as in the
former examples, a long rod is jointed to the valve-spindle, and
supported at the link end with a vertical oscillating arm, having a
double joint and pin direct, passing through the long rod, the link-
block working in a double joint on the end of the rod, the block
moves slightly up and down, following the arc of the oscillating
IO6 MODERN STEAM PRACTICE.
arm, the pin for the arm being placed as near the link-block as
convenient.
It will thus be seen that link-motions for the locomotive are of
three classes. In the first the link moves, or is lifted vertically, carry-
ing the eccentric rods along with it. In the second the link is
stationary, having no vertical movement, but simply oscillating on
the suspending rod, the valve-rod being lifted and depressed for
the forward and backward movements. And thirdly, the link is
likewise stationary, Oscillating on pins placed on the valve-rod;
the eccentric rods are connected to the sliding-block in the link,
the rods and block being raised vertically, so as to suit the
forward and backward movements. The latter plan appears the
best motion, as the action of the valves is more correct, from the
link being fixed at the centre, and the valve-rod guided in a
straight line,
For modern marine engines, although the
long and short D slide-valves have almost
become obsolete, they are at times still
adopted, the sectional area resembling the
letter D, hence the name given to this class
of valve; with the long D, the valve is cast
all in one piece, the steam-ports in the cylin-
der being as short as possible. The steam
from the boiler, instead of passing into the
valve-casing, as with ordinary arrangements,
is admitted on the face of the valve, and the
back or curve of the valve is made perfectly
steam-tight by means of a plaited gasket,
and packing pieces of metal inserted in the
recesses at the top and bottom; the steam
exhausting into the condenser at the top and
bottom edges of the valve, the long D-valve,
from its great size, in Some instances ex-
ceeding 8 feet in length, was necessarily a
heavy casting, so two short D-valves are
Fig. 56.-Long D-Valves.
a, Steam from boiler. B, Packing generally adopted, held together by means of
Spaces.
wrought-iron rods. The steam is admitted
into the valve-casing through what, in ordinary engines, forms the
exhaust-port in the cylinder, and passes all round the valve, which is
made steam-tight, as before stated, with hemp packing. The cover

REGULATION OF STEAM. IO7
for the valve is suited for the under side of the top port and the upper
side of the bottom port, while the exhaust takes place at the top and
bottom edges of the steam-ports. The face on the cylinder is gene-
rally made of brass, rivetted to the cylinder, with brass pins screwed
into the cast-iron. The valve-gear for paddle-wheel engines is
generally fitted with a loose eccentric, revolving with the main
shaft, having all the necessary stops on the eccentric and the shaft
for the forward and backward movements, the eccentric rod end
taking a lever on the weigh-shaft, fitted with the usual gab for
throwing the valve out of gear, having a long lever handle on the
weigh-shaft for working the valve by hand. As these valves are at
times very stiff to move, provision is made for securing a rope to the
end of the lever, so that a number of men may be employed to shift
them. The weigh-shaft is fitted with a lever for the valve rod, and
another for the back balance weight. This class of valve was gene-
rally used for the side-lever engine, and it is evidently desirable
that it should be capable of being easily and quickly handled, as
men pulling at a rope, perhaps when the vessel is pitching and
rolling about in a heavy sea, is inconvenient and dangerous. A
wheel and pinion, therefore, is sometimes introduced to secure
greater ease in working the valve.
The slide-valve for oscillating engines is generally of the same
type as is adopted for land engines, being fitted with a pack-
ing ring on the back of the valve to relieve it from much of the
steam pressure. The valve mechanism being entirely different from
any other class of engine, the eccentric is loose on the shaft, and
fitted with all the necessary stops for the forward and backward
movements. The eccentric rod is fitted with a gab at its end,
working on a pin attached to an open curved link, made so as to
suit the oscillation of the cylinder; a rod passing upwards is forged
along with the link, having means of guiding it at the top with a
bracket fitted to the head-stock or framing for the main-shaft, the
link itself being guided at the bottom with suitable slides, fitted to
the pillars for supporting the head-stock. This valve gear, in its
simplest arrangement, has a plain handle, fitted with a rod for
attachment to the quadrant, with a means of throwing the gab on the
eccentric rod out of gear; thus the valve can be moved very quickly
for small engines. The cylinder is usually fitted with two valves,
but sometimes with only one; the double arrangement is introduced
to balance the cylindel. The valve spindles have guide-bars forged
IO8 MODERN STEAM PRACTICE.
on at the top, fitted with sliding blocks. There is a weigh-shaft,
working in suitable bearings, placed on the cylinder. This shaft
sometimes curves round the cylinder, with a bearing for each end,
---------> - but the general plan is to forge
2’ `s, in one piece the levers for taking
/ \ the valve rod and quadrant, in-
2 is \ troducing a long bearing between
-i-º-º: *** - __ them, oscillating on a single jour-
* ~ \ \sº º nal fitted to the cylinder. Both
\ ---|-}. / ends of the levers for taking the
quadrant and valve spindle are
fitted with pins and loose sliding
blocks. Where but one valve is
fitted, the centre of the pin in the
lever for the sector end is placed
on the centre line of the engine.
When the valve is at half stroke,
the levers being at right angles
to the centre line of the valve
spindle, the distance from the
# = centre of the pin to the centre
line of the trunnion for the cylin-
> der is the radius of the link or
Fig. 57.-Valve Motion for Oscillating Engines. SectOr. Two valves are, how-
A A, Sector slide "......" for the gab end of ever, generally adopted, necessi-
tating the blocks for the sector
being kept slightly apart; then the radius for the sector is measured
from the centre of one of the pins to the centre of the trunnion.
Thus it is evident that the arc of the sector must sweep the centres
of both pins on the levers, however far distant from each other they
may be placed.
The hand-gear for small power is simply a lever, with link attach-
ment to the sector, but for heavy engines a hand-wheel and pinion,
working in a rack connected to the sector, is usually adopted;
while other arrangements have double eccentrics and link motion,
with suitable pin and block fitted to the sector, at a convenient place
as near to the centre of the sector as practicable. The valve levers
in connection with the quadrant being placed at the half travel of
the valve, the vertical distance from the centre of the guide-block
pin on the quadrant to the centre of the main shaft is the radius of

REGULATION OF STEAM. IO9
the reversing link. The forward and backward movement of the
link is actuated by a starting-wheel working a worm-wheel and sector,
the shaft for carrying the sector-wheel being fitted with levers and
rods for connecting to it. Although the link motion and gear for the
oscillating engine is somewhat complicated, the action of the double
eccentrics and link is similar to the locomotive; each must be set
identically the same in relation to the main crank of the engine;
the only difference necessarily existing is the sector, for communi-
cating motion to the valves, and at the same time accommodating
itself to the vibration of the cylinder.
For direct-acting horizontal marine engines the valve now gen-
erally adopted is of the multiple-ported type, having the ports
double or in some cases in triplicate. This valve was introduced
so that a large opening of port by valve could be obtained, with
a moderate throw of eccentric, thus reducing the size of the eccen-
trics and gear into as small a compass as possible. The valve
is usually placed on its edge, so that it is worked directly from the
engine shaft by double eccentrics and the link motion. Some
engineers place the valves on the top of the cylinder, working them
with a system of wheel-gearing similar to the back motion of a
turning lathe; the valve spindles are connected by suitable rods
to a revolving crank shaft, then by a series of wheels driven off the
main shaft of the engine, so by shifting the position of the two inter-
mediate wheels the relative position for the forward and backward
movement is obtained in relation to the main crank of the engine.
This motion, somewhat modified, is considered by some authoritics
as perfect a motion for actuating the slide-valve as can be conceived,
although the wheel-gearing is very objectionable, and certainly the
link motion and double eccentrics is better calculated for modern
marine engines. As the valves for large engines are of considerable
size, and consequently the gearing heavy, and although only a portion
of the dead weight of the eccentric rods, link, &c., has to be lifted,
that, along with the friction, is considerable; and in all cases where
matter is to be actuated by hand, time must be had, and conse-
quently power, to do so, it is therefore necessary to arrange proper
mechanical appliances for the handling of the valve mechanism of
the marine engine. The usual hand-wheel, with worm-wheel and
sector-wheel, lifting levers and rods, is by far the best plan, as the
link can be held up in any position, so as to work expansively if
required; but this is rarely resorted to, as it is a much better arrange-
I IO MODERN STEAM PRACTICE.
ment to provide a separate valve to work expansively, allowing the
slide-valve to move always in full gear: thus the valve faces are
worn evenly. Some makers have introduced a cylinder having a
piston and rod so connected to the link that the reverse movement
is actuated by steam pressure; and where marine engines, such
as those in the Royal Navy, require an expeditious means of hand-
ling, this plan has a decided advantage in being able to reverse
the engine, or manoeuvre the screw propeller quickly, when the ship
is in action.
There are a variety of arrangements for link motions applied to
the slide-valves of marine engines, but the arc of the link is described
the same way in all cases, no matter whether the link is slotted out,
or simply solid; when the valve and adjuncts are at half stroke, from
the centre of the crank shaft to the slide-valve block, or centre of
the pin on which the link vibrates, is the length of the radius that
- describes the arc of the link. Some
examples of valve-gear have two valve
rods, with eccentric rods on the return
principle, one of the valve rods being
placed above and the other below the
main shaft of the engine. The rods are
guided on the condenser with a long
sliding bar, having snugs forged on
to take the rods. The lifting lever is
** *
!---------------, r
\ _2^ *s
\ eſ ^
t z \
t A Y
C} - z ... *
º -
w
\
Fig. 58.-Link Motion and Starting Gear for Marine Engines.
placed on the top of the condenser, having a rod passing down-
wards, taking the reversing link at the centre and on the arc line;
the lever shaft carrying a toothed sector, working into a worm-wheel
placed vertically, having the starting handle or wheel horizontal.
In this arrangement the reversing lever makes a half revolution,
consequently this mode of suspending the link is not well calculated

REGULATION OF STEAM. - I I I
to work in any other grade than full gear; but should it be desirable
the lifting lever can be made longer, and so arranged as to travel
merely a portion of the circle, keeping the lifting link nearly vertical
throughout. Thus the suspension of the link in this manner is
better calculated for working expansively; but it must be borne in
mind that when the slide-valve works for any length of time in an
intermediate position it is apt to wear a hollow on the cylinder face.
Instead of the two rods for the slide-valve, as in the previous ex-
ample, with the return eccentric rod system retained, one valve rod
has been substituted, placed above the main shaft of the engine. The
action cannot be so good as with two rods, owing to the eccentric
rods working at a considerable angle, the proper position being in
as nearly a straight line as possible with the valve rods. When so
fitted for direct action the valve rod is guided with a suitable cross-
head, placed at the side of the rod. This works in cast-iron guides,
bolted to the valve-casing; the link is suspended similar to the
:
\f
Fig. 59.-Link Motion and Starting Gear for Marine Engines.
locomotive arrangements, thus working expansively by the link.
The plan may be adopted for small engines, but undoubtedly for
large power there should be a separate valve for working expansively.
The brackets for taking the reversing lever are placed on the main
framing, the starting wheel is on its edge or at an inclination; the
shaft for carrying it is supported at both ends, and is fitted with a


II 2 MODERN STEAM PRACTICE.
worm-wheel and pinion. This gear is very generally adopted, as
the link is locked at any position without any other mechanism for
holding it up. Some arrangements for direct action have the eccen-
tric rods too short; where it is not convenient to get in a length of
rod that is the radius of the link, at least six times the throw of
the eccentric, indirect means are preferable for working the slide-
valve; and certainly the return eccentric rod system, as before de-
scribed, seems as good an arrangement for indirect motion as can be
devised. It is essential that the suspending rod for the link should be
made as long as Convenient: this is a very necessary point to attend
to when arranging link motions, as when the rod is too short the
versed sine of the chord of the arc that it describes becomes very
great, causing the link to have an up and down motion, which sen-
sibly affects the working of the valves, more especially when the
eccentric rods are short. Indeed, when such faults are both com-
bined in one arrangement there is no truthful action of the valve
whatever, and in all cases this can be avoided with proper attention.
It is quite unnecessary to describe such malformations.
The modes adopted for guiding the lifting rod in a vertical manner
must next be considered, and this apart from the starting-wheel,
as its position varies very much, and is simply arranged in the best
locality for handling the engines, which undoubtedly is on the same
level as the stoke-hole, although some engineers place the starting
gear on the top of the condenser, or about the same height as it,
thus getting a good view of the machinery in motion. With bevel-
wheels and cross shafts it is a very simple matter to place the start-
ing gear in the most convenient situation; but all means should be
as direct as circumstances will admit of. In guiding the lifting rod
for the link in a vertical manner a simple kind of parallel motion is
sometimes used. The lifting rod is suspended downwards, the bot-
tom pin is fixed to the middle of a short link, the ends of the link
taking an arm placed above and another below the lifting centre;
one of these arms merely vibrates on a fixed pin, while the other
or bottom one is keyed on the reversing shaft that passes across the
engine. This shaft is likewise fitted with an arm for taking the
reversing rod, passing along to some convenient part on the con-
denser. In this example the reversing rod is attached to a cross-
head moving in suitable guides, the starting-wheel actuating a screw
cut in its shaft, the cross-head having a female screw to correspond.
It is quite essential that all link motions should be balanced with a
REGULATION OF STEAM. . II.3
counter weight, keyed and fixed to an arm on the reversing shaft.
Instead of parallel motion for keeping the lifting rod in a vertical
line, a plain cast-iron guide is at times adopted, having a sliding
block for taking the lifting pin, and the reversing levers, similar to
Fig. 6o.—Link Motion and Starting Gear for Marine Engines.
the foregoing example, fitted with a short link for connecting the
reversing arm and sliding block; the lifting rod being attached to
the pin on block and main link, doing away with the top arm, as in
the previous example. In some designs the link is not suspended
for the forward movement, but simply rests on the slide block.
When the link is full down, the lifting pin on the arm passing
through a short slotted hole in the rod, the pin being free to move in
the slot to suit the vibration of the link, there is neither upward nor
downward movement in the link, as it is always resting on the slide-
block for the forward movement, the pin in the elongated hole
accommodating itself to the versed sine of the lifting rod. Another
mode of lifting the link is by means of a screwed rod placed verti-
cally (Fig. 61), having bevel-gear overhead in connection with the
starting-wheel. On the screwed part of the vertical shaft at the
bottom is fitted a nut, having two pins, for taking the short links that
are fitted to the lifting arm, the lifting rod for the main link being
jointed thereto; the pin is placed between the end and the centre of
vibration of the lifting arm. The shaft for the lifting arm passes
across the engine, having merely a plain lever and rod at the other
end for actuating the main link.
A variety of other examples suited for the slotted link as well

8
I I4 MODERN STEAM PRACTICE.
as for the solid one could be given. Suffice it to say, however, that
when solid links are adopted the eccentric rods are connected to
e--""---J
*
*
Fig, 61.-Link Motion and Starting Gear for Marine Engines.
the ends of the link, one of the pins taking the lifting rod being con-
nected to the lifting arm with similar mechanism as for the slotted
link. However, when the link is suspended from any other centre
than the true one, at or near the centre of the link, the motion of
the valve is not so correct as with the plans described above. For
very small engines we would certainly adopt the usual starting gear
as applied to the locomotive engine, having a plain lever handle
fitted with a catch, and quadrant notched to suit a varying expan-
sion; but of course this must only be used where the strength of
one man is sufficient to work the valve-gearing.
From the brief sketch above given of some of the plans most in
use for giving motion to the slide-valves of the marine engine, it
will be seen that, where circumstances admit, the two former
examples are the simplest motions, as having fewer working parts;
and it must be borne in mind that simplicity in the machinery on
board ship is the main thing to be studied.
In concluding this part of the subject attention must be drawn to
a species of valve and gear for working expansively, termed the
gridiron expansion-valve, of which there are two kinds; one being

REGULATION OF STEAM. II 5
quite flat, while the other is circular. The former is simply a flat
plate, having a number of slots or openings, strengthened with ribs
cast on the back; the valve is of brass, as likewise is the face it works
upon. It is placed as near to the main slide-valve as possible. There
is a considerable steam pressure on the flat type, and to obviate that
Fig. 62.-Expansion Valve Gear.
A B, Line of crank, c, Valve chest. D E, The radius of expansion link. F, Lever end for ditto.
G, Centre of eccentric at the beginning of the stroke.
defect circular valves have been introduced, one species being in
equilibrio, consisting simply of a series of rings and openings cast all
in one piece, and having a central boss with ribs radiating from the
centre. These ribs hold all the rings together, the openings being
I inch broad for large valves; five of these openings have been
adopted, giving ample area. This valve is accurately turned to fit a
similar cylinder of brass, with openings to correspond, held together
with vertical ties, cast all in one piece—the whole being encased in a
cast-iron valve box, having an annular space all round. The steam
from the boiler passes down through the hollow valve, and then round
the annular space into the slide-valve chest on the cylinder. At the
commencement of each stroke the ports are full open, and the valve
gear is so arranged as to cut off up to a little more than one-half of
the stroke; at least, practically speaking, this is attained (while the
slide-valve for the engine is arranged to cut off at five-eighths of the
stroke of the piston). The valve gear consists of an eccentric,
having a throw of 2 inches, the eccentric rod taking a lever 4 inches
in length. This lever vibrates on a short shaft, on which is fitted a
slot link with a movable sliding block, to which is attached the con-

II 6 MODERN STEAM PRACTICE.
necting rod for the valve spindle. As the circular valve depends on
its fit to make it steam-tight, it is evident that it should be arranged
vertically, so that the wear may be as little as possible. To set out
this valve-gear the line of the main crank is placed level, the crank
pin being at the commencement of the IN stroke; the valve is set full
Open, and at a point on the valve spindle, with a certain radius to
suit, describe an arc: this is the curve of the link. It is evident
that when the sliding block in the link is moved to and fro along
with the radius rod in connection with the valve spindle, the line of
the crank being level, that no motion is imparted to the valve, or
even when the crank is revolving the radius link can be drawn to the
centre of vibration of the lever shaft; thus the valve always remains
open when required, the lever and link simply vibrating to and fro.
The motion of the lever is always constant, travelling in an arc due
to the throw of the eccentric, while the pin and block working in
the slotted link can be moved out at pleasure, giving a varying
throw. Hence the valve can cut off the steam supply up to one-half
of the stroke of the piston; but from the nature of the motion, the
eccentric passing the dead centre of its throw, while the crank for
the engine is gaining rapidly, the valve does not commence to open
until the piston has travelled about five-eighths of its stroke, when
the main slide-valve has come into action, and consequently no
more steam can be admitted into the cylinder. Thus the expansion-
valve gives a varying cut off from the valve-casing, while that of the
main slide-valve admits a constant volume into the cylinder, de-
veloping the full power of the engine while so doing. The block
and pin for the separate expansion-valve can be drawn back to the
centre of vibration, lcaving the passages in the expansion-valve
always full open. This single eccentric and link motion for work-
ing an expansion-valve separately from the main slide-valve
can be arranged for any class of valve, as likewise the locality of
the valve in relation to the eccentric on the main shaft, the arrange-
ment given being originally designed by the author for marine
engines.
The geometry of the steam-engine next calls for attention, at
least that portion of it which immediately bears on the subject of
valve motions. This must be always carefully studied, in order to
determine all the points requisite in arranging the slide-valve, the
lap and lead of the valve to suit a given cut-off in the cylinder being
of the first importance.
REGULATION OF STEAM. I 17
THE CONNECTING ROD AND CRANK.
The length of the connecting rod varies considerably, those of
direct-acting marine engines being much shorter than in other
arrangements. Taking an example, however, where the length
equals five times the length of the crank from centre to centre; when
the centre of the cross-head, where the connecting rod is attached,
is placed at half stroke, from the centre of the engine shaft to the
centre of the cross-head is the length of the connecting rod, delin-
Fig. 63.—The Connecting Rod and Crank.
A, Centre of engine shaft. B, Half stroke of piston. C., Point on crank path at half stroke.
D E, Stroke of piston. F, Point on crank path at 5%ths of the stroke.
eated as from A to B. With B A as the radius describe the arc AC,
draw a straight line from the centre A to the point C on the crank
path; this is the centre line of the crank at half stroke, the point C
being the centre of the crank pin above or below the centre line of
the engine. It will be seen that there is a great difference of the
travel of the crank pin on its path for the IN and OUT strokes, the
arc described for the IN stroke being greater than that for the
OUT, as delineated from IN to C above the centre line, and from
OUT to C below the centre line of the engine. There is no remedy
for this variation; it is inherent in all crank motions, and varies as
the length of the connecting rod. It therefore becomes imperative
to find the point C to suit the length of the rod, as likewise to deter-
mine the point on the crank path for the particular part of the
stroke of the piston that may be determined on for cutting off the
steam. Thus supposing it is desirable to cut off at five-eighths of
the stroke of the piston, the arc A C will be greater than for the
half stroke, and vice versa when the point of cut-off is sooner than
the half stroke. The particular point is easily found by taking
the radius, and placing the point of the compasses on the first point

I 18 - MODERN STEAM PRACTICE.
from B to E, then cut the crank path at F, the dotted line A F is the
line of cut-off by crank when the piston has travelled five-eighths of
its stroke. This angle is always the same, no matter whether the
stroke or length of the crank is longer or shorter; that is to say, if
the connecting rod bears the same proportion to the crank, namely,
five to one. -
THE CRANK AND ECCENTRIC PATHS.
The crank and eccentric paths are identical; the path of the one
is exactly the path of the other. Each revolves around the same
centre, namely, that of the main shaft of the engine. The crank and
eccentric centres each describe an arc, the length of the chords
varying with the circles described. The chord A B described by the
crank Centre being greater than that delineated by the eccentric
Fig. 64.—The Crank and Eccentric Paths.
a B, Chord of the arc of supply on crank path. C D, Chord of the arc of supply on eccentric path.
E F, Versed sine of the chord of the arc of supply on crank path. G. H., Versed sine of the chord
of the arc of supply on eccentric path. I, Centre of engine shaft.
centre on CD, consequently their versed sines must likewise vary.
Thus, in the example, the large circle denotes the path of the crank,
and the small circle that of the eccentric; A is the commencing of
the IN stroke, and B the point of cut-off determined on. It is very
evident that the point A, or crank pin, has travelled from A to B,
while that of the eccentric has travelled from C to D; draw the lines
A B and C D, bisect A B at F, and draw the lines E F and G H through
the centre I. The line E F is the versed sine of the chord for the crank
path, and G H is the versed sine of the chord for the eccentric path.
In all cases the versed sine of the chord for the crank path must, in

REGULATION OF STEAM. II9
the first place, be found due to the length of the crank and connecting
rod, as likewise the point of cut-off; then when the versed sine of
the eccentric is likewise known, which equals the opening of the port
by valve, minus one-half of the lead, then the eccentric circle can be
found by the rule of three (based on the known property that the
versed sines of circles of similar segments are as the diameters of
the respective circles). Thus, supposing the crank circle was
18 inches in diameter, the versed sine E F being 4 inches, while the
versed sine G H is 1% inch: we have
4 : 18:: I'25 = 5.62 inches diameter of the eccentric circle.
THE CRANK AND ECCENTRIC PATHS DELINEATED AS REGARDS
THE COVER, LEAD, AND CUT-OFF.
The length of the eccentric rod being not less than six times the
throw of the eccentric, the versed sine of the chord described by the
arc on the eccentric path equals the opening of the port by valve,
minus one-half of the lead nearly. Thus, supposing the versed sine
of the chord of the arc of supply on the crank path was 4 inches,
the opening of the port by valve I }% inch, and, for the sake of
illustration, the lead or opening of the port at the commencement
of the stroke of the piston is 9% inch, we have I }%—% = I } inch,
the versed sine of the chord of the arc of supply of the eccentric.
Fig. 65.-The Crank and Eccentric Paths delineated as regards the cover, lead, and cut-off.
Let A B represent the line of the crank at the commencement of
the IN stroke; as the point A or crank pin travels from A to C, the
point of cut-off, it is evident that the valve must open and shut
while the crank-pin centre describes the arc A. C. It is therefore
necessary to lay off the eccentric centre on the opposite side of the
path, as at F. Set off F E, which equals the full opening of the port

I2O MODERN STEAM PRACTICE,
by valve, minus the lead, or I inch; this is the distance from E to F.
Then set off E D, the lead equals 9% inch, while the remainder of
the radius of the eccentric circle, or B D, equals the outside cover
or the lap of the valve. With the length of the eccentric rod as the
radius from E, the point 2 on the valve can be determined; this,
for sake of illustration, is measured from the edge of the valve,
instead of the pin on the valve rod for taking the eccentric rod,
and from the edge of the valve, as at 2, cut the eccentric path at
2, and from the point D fix the point 3 on the valve; cut as before
the point 3 on the eccentric path, join the line from 2 to 3 on
its path; that line is the chord of the arc of supply by eccentric.
It will thus be seen that the figures on the eccentric path cor-
respond with the figures on the valve; thus the point 2 gives the
lead, the point I the full opening of the port by valve, and at the
point 3 the valve has returned and just covers the port, this being
the point of cut-off, or no more steam is admitted into the cylinder,
the remainder of the stroke of the piston being actuated by the
expansive force of the steam in the cylinder. It will thus be seen
that when the crank centre is at the commencement of the IN stroke,
as at A, the port is open 9% inch; when the crank pin centre travels
to G the port is full open, and the valve returning, until the crank
centre has travelled to C, then the cut-off takes place, the valve
having closed the port; thus the expansion of the steam in the
cylinder commences. This only provides for the IN stroke; that
for the OUT stroke must be found in like manner, and it will be
seen that with the same throw of the eccentric the opening of the
steam port by valve is less for the OUT stroke than for the IN stroke;
consequently the lap for the OUT stroke must be greater than for
the IN stroke. When great nicety is required, the area of the port
on the cylinder should be arranged for the OUT stroke, and the
length of the port for the IN stroke reduced accordingly, so as to
get equal area of port for IN and OUT stroke, as likewise equal cut-
off in the cylinder. Thus when the versed sine of the chord of the
arc of supply is given for the crank path, and the versed sine of
the chord of the arc of supply can be determined, it becomes an
easy matter for the student to practically delineate the various
points of the crank and eccentric paths in relation to each other.
To find the versed sine of the eccentric rod, working to the for-
mula V = R—(w/ R*—C*) [V = versed sine, R = radius, C =semi-
chord], we can take as follows:—Throw off the eccentric, or the
REGULATION OF STEAM. 12 I
diameter of the circle of the eccentric pulley centre, round the
centre of the crank shaft (C. × 2) = 50 parts. Eccentric rod, 3OO
parts in length (R); opening of port, 20 parts; lap, 5 parts.
- 3OO*= 90000; C = 25; C*=625.
Then taking 90000—625 = 89375, and &'89375 = 299–. Then
V or the versed sine would but equal 300–299—; or I × : equal
to but tºo of the entire travel of the valve.
T)OUBLE ECCENTRICS AND LINK MOTION.
The mode of setting out the link motion for the marine engine
differs but little from that pursued for the locomotive type. With
the former the double eccentrics and link are simply introduced, so
as to get a convenient arrangement for handling the engines, the
link being rarely used to work with varying expansion, it being
either full up or full down. The reversing lever in general makes
* *
*~...~~~"
Fig. 66–Double Eccentrics and Link Motion for the Marine Engine.
a half revolution around its axis, the point of suspension on the
lever being either up or down, the link being in full gear for the for-

Iſ 22 MODERN STEAM PRACTICE.
ward or backward motions, as the case may be. In some instances
the lifting or reversing lever only describes a small arc of a circle,
having the radius of the lever much longer than by the former
arrangement; then the point of suspension is at some intermediate
part of the half circle; in fact, just similar to the examples given
for the locomotive engine in the preceding pages. In all examplcs
the most convenient method of setting out the link is by placing
the valve and adjuncts at half stroke, A being the centre of the
crank shaft, and B the centre of the pin on the valve spindle for
taking the block on which the link slides. With the radius A B
describe the arc D. D.; this is the centre line of the curve of the
link; make the distance between the pins for taking the eccentric
rods, as at E E, equal to three times the throw of the eccentric
or diameter of the path. Then from the point B, with a convenient
length of lifting rod as the radius, describe the arc CF; it gives the
position at the half lift of the link of the reversing lever, or, as in
the main connecting rod for the engine, the vertical distance from
B to C is the length of the lifting rod, the radius of the lifting arm
C F being half of the distance between the centres of the pins on
the link for the eccentric rods. Thus we have given the leading
points to attend to in setting out the double eccentrics and link
motion.
THE LAP OF THE VALVE VARIES AS THE CUT-OFF AND
LENGTH OF CONNECTING ROD.
With the opening of port by valve, and the lead remaining the
same, the lap of the valve must vary as the cut-off. The less the
chord and versed sine of the arc of supply becomes on the crank
path the greater is the chord of the arc of supply on the eccentric.
The figure shows the chord of the arc of supply on the crank path in
plain lines, while the eccentric circles are delineated by dotted lines.
The line A A is the opening of port by valve, while the curved line
represents the laps for the various points of cut-off. It will be seen
that when the steam is cut off at five-eighths of the stroke of the
piston that the valve at B has less cover than at C; or when the steam
is cut off at five-eighths of the stroke the valve requires less lap than
for cutting off at the half stroke of the piston, and so on increasing
the diameter of the eccentric path. The diameter of the sheave like-
wise increases rapidly, more especially when cutting off at one-eighth
REGULATION OF STEAM. I23
part of the stroke of the piston, when we have, as in the figure, the
diameter of the eccentric path much greater than the diameter of
the crank path. It thus becomes apparent that the valve must be
altered, the multiple-ported type being adopted. Thus, by intro-
ducing three steam ports at each end of the valve, with one central
exhaust port, we gain the same area of port on the valve, while the
opening of each port is only one-third of that of the single-ported
arrangements, so when the steam is cut off at one-eighth or one-
fourth part of the stroke of the piston, a valve should be adopted
having three steam ports at each end, with one central exhaust port,
thus greatly reducing the stroke of the valve, and consequently the
lap; the lead may be presumed equal, at least as far as a particular
engine is concerned. The lead is greater for high-speed heavy pistons
than for engines of the locomotive type, some marine engines hav-
ing 3% inch of lead, and even at times more, according to the weight
and speed, while for high-speed light pistons ºr of lead suffices.
It must be borne in mind that the length of the connecting rod
materially alters the chord of the arc of supply on the crank path.
With a short rod the chord becomes longer, and vice versa; and as
the versed sine of the chord of the arc of supply on the crank path

I 24 MODERN STEAM PRACTICE.
must be a known quantity, as likewise the diameter of the crank
path, when the opening of port by the valve is determined on, as
we now propose to do, the slide valve can be set out as generally
adapted for all classes of engines.
OPENING OF PORT BY VALVE.
The diameter of the cylinder and speed of the piston must also be
determined on to find the opening of port by the valve. Sup-
posing it is required to find the opening of port by the valve, with
a piston speed of 3OO feet per minute giving out for a single cylinder
2OO nominal horse-power, multiply the constant 33,OOO by the power
required, and divide the product by the speed of the piston per
minute, multiplied hy the constant 7 lbs., and the quotient added
to half the area of the piston-rod will give the number of Square
inches of cylinder area; thus,
33OOO X 200
as: # = 3142 + 28 = 3170 square inches,
or say 63% inches, is the diameter of the cylinder, this being the
recognized rule for the nominal horse-power of marine engines. For
high-pressure engines we simply take the steam pressure in boiler
instead of the constant 7 lbs., making an allowance of 15% of the
power required, and the rule for finding the cylinder's diameter is
the same as for the marine engine. Thus, supposing the power
required was 20 horse, and the speed of the piston 200 feet per
minute, with a steam pressure of 30 lbs.,
*...* = 1787 = say 15 inches diameter.
To find the full area or opening of port by the valve we will take the
former example as for the marine engine, namely 317O, as area of
the cylinder in square inches, with a piston speed of 3OO feet per
minute. Multiply the cylinder area by the speed of the piston in
feet per minute, and divide the product by the constant IO,OOO, the
quotient gives the area of port by the valve—
3170 × 3OO
# = 95 square inches.
Thus, the area of the steam port by the valve, divided by the
length of the steam port, will give the opening. The length of
the port is found by dividing the cylinder diameter by 17; thus,
63.5 + 17 = 37.5, or say in round numbers 38 inches, is the length
REGULATION OF STEAM. - I25
of the port; and again 95 -- 38 = 2.5 inches, this is the linear
opening of the port by the valve for a single port. As double-
ported valves are generally adopted, the linear opening of each will
be I'25 inches.
The steam ports in the cylinder are much in excess of this, the
area for the steam port being ºr of the cylinder area, and for the
central exhaust 9% of the cylinder area is generally allowed,—
317O – &
* = 171 square inches for the steam port,
sº =396 square inches for the cxhaust port.
Thus we would have for steam port 171 +38 = 4.5 for main steam
port on cylinder, but as two are required the width of each will be
2:25 linear inches. As double-ported arrangements have a bridge or
strengthening piece on the centre line of the steam port, say I }% inch
broad, we would have four steam ports in the cylinder, 19 inches
long and 2% inches wide. The exhaust or central port in the cylinder
is 39% inclies long, and say IO inches wide, or nearly so, to give
the required area, care being taken that the passages into con-
denser are not contracted.
SETTING OUT THE WALVE FACES.
tº 5 valve 5
2: B : >
arº sº cº
>| : f ; --
º id * s § *N S tº § § /
# 5 Tºzy % % % % : Z. % Z
; =} CYLl NDER !al
cº H.
§ : tº
tal Fig. 68.
inches.
We will suppose the lap of the valve is....................................... I 7%
The width of the outer steam ports on cylinder............ 2%
The width of the outer exhaust port equals the half travel of valve.... 3%
The width of face on valve....................................................... I}{
The width of the inner steam port.............................................. I 4
The lap of valve for inner steam port.......................................... I 7%
The width of inside steam port on cylinder............. tº e º º ºs e º ſº e º 'º e º ºs º ºs e º ſº tº e ∈ 2%
The width of face on cylinder.................................................... I3%
The half width of exhaust port.................................................. 5
.20%
2056 × 2 = 4.1% inches, is the length of the slide valve.
The face on the cylinder between the outer and inner steam ports
is found as follows:–

I 26 MODERN STEAM PRACTICE,
inches.
The outside exhaust port on valve.............................................. 3%
The width of the narrow face on valve........................................ I}4
The width of the inner steam port on valve.................................. I}{
The inside lap for steam port.................................................... 178
7%
Thus the valve and adjuncts can be delineated from the foregoing
dimensions. The packing ring on the back should be as large in dia-
meter as the length of the ports will admit of. The rubbing ring on
the back of the valve is of brass, while the one the set screws press
against is of wrought iron, a common gasket packing being inter-
posed between the rings. Some have proposed springs along with
the packing, with the object of relieving the cylinder in case of
priming. It need scarcely be stated that when springs are intro-
duced they must be placed so that the set screws press them against
the wrought-iron ring.
RELIEVING THE CYLINDER FROM INTERNAL PRESSURE,
With the desirable object of relieving the cylinder from internal
pressure the author has arranged a species of valve differing mate-
rially from the double-ported class, having the rings on the back
for relieving the valve from back pressure. The arrangement pro-
posed admits the steam from the boiler into the cylinder through
the middle port cast on the cylinder, the valve-casing communicat-
ing with the condenser. The steam by this plan has a tendency to
blow the valve off the face, and to prevent this occurring the valve is
provided with a steel plate on the back, let into and securely attached
to the valve; rollers bear on this plate, fitted with journals and
guide-rods, which pass through the back of the valve-chest cover,
having suitable stuffing-boxes perfectly air-tight. There are curved
springs secured with mid shackles to the valve-casing cover. These
springs have holes drilled at the ends, through which the spindles
pass; the ends of the spindles are screwed and fitted with nuts, so
that by adjusting the springs any amount of pressure on the valve
face can be obtained. It will be seen that, from the steam passing
through the valve, the latter is very nearly in equilibrio; still the
steam has a tendency to blow the valve from the face. This is
counteracted by the rollers, which can be so adjusted as to throw
back a little more than the outward pressure; thus the only pres-
sure on the face of the valve is the difference between the outward
REGULATION OF STEAM. I27
pressure of the steam acting on the valve and the pressure imparted
by the springs, which can be adjusted to the greatest nicety. This
Jęeam. Q.
* Fror. Žoržejºz
@ iſ
º
º Sºº SSF
> SSSSSSSSSSSS 2.
W.
Figs. 69, 7o.—Slide Valve by the Author.
valve requires no packing rings, and should priming occur the
cylinders are instantly relieved from the water. This roller motion
should work easily and with less friction than the arrangements
with packing rings on the back. Should the boiler pressure, too,
become higher than the working pressure, this arrangement will
act as a safety valve, blowing the steam through the exhaust into
the condenser or into the atmosphere, as with high-pressure engines.
RELIEVING THE SLIDE WALVE FROM BACK PRESSURE.
The double-ported valve for high-pressure engines differs very
little from those for the marine engine; in fact, the only difference
consists in making the exhaust ports at each end of the valve
smaller, as likewise the ports in the cylinder may also be reduced in
width, and when made very small no packing rings are required,
neither is it necessary that marine engines should be so fitted, as
with small valves the pressure is not much felt. However, correctly
speaking, all valves should be relieved from the back pressure, whether
they are double-ported, or simply the original arrangement, with only




I28
MODERN STEAM PRACTICE.
three ports in the cylinder. Some of these valves for marine engines
simply consist of a frame, having metallic packing rings bearing on
Fig. 71.—Equilibrium Valve.
the back of the valve casing or cover. In the
valve delineated the middle recess is simply
formed to lighten the casting as the exhaust
steam passes through the valve itself in its
passage to the condenser. The packing ring
fits into a recess on the back of the valve, a
plaited gasket is interposed between the pack-
ing ring and a thin metallic plate with springs
for pressing the valve and ring to their respec-
tive faces. It will be seen that this valve very
nearly approaches to what we may term an
equilibrium valve. The only objection to this
class is that there are two faces to keep tight,
and that the ring depends on its accurate fit,
along with the gasket packing, to keep it steam-
tight. To obviate this difficulty a variety of
packing rings have been devised, depending on
their metallic contact alone so as to make them
steam tight; and as it is an object in some engines of the high-
pressure type, having great piston speed, to reduce the weight of
%
Fig. 72.-Equilibrium Valve.
the reciprocating parts, the rings have been
made very light. An improvement upon the
preceding example is that the valve is fitted
with a metallic piston, having a spring ring
fitted to the piston, the piston and slide valve
being pressed to the faces with springs inserted
at the bottom of the cylinder, which is cast on
the slide-valve. The exhaust, as in the pre-
vious example, passes through the valve into
the condenser; in such cases it is advisable to
fit a brass face on the condenser casting, the
steam chest for the valve, as it were, forming
part of the condenser, that is, the valve chest
and the condenser are cast all in one piece.
Another form has the piston and face for press-
ing to the back of the valve-casing of a lighter
section, and the piston made steam-tight with steel-spring rings
recessed in the piston. The piston in this arrangement is simply
§

REGULATION OF STEAM. I29
a ring of metal, the bearing surface on the back of the valve-casing
being merely the thickness of the metal forming the ring. It is
N SNS SNS S
º
Ø
s
:
%
|%
%
§
§§§
§§
rºamºrºſiº º
º §
Fig. 73.-Equilibrium Valve.
held to the face on the valve-casing with two flat springs placed
inside of the valve, thus pressing the valve and the piston ring
to their respective faces. A pin is inserted in the valve and ring
to prevent the latter turning round; the valve is fitted with a hoop
to which the valve rod is attached. This arrangement is about
as effective as any. Some engineers have split the piston ring;
others consider, however, that this is not required, as it is a more
preferable plan to make the piston steam-tight with light steel rings
recessed into the piston as already described, as the ring of itself
with a good fit would nearly be steam-tight, while the steel rings
make it perfectly so. This valve is admirably suited for the loco-
motive engine; the rubbing surface on the packing ring is very
small, and there can be no doubt that this is a benefit. Care must
be taken, however, to have ample provision made for running off
any water that may collect when the engine is standing still, so that
the narrow rubbing surface may be kept quite dry. In the large
marine compound engines, piston valves are now being used.
There are other plans for tightening up the slide-valve rings.
The casing, for instance, is pro- %
ided with a cover on the back, % 2^
V Wit COVer On the Da. *-i- ae,’’.º.º.º.
its inside face being truly planed
and scraped. To the valve is
fitted a ring with snugs cast on
it, each snug being provided
with a ratchet screw bolt and
spring. This ring carries two
packing rings, which are pressed
up against the valve chest door with the set screws. There are
holes tapped in the valve-casing door for the reception of screwed
plugs. These holes correspond with the snugs and screws for
Fig. 74.—Ratchet-bolt for Valve Rings.






9
I 30 MODERN STEAM PRACTICE.
tightening up the packing rings, which is done by means of a
‘box spanner inserted through the hole, taking a square part on
the screwed studs, which, being turned in a particular way, causes
the ratchet to click. Thus the engineer, by counting the number
of clicks for each set bolt, can set up the faces equally. It is
advisable that the rings should be tightened up under steam, so as
to adjust the faces for the expansion of the metals. This plan is
neat, but many engineers consider it not nearly so effective as the
usual method with plain set screws, packing rings, and plaited
gasket, as before described.
To enter into details of an arrangement for taking the pressure off
the back of the slide valve, with a piston having an oscillating link,
&c., would be of little practical benefit, as such has been very rarely
adopted. Suffice it to say, that the piston works in a short pipe
accurately bored out, and placed or cast in the valve-casing cover,
having a link for connecting the valve; the steam pressure acting on
the piston tends to pull the slide-valve from the face. Thus the
force is suspended, as it were, on the link pin, and consequently
the valve is more easily moved. Sometimes a piston has been intro-
duced to balance the weight of the slide-valve when placed verti-
cally, and no doubt the plan is good when the slide-valve is very
large, as the strain on the valve gear is not so much felt. The
piston should be fitted with small steel spring rings, thus simplify-
ing the arrangement.
THE INDICATOR DIA GRAM.
When the steam in the cylinder is cut off at any part of the
stroke of the piston, and were no condensation taking place, the pres-
sure of the steam at the end of the stroke, or at any intermediate
portion of it, could be calculated to a nicety. The curved line that
would delineate the steam pressure inside of the cylinder from the
point of cut-off would then be quite regular. But in practice there
are various causes that tend to make the line of expansion a very
irregular figure; for instance, with a slow cut-off, as with the eccen-
tric motion, the line of expansion does not approach so nearly the
THE INDICATOR DIAGRAM. I31
theoretical curve as when the valves are suddenly shut off with a
cam motion. To ascertain the pressure of the steam in the cylin-
der, as likewise how the valve acts in its admission, recourse must
be had to a very simple contrivance, termed the ſ
indicator, or miniature cylinder and piston, similar
to that of the engine itself. This instrument, in H H
its original form, has a small cylinder, fitted with
a piston and rod. On the top of the cylinder a
light spiral steel spring was placed, fixed to the
cylinder at one end and to the piston rod at the
other end, a pencil fastened to the piston rod
moving along with it. The steam pressure raises
the piston above a line termed the atmospheric
line, and when there is a vacuum in the cylinder
the piston is depressed below the atmospheric
line. Thus the rising and falling of the piston
denotes in the first instance the steam pressure
above the atmosphere, and secondly the vacuum
below it. A roller is placed alongside, fitted
with a pulley, having a cord attached to it; by
pulling the cord the roller rotates, and by slack-
ening the cord it returns to its original position,
being moved by a spring. The cord is fastened Fig. 75.-M“Naught's
to some reciprocating. part of the engine, and Indicator.
by a reducing lever motion is imparted to the A.Roller. 3, Pulley and cord.
roller; thus the full stroke of the piston is taken 3. i. Ż:
in miniature, the motion being simply changed
from reciprocating action to that of a rotary motion. A roll of
paper is fastened round the roller, and secured with a clip. The
pencil fastened to the piston rod is made to press on the paper
with a slight spring. The cord is moved by hand, and the pencil
marks a straight line on the paper, termed the atmospheric line.
When the engine is in full working order this line never varies until
the steam is admitted by a hand tap to the under side of the
piston, which instantly rises, distending the spiral spring accord-
ing to the pressure of the steam. The roller being in motion, a
figure is traced on the paper with the pencil, delineating the pres-
sure on the piston of the engine, above the atmospheric line, as
likewise, on the return stroke, marking the vacuum in the cylinder
below the line, the spring being compressed by the pressure of the

I32 MODERN STEAM PRACTICE.
atmosphere acting on the top of the piston. This is all the indicator
can give off, except showing at what part of the stroke the steam is
cut off, and the behaviour of the valve in admitting the steam into the
I) C.
4. Atmospheric Line B
:
*H
Fig. 76.—Indicator Diagram, from Eccentric Valve Motion.
engine cylinder. Such a diagram is delineated: A B is the atmos-
pheric line, C denotes the pressure above it at the commencement
of the stroke, D is the point of cut-off, E is the point where the steam
in the cylinder falls to the atmospheric line, F G is the vacuum line,
and G H is in compression. The valve has shut the opening from
the condenser, and the compressed vapour and steam admitted by
the lead of the valve causes the pencil to rise rapidly to the point C
on the commencement of the stroke. Then from C to E denotes the
steam pressure on the engine piston, and from F to G the vacuum,
while G H is the volume of cushioning required to check the motion
of the piston at the end of the stroke, in a gradual manner. The
amount of compression being greater for a heavy piston having a
high velocity than for a lighter piston having the same velocity,
bearing in mind that lighter pistons of exceeding high velocity may
require more cushioning or opening by valve, technically termed
“lead,” than heavy ones moving slowly. It must be noted that the
point D in the diagram only approximately shows that part of the
stroke where the steam ports are entirely shut, or the communication
from the boiler cut off by the valve. This defect in the diagram is
inherent in all when the valve is actuated on by an eccentric, as the
motion of the eccentric is very slow when shutting the ports, while
that of the piston is rapid. Thus, to a certain extent, the steam is
wire-drawn, so that the pressure in the cylinder is gradually reduced,

THE INDICATOR DIAGRAM. I 33
and rounds off the diagram, rendering it difficult to define the
exact point of cut-off. To illustrate this more fully a diagram is
given from an engine fitted with Corlis's valve gear. This species
of gear shuts off the steam from
the cylinder very quickly. The
steam pressure in this example was
50 lbs. per square inch, the cylin-
ders had a diameter of 38 inches,
while the speed of the piston was

C. ID
A. Atmospherec Line P
*— AP
Fig. 77.-Indicator Diagram, from Corlis's Valve Gear.
500 feet per minute. With such high pressure and piston speed
the diagram approaches more closely to the theoretical figure than
that obtained from a valve actuated by the common eccentric.
All manufacturers strive to obtain a diagram from their engines as
near the theoretical curve as possible, not that the engine gives out
more power or indicated measure, but simply that the valve gear
is quick and effective. But as the power given off is measured by
the steam pressure and vacuum as taken from the diagram, no one
will dispute that a full figure in the diagram indicates less power
than a fine figure; on the contrary, more power must be developed,
the speed of piston being identical.
The indicator diagram is of great importance to the engineer, as
from it he can at once tell the steam pressure in the cylinder as
compared with that in the boiler, whether to ascertain the pressure
at the commencement of the stroke, or to discover at what part
of the stroke the steam is cut off-to notice if “wire-drawing”
occurs, or a sharp cut-off, at what part of the stroke the steam
pressure falls to the atmospheric line, and whether the vacuum is
quickly and effectually maintained until the point of compression is
reached. By comparing the boiler and cylinder pressures, too, he
can tell what amount of condensation takes place in the pipes, and
adopt means to prevent it. In short—and in this lies the great
value of the indicator—by a proper diagram taken off the engine he
I34. MODERN STEAM PRACTICE.
can tell how it is performing its duty. By means of the indicator
noting the steam pressure and vacuum acting on the piston, as well
as the velocity of the piston, at the time of trial, a true estimate of
the working of the engine is obtained, and thus steam users are
satisfied and disputes avoided.
Some authorities say Watt invented the indicator, others assert
that M'Naught successfully introduced it, although improvements
have since been made by others to suit modern high-speed engines.
The long stroke of the piston and spiral spring causing the pencil
to, as it were, “jump,” made the diagram very irregular. To obviate
this defect the stroke of the piston was reduced, and the range of
the pencil multiplied with a lever parallel motion. Certainly the
improvement is very effective, and fully answers the object in view.
To suit the varying steam pressures it is found advisable to supply
springs of different degrees of power. Thus we have springs for
60 lbs. to the inch, and others I 5 lbs. to the inch; and it will thus
be understood that when the 60 lb. spring is used, and the steam
§
§
High-pressure Cylinder.
Toſh. Botto ºn.
We

le
cº
H-
§
$
Q:
e
~
>{ Tisº.
o
re.
i
º
T-
L–
`s
4tmoſpherve 1.21— >
º * s s 3 : 3. : § §
t * ** ©
* Ǻ
Steam, 45 lbs. Vacuum, 28% inches. Revolutions, 61.
Indicated horse-power, 298'os H. P. cylinder.
Do. do. 31o’88 L.P. ,
608'93
Low-pressure Cylinder.
Tof. JBottorn. §
* & & *
Atmospheric ºne -H ---Tº - |
r"------
* - Vº * -
& “s . i t- 6, : g s * N.

wº- *
Figs. 78, 79.-CoMPound ENGINE DIAGRAMs. |
in the cylinders only 15 lbs., that the steam line on the diagram
will only be 34 inch from the atmospheric line, and with the vacuum
THE INDICATOR DIAGRAM. I 35
proportionately less also; consequently this reduction is obviated by
using the 15 lb. spring to suit the pressure in the cylinder of the
engine. For compound engines varying springs are necessary; but
it is considered that for ordinary marine engines, and in all engines
where the variation of the steam pressure is not great, that one
scale, and spring to suit, is quite sufficient, as a variety only creates
confusion. To show this more fully, take two diagrams from marine
engines of the compound type. The full figure shows the behaviour
of the steam in the high-pressure cylinder, and the lesser diagram
steam in the low-pressure cylinder. The same scale is used for
both (the diagrams being reduced from the original). It will be seen
that the diagram for the low-pressure cylinder is very lean, while
that for the high-pressure cylinder is well defined; and to make the
former bolder it is evident that a different spring and scale must
be adopted. This would improve the appearance of the low-pressure
diagram, but were the same scale and spring adopted for the high-
pressure diagram it would make the figure too large. The reading
of the high-pressure diagram is somewhat different from ordinary
high-pressure engines. The diagram in such cases would show the
pressure, commencing from the atmospheric line, while in the
example before us there is a slight back pressure. This is due to
the steam expanding into the large cylinder instead of into the
atmosphere, as with ordinary high-pressure engines.
We give examples in which both the high and low pressure cylin-
ders have diagrams taken from them. Both of the figures are
well defined, the scale for the high-pressure diagram being double
that for the low-pressure diagram, or the spring of double the power.
Thus it will be seen that it is quite necessary to have two sets of
springs for combined engines, so that there may not be so great a
difference in the diagrams, or that the figure be not too minute in
the one nor too bold in the other. When the operator is taking
diagrams off an engine he generally takes them for both ends on the
same paper, provision being made on the cylinder for doing so, the
Small steam pipes fitted being in communication with both ends of
the cylinder. Thus the double figures are represented, one for the top
or OUT stroke, and another for the IN stroke of the piston. Care
must be taken that the area of the small pipe connecting both ends
of the cylinder is of sufficient size, not less than 34 inch in diameter,
so that the full pressure may be conveyed instantly to the piston of
the indicator. This pipe must be fitted with a hand-tap for each end
I36 MODERN STEAM PRACTICE.
of the cylinder, so that when one of them is shut the other is open to
the indicator, and so on for each end of the cylinder. The examples

Ton High-pressure Cylinder. JBattom.
3. s * : § t 3. _3–4° :
is tº __ _-T
Tijº
L^ \
→
|_ _H-T
--—
º {
*} º º
sº
T-
|-
º
;
H----
-—
º
§
He
--- º *
§ § Ǻ
º
wº
Steam, 54 lbs. Vacuum, 28% inches. Revolutions, 60.
Indicated horse-power, 457 66 H. P. cylinder.
Do. do. 7I3’75 L.P. Jº
1171 41
Tor. Botforn.
T.ow-pressure Cylinder. LT Sº
& s We ury © Q 2–º º &
sº $2 So Ys : º *
==<! /
__^ D- *
d |- H. *
*. § }
ery Wºo º o: : § º º s º $

º
Figs. 80, 81.—CoMPOUND ENGINE DIAGRAMS.
illustrated are taken from combined engines of the vertical type;
the top and bottom of the cylinders are taken in the literal sense,
but the IN stroke of all engines—that is, when the crank is moving
inwards towards the cylinder—should be termed the IN stroke, and
when the crank is moving from the cylinder the OUT stroke is
signified: by adhering to these terms confusion is prevented.
Although the two preceding examples show back pressure on
the return stroke of the high-pressure piston, as delineated by the
diagrams, yet the expansion may be carried so far that the steam
may fall to the atmospheric line at the commencement of the stroke
of the large piston or low-pressure cylinder. The following dia-
grams show that this has taken place in the up or top stroke of the
high-pressure piston, the steam expanding to the top of the large
THE INDICATOR DIAGRAM. I 37
cylinder, or down stroke of the low-pressure piston. For large
power this is an advantage, as the descent of the large piston is
High and Low Pressure Cylinders combined.
Top.
^ -
Total indicated power, 1551.
Steam, 40 lbs. Vacuum, 28 inches. Revolutions, 33.
G
:
§
§
;
:
:
§
:
&
s
i
Ka
§
ob
* T
~
Figs. 82, 83.-CoMPOUND ENGINE DIAGRAMS.
better balanced than if great steam pressure was admitted into the
cylinder. Again, when the steam is raising the small piston, it will
be seen that more steam is admitted, the cut-off taking place at a
later period. The diagram for the large cylinder shows steam pres-
sure above the atmospheric line for a very short period, which of
course is beneficially utilized in raising the large piston. These
two diagrams admirably show the action of the slide-valve, the
opening of the valve being greater for the IN stroke than for the
OUT stroke. This takes place with valves having the same amount
of cover on each steam end, actuated by an eccentric motion.
For reading off the steam and vacuum measures the diagram is

I38 MODERN STEAM PRACTICE.
divided into ten parts on the atmospheric line; the tenth space
is subdivided, having one-half at each end, thus having ten ordinates
as shown; so by measuring each ordinate by the scale adopted, the
sum of the ordinates divided by IO gives the mean pressure in the
cylinder. The power is run out by the usual formula—
Area of cylinder in square inches x mean pressure x speed of piston in feet per minute,
330OO
thus the real or indicated power of the engine is obtained.
The theoretical line of expansion of the steam in the cylinder is
only useful to show how nearly the diagram as taken by the indi-
cator approaches it. Without comparing the theoretical measure
with the diagram illustrated, we will explain how the theoretical
line of expansion is obtained. It is based on the natural law that
governs pneumatics, namely, that the pressure of an elastic fluid
varies inversely as the space into which it is expanded or com-
pressed. Thus if the steam in the cylinder is cut off at one-fourth of
the stroke of the piston, the space it occupies at the end of the
A B stroke will be four times the volume of
• T-I-Hi the steam admitted into the cylinder; it
has expanded into four times its bulk,
and the pressure at the end of the stroke
will be only one-fourth of the original
t volume admitted into the cylinder. To
X- ----------- &-----|--|--|-- find the pressure of the steam at the end
- I
–
5
O
| of the stroke, or at any intermediate
* - - - - - - - * * * * * * - - - - - - - - w part of the stroke of the piston, multiply
J.--------------------------- c the number of inches the piston has
travelled when the steam is cut off by
thee pressure, dividing the result by the
k--------------------------- } total length of the stroke in inches, or
Fig. 84.—Theoretical Diagram. by that portion of it that is required.
Thus, supposing A B in the figure repre-
sented one-fourth of the stroke, B being the point of cut-off, and the
stroke of the piston is 36 inches, with a steam pressure of 20 lbs. per
square inch, we would have—
* = 5 lbs. Steam pressure at the end of the stroke,
*** = 666 lbs. steam pressure at three-quarters of the stroke,
9 × 20
*...* = I0 lbs, steam pressure at one-half of the stroke.

THE INDICATOR DIAGRAM. 139
Thus there is one-fourth of the original pressure at the end of the
stroke, at three-fourths of the stroke one-third, and, at half stroke
one-half of the original pressure. The initial pressure will be 20 lbs.
cutting off at one-fourth of the stroke of the piston, at one-half it
will be IO lbs., at three-quarters 6-66 lbs., and the terminal pressure
will be 5 lbs. The stroke is delineated by the horizontal line in the
figure, and the vertical line represents the diameter of the cylinder
with the lbs. pressure marked off, the curved line from B to C being
the theoretical curve of expansion.
The diagram is taken as follows:—The mechanism attached to
the engine for actuating the roller on which the paper is fixed should
be of the simplest construction. A plain arm vibrating on a fixed
pin, having a slot at the downward end so as to take a pin fixed
to the crosshead or piston rod, for direct-acting engines, is by far
the simplest arrangement, the cord being attached to the top, a short
distance from the vibrating centre. A B in the figure represents the
full stroke of the piston, and C D the reduced stroke for the diagram.
The cord can be led away with suitable pulleys should the point of
attachment to the indicator diverge from the straight line, and it is
convenient to have a small pulley, fixed i
on a ball-and-socket joint, placed next to
the indicator, so that the cord from the ; : \
vibrating lever can be placed at different / ||\
angles to that of the part interposed be- | || \
tween the pulley and the roller on the / || \
indicator. For vibrating cylinders, and / : \
other arrangements, the cord can be / : \
attached to the crosshead, and the motion / : \
reduced with a large pulley, a band being 4. § \
wound round it, the length of the band /* j \
being about equal to the stroke of the
engine. This pulley is fitted with a strong
spring, similar to a watch-spring, and the
strain is imparted to this spring instead of to the delicate one in the
instrument. Of course it is necessary to have a smaller pulley on
the same spindle, so as to reduce the stroke for the diagram. Any
part of the mechanism of the engine can, if corresponding with the
motion of the piston, be used as the point of attachment for the
cord, and simple levers for reducing the stroke, with direct means
of guiding the cord to the pulley on the roller of the indicator, is

Fig. 85.—Lever for actuating the
Roller of Indicator.
I4O MODERN STEAM PRACTICE.
far preferable to intermediate pulleys for taking the motion of the
reciprocating part to which the cord is fixed. The cord is attached
to the instrument with a hook and running eye; thus the exact length
of the cord is easily adjusted. The indicator should, if convenient,
be fitted to each end of the cylinder, and a diagram taken off for
both ends, without having a small pipe in communication with both
ends of the cylinder; but when a pipe is fitted it must be of suffi-
cient size, not less than 3% inch in diameter, so that the pressure
may be the same for both ends. If the pipe is made too small, the
friction of the steam on the internal circumference materially tends
to reduce the pressure on the small piston of the indicator. For
vertical engines the plug-tap, for admitting the lubricant into the
cylinder for the lubrication of the piston, is provided with a screwed
part for taking the indicator, while another plug-tap is fitted to the
bottom of the cylinder. These taps are screwed into the covers or
ends of the cylinder. For horizontal engines they can be placed on
and screwed into the metal surrounding the steam ports; but it
is best when they are fitted into the cylinder itself, or at each end
on the covers, or otherwise, as the rapidity with which the steam
flows through the passages tends to decrease the pressure acting
on the indicator piston, although the actual difference may be very
minute. Care must be taken that no abrupt bends are made in the
small pipe connecting the top and bottom of the cylinder with that
of the indicator. Of course there must be a small plug-tap fitted
to the pipe, so that the communication from the top is shut off when
the operator wishes to take a diagram from the bottom end of the
cylinder, and vice versa. It is essential that the indicator should
be placed vertically, so in some instances large easy bends on the
small pipe are admissible, but in all cases where bends are used
there must be provision made for running off the water collecting
from condensation.
When all is in readiness—the engine going at its accustomed
number of revolutions, and all water in the cylinders and pipes
ejected, with all the run-off valves shut—the operator turns on the
steam to the indicator, the handle for doing so being provided with
a stop, so as to have the passage in the plug-tap full open. When
the instrument has made a few strokes the cord can be unhooked
—the diagram has been taken; and it is only necessary to note
on the card the pressure of the steam in the boiler, inches of mercury
in the gauge, the number of revolutions, and the scale adopted.
THE EXPANSION OF STEAM. I4 I
THE EXPANSION OF STEAM.
With a given pressure of steam, and the cut-off taking place at
any part of the stroke of the piston, to find the mean pressure
exerted on the piston during the stroke, by means of the following
table of hyperbolic logarithms. Rule:–Divide the length of the
stroke of the piston by the length of the space when the steam is
cut off from the cylinder; find in the table the logarithm of the
number nearest to the quotient, and add I to it: the sum is the ratio
of the gain. Then find the terminal pressure by dividing the initial
pressure by the proportion of the stroke during which the steam is
admitted into the cylinder, and multiply by the logarithm + I, as
above; the product will be the mean pressure exerted on the piston.
Example.— Suppose the length of the stroke to be 24 inches,
initial pressure 40 lbs. per square inch, and the steam to be cut off
at 6 inches from the commencement of the stroke, we have—
24 + 6 = 4; hyp. log. of 4 is I 386 + I =2:386.
Then 40 + 4 = IO × 2:386 = 23:86 lbs. mean pressure.
HYPER BOLIC LOGARITHMS.

Number. Logarithm. || Number. Logarithm. || Number. Logarithm. || Number. Logarithm.
I'O3 ‘OA8 2'O5 717 3'O5 I II 5 4'O5 I'398
I "I ‘O95 2"I '741 3' I I 13 I 4’ IO I'4IO
I’ I 5 "I 39 2’ I 5 '765 3’ I 5 I "I 47 4’ I 5 I'423
I ‘2 * I 82 2°2 788 3'2 I’I63 4'2 I ‘435
I'25 ‘223 2'25 ‘8 IO 3'25 1:178 4'25 I'446
I'3 *262 2'3 '832 3'3 I'IQ3 4’3 I'458
I'35 '3OO 2'35 | 854 3.35 | 1.298 4’35 I'47O
I'4 "336 2'4 '875 3'4 I'223 4'4 I'481
I'45 '37 I 2°45 ‘896 3'45 I-238 4'45 I'492
I'5 '405 2'5 '916 3'5 I'252 4' 5 I'504
I'55 ‘438 2'55 ‘936 3’55 I-266 4'55 I'5I 5
I'6 “47O 2’6 ‘955 3:6 I ‘28O 4-6 I'526
I-65 ‘500 2’65 ‘974 3.65 I’294 4-65 I'536
17 ‘53O 27 ‘993 37 I'308 4'7 I'54
I'75 ‘559 275 I'OI I 375 I’32 I 4°75 I'558
I '8 '587 2-8 I'O29 38 I'335 4'8 I'568
I'85 ‘615 2.85 I'O47 3'85 I'348 4'85 I-578
I'9 ‘64I 2'9 I'o64 3'9 I'360 4'9 I'589
I'95 '667 2.95 I'OSI 3'95 I'373 4'95 I '599
2"O '693 3'O I'oo8 4'O 1386 5'O 1:609
I42
MODERN STEAM PRACTICE.
HYPERBOLIC LOGARITHMS— Continued.

Number. Logarithm. || Number. Logarithm. || Number. Logarithm. || Number. Logarithm.
5'O5 I'619 67 I'902 8:35 2*I 22 9'95 2.297
5' I I-629 6.75 I'909 8’4 2"I 28 IO" 2'3O2
5’ I 5 1:638 6'8 1916 8’45 2"I 34
5’2 I-648 6'85 I '924 8'5 2"I4O II* 2'397
5’25 I-658 6'9 I '93 I I2" 2'484
5'3 I'667 6'95 I'938 8'55 2"I45 I3' 2°564
5'35 I-677 7'o I'945 8-6 2’ I 5 I I4” 2’639
5'4. I'686 8:65 2’ I 57 I 5’ 2708
5'45 I'695 7"O5 I’953 87 2'I63 I6” 2772
5'5 I'704 7"I I'960 875 2' 169 17. 2'833
7"I 5 I'967 8:8 2' I Z4 I8- 2.890
5'55 I'713 7.2 2‘974 8.85 || 2: 180 I9' 2'944
5-6 I'722 7'25 I'981 8-9 2 I 86 2O" 2'995
5-65 I'731 7'3 1987 8'95 2' 191
5'7 I'74O 7'35 I'994 || 9'O 2'IQ7 24' 3' 178
5’75 I'749 7'4 2"OOI 28° 3'332
5'8 I'757 7'45 2'OO8 9'O5 2'2O2 32" 3.465
5'85 1766 7' 5 2'OI4. 9' I 2°2O8 36' 3'583
5'9 I'774 9’ I 5 2'2 I3 || 4O' 3.688
5'95 1783 7' 55 2"O2 I 9'2 2'219 44." 3784
6'o I'791 7:6 2'O28 9°25 2'224. 48° 3'871
7-65 2'O34 9'3 2'23O 52" 3’95 I
6'o; I '8oo 77 2‘O4. I 9'35 2'235 56. 4'O25
6' I I '808 7.75 2'O47 9'4. 2'24O 6o' 4'O94
6’ I 5 I '816 7-8 2’OS4 9'45 2'246
6°2 I '824 7.85 2'o6O 9'5 2'25 I 64' 4’ I 58
6.25 I'832 7-9 2'o66 68" 4'21.9
6'3 I'84o 7'95 2'O73 9'55 || 2:256 72. 4:276
6'35 I '848 8'O 2‘O79 9:6 2°26 I 76. 4’33O
6'4 1856 9'65 2'266 8O' 4.382
6'45 I '864 8'o; 2°o85 97 2'272 84' 4'43O
6'5 I'871 8' I 2°09 I 9°75 2.277 88: 4'477
8:15 2:098 9.8 2°282 92° 4' 52 I
6'55 I'879 8'2 2” IO4. 9'85 2287 96. 4564
6'6 I'887 8'25 2” I [O 9'9 2'292 IOO" 4-605
6.65 I'894 8:3 2'I I6
TABLE OF HYPERBOLIC LOGARITHMS,
TO SUIT GIVEN RATIOS OF EXPANSION.
Portion of the Stroke i ºperboli Portion of the Stroke i e
... º. #: ||. E.; É:
Hºw IO" 2-302585 I 1%; I'66 '5068176
# 8. 2’O7944I4 # I'6 ‘47OOO36
+% 5’ I'6094379 +'s I'42 '3506568
# 4' I'386.2943 # I’33 2851788
#, 3'33 I’2O297.22 #, I'25 "223 I435
# 2'66 ‘978326o # I'I 4 “I 3IO284
* 2'5 '91629O7 +% I “I I “IO436OO
# 2" '6931472

THE EXPANSION OF STEAM. I 43
PROPERTIES OF STEAM AND OTHER GASES.
Pressure, density, and temperature are the important character-
istics of steam, as they are the properties which regulate the econo-
mical production and application of steam power. Steam as a gas
is amenable to the common laws of gaseous fluids; and, according
to those laws, the pressure, the density, and the temperature bear
fixed relations to one another. The influence of temperature on
the expansion of gases under constant pressures is nearly uniform
for equal increases of temperature, and is nearly the same for
different gases. The expansion of air may be assumed to represent
that of other gases, and it is found by experiment that air expands
złoth of its volume at 32° for each degree of temperature communi-
cated.
The relation betwixt pressure and volume under constant tem-
peratures is also sensibly uniform within ordinary limits. For an
expansion of four times the initial volume, experiments on various
gases show a corresponding diminution of pressure in the ratio of
I to 3-99, or sensibly I to 4.
The total or constituent heat of saturated steam is at all temper-
atures separable into two parts—latent and sensible heat. The
sensible heat is that indicated by the thermometer, and it varies as
the pressure. The latent heat absorbed during the conversion of
water into steam constitutes by far the greater proportion of the
total heat. Thus for saturated steam we have the following
values:–
Pressure. Temperature. Latent Heat. Total Heat.
I4*7 lbs. tº ſº tº 212° tº gº tº 966°-6 dº º º I 178°-6
90 lbs. * * * 320°2 ... 89.1°4 tº ſº tº I2I 1°-6
The difference of total heat is, in this case, 33° in favour of the
higher pressure. It appears, then, that by expansion perfectly dry
steam becomes slightly surcharged, in virtue of the excess of total
heat due to higher pressures; and should it contain a portion of
water in a state of suspension, a small part of this water must be
evaporated during expansion.
For steam, and for gases generally, the following ratios may be
adopted:—
With a constant temperature, the pressure varies simply as the
density, and inversely as the volume.
With a constant pressure, expansion is uniform under a uniform
I44 MODERN STEAM PRACTICE.
accession of heat, at the rate of +}oth of the volume at 32° for each
degree of heat. If then we add (490°–32°) 458° to the indicated
temperature, the sum is directly as the total volume by expansion,
and inversely as the density.
With a constant volume, or density, the increase of pressure is
uniformly +}oth of that at 32° for each degree of temperature
acquired, and adding, as in the previous case, 458° to the indicated
temperature, the sum is directly as the total pressure.
Though the law of the formation of saturated steam has been the
subject of much and varied experimenting, it can as yet be reached
only by the aid of empirical formulas. The weight of a cubic foot
of steam at 212°, raised from water under the ordinary atmospheric
pressure, namely, I4.7 lbs. per Square inch, is ‘O3666 lbs., and this
is an expression of the density of the steam, as weight is a direct
measure of mass or quantity of matter. A cubic foot of pure water
at 62° weighs 62.32 I lbs.; and the ascertained relative volume of
saturated steam produced under the atmospheric pressure is 17OO
times that of the water at 62° of which it is made; therefore Throth
of the weight of a cubic foot of this water expresses the weight of
an equal bulk of the steam so formed, and it is in this way that the
weight of steam already noted was determined. From these data,
with the aid of the ratios already established, the relations of pres-
sure, volume, and temperature may be found.
To find the relative volume of steam.—Add 458 to the temper-
ature; divide the sum so found by the total pressure, and multiply
by 37.3. The product is the relative volume.
To find the total pressure of steam.—Add 458 to the tempera-
ture; divide the sum by the relative volume, and multiply by 37'3.
The product is the total pressure.
To find the temperature of steam.—Multiply the total pressure
by the relative volume, and divide by 37°3; from the quotient sub-
tract 458. The remainder is the temperature.
To find the weight of steam.—Divide 62.32 I by the relative
volume; the quotient is the weight per cubic foot.
Motion of Steam.—It is well understood that steam unimpeded
moves with great velocity from one locality to another, under
slight differences of pressure. Steam may flow into a vacuum, or
it may deliver itself into the atmosphere, or, further, it may flow
into steam of less density. The conditions of its flow in the first
and in the other cases are different; as in the second case, for
THE EXPANSION OF STEAM. I45
example, 14.7 lbs., or approximately 15 lbs., of its total pressure go
for nothing in counteracting the atmospheric resistance, before the
slightest motion is possible. Thus, in the second case, at all pres-
sures the motion of the steam is due solely to the difference of its
inherent pressure and that of the atmosphere. The ordinary
method of estimating the velocity of the flow of gases or liquids
under pressure is founded on the laws of falling bodies; it is a very
beautiful application of the law of gravitation, and it yields results
simply and directly. A quantity of steam confined in a boiler, of
a given pressure and known density, would flow into a vacuum
through an opening from the boiler with a certain initial velocity,
and this velocity would be the same as that which would be given
to a liquid of the same weight as the steam, flowing out under the
same pressure. The velocity of efflux referred to, when unretarded
by physical obstructions, is precisely that which the liquid would
acquire in falling through the height of a column of the same liquid
I inch Square, equal in weight to the pressure of the steam per
square inch. By the laws of falling bodies it is known that the
velocity, v, acquired in falling freely through any height, h, is equal
to eight times the square root of the height, or z = 8 x/h. Thus the
velocity of efflux into a vacuum is determinable, and the following
is the method of finding it:-
Given, the total pressure of the steam, which we suppose to be
Saturated, as in all ordinary cases it is; divide the pressure per square
inch by the weight of a cubic foot of the steam; the quotient is the
height of a uniform column of steam I foot Square, equal in weight
to the pressure of the steam per square inch, Multiply the quotient
as found by I44, the number of square inches in a square foot of
base, and the product is the height of a I-inch column of the steam,
equal in weight to the given pressure of that steam on the square
inch. *
To find the velocity with which saturated steam flows freely into
a vacuum.—Divide the total pressure per square inch in lbs. by the
weight of a cubic foot of the steam in lbs., and find the square root
of the quotient; multiply this result by 96. The product is the
required velocity in feet per minute. *
To find the velocity wit/, which saturated steam freely flows into
the atmosphere, or into steam of inferior pressure.—Take the differ-
ence of pressures of the two steams for the effective pressure, divide
the effective pressure in lbs. per square inch by the weight of a cubic
10
I46 MODERN STEAM PRACTICE.
foot of the denser steam in lbs., and multiply the square root of the
quotient by 96. The product is the required velocity in feet per
second.
To find the pressure to which saturated steam is reduced when it
flows freely, with a given velocity, from one vessel into another.—
Multiply the square of the velocity in feet per second by the weight
in lbs. of a cubic foot of steam of the initial total pressure, and divide
the product by 92.16. The quotient thus found expresses the differ-
ence of the initial and final pressures; subtract this quotient from
the given initial pressure, and the remainder is the reduced total
pressure sought.
Of the loss of pressure generally which accompanies the movements
of steam.—It has been seen that a reduction of pressure, great or
small, necessarily accompanies even the free motion of steam, the
difference being consumed in communicating that motion. By far
the heaviest losses are, however, due to the resistances of bends and
surface friction of pipes, &c. It has been found from experiment on
stationary engines and boilers that the losses on various accounts
follow these general ratios.
The difference of pressures in the boiler and cylinder is—
Ist. As the density of the steam, and as the square of the speed
of piston.
2d. As the square of the ratio of area of piston to cross section of
steam pipe.
3d. As a factor dependent on bends and friction.
The permanent difference of pressure caused by passing through
a stricture in a pipe, otherwise of uniform diameter before and
behind the stricture, is as the density of the steam, and as the
square of the difference of speeds through the larger and smaller
parts of the pipe.
The friction of a fluid through a pipe appears to vary more or
less—
1st. As the length directly.
2d. As the diameter inversely.
3d. As the square of the velocity directly.
4th. As the density directly.
THE EXPANSION OF STEAM.
I47
PROPERTIES OF SATURATED STEAM AT DIFFERENT
PRESSURES.
Fº º:h: Volume of Steam produced º
square inch Temperature | Total Heat produce by 1 of water. X.
above the in degrees of in degrees of | 1 cubic foot .§.”
Pºe Fahrenheit. Fahrenheit. ...tº;O Other in lbs.
htmºre i. Pambour. Authorities.
I 216.3 I 1799 I'O9 I 572 I5 I 5 ‘O397
2 2 I 9'5 I 1809 I’I6 I487 I43 I ‘O419
3 222'5 II 8 I '8 I "22 I4 IO I 357 "O442
4. 225'4. 1 1827 I 28 I 342 I29O ‘O465
5 228°o I 183’5 I'35 I 28o 1229 ‘O487
6 23o'6 I 184’3 I'4I I224 II 74 ‘OSIO
7 233"I I 185°o I'47 I 172 II 23 ‘O532
8 235' 5 11857 I'53 II 25 IO75 ‘OS 54
9 237'9 1186.5 I'59 Io82 Io36 'o;76
IO 24O'2 1187.2 I-65 IO42 996 ‘OS98
I I 242'3 I 1879 I'71 IOO5 958 'o62o
I 2 244'4 1188.5 177 97 I 926 ‘O642
I3 246'4 I 189' I I'84 939 895 'o664
I4. 248-4 I 1897 I'91 909 866 ‘O686
- I 5 25O'4 I IQO'3 I '95 88 I 838 'oZo.7
I6 252'2 . I 1908 2"O2 855 813 ‘O729
17 254"I I IQI'4 2'o'7 83o 789 ‘O75 I
I8 255'9 II92'o 2"I 3 807 767 'oZ72
I9 257-6 II92'5 2 IQ 785 746 ‘O794
2O 259'3 II93'O 2°25 765 726 ‘o815
2 I 26O'9 II 93° 5 2'3 I 745 707 ‘o837
22 262-6 I IQ4'O 2'37 727 688 ‘o858 .
23 264-2 I IQ4' 5 2'43 709 671 ‘o879
24. 265.8 II95'O 2'49 693 655 ‘O900
25 2673 I IQ5'4 2'55 677 64O ‘O921
26 2687 I IQ5'9 2’6 I 66 I 625 ‘O942
27 27o-2 I 1963 2-67 647 6 II ‘O963
28 271-6 1196.8 272 634 598 ‘O983
29 273'O II 97.2 2.78 62 I 585 ‘IOO4
3O 274'4. 1197:6 2-84 608 572 ‘IO25
3I 275'8 I 198°o 2.89 595 56I “IO46
32 277. I I 1984 2’95 584 55O ‘Io67
33 278°4 I 1988 3'OI 573 539 ‘1087
34 2797 II99'2 3'O7 562 529 “I IO3
35 281 to II99'6 3"I 3 552 518 "I 129
36 282-3 I2OO"O 3'18 542 5O9 "I I 50
37 283'5 I2OO'4 3'24. 532 500 ‘I 171
38 284-7 I2OO'8 3'30 523 49 I "I I 92
39 285'9 I2OI"I 3'36 5 I4. 482 * I 2 I 2
40 287. I I2OI’5 3'4I 506 474. “I232
4 I 288-2 I2OI '8 3°46 498 466 ‘1252
42 289.3 I2O2°2 3’52 490 458 '1272
43 29O'4 I2O2°5 3'58 482 45 I ‘I 292
44 291.6 I2O29 3-64 474. 444 "I 3I4
45 292.7 I2O3'2 3'70 467 437 "I 335

I48
MODERN STEAM PRACTICE.
PROPERTIES OF SATURATED STEAM–Continued.

Pressure in Cubic inches
lbs. per of water to Volume of Steam produced Weight of
square inch | Temperature | Total Heat produce by I of water. ; }. t
above the in degrees of in degrees of | 1 cubic foot *; §:
Pºlº Fahrenheit. | Fahrenheit. .#O. Other in lbs.
atmººre. . Pambour. Authorities.
46 293.8 I2O3-6 3°75 460 43O ‘I 356
47 294'8 I2O3'9 3.81 453 424. '1376
48 295'9 I2O4'2 3.86 447 417 ‘I 396
49 2969 I2O4'5 3'92 44O 4 II ‘I416
50 298'o I2O4.8 3'98 434 4O5 “I436
5 I 299'O I2O5' I 4'O3 428 399 "I456
52 3OO'o I2O5'4 4'O9 422 393 "I477
53 3OO'9 I2O57 4. I4. 417 388 “I497
54 3OI '9 I2O6'o 4'2O 4 II 383 ‘1516
55 3O2'9 I2O6'3 4'25 4O6 378 "I S35
56 3O3'9 I2O6-6 4’3O 4OI 373 "I 555
57 3O4.8 I2O6-9 4:36 396 368 "I 574
58 305'7 I2O7·2 | * 4'4I 39 I 363 "I S95
59 306.6 I2O7·5 4'47 386 359 "I616
6o 3O7'5 1207-8 4'53 381 353 '1636
6I 3O8.4 I2O8°o 4'58 377 349 ‘1656
62 3O9'3 I2O8'3 4-64 372 345 *1675
63 3IO'2 I2O8-6 4'69 368 34. I ‘1696
64 3II*I 12089 4’74. 364 337 '1716
65 312'o I2O9"I 4'81 359 333 '1736
66 312.8 I2O9'4 4'86 355 329 '1756
67 313-6 I2O97 4'92 35 I 325 '1776
68 3I4' 5 I2O99 4-96 348 32 I “I795
69 3I 5'3 I2 IO"I 5'O2 344 3.18 "I814
7o 316. I I2 IO'4 5:08 34O 3I4. "I 833
71 316'9 I2 Io'7 5'12 337 3II ‘1852
72 317-8 I2 IO'9 5'18 333 308 ‘1871
73 318:6 I2 II "I 5’23 33O 3O5 ‘1891
74. 3I9'4 I2 II'4 5'30 326 3OI ‘1910
75 32O'2 I2 II'6 5'43 323 298 “Ig29
76 32 I'O I2 II '8 5'4O 32O 295 “IQ5O
77 321-7 I 2 I 2 "O 5'45 317 292 *1970
78 322'5 I2 I2'3 5'52 3I 3 289 "I Q90
79 323'3 I2 I2'5 5'57 3IO 286 *2O IO
8o 324' I I2 I2-8 5-62 3O7 283 ‘2O3O
8 I 324'8 I213'o 5'66 3O5 28 I ‘2O5o
82 325'6 I2 I3'3 5'72 3O2 278 ‘2O7o
83 326'3 I2 I3'5 5'77 299 275 ‘2089
84 327 I I2 I37 5'83 296 272 "2 IO8
85 327-8 I2 I3'9 5'89 293 27o 2127
86 328'5 I2 I4'2 5'95 29O 267 "2 I49
87 329' I I2 I4'4. 6°oo 288 265 2167
88 329'9 I214-6 6'O6 285 262 “2184
89 33O'6 I2 I4'8 6'Io 283 26o "22OI
90 33 I'3 1215'o 6'14 28 I 257 "2218
9I 33 I '9 I2 I 5’2 6'2I 278 255 ‘223O
92 332’6 I2 IS'4 6'26 276 253 ‘2258
THE EXPANSION OF STEAM. I49
PROPERTIES OF SATURATED STEAM–Continued.
Pressure in Cubic inches l
lbs. per £, ºf water to Volume of Steam produced Weight of
square inch| Temperature | Total Heat produce y 1 of water. 1: . º: |
above the in degrees of in degrees of 1 cubic foot of Steam
Pºe Fahrenheit. Fahrenheit. 3.#. Other in lbs.
2 f º sph ere. #. Pambour. Authorities. ;
93 333'3 1215-6 6'32 273 251 2278
94. 334’O 1215.8 6-37 27 I 249 ‘2298
95 334-6 1216'o 6'42 269 247 “2317
96 335'3 I216-2 6'47 267 245 "2334
97 336'o 1216'4 6'52 265 243 ’235 I
98 336'7 I2 I6'6 6'57 263 24I ‘237O
99 337°4 I2 I6'8 6'62 261 239 2388
IOO 338°o 1217'o 6.67 259 237 ‘24O6
IOI 338-6 1217.2 6'72 257 235 ‘2426
I O2 339'3 I2 I7'4 6-77 255 233 ‘2446
IO3 339'9 1217:6 6'82 253 23 I ‘2465
IO4. 34O'5 1217.8 6'88 25 I 229 ‘2484
IO5 34I "I I218°o 6'93 249 227 ’25O3
Ioé 34I '8 I2 18-2 6'99 247 225 "2524
Io/ 342'4. I2 18-4 7'O4 245 224 "2545
Io8 343'O I2 I8-6 7'I I 243 222 ’2566
IO9 343.6 1218.7 7:17 24. I 22 I 2587
IIO 344'2 1218.9 7'23 239 219 *2608
I I I 344-8 I219"I 7:26 238 217 *2626
I I 2 345'4 I2 I9'3 7'32 236 2 I 5 ‘2644
II 3 346'O I2 I9'4 7:38 234 2I4. *2662
I I4. 346"6 12 19:6 7'45 232 2 I 2 *268O
II 5 347".2 1219.8 7'48 231 2 II ‘2698
I 17 348-3 I 22O"2 7' 57 228 2O8 ’2735
I IQ 349' 5 1220.6 7-68 225 2O5 ‘2771
I 2 I 350-6 I22O'9 7-78 222 2O2 ‘2807
I23 35 I'8 I 22 I "2 7.84 2 IQ I99 ‘2846
I 25 352'9 I22 I'5 8°o 216 I97 ‘2885
127 354'O I22 I-9 8’ II 2 I 3 I94 ‘2922
I 29 355'O I222*2 8'22 2 IO I92 ’2959
I3 I 356. I I222'5 8:3 208 189 ‘2996
I33 357'2 I222'9 8’42 2O5 187 *3033
I35 358-3 I223'2 8'51 2O3 I84 "307o
I45 363'4 I224'8 9'O4 I9I I74 '3263
I 55 3682 I225' I 9' 54. I8I I64 "3443
I65 372'9 1227.7 IO'O4. 172 I 55 '3623
I75 377' 5 1229' I IO'S3 I64 I48 '38oo
185 3817 I23O'3 II "O I 57 I4 I “397O

AVote.—According to Rankine and others, the relative volume of steam is less than has
been commonly assigned to it by Pambour, following the laws already explained; Pam-
bour having treated steam as a permanent gas, instead of as being, what it is in actual
practice, highly Saturated.
STATIONARY ENGINES.
PUMPING ENGINES FOR MINES.
One of the earliest and still a principal use of the steam-engine
Fig. 86.-Cornish Engine.
is for pumping the water out of the mines from which we obtain

STATIONARY ENGINES. - I5 I
our coal, ironstone, and other ores. There would be great difficulty
in reaching those vast stores of hidden treasure without the power-
ful aid of the steam-engine, which enables us to overcome many of
the risks and difficulties encountered in mining operations.
The single-acting beam engine is generally adopted for pumping
the water from great depths. These great beams of cast-iron—
and in some cases of wrought-iron plates, stiffened with angle or
T-iron—are supported by pillow blocks, resting on a wall of masonry
carried up to a convenient height above the top of the cylinder.
The beam is in two halves, with gudgeons between them, and is
connected to the piston-rod of the steam cylinder by a crosshead
Fig. 87.—Crosshead and Side-links of Parallel Motion for Piston-rod of Cornish Engine.
A, Crosshead. B, Piston rod. C, Loose collar. D, Key. E, Links. F, Beam gudgeon.
G, Bearings for parallel bars. .
and parallel motion; and in some instances the crosshead of the
piston-rod works in suitable cast-iron guides, and is connected to
the beam gudgeons by plain links. This motion is not so expen-
sive in first cost, and the wear and tear is greatly reduced.
The cylinder A is a plain casting with port C cast on at the top,
incased in an outer cylinder B, to which it is bolted, flanges being
cast on each at the top for that purpose. The outer casing or
cylinder is bolted to a separate bed-plate D at the bottom. A space
is left between the two cylinders for the admission of steam from
the boiler; and they are made steam-tight at the bottom, raised strips

I52 MODERN '. STEAM PRACTICE.
being cast on each, and turned slightly conical. A small branch
pipe is cast on the outer casing at the top for the admission of the
- steam, which forms a steam-jacket
around the internal cylinder, and
one at the bottom to run off the
water from the condensation of
the steam in the annular space
between the two cylinders; each
of these pipes is fitted with a plug
tap. The bed-plate D is a strong
casting, with port E cast on, and is
bolted down through the founda-
tions with six holding-down bolts.
There is a bottom plate F fitted
into and made tight by a rust joint.
The cylinder cover G is an open
casting, with separate covering
plate H, and has the stuffing-box I
cast on, which is fitted with the
usual lantern brass K, and gland L,
for the packing of the piston rod.
The piston M is also an open cast-
ing, ribbed at the under side, and
fitted with a junk ring N, having
bolts with nuts recessed in the
body of the piston; there are two
spring packing rings O, of cast iron,
accurately turned and made per-
fectly steam-tight. The piston rod
is let in through the under side,
and is turned conical, fitting into
a corresponding hole in the piston,
Fig. 88.—Cylinder, Piston, &c. the rod being secured with a cot-
ter P at the top. The cylinder is
fitted with a ring Q of wood at the bottom, to deaden the shock
should the piston descend so far.
The pump rods are directly attached to the gudgeon at the other
end of the beam by suitable wrought-iron straps, jib, and key. The
end of the pump rod is covered by plates on each side, fastened by
cross bolts passing through and through, to prevent the wood strip-
§-
&
5
2:
_ET
%
5.
sº
- Sº- ----
#9
ñº
º
&SS S.
> <$
Sº º
lºssº ~
*\ º
- º
















STATIONARY ENGINES. - I53
ping. The pump rods of timber bend to the versed sine described,
but being of great length the motion is but little felt.
The pumps are of two kinds—lifting or bucket pumps and for-
SN
2
|
%
%
Fig. 9o.—Lifting Set. Bucket, 18 inches in diameter.
A, Wooden rod. B B, Wrought-iron A, Suction pipe. B, Suction-valve chest.
straps, with jib and cotter. C, Side plates. c, Working barrel. D, Delivery-valve chest.
D, Beam gudgeon. E, Wrought-iron strap shrunk on.
cing or plunger pumps; and in some instances a combination of the
solid bucket and plunger pump is adopted.
In the former of these, as indeed in all pumps, the water is forced
up the pipe by the pressure of the atmosphere, when a few
strokes of the pump bucket have caused a partial vacuum in the
pump barrel. The suction valve should be placed somewhat less











I54 - MODERN STEAM PRACTICE.
than 30 feet from the surface of the water in the shaft or pit to be
drained, 28 feet being a convenient height; that is to say, when the
water passes through the valve to the top of a solid bucket. But
when a hollow bucket is adopted, with the discharge valve fitted
thereto, the distance from the level of the water to the height to
which the bucket ascends in the pump barrel should not exceed
28 feet; consequently the suction
valve in the pipe will be lower down.
In the former of these arrangements
the water is drawn through the suc-
tion valve on the down stroke of the
solid bucket, and in the up stroke G
|
º
3
~2
º
º
%
%\
7
N
N*N §
º AU RN
the suction valve closes, and the § s
water is discharged through a valve Nø
placed in the stand pipe above the
suction valve, until the return or
down stroke of the bucket, when the
discharge valve closes simply by
the weight of water upon it; the
s
%
s
F
i
i
Fig. 91.-Forcing Set. Plunger 18 inches in diameter, arranged with one door for each valve.
A, Suction pipe. B, Suction-valve seating. C, Delivery-valve seating. D, Plunger. E, Air valve,
F, Stand pipe. G, Stuffing-box piece and gland.
suction valve then opens, and the pump barrel is filled as before;
and so on. With the hollow bucket the water is drawn through the
suction valve in like manner, but with this difference, that the

























STATIONARY ENGINES.
I 55"
bucket is ascending, consequently it is discharging and drawing the
water into the pump barrel at the same time, and the down stroke
of the bucket simply allows the water above the suction valve to
pass through the valve fitted to the bucket, to be again discharged
as already explained.
The force or plunger pump is just a vertical arrangement of that
type universally used as
feed pumps for all classes
of engines, the upward
stroke of the plunger, after
the vacuum is fully esta-
blished in the pump barrel,
drawing the water through
the bottom valve, and dis-
charging it through the top
valve fitted to the stand
pipe. The height to which
the bottom of the plunger
ascends should not exceed
28 feet, as in the previous
example; and the suction
and discharge valves should
be arranged below that
height.
this pump will discharge a
column of water equal to
the area of the plunger and
length of its stroke, as in-
deed do all pumps, whether
they are lifting or forcing
sets. It is found advisable,
however, to fit a small valve
opening outwards, so as to
discharge the air collecting
at the top of the barrel,
and consequently a little
water is ejected at each
stroke.
It is evident that
: č ...;
Nº ; SV. % *
Zāş : sha %
S㺠! %
31|| || ||
º t | SSS S
32% : ! sº
N N F.
s ; R & }% tº
-- ; N ŽS % E
§ N º ſ Hº
§ § º %
N § ºff #.
§ § & 1H:
N N º % L
§ § ºf |H
§ § "N §§§ E
§ § §§§ E
N s^ §Sø
N N&S N
§ §§ §§
§ islaº º
§ #|Nº *
§ : %
N : %
N t %
N ! %
N
N %
§ tº
N N ſº
N §" Tº 6:
§ § 4 Ö 3
N N. &
N N É
§ N 4
§ § {
§ § {
N § 2.
Fig. 92.-Forcing Set.
Plunger 23% inches in dia
arranged with one door for both valves.
A, Suction pipe.
seating. D, Plunger.
E, Branch from air walve.
pipe. G, Stuffing-box piece and gland.
meter,
B, Suction-valve seating. C, Delivery-valve
F, Stand
The plunger is a plain cylinder turned all over, and secured
directly to the wooden pump rod; the rod is turned, and then
driven tightly in and wedged with iron wedges at the ends, a collar













I56 MODERN STEAM PRACTICE.
being left at the top. All the flanges of the pump fittings should
be bracketed, and the valve-chest doors strongly ribbed in the
casting, and secured with deep nuts, the hoop bolts passing round
the valve chest, the flanges having strong wrought-iron hoops shrunk
on. The arrangements shown are very compact; the bottom
of the pump resting on the cistern placed high up above the lifting
set, the suction pipe of the latter (Fig. 90) being as long as possible
in order to make provision for inspecting the valves in the event of
the water accumulating or rising at
the bottom of the shaft; the valves
also are so arranged that in the
event of the water rising above the
doors they can be drawn out from
the surface for inspection, and again
placed in. .
In the combination of the solid
plunger and bucket pump the water
delivery is equalized; the barrel is
accurately bored out, and fitted
with a gland at the top for the
plunger to pass through, making it
perfectly air and water tight. The
area of the plunger is exactly one-
half of the area of the pump barrel,
Consequently at the down stroke,
the barrel being full of water, it is
forced through the valve in the
bucket; and the water being forced
into one-half of the space, one-half
of the contents of the pump is dis-
charged in the down stroke and
one-half in the up stroke. The
plunger in this arrangement can be
made to act as an air vessel, thus
the flow of the water is very regu-
A, Suction pipe. B, Clack or suction valve. lar, and the shock of the valves be-
• *.*.*.*.*, Sºnd pipe comes somewhat easier. This pump
F, Stuffing-piece box and gland. tº te *
• can be arranged with a solid piston,
having suction and delivery valves as in ordinary pumps. There
must, however, be a passage in connection with the top of the barrel
Fig. 93.—Combined Plunger and Bucket Pump.



STATIONARY ENGINES. I57
of the pump and the discharge pipe, and in this way the water at
the down stroke of the piston, being forced through the discharge
valve, one-half flows above the piston and the other half is dis-
charged up the stand pipe; until the up stroke takes place, when
the other half is also discharged. , Thus in the up stroke the piston
is drawing the water up the suction pipe, filling the pump barrel
and discharging one-half of its cubical contents at one and the same
time; while during the down stroke the water is forced out of the
barrel, one-half of it fills the vacuity above the piston and the other
half is discharged. It will thus be seen that a smaller stand pipe
will suffice for this class of pump; and where the flow of water from
the pump requires to be uniform, this arrangement has a decided
advantage over the foregoing examples. At the bottom of the air
pipe a suction piece is fitted, having a number of holes of about
I inch in diameter, to prevent extraneous matter lodging in the
pump and destroying the proper action of the valves. All classes
of pumps are so fitted, and lifting sets have in some cases a foot
valve placed at the bottom of the air or suction pipe.
In connection with the stand pipe and suction pipe in lifting
arrangements with solid bucket a small pipe is fitted, having a
branch to the space between the suction and the top valve. The
object of this pipe is to allow water from the stand pipe to flow
into the pump and suction pipe, as at times, when the pumps
are not working, the water would flow past the valves, and were
not the air in the pipes ejected by the water flowing in from the
stand pipe, the shock to the machinery would be very great. There
are three plug valves, one on each end of the small pipe and
branch, to shut the water off when the pipe and pump are full,
which is known by the small pet plug tap placed below the dis-
charge valve passing water—a sure sign that all the air is expelled.
At the bottom of the suction pipe a loaded valve is placed a little
above the water in the well, or sump, the technical term for the
space below the roadway at the pit bottom where the water is col-
lected. This valve is loaded to a pressure of 15 lbs. per square
inch, and is used to test the action of the valves. Should the suction
valve be passing water when the solid bucket is lifting, the valve
will discharge water, simply because the water sucked up the air
pipe is forced down again, and as it cannot pass the foot valve when
in good working order, it naturally escapes at the loaded valve,
where the pressure on the valve is not so great as on the discharge
I 58 MODERN STEAM PRACTICE.
valve, subjected as it is to the full head of water in the stand or
delivery pipe. This valve can also be used to test if the discharge
valve closes properly, the engine being stopped for that purpose;
the plug tap above the suction valve and the one on the air pipe are
opened, and a communication through the small pipe already men-
tioned is effected between the pump and the suction pipe. If the
discharge valve passes water the loaded valve at once lifts, being
acted on by the full hydrostatic head in the delivery pipe. This
valve is therefore of great use in testing the efficient working of
the pump.
The pump valves are gen-
erally of the double or treble
beat kind. They are intro-
duced to obviate the objec-
tions inherent in the flap
and conical type of valve,
due to the great lift neces-
sary in the former to pass
the water, and also on ac-
count of the full head of
water in the stand pipe,
which, acting on a large
area, causes the valve to shut
with great violence, tending
to shatter the machinery
and foundations. This evil
is greatly obviated in the
double-heat valve, as it is
adapted to pass a large body
of water with a moderate
lift, which is the principal
object to be attained in all
valves subjected to hydro-
f == static pressure. The valve
Fig. 94.—Double-beat Valve. consists of a metallic cylin-
a, Valve seat, b, Valve... cc, Wooden beats. der, contracted at the top,
D, Guide piece. E, Flange and bolts. & * *
having a central ring with
arms radiating from it, and passing down the side of the cylinder to
strengthen it; there is an inside projection at the top of the valve,
which is truly faced in the turning lathe, as is also the bottom edge


STATIONARY ENGINES. I59
of the cylinder, the central ring being accurately bored out. The
seating consists of a bottom ring and a solid disc at the top, having
a guiding piece at the top of the disc, with a loose flange secured
by bolts; the bottom ring and disc plate are connected by feathers
or arms, cast all in one piece. The bottom ring and top plate are
recessed for the reception of a ring of wood or soft metal, termed
the beating surface. The amount of contraction at the top of the
valve is due to its weight, and the pressure brought to bear on it
should be slightly in excess of the total weight of the valve. Thus
very little force is lost in lifting it; and as the head of water in the
discharge pipe only acts on a small area, in comparison to the
water way through the bottom ring—and as the lift of the valve is
moderate, owing to the water being forced or drawn through two
circumferential openings
—the beat on the wooden r
or white metal rings, if
so fitted, is very gentle
and but little felt, in
comparison with that
of flap valves made of
leather, fitted with me-
tallic facings to prevent
the leather being forced i

through the 'seatings. :
S <> V w - - E
For moderate lifts, how-
ever, and more especially *— : C ºn : ** = 0 =
for lift pumps, the flap ! I C—— ; sº------tºr'
valve is still used. AP :
The top and bottom |
valves, or clacks, as they ;
are technically termed, H H
have deep seatings of l
cast iron, turned slightly 75 :
Q º Or e º wº
conical, fitting into cor Fig. 95.—Clack Valve with Leather Hinge.
responding parts bored. A, Clack seat. B, Leather disc. C C, Top and bottom plates.
out in the pump Cast– D, Bow. E, Cross piece with cotter for securing the bars.
FF, Recesses.
ings, and are fixed in
position with thin red lead and spun yarn laid into recesses
turned out on the circumference of the seat; there is a single
feather cast along with the seat, having an oblong hole in the centre.
I6O MODERN STEAM PRACTICE.
The valve is a disc of leather, with top and bottom plates of wrought
iron, securely rivetted through and through, and it is held in
position by a central bar of iron, with long projections on the
under side for taking the entire
diameter of the valve. A key is
driven through the bar, drawing it
up against the under side of the
seating, which likewise presses
down the bar placed on the top of
the leather; thus the valve hinges,
as it were, on the mid feather, and
is perfectly water-tight. The valve
is prevented from opening too far
by pieces forged on the bar, and at
the top of the bar a bow is formed,
for attaching a hook and chain
/~ when drawing the clack from
• ---" the surface, as provision must be
made that the clack can be drawn
when the water is above the valve-
E
chest door. Some of these valves
hinge on a bar, which passes
through lugs forged on the top
/*S º- *
=_4(&\ = plate and through holes in the
bow, for fishing the valve to which
the bow is securely bolted; there
is also a wrought-iron piece at the
centre of the valve seating on which
Fig. 96.-Clack Valve with Wrought-iron tº .
- Hinge Plates. the valve hinges. There should be
A, Clack seat. B, Leather disc. C C, Hinge al slight play in the holes to Suit
plates. P. Round bar for hinge. e. Bow, the varying thickness of the leather
F, Centre stud. *
forming the valve.
The working bucket (Fig. 97) is constructed similarly to the
ordinary clack valve with leather hinge, having means of attaching
the bar to the pump rods; and is packed with deep rings of gutta-
percha, let into recesses formed on the outside circumference, and
pressed against the barrel with hydraulic pressure, holes being bored
from the top of the bucket for this purpose. This plan is much
more preferable than the old mode of packing the bucket with a
plaited gasket or ring of leather.


STATIONARY ENGINES. 161
The economy of the single-acting pumping engine depends on the
high steam pressure adopted—the higher the pressure in the boiler
is the less water is required to be evaporated or boiled off propor-
H
t
F ig. 97.-Bucket.
A, Bucket. B, Leather disc. c c, Top and bottom plates. D D, Gutta-percha rings. E, Holes for
water pressure for the packing rings. F, Rod. G, Cross bar for securing the rod with jib and
COtter.
tionally; and, in addition, the facility of cutting off the steam at any
part of the stroke to suit the load on the engine, and the careful cloth-
ing of all the parts where radiation takes place with a non-conducting
material, keeping those parts warm and the surrounding atmosphere
cool. To effect this the cylinder is surrounded with a steam casing
or outer cylinder. Steam is admitted between these two, and the
outer one is covered with felt and wood over all, and in some cases
brickwork; the cylinder cover is hollow, admitting steam, and it is
protected with wood lagging, as it is technically termed. The


- - 11
I62 MODERN STEAM PRACTICE.
steam pipes are covered with felt and canvas, and the valve chests
with felt and wood, neatly covered in with ornamental plates. The
boilers are protected with fire-brick or other material on the top.
Thus, with all these precautions, very little radiation takes place,
even although the engine may not have been working for a consid-
erable time.
The action of the single-acting pumping engine is quite different
from that of the reciprocating engine, having the connecting rod
coupled to a crank shaft. The steam from the boiler only acts on
the top of the piston, lifting the water at the other end of the beam,
or as it were the IN-stroke of the pump, when lifting pumps are fitted;
Fig. 98.-Equilibrium Valve.
A, Valve. B, Spindle for valve. C, Seat for valve. D. Holding-down bolt. E, Cross bar.
and when forcing sets are used in connection with lifting pumps, as
is often the case when pits are very deep, the water is forced up the
stand pipe by the mere weight of the pump rods, &c.
The valves are of the equilibrium kind; two are fitted to the top

STATIONARY ENGINES. 163
chest, namely, the steam and equilibrium valves, and the exhaust
valve is placed in the bottom chest. There is likewise, in some
examples, a regulating valve worked by hand, for regulating the
supply of steam from the boiler; and a throttle valve is placed in
ºr. º, ºn Tºra, a Aſº
º ºn-gi ºr w
ºil ------------ º ºf Hºº - * * * * ~ * * ~ * =
º * - L. º.
zºº
& E
fº::...NS:
ãº
º
:
º
ºs º- - - - - - - - - - --.
* * - sº gº º $ tº sº º
i
S
Šs
*
º
º
G STINSNTS
ãºsus º
%
% º
2-zzzzº
H
T
f
SS
SS
SS
SSN
|
2,2'-tº-2
Nº|| $
Nºll lº
Nai-lº
t tº
=}_k=-&
ŞāIISSS}}
ge=eº
Fig. 99.-Nozzle-valve Chest boxed in. Fig. 10o.—Nozzle-valve Chest not boxed in.
A, Steam-valve seating. B, Equilibrium-valve seating. A, Steam-valve seating, B, Equilibrium-valve
C C, Exhaust-valve seating. D, Regulating-valve seating. C, Exhaust-valve seating. E E, Pipes
seating. E, Pipe for conveying the steam from the for conveying the steam from the top to the
top to the bottom of the cylinder. bottom of the cylinder.
the pipe communicating with the top and bottom valve chests, which
is also regulated by hand, and is introduced to throttle, or rather
wire-draw the steam after passing through the equilibrium valve;
thus the engineman can control the upstroke of the piston with the
greatest nicety without requiring to alter the lift of the equilibrium
valve. -
There are three shafts or arbors placed across the engine, arranged
one above another in a vertical line; the top one is for the steam-

















I64 MODERN STEAM PRACTICE,
valve gear, the middle one for the equilibrium, and the bottom shaft
for the exhaust-valve gear.
An arm is keyed on each shaft, having
a connecting rod coupled to the lever for lifting each valve; each
shaft has also an arm with a connecting rod passing downwards to
a loaded lever, the weight of which lifts each valve respectively.
C. O Q
\
* N."
ti
11
it.
!"
I
t l
** t
tº º
* \ |
n |
!
I
\ | ! .
; : ! l
! t
1 * I
* \ 1.
* * * !
* \ º ‘R
O } \ i O
**~~~~~ \ \ ;-- *
O-- * * "Sºzi
**--- * \ iš%;
**----- 1s2
----o ! S
i
; : \
: ! -
t
b 1 \
t -
w
t
t
Fig. Ior.—Cornish Valve Gear.
The valves are shut with tappets placed on the vertical rod worked
by the engine, and named the plug rod; the tappets act on slide

STATIONARY ENGINES. 165
handles or horns keyed to each shaft. The tappet or sliding bar for
the steam valve is a long wrought-iron bar, quite parallel in its
entire length, secured to the plug rod with eyes at the ends, and
set screws passing through these eyes, the point of the screw press-
ing against the plug rod. This is necessary, as the steam may be cut
off quickly, or say at one-fourth of the stroke of the piston, conse-
quently the bar would require to be somewhat more than three-
fourths of the stroke of the plug rod, so as to keep the steam valve
shut. The two other tappets are round arms, secured to the plug
rod in the same way, having a series of leather washers Screwed up
against a collar, with a nut and metal washer at the end of the
projecting bar. On the steam and exhaust shafts a catch and paul
are fitted for each, keeping the valves shut until released by the
cataract, which consists of a pump worked by the down stroke of
the plug rod, with a weighted lever so arranged that the oil or water
is forced out of the pump, the delivery being regulated by a valve
or plug tap. On the end of the weighted lever there is a rod
passing upwards for raising the pauls, which can be adjusted at
pleasure; thus the catches are freed, and the weight arm lifts the
valve. A quadrant is keyed on the middle and bottom shaft to
keep the equilibrium valve shut. When the exhaust valve is open
the top quadrant abuts on the lower one, and keeps the equilibrium
valve shut until it is released, when the tappet for the bottom shuts
off the exhaust, and allows the quadrant to pass the equilibrium
quadrant, thus releasing it, and the valve is instantly opened by
the weight arm.
Now we will suppose the piston at the top of the cylinder, and
the exhaust valve full open by the cataract releasing the bottom
catch; the cataract rod, still moving upwards, releases the top catch,
and the steam valve is instantly raised by the weight-arm, the piston
at once descends, until the long parallel tappet cuts off the steam; the
plug rod still moves on until One of the tappets shuts the exhaust at
the end of the piston stroke, and as the equilibrium valve was held
in position by its quadrant, at the moment the exhaust is shut the
equilibrium valve opens; so the steam is thus allowed to escape
from the top of the piston to the under side of it, the descent of the
pump rods placed at the other end of the engine beam being regu-
lated by the amount of opening of the equilibrium valve, which can
be further regulated by the throttle valve at pleasure wire-drawing
the steam in the passages from the top to the under side of the
I66 MODERN STEAM PRACTICE.
piston; and in this way the outgoing stroke or descent of the pump
rods may be very slow indeed. The plug rod, ascending, shuts off
the equilibrium valve, thus stopping the further descent, or produc-
ing only a slight motion, of the plunger and weight, until the
cataract releases the exhaust and then the steam valve. It will
thus be seen that for a part of the downward stroke the steam and
exhaust valves are both open, and the exhaust remains so until the
end of the stroke, when it is closed; while in the up stroke of the
piston the equilibrium valve is open, and all the rest shut off.
In order still further to explain this intricate valve gear, in Figs.
IO2, Io9, we give an example fitted to an engine at one of our
Cornwall mines, the diameter of the steam cylinder being 90 inches.
“The action of the gear will be better understood if we describe
each stroke separately. First, the steam, or indoor stroke:—This is
the down stroke of the piston, and is produced by the admission of
steam through a valve termed the steam valve, situated in the top
nozzle, and which is actuated by means of the lever B fixed on an
arbor carried in bearings in the two upright castings at the sides,
which are termed arbor posts. It is usual to connect the lever B
directly with the steam-valve lever—by means of a rod carried up-
ward, instead of indirectly by means of a rod carried downwards, as
in the example before us; the reason for the latter arrangement we
will explain as we go on. The lever B is attached by means of a
rod with a ‘treadle' or weighted lever of wood situated under the
engine-house floor; the treadle is connected to the steam-valve
lever, so that when the lever B is raised it closes the steam valve.
On the steam arbor, or the arbor carrying the lever B, is placed
a quadrant K, which is supported by means of the catch U, which
catch keeps the steam valve closed till the cataract rod A shall
have released the quadrant K by means of the lever M, and thus
allowed the weighted treadle to pull down the lever B and open the
steam valve. The cataract is actually the governor of the engine,
and acts in the following way. (See illustrations of cataracts, Figs.
IO4, IO5, IO6.) In this case a plunger is attached to the lever, on
the opposite side of the fulcrum is placed the cataract rod A, and
on the plunger side of the fulcrum a weight. The plunger works
in a kind of force pump, fixed in a cistern full of water. When the
plunger is raised water follows it up through the suction valve, and
during the down stroke the water thus drawn from the cistern is
forced back again through a delivery valve which is capable of being
STATIONARY ENGINES. I67
varied in the height of its lift by means of a screw on the cataract
governor valve rod, which rod is under command of the engine-
driver. It is evident that the smaller the opening of the delivery
valve the slower will the plunger descend, the weight forcing it
being constant. As the plunger descends the rod A rises, and brings
the roller shown in the front elevation to bear on the lever M, and
thus releases the quadrant K. Let the cataract plunger be up, then
the engine is at rest, and remains so until the rod A shall have raised
the lever M and released the catch U; the weight attached to B then
suddenly falls and opens the steam valve. Steam being suddenly let
in on the piston causes it to commence its indoor stroke, and in doing
so to give a downward direction to the motion of the plug rod S, the
tappets of which coming into contact with the steam horns depress
them, and thus raising the lever B close the steam valve, at the same
time the piston continues its stroke under the expansive force of the
steam in the cylinder, and towards the end of the stroke raises the
plunger of the cataract to prepare it to repeat its functions during
the next indoor stroke. The horn or lever of the cataract being thus
depressed whilst the steam valve is closed, the catch U falls under the
influence of the weight of the lever M under the projection on the cir-
cumference of the quadrant K, thus preventing the opening of the
Steam valve when the steam tappets have been raised, during the up
or outdoor stroke of the piston, above or clear of the steam horns, until
the cataract weight shall have fallen sufficiently far to release the catch
U, when the steam valve suddenly opens, as before described, and
the next indoor stroke is commenced. Having described the func-
tions of the steam or top arbor and tappets, we will consider next
the equilibrium stroke. The middle, is the equilibrium arbor, and
the horn is shown in the side elevation. There are two quadrants on
this arbor. The first G is released by means of a cataract constructed
precisely like the one just describcd. The rod of this cataract is
placed inside the gear posts, as shown on the front elevation, whereas
that of the steam cataract is placed on the outside. There is an
adjusting Screw A on the equilibrium cataract rod, and two such, P,
on that of the steam cataract. The lever C opens and closes the
equilibrium valve. The opening is done by means of a counter-weight
attached to the lever E, which operates on the release of the quadrant
G. At the completion of the indoor stroke the piston pauses until
the catch O, actuated by means of the cataract, releases the quadrant
G. It will be seen that this cataract rod releases on its down stroke,
MODERN STEAM PRACTICE.
|
|
|
|
|
|
Zacºn!Nozze
|
|
Fig. Io2.—Valve Gear of a 90-inch Cornish Pumping Engine.—Front Elevation.
whereas the other does it on its up stroke. In the former case the rod

STATIONARY ENGINEs. I69
* * * * *
|cº* * *
-rd*
- •
* h
k
| k
Fig. Io9.—Valve Gear of a 90-inch Cornish Pumping Engine.—Side Elevation.
A is attached to the cataract lever on the same side of the fulcrum as





/
17O MODERN STEAM PRACTICE.
the plunger. The quadrant G being released, the equilibrium valve at
the top of the cylinder suddenly opens, and a free communication
is established between the top and bottom sides of the piston through
the perpendicular or equilibrium pipes shown in outline on the
woodcut. The outdoor stroke now commences; the piston, being in
equilibrium, is raised by means of the weight of the pump rods and
attachments, which is sufficient to force the water in the pumps and
overcome all other resistances. During this stroke the plug rods
move upward, and towards the end the equilibrium tappet comes
in contact with the horn on the equilibrium arbor, and lifting it
closes the valve, at the same time allowing the catch O to fall under
the projection on the quadrant G. A portion of steam is thus
confined in the top of the cylinder, which gradually brings the piston
to rest, and prevents it striking the cover. The piston now pauses
till the steam quadrant shall be released. The eduction stroke is
performed simultaneously with the steam stroke. The eduction
valve is situated in the bottom nozzle, and opens a passage to the
condenser for the steam passed from the top to the under side of the
piston during the equilibrium stroke. The lever D actuates the
valve through the lever T. As the piston completes its indoor
stroke the eduction tappet comes into contact with a horn on the
eduction or lower arbor. The valve is opened by means of a coun-
terweight at F, when the quadrant L is released by the cataract.
The quadrants H and I are for the purpose of keeping the equilibrium
valve closed until the closing of the eduction valve. It will be seen
that, although the catch O may be released, the quadrant H prevents
the opening of the equilibrium valve until the eduction valve is
closed and the quadrant H brought into the position shown on the
woodcut. It will be seen that if the catches M and N are released
simultaneously the steam and eduction valves will open at the same
time, but the times can be varied by means of the adjusting Screws
P and R. The hand wheel X is for the purpose of adjusting the
amount of fall given to the weight which opens the steam valve, so
as to give the valve a greater or less opening. The degree of
expansion is varied on the plug rod by means of the screw S.”
The cataract, as a means of regulating the number of strokes of
the Cornish pumping engine, is exceedingly simple. One arrange-
ment consists of a wooden box, open at the top, fitted with another
box internally, having flap valves at the bottom opening upwards,
* The Engineer.
STATIONARY ENGINEs. 171
as also a plug tap, which can be regulated at pleasure from the
engine-room floor. There is a central rod secured through the
bottom of this internal box or
tray, and connected to a lever
weighted at the end, with a fixed
pin as the fulcrum, placed be- $4
tween the weight and the box;
this weight is slightly in excess
of the tray and adjuncts when
the internal box is full of water.
The action is as follows:—The
outside box, in the first place,
must be nearly full of water, and
we will suppose the tray empty
and raised by the weight acting
through the oscillating lever; the
plug rod of the engine descend-
ing acts on mechanism that de-
presses the tray, and water flows Fig. ro4.—Cataract with Wooden Tray.
through the flap valves in the bot- ‘....isºlº º, º
tom until the plug rod ascends,
when the preponderance of the weighted lever raises the internal
box or tray above the level of the water in the outside box, conse-
quently the water in the tray gravitates into the external reservoir—
hence the name cataract; and the time the water takes to flow out
of the one into the other is regulated by the plug tap, iſ it is full
open the water will flow out quickly, and the tray will rapidly
ascend, the cataract rod releasing the valves; but should the plug
tap be nearly closed, it is evident that the water will flow out of the
tray slowly; and as this tap is regulated, the number of strokes of
the engine will be increased or diminished: but the number of strokes
rarely exceeds twelve per minute as the maximum, and four per
minute as the minimum. This form of cataract is exceedingly
simple, and even rude in construction, yet it answers the purpose
admirably so long as the level of water is maintained in the external
box, which must be looked to occasionally, as evaporation will take
place or leakage occur.
Instead of the wooden tray a plunger pump (Fig. IO5) is sometimes
fitted inside of a box of cast iron, having a valve at the bottom for
admitting water or oil into the pump, fitted with a tap for regulating
a

172 MODERN STEAM PRACTICE.
the exit of the fluid. The weighted lever is so arranged that the plug
rod lifts the plunger and weight, and the cataract rod for disengag-
- ...?
N b
G. #

=3). ð (3) E ++ | |
:=E
* * *m. Tº * *mº
Fig. 105.—Cataract with Plunger Pump.
A, Cast-iron box, B, Plunger. C, Inlet valve. D, Plug rod. E, Lever, F, Weight.
G, Regulating spindle and valve.
ing the valves ascends as the plunger and weight descend, the
motion being changed by a lever; the cataract rod for lifting the
paul is jointed at one end of the lever, and the rod passing down to
the arm for the weight and plunger at the other end.
In some examples of the plunger type, when two cataracts are used,
the plug-rod tappet acts on the two levers for lifting the plungers
simultaneously; on the centre of motion of the levers a grooved
wheel is fixed, and the lever for the cataract pump is connected by
means of a chain wound round the wheels, and as the tappet or
plug rod comes in contact with the levers the wheels are partially
turned round, pulling one end of the cataract lever down, and
raising the other end, to which the plunger and weight are fitted.
Some arrangements of cataract pumps have a Solid piston, or one
fitted with cupped leather washers, and on the top of the piston rod
a crosshead and side rods passing down under the floor of the
engine house, and in communication with the mechanism for lifting
the piston and weight placed on the top of the crosshead. A central
metallic valve is placed at the bottom of the pump, and a tap is
likewise fitted for regulating the ejection of the oil, which is gene-
rally used when the cataract is placed on the engine-room floor.
This type of cataract has likewise a reservoir for receiving and sup-
plying the oil; and as leakage past the piston ring occurs after
being long in use, an air passage is formed above the piston in
communication with the reservoir, and any oil passing the piston is
STATIONARY ENGINEs. 173
allowed to fall by gravitation into the cistern or metallic box. In
another example, where refinement of construction is a desideratum,
the cistern is dispensed with, and the oil is
ejected through a valve fitted to the piston
on the down stroke, and passes through the
same valve on the up stroke, it being forced
through by suitable mechanism in the
down stroke, and the ascent of the piston
is acted on by the weight, as in the former
examples. This plan of cataract necessi-
tates a hollow piston rod, with stuffing box
on the pump cover, fitted with an internal
rod attached to the valve, passing up to the
crosshead, for taking the disengaging rod;
this hollow rod is fitted with a stuffing box,
and the internal rod has a thumb screw at
the top for regulating the lift of the valve.
Thus this valve allows of the oil passing
from the bottom to the top of the piston,
and also regulates the flow of the oil from
the top of the piston to the under side of
it, forming a self-contained and handsome
Cataract pump.
The condenser (Fig. Ioz) for the Cornish gº &
ſº tº A, Cylinder. B, Cupped leather pis-
engine is generally a separate vessel, worked ton with valve, c, Hollow rod.
on the injection principle. As the exhaust : tº: d i. gland.
pipe from the steam cylinder is of large
diameter and of considerable length, it is obvious that the cubical
contents of the condenser need not be so large as for ordinary
engines, the exhaust pipe acting as a receiver, and the steam being
condensed in a vessel placed at the extreme end.
The air pump is of the ordinary kind, with metallic head and foot
valves, the bucket being open, with a metallic valve placed on the
top, and it is made tight with ordinary hemp packing plaited, or what
is termed a gasket. In another example (Fig. IO8) the air pump and
condensing vessel are placed inside of a cast-iron tank, which is kept
constantly full by means of a pump termed the cold-water pump.
When this arrangement is adopted the condensing vessel is kept quite
cool by the surrounding water, and to a certain extent acts as a surface
condenser, in combination with the injection system. The tank
|
i
%
l
§
L
Fig. 106.-Cataract without Cistern.







I74 MODERN STEAM PRACTICE.
Fig. Ioz.—Condenser and Air Pump, with Foot-valve Seating.
A, Condenser. B, Air pump, c, Foot-valve chest.
r H
H- Al - B - tº
— —
:=
Fig. Io9.—Air Pump and Condenser without Foot Valve contained in a cast-iron Tank.
. A, Condenser. B, Air pump, C, Tank.


STATIONARY ENGINES. I75
*
must be fitted with an overflow pipe, which is placed in communi-
cation with the discharge from the air pump. When the water is
very bad the air pump should be lined with a barrel of composition
metal, or a brass barrel is so placed, centrally with the condenser;
and when suitably strengthened and supported from the con-
denser vessel, the latter proves a very compact arrangement, com-
bining the condenser and air pump in one. The foot valve, in
ordinary arrangements, is placed at the bottom, between the con-
denser and air pump. It is a flap valve hinged vertically, and is
Sometimes made of wrought iron, faced with a brass beating surface,
with a corresponding brass face securely pinned on the cast-iron
seat. The valve is bent to form a hooked hinge, so that it can be
readily taken off the spindle on which it hinges without disturbing
the seat, a door being fitted to the condenser casting for inspecting
NA
§rſ-us
Šssº's N
Fig. Io9.—Head Valve with Wooden Beat Fig. Iro.—Air-pump Bucket, with Brass Seat for
on Seat. India-rubber Valve.
A, Valve. B, Seat. c c, Wooden beat. A, Bucket. B, Brass seat for valve. c, India-
D, Stuffing box and gland. rubber disc. D, Guard. E, Rod secured with
a nut at the bottom.
and adjusting the valve. The head valve, placed at the top of the
air pump, is a disc of metal having a deep boss at its centre,
strengthened with ribs radiating from the centre, and having a hole
bored through the boss for receiving the air-pump rod, which acts
as a guide for the valve. Sometimes this boss is fitted with a gland






176 MODERN STEAM PRACTICE.
and packing space, thus making it perfectly water-tight. The seat
in this example is cast separate, and bolted to the air-pump, and
fitted with a ring of wood for the valve to beat against. The valve
fitted to the top of the air-pump bucket is of a similar description,
with a plain hole lined with brass, which acts as a guide. In some
cases the valve on the bucket (Fig. I IO) is of india rubber, working
on a grating of brass bolted to the bucket. The air-pump bucket
is fitted with a junk ring and packing space, and when a brass
barrel is used may be packed with hemp, or a metallic, or even
wood packing will be found to answer. Thin metallic rings sprung
into recesses make a first-class packing, and last much longer than
hemp.
The Ejector Condenser—In the ejector condenser the air pump is
entirely dispensed with. The principle of the apparatus may be
described as follows:—In every injection condenser the cold water
rushes into the vacuum with a velocity of about 43 to 44 feet per
second; while the exhaust steam from the cylinder of the engine, at
the pressure of IO lbs. per square inch below the atmosphere, rushes
into the condenser with a velocity of about I2OO feet per second, when
a vacuum of 25 inches of mercury is maintained. In the common
condenser these rapid motions of the water and the steam are com-
pletely checked, and their energy is wasted, and hence an air pump is
imperative, so as to extract the water, air, and condensed steam from
the condenser. In the ejector condenser the exhaust steam from the
cylinder of the engine after each stroke is so directed through a
discharge nozzle as to unite in a jet with the condensing water, by
which it is itself condensed, having, however, imparted a sufficient
velocity to the combined jet to enable it to issue directly into the
atmosphere in a continuous yet impulsive stream. The contents
of the condenser, both water and air, are thus ejected without the
use of an air pump, and at the same time without impairing the
vacuum in the condenser. This result is obtained, however low the
pressure may be to which the steam is expanded before the exhaust
from the cylinder takes place, if the injection water be supplied
with a few feet of head pressure: and the effect is produced by
taking advantage of the high velocity at which the exhaust steam
and the injection water flow into a vacuum. The ejector condenser
not only discharges the products of condensation into the atmo-
sphere from a pressure of I2 lbs. per square inch below the atmo-
sphere, but with a steam pressure equal to the atmosphere at the
STATIONARY ENGINES. 177
commencement of the exhaust, the condenser, when applied to a
pair of coupled engines, is found capable of lifting the condensing
water from a lower level of 6 to 8 feet, or raising the discharged
water to a proportionate height above the condenser.
In the simplest arrangement the injection water enters the con-
denser in the form of a central jet through the conoidal nozzle
A, which is supplied by the branch
pipe B; and the area of the ori-
fice is regulated by an adjustable
central spindle C, which is raised
and lowered by an external screw
and hand wheel. The exhaust
Aſ ºf 3
s
§
#
:
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* * Žá
steam entering at the branch pipe jº ſ: ::::::::
D, passes through the annular #. ---
§ * §§§ gº..…;
space surrounding the central ~. ſº *g
water jet, and the combined cur-
rent passes on through the fixed . . . .” < * tºº. ºf ::: * ~ *
conoidal nozzle F, into the dis- *|† * a.º. Žº
charge tube G leading to the * *\,A}\ºsſ”
hot well. This tube is trumpet-
mouthed, so as gradually to di-
minish the velocity of the current
as it passes through, and utilize
its moving force by avoiding use-
less velocity at the point of dis-
charge, the enlargement of the sº
tube increasing more rapidly to-
N
wards its outer extremity. *>zº
In starting the condenser the Fig. III.-Condenser supplied with Head
• * gº & f Iniection Water.
centre spindle is raised by means of injection Water
of the hand wheel, and a jet of injection water is discharged
through the centre of the current of the exhaust steam from the
engine: the injection water being in this case supplied from a head
of water a few feet above the condenser, so as to flow into it by
gravity. The condensation of the steam by contact with the injec-
tion jet produces a vacuum within the condenser, and the water
then enters with the velocity due to the difference of pressure between
the external atmosphere and the degree of vacuum maintained in
the condenser, added to the velocity due to the head of water in
the injection supply. The water jet having a straight passage for





















12
178 MODERN STEAM PRACTICE.
its exit, without any obstruction, retains its initial velocity, and
rushes on through the combining nozzle F and the expanding dis-
charge tube G, and issues into the atmosphere in a continuous
stream, carrying with it any air mixed with the exhaust steam, the
action being somewhat similar to that of the injector for feeding
boilers.
It is requisite for the injection water to enter the combining
nozzle in a straight stream, without any eddy or rotation of the
water; and whenever the injection is supplied with the pressure of
a head of IO feet or upwards, a provision is made for stopping any
rotation of the stream, by inserting within the nozzle a guiding piece,
R, with several straight radial vanes, as shown in Fig. I I I.
The proportion that has been found most effective for the injec-
tion jet is for the length of the free portion of the jet, which is
exposed to the action of the exhaust steam, to be about three times
the diameter of the jet, except when the injection water is supplied
with a head of IO feet and upwards, in which case the length of the
exposed jet is increased with advantage to 3% diameters.
The moving force in the current of the exhaust steam rushing
into the condenser communicates an additional velocity to the
water jet on issuing from the water nozzle, the amount of this
addition being dependent upon the difference of pressure between
the exhaust steam and the condenser; and when the steam is not
expanded down in the cylinder of the engine to a very low pressure
before its exhaust, the combined moving force in the water jet is
found to be sufficient to effect a continuous discharge into the
atmosphere, not only without aid from a head of water in the injec-
tion supply, but leaving a surplus power Sufficient for raising the injec-
tion water from a lower level of several feet below the condenser.
When the injection water is not supplied by a head pressure, but has
to be raised from a lower level, the working of the condenser (Fig. I 12) '
is started in the first instance by means of a jet of steam direct from
the boiler, introduced through the central spindle C, so as to act in
the axis of the water jet. The steam is admitted to this jet through
the small piston valve J, which has a second piston valve I, fixed
below on the same spindle. This lower piston is supported by a
spiral spring, and communicates with the condenser on the under
side by the pipe H ; and as soon as a vacuum is formed in the
condenser, the piston valve is moved, the pressure of the atmosphere
acting on the top of the upper piston J causing this piston to shut
STATIONARY ENGINES.
I79
off the steam jet. In the event of the vacuum ever becoming
impaired from any cause, the piston valve is instantly raised by the
pressure of the spring below it,
and a jet of steam from the boiler
is thus applied by self-acting
means to the extent that may
be required for restoring the full
action of the condenser.
When the piston of the engine
makes only a few strokes per
minute, the impulse received ſrom
the successive discharges of the
exhaust steam fluctuates, a por-
tion of the water fails to get the
full velocity of discharge imparted
to it, and escapes at the nozzle
into the chamber K. This over-
flow water is removed continu-
ously by means of the side return
passage L, which communicates
with an annular space surround-
ing the water nozzle A, and
the water is carried forward by
being brought again into con-
tact with the jet of exhaust
Steam.
In another form (Fig. I 13) the
condenser is shown as applied to
a pair of engines coupled at right
angles; the only alteration being
#5:
%
H
#
E
:
º
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-
:
*:
| % :
§ 2% *
N &Zá...::::: †
:
:
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&
§
&
S
|
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SS
Š
%
S
§|
£I..."?
; pºsſi;
!---2
Fig. 112. –Condenser with Self-adjusting Jet of
Steam.
the addition of a second combining nozzle N, fixed beyond the first
one, and communicating with a second branch pipe M, which brings
the exhaust from the other cylinder of the coupled engines. The first
nozzle F so completely separates the two steam jets from each other
that the alternate discharge of the exhaust steam from either cylin-
der cannot in any way impair the vacuum in the other cylinder:
the degree of vacuum is found in some cases to be rather higher
in the upper nozzle than in the lower one, the steam in the upper
nozzle being the first to come in contact with the injection water.
In this arrangement, as well as in the preceding one, a foot valve P










18O - MODERN STEAM PRACTICE.
is provided at the exit orifice of the discharge tube to prevent any
inflow of water from the hot well into the condenser, when the
ſi
º
i
i
&
º
§
Ş
SS
%
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; N aff
r:::::::::..NSS Ş
N
N
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S
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sº
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g
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Fig. 113.−Condenser ſor a pair of Coupled
Engines.
vacuum ceases when the engine is
stopped.
Mr. Alex. Morton of Glasgow in-
forms us that he has fitted these con-
densers to all classes of land en-
gines, from the slow-going pumping
engine making three revolutions
per minute, to other engines hav-
ing a piston speed of 500 feet per
minute, and even engines having
a greater piston speed than this
have been fitted with ejector con-
densers.
We give side and end views of
an ordinary horizontal pumping
engine (Figs. I 14, II 5) fitted with
the condensing apparatus. The con-
denser is placed below the level of
the steam cylinder of the engine, and
may be in any convenient position
either inside or outside of the en-
gine house. The rising main from
the pit pumps delivers the water
into a tank a few feet above the level
of the condenser; having a pipe for
supplying the injection water to
the condenser, and the discharge
from the condenser passes through
a pipe into a drain, as shown.
In another example of blow-
ing engine at an iron-works near
Bridgend in Glamorganshire, the cylinder being 40 inches diameter
and 10 feet stroke of the piston, making fifteen revolutions per
minute, the condensing apparatus maintains a constant and steady
vacuum of 12% lbs, below the atmosphere. The injection water in
this case is supplied from a head of 1% foot above the condenser,
and the discharged water has a fall of about 9 feet, consequently
no starting jet is required in such cases.















STATIONARY ENGINES. I8 I
The cold-water pump is a cast-iron barrel, fitted at the bottom
ſ #
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with a suction valve of the flap type, consisting of a disc of leather
securely fastened down with a bar of iron to the conical valve seat,

I82 MODERN STEAM PRACTICE.
and arranged with a central feather, the disc being fitted with wrought-
iron plates on the top and bottom, securely rivetted through and
through. The bucket is fitted with a valve of a similar description,
having means of securing it to the pump rod; and it is usually
packed with a plain hemp gasket let into the recess formed in the
bucket, and fastened by means of plain wooden pins driven through
holes bored in the side. Some consider, however, that these buckets
should be fitted with gutta-percha rings, let into recesses formed on
the bucket, with holes bored from the top in connection with the
recesses; thus when the gutta-percha rings are cut and sprung into
the recesses, the head of water acts on the inside of the rings, keeping
them up to the face.
The feed pump is of the ordinary plunger type, fitted with
metallic valves, and draws the water from the hot well above the
air pump, the water being partially heated by the steam in the
process of condensation. All these pumps are generally worked
from rods directly fastened to the engine beam, on the opposite
end from that of the steam cylinder. The rod for the air pump
is generally placed midway between the main centre and the end
of the beam; the cold-water pump rod is situated between the
air-pump rod and the end of the beam; while the feed-pump rod
has a shorter stroke than either, being placed between the air pump
and the main centre on which the beam vibrates.
The beam is generally shorter on the pump end, the steam piston
having a longer stroke; thus the motion of the main plungers or
buckets, if so fitted, is slower than that of the steam piston, and this
diminution of velocity decreases the wear and tear of the pump
gear. Moreover, increased length of piston stroke requires less
diameter of cylinder, which is a great desideratum when high steam
pressure with a large measure of expansion is used, as the parts
need not in this case be made so heavy. Some makers have intro-
duced a small high-pressure cylinder in combination with a larger
one; the steam in the first place acts on the Small piston, and then
expands into the large cylinder. The large cylinder and its adjuncts
need not therefore be so heavy as with the single-cylinder arrange-
ment, but it is obvious that greater complication is entailed, and for
economy of fuel the single cylinder with a long piston stroke is to
be preferred. Cornish engineers endeavour to economize fuel by a
careful clothing of the parts where radiation takes place. The
cylinder is inclosed in a steam jacket, as already described; the
STATIONARY ENGINES. I83
outside cylinder or casing is covered over with felt or non-conducting
material, and then carefully lagged with wood, with four or more
metallic straps girding it all round; in some instances heated air
has been applied all round the steam cylinder, the annular space
being encircled with brick-work. The thorough protection of the
inside or working cylinder So as to prevent surface condensation,
and the covering of the steam pipes from the boiler with felt and
canvas to prevent radiation—combined with the high steam pressure
used and the large measure of expansion obtained—have raised
the duty performed by the Cornish engine far above that of the
ordinary class of engine used for land purposes.
Figs. I 16 and I 17 give side and end elevations of an overhead-beam
pumping engine erected at a pit near Kilmarnock. The principal
advantage in the arrangement here is that it leaves the pit mouth
clear, and in sinking a pit enables the rods to be easily lengthened
as required.
The cylinder is 84 inches in diameter, suited for a 12-feet stroke
in the pump. The piston rod is connected to a strong malleable-
iron beam, made of two plates placed I5 inches apart. The pump
rod is connected to one end of the beam, and the other end is sup-
ported by vibrating columns oscillating on journals working in two
bearings, which are bedded on the top of the stone pedestals for the
foundation, and secured with bolts and nuts passing down through
the foundation, and having a cotter and wall plate at the bottom.
The parallel motion for the piston rod consists of two motion
rods, one on each side of the beam, connected to cast-iron standards
bolted to projecting flanges on the top of the cylinder. The plug
rod for the valve mechanism is worked directly off the beam, from
the same gudgeon as for the parallel-motion bars, and is guided
with a bracket placed underneath the engine-room floor.
The engine is fitted with a blow-through condenser, on a plan
which works as follows:–Steam being admitted to the bottom
of the cylinder, the piston is forced to the top of its stroke; the
steam valve is then shut by suitable gearing, and the steam
passes from the bottom side of the cylinder to the top side, the
piston is then in equilibrium, and the weight of the pump rods
carries it to the bottom, but before it reaches this point the injector
valve is opened with a tappet placed on the feed-pump rod, with
levers and rod carried along to the valve; water is thus admitted
into the condenser, and the valve remains open until the steam is
I84 - MODERN STEAM PRACTICE.
shut off, and the piston nearly at the end of the up stroke; the
remaining exhaust steam in the top blows the water and condensed
Fig. 116. —Overhead-beam Pumping Engine. Side Elevation.
steam out of the blow-through valves at the bottom of the condenser
into the overflow cistern, from which it is led into a drain. In
working, the water in the condenser rises to nearly the level of the

STATIONARY ENGINEs. 185
injection valve. Besides the ordinary steam and exhaust valves,
there is a valve worked by hand for regulating the descent of the
& 1 &
N NNNS
^
Fig. 117.—Overhead-beam Pumping Engine. End Elevation.
piston, and placed at the bottom of the passage leading to the top
The feed pump is of the plunger type, worked
of the cylinder.
directly off the overhead beam; the suction valve is placed at the


I86 MODERN STEAM PRACTICE.
bottom of the barrel, and the delivery valve at the top. The annular
space round the plunger is equal to the area of the plunger. With
this arrangement no air can collect at the under side of the gland,
as when the delivery valve is placed at the bottom of the barrel.
The main pump for this engine is of the plunger type, the rods
being cottered to the plunger, instead of the wooden rod passing
|-
Fig. 118.-Pump.
A, Plunger. B, Stuffing box and gland. c. Suction valve. D, Delivery valve.
E, Stand pipe with air vessel. F Pump rod.
down through it, as has been already explained. The diameter of
the plunger is 18 inches, with an annular space all round equal to the
area of the rams. The suction and delivery valves, of the flap type,
are placed at the top of the pump barrel—this arrangement getting
rid of the air that collects in a barrel having the valves arranged at
the bottom. On the stand pipe an air vessel is fitted, to relieve the
shock on the ram in the act of forcing the water. This arrangement of

STATIONARY ENGINES. 187
pump necessitates the use of a separate suction pipe, which is fitted
to the side of the valve chest placed underneath the suction valve.
Side-lever engines have been introduced with the object of re-
ducing the great height of the massive lever wall for carrying the
O
main beam, and of simplifying the engine by dispensing with the
expensive parallel motion. The arrangement possesses certain
advantages; the main one being that the engine is self-contained,
having a bed plate for carrying the cylinder, main pillow blocks,
condenser, air pump, &c. The side levers are connected to the
piston rod by means of side rods, and a crosshead working in cast-
iron guide frames; the expense of keeping in repair those guides, in

I 88 MODERN STEAM PRACTICE.
Comparison with the numerous brasses of the parallel motion, is
very trifling. The air pump is worked in a similar manner, while
the plug rod is actuated with a separate wrought-iron beam, placed
above the main crosshead, and worked therefrom by means of a
Small crosshead, fitted to the top of the piston rod with a parallel
motion—an unnecessary refinement, as when the plug rod is guided
at the top and bottom a plain link attachment is all that is needed.
Fig. 120.-Single-acting Side-lever Pumping Engine.
The other end of this beam vibrates on a gudgeon, with pillow
blocks resting on the end wall of the engine-house. The spring
beams of wood are placed on each side of the foundation, these
springs being necessary to check the shock should the engine miss
a stroke or come in or out too rapidly—the ends of the side levers,
striking against the spring beams, greatly reduce the blow, which
would otherwise be felt very severely on the machinery.
There is another example of the side-lever pumping engine, Fig.
I2O, which although not possessing the advantage of being securely

STATIONARY ENGINES. 189
bedded on a base plate, yet reduces the height of the lever wall
considerably, while its arrangement is somewhat simpler than in the
foregoing example. The valve gear is placed between the cylinder
and the main centre of the side levers; thus the additional beam
for working the plug rod is dispensed with, the rod being worked
directly from a cross gudgeon between the two side levers; this
gudgeon has an elongated hole for the rod to pass through, and is
fitted with two side links connected to a crosshead on the plug rod,
the rod being guided through bushes at the top and bottom. All
the other pumps are worked directly from a gudgeon placed between
the side levers, and securely keyed to them; but the main pump
gudgeon has a bearing at each end, working on turned bushes on
the under side. This gudgeon is made flat in the body, being
deeper at the middle, and the pump rods of wood are securely
fastened to it by means of wrought-iron straps, the great length of
the pump rods causing them to bend with the versed sine described
by the side levers. The pillow blocks for carrying the side levers
are provided with a broad base plate, securely bolted down to the
lever wall; the caps for the pillow blocks are simply shells, fitted for
the sake of appearance, as indeed are all the covers for the pillow
blocks of Cornish engines when adapted for mining purposes. This
arrangement is adopted owing to the steam acting on the top of the
piston at one end of the beam, while the great weight of the pump
rods is being lifted at its other end; and in the outgoing stroke, or
descent of the pump rods, the steam pressure on the top of the
piston is in excess of the under side, and consequently the side
levers have no tendency to lift.
Some mine-pumping engines have been erected on the direct-
action principle, the steam cylinder being placed directly over the
pumping shaft, with the pump rods attached directly to the piston
rod, the steam acting on the under side of the piston. There is no
equilibrium valve fitted to this class, as the steam, after doing duty
in lifting the pump rods, is exhausted into the condenser, which is
in connection with the top of the cylinder, and the downward
motion of the pump rods is retarded. The weight of these rods is
always in excess of what is required for forcing the water, and is
due to the diameter of the pump and the great length of the rods.
Of course the steam in the cylinder can be throttled in its passage
to the condenser, thus gradually reducing the pressure and prevent-
ing the pump rods descending too rapidly. The air pump is worked
I90 MODERN STEAM PRACTICE.
by a vibrating lever, linked to the piston rod, and placed underneath
o O
Fig. 121.-Direct-acting Pumping Engine. Side Elevation. “
the cylinder floor; the motion of the lever working the plug rod for
the valve mechanism. This class of engine, modified, has come


STATIONARY ENGINES. I91
into extensive use, and, although cheaper in first cost, we unhesi-
Fig. 122.-Direct-acting Pumping Engine. End Elevation.
tatingly give the preference to the beam engine, or the more
recent example the side-lever Cornish engine, when the depth of
the mine is considerable. .
Figs. I2 I and I22 show side and end elevations of a pit engine
which may be considered an improvement on the foregoing
example. The steam cylinder has a diameter of 84 inches,

I92 MODERN STEAM PRACTICE.
Suited for a 13-feet stroke. The pump rods are connected directly
to the piston rod, which is guided by means of a crosshead and cast-
iron guides placed underneath the cylinder. The light wrought-iron
beam for working the plug rod, air pump, and feed pump is placed
overhead, and is worked from a continuation of the piston rod. The
vertical motion of the plug rod is maintained by means of motion
rods fitted on each side of the beam, and is guided with a bracket
bolted to the nozzle chest; the other end of the beam slides in cast-
iron guide bars, with gudgeon and sliding blocks fitted to it. The
air pump is placed centrally with the condenser, and is worked off
a continuation of the plug rod; the air-pump bucket foot and head
valves are fitted with small disc india-rubber valves, with guards
secured by a single stud bolt in each. The feed pump has a hollow
plunger, and is worked off the overhead beam directly, the pump
being bolted to the side of the hot well. This engine goes far to
meet the requirements of the practical miner, being well arranged,
with easy access to all the parts; and it is much cheaper in first cost
than some other beam engines.
The pumps for this engine consist of two lifting sets 20 inches
in diameter, and one forcing set 26 inches in diameter, placed one
above the other, as shown in Fig. 123. In deep pits this plan is
always adopted, the lifting sets placed at the bottom of the pit
discharging into a cistern from which the forcing set draws its
supply. By this means the bucket and clack of the lifting set can
be withdrawn and replaced should anything go wrong, and the
water rise above the valve chests, which could not be done were the
forcing set placed at the bottom of the pit. The pump valves are
of the ordinary description, with inclined seatings; the plunger of
the forcing set has just the necessary clearance in the barrel, the
valve chests being arranged at the bottom; the water is discharged
into an air vessel surrounding the stand pipe, by which means the
shock in forcing it up is greatly softened.
For very deep pits a series of lifts is necessary. The following
example (Figs. 124 and 125) of pit work in Cornwall forms a good
arrangement: “The diameter of the steam cylinder is 90 inches.
The stroke is II in and IO out, in miners' parlance; that is to say,
II feet in the cylinder and Io feet in the pumps. The first lift of
pumps from surface, or 'grass, is the house lift, which is employed in
lifting water from the adit to the condensing cistern of the engine.
The plunger of this lift is 12 inches in diameter, and the rising main the
STATIONARY ENGINES.
193
&
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same size
in the same
t is usual to make the “pumps
the plunger. The adit is 31 fathoms below the su
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Fig. 123
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dvantage to have the adit as deep as
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Of course it
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valley.




















13
194 MODERN STEAM PRACTICE."
to do. The second lift is situated 47 fathoms under the adit, and .
is provided with two suction and two delivery clacks. The third
lift is 80 fathoms under adit; the fourth I2O fathoms, and the draw-
ing lift I4O fathoms. It is not advisable to put in a lift of pumps
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with ordinary valves more than 40 fathoms long, because the valves
will not stand the wear and tear consequent on the great pressure
of the column of water. For ordinary use the clack valve with












STATIONARY ENGINEs.
I95
ided with a
The H-piece is prov
that is, the case into which the plunger enters, is placed on one leg
leather seats enjoys the greatest favour in Cornwall. The pole case,
of what is termed the H-piece.
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Fig. 125.-Pit Work, showing Pumps, Rods, Cisterns,
The seating of the valve is made conical on the outside, and is
door or cover, through which the suction valve may be examined.
somewhat smaller than the conical neck formed to rece





























I96 MODERN STEAM PRACTICE.
H-piece. Around the seating is wrapped a strip of coarse flannel
or baize, which makes the joint when the seating is forced into its
place. Above the door of the H-piece is placed the door piece,
which contains the delivery valve, which is fixed in the same way as
the suction valve. On the door piece the pumps or rising main, in:
9-feet lengths, are placed. It is usual to place a wind bore directly
under the H-piece, leading into a cistern from which the pump takes
its water, but in the example under notice a much better arrange-
ment has been adopted. The cistern is placed just above the
suction valve, so that the water may more readily follow up the
plunger, and thereby cause the pump to be “charged solid.’ It is
of very great importance that no vacant space whatever should be
left in the pumps at the termination of the indoor stroke of the
engine, for if there be a space not occupied with water, then a shock
ensues, and the engine works as if working in ‘fork,' or as if the
pumps were taking air. A 6-inch branch and blank cover is pro-
vided in the U-piece under the H-piece, for the convenience of
getting out anything which may accidentally drop into it. A blank
end and “matching' piece is put on to the H-piece under the pole
case, which takes its bearing on the timber bearers below. The
main rods are of Memel timber, perfectly sound and straight, with-
out knots or faults; for the first 50 fathoms they are 18 inches
square, for the next 40 fathoms I6 inches square, and for the last
3O fathoms 14 inches Square. The rods are obtained as long as
possible, and are jointed by means of “strapping plates,' bolts, and
nuts. The timber is sometimes cut in the form of a splice, and
made to form a lap joint, but in this case the rods are all butt-
jointed, the strapping plates are first firmly secured to the piece to
be attached, and then the piece is put in its place on the main rods,
the joint being brought up tight by powerful lifting jacks. The
main rods are kept in a line by means of wood guides fixed at
intervals. The plungers are cast with a plain core through them,
and a little longer than is necessary for the stroke; the casting
should be entirely free from specks—it is usual to cast them on the
side, but we prefer to have them cast on end. The plunger is
‘stocked’ on the mine; a piece of Memel timber, square in section,
and equal in diameter to the plunger, is obtained, about 12 feet
or 14 feet longer than the ‘pole.' For a portion of its length equal
to that of the pole it is rounded down, and the pole is then forced
on to it. When stocked it is fixed by means of staples and glands
STATIONARY ENGINES. I97
to the main rods, a set off, or filling piece, being provided between
the stock of the pole and the main rod, to bring the axis of the pole
in a line with that of the pole case. Key-ways should be provided
in the joint between the stock and set off, and also between the set
off and main rod; when the staples and glands are firmly secured,
the keys—of hard wood—should be driven. It requires great care
that the ‘pole connection’ may be well made. Square nuts should
always be used for the pit work, because it is not always convenient
to have snugly-fitting spanners, and square nuts are then more
easily managed than others. The stuffing box of the pole case
should be packed with a well-made gasket and tallow.
“The working barrel of the ‘drawing lift' is bored a little taper
for 9 inches or I foot at the upper end, that the bucket may easily
enter when dropped in from above; sometimes a door piece is pro-
vided above the working barrel, that the bucket may be examined
without the necessity of drawing it; but the plan is not a good one
when forking, as the water may rise too fast, and if it gets above
the door before the joint can be properly made the consequence
becomes serious. Directly under the working barrel is placed the
“bull's-head,' which is, in fact, a supplementary valve box, available
when the “door piece’ is under water. The neck of the bull's head
should be bored conical, and the valve seating geared similarly to
an ordinary bucket, but the ring should be a little conical, that it
may be prevented from falling through the neck of the bull's head
and retained in its place. A wrought-iron loop or Staple is provided
on the seating, by means of which it may be fished up from above
when occasion requires. A Small bar is placed across the Staple,
which acts as a guard to the clack valve. The ring of the bucket
should be of wrought iron, nearly the size of the barrel, parallel on
its outer face and conical within. For the convenience of removing
the doors and replacing them again a chain with swivel and screw
is sometimes used, suspended from a piece of timber above. For
the facility of sinking, under the suction valve is suspended a
turned pipe which enters a stuffing box placed above the wind bore.
The wind bore is suspended in chains provided with lifting screws,
for the convenience of lowering as sinking proceeds. It will be
seen that as sinking proceeds it becomes necessary to lower the
drawing lift constantly, and that it may be conveniently done the
pumps are suspended in “yokes' which take their bearings on tim-
bers fixed across the shaft. Yokes are glands made to fit the body
I98 MODERN STEAM PRACTICE.
of the pump; they are placed directly under the ribs, and when it
is required to lower the lift the yokes are loosened to let the lift
drop through. Each time there is a new length or pump put in,
the bucket has to be lowered, and that it may be done without the
necessity of making a new drawing lift connection on the main rods,
the arrangement shown in Fig. 125 is introduced; a chain and hook
serves to make the connection between the main rods and the pump
rod, one staple only being used to steady the top of the pump rod.
This arrangement affords facilities both for drawing the bucket
and putting in a new pump. The pump joints are made with flat
rings of wrought iron, covered with baize and dipped in tar.
“Balance bobs are sometimes placed below the surface to take up
some of the weight of the pump rods. The connection with the
main rods is usually of wood; the vibration is given by the elasticity
of the wood. In the example shown in Figs. I24, 125, the connecting
rod is I5 fathoms long, and it is guided and steadied by means of
a plain turned pulley, which bears against a curved filling piece
bolted on to the connecting rod. Plungers are sometimes substituted
for balance bobs, and are, when so employed, constantly submitted
to the pressure of the column of water in the pumps; they are fixed
to the main rods precisely in the same way as the ordinary plunger.”
With the view of securing greater regularity in the motion,
and of equalizing the strain on the various parts, the compound
or double-acting engine has been introduced. An example of
this engine is shown in Fig. I26. The high-pressure cylinder is
36 inches in diameter, and the low-pressure cylinder 54 inches
in diameter, both working an 8-feet stroke in the pumps. The
piston rod of each cylinder 1s coupled directly to the pump rods,
and from the crosshead of each piston rod run two short connect-
ing rods, attached to two bell cranks; these cranks are connected
to each other at the top by the connecting rods on each side, thus
coupling the two engines and equalizing their duty. From the
longitudinal centre of one of the bell cranks the motion for the
tappet rod is taken, and from the back of the other one; an arm is
cast on each, with connecting rods for taking the crosshead for the
air pump. The cylinders, with their covers and ends, are steam-
jacketed, and securely bolted down to a bed plate resting on foun-
dations of stone. The cast-iron guides for the piston-rod crosshead
are bolted to the under side of the bed plate, and the bottom end is
* The AEngineer.
STATIONARY ENGINES. I99.
secured to the cast-iron beams upon which the bell-crank pillow
blocks and air pump and condenser are fitted. The air pump is of
the ordinary kind, fitted with india-rubber valves for bucket, head,
and foot valves. The condenser is a separate vessel placed alongside
: H-II—II
Fig. 126.-Direct-action Compound Pumping Engine.
of the air pump, the waste-steam pipe coming in at the top, and
fitted with a packed gland. The valve gear for these engines is of
the usual description, with cataract pumps for regulating the number
of strokes. Although the machinery in these engines is rather com-
plicated, yet when economy in fuel and great regularity in working





2OO MODERN STEAM PRACTICE.
have to be studied, they may be beneficially used for pumping water
from moderate depths and forcing or lifting it to moderate heights.
For moderate depths horizontal high-pressure pumping engines
have been used, connected to two bell cranks, directly from the piston-
rod crosshead, with long links, one on each side, taking the long
arm of the bell crank nearest the engine; and the two bell
cranks are connected to each other with wooden connecting links
strapped with wrought iron, the pins for carrying these links
being nearer the centre of vibration of the bell cranks; thus the
stroke of the engine is somewhat longer than that of the pumps.
The bell cranks are so arranged that the one goes up and the
other down alternately, the steam being admitted into each end
of the cylinder as in ordinary high-pressure engines. The valve
mechanism is worked in a similar manner to that of the Cornish
engine, with tappets, cataracts, and all the necessary starting handles.
One useful feature in this class of engine is that it can be driven at
a higher or lower rate of speed, or more or fewer strokes given, as
the increased or diminished quantity of water in the pit may require,
The exhaust steam is made to pass through a series of tubes, around
which there is a constant circulation of cold water; thus the steam
is partially condensed, and the water pumped into the boilers again,
as in Surface-condensing engines. A jet of steam, however, escapes
into the atmosphere at each stroke, which is due to the tube surface
not being of sufficient area, and to give the condensing vessel the
requisite area would make it too bulky and expensive. By this
method of allowing the exhaust steam to pass through the tubes
the water around them is heated to a high degree, and it can be
pumped into the boiler separately, or mixed with the water collecting
in the receiver; but in either case the tube surface acts as a feed-
water heater.
Horizontal high-pressure engines with slide valves and eccentric
motion are sometimes used for pumping water out of coal and other
mines. The valve gear is of the simplest description, consisting of
a rocking lever, fitted with a link for the valve rod, and a pin for
taking the gab end on the eccentric rod, which is made to throw
out of gear when required. The cylinder is securely bolted to one
end and the pillow block for the crank shaft to the other end of the
bed plate, which consists of a heavy box casting placed on each
side of the cylinder, running the entire length of the foundations,
and secured at the ends with cross pieces all cast together, and
STATIONARY ENGINES. 2OI
bedded on balks of timber, which in some instances form the founda-
tion. In these engines a long stroke and low rate of piston speed
are adopted, the motion for the pump being as simple as practicable
to suit the requirements. The connecting rod is coupled to the pin
on the crank, or cast-iron disc when so fitted, by a strap with jibs
and key, and the crosshead end has a short fork forged on the
connecting rod, fitted with straps, jibs, and keys. The crank shaft
is generally as short as practicable, and is supported by a bearing
on the bed plate, and one at the end carried on a pillow block bolted
to a box girder Secured to the foundations. The fly wheel is made
heavy, and is placed at the middle of the shaft between the two
bearings; and at the extreme end a cast-iron crank is fitted, with
holes for the pin to vary the stroke of the pump when required.
The motion for the pit pump is transmitted by a wooden connecting
rod, strapped with wrought iron secured with bolts; the other end
of the rod taking a bell crank or arm fitted to the shaft on which
the bell crank is placed. The latter can be suited to any angle at
which the pump may require to be placed, as in working the edge
Coal in certain localities.
In other arrangements, when the pumping shaft is vertical, the
motion for the pump is taken from a crosshead fitted to a pro-
longation of the piston rod, which is continued through the end of
the cylinder; the crosshead is guided the same as for the main con-
necting-rod end, and is connected to the bell crank by wooden rods
strapped with wrought iron. In such examples the pit pumps are
in duplicate, with a bell crank for each, connected together in the
same way; by this means the engine is better balanced, as one set
of pump rods is moving upward and the other set downward. The
pillow blocks for the bell cranks are fitted to balks of timber, and
the foundation for the engine is built of brickwork laid on the top
of these balks, the brickwork being overlaid with timber for bedding
the engine; the bed plate is secured by long bolts passing down to
the bottom of the foundation. There is no feed pump connected
to these engines, a steam pump being fitted for supplying the boilers
with water.
There are a variety of engines for pumping water of the geared
description, working plain cranks connected to bell cranks by a
single rod, the bell crank having a jaw cast on it, with a pin for
taking the end of the connecting rod passing through the jaws.
This type of engine is generally adopted for low lifts, and is a very
2O2 . MODERN STEAM PRACTICE,
convenient form for transportation, as the cylinder is of small
diameter, with a high rate of piston speed, and reducing gear for
the pumps. When the engines are of the horizontal type the whole
of the wheel gearing should be arranged on the same bed plate
as the engine, and kept as compact as possible, since detached
machinery cannot be so securely bolted down on the foundations
as when all the parts are well bonded together on a single bed
plate.
PUMPING ENGINES FOR WATER-WORKS.
Having considered engines for pumping water out of mines,
we now come to that class of Cornish engine used for pumping
water for the supply of large towns. The construction of the
water-works engine differs materially from that of ordinary mine-
pumping engines. It is generally of the single-acting type; the
whole power of the engine is employed to lift a weighted plunger
placed at the end of the beam farthest from the cylinder, and
which acts as an accumulator, forcing the water up the stand pipes
to the height required for distribution through the mains. This
height of course depends on the altitude of the city or reservoir
above the source from which the pumps draw the water. The
engine beam is supported on Columns, carrying a spring beam on
which the main pillow blocks are securely bolted, and the ends
are let into and rest on the end walls of the engine house. The
perpendicular motion of the piston rod at the one end of the beam
and of the weighted plunger at the other end, is effected by means
of parallel motion of the ordinary description, with connecting links
from the crosshead, radius, and parallel bars. The air pump is
worked off the centre of the back link for the parallel motion, at
the main pump end; while the feed pump has a shorter stroke, being
connected by means of a long rod with a pin passing through the
main beam. The plug rod for working the tappets of the valve
gear is attached to the beams in like manner, the valve gear being
fitted with all the necessary cataracts, as in the mine-pumping engine.
An engine house incloses all the machinery except the stand pipes,
which are of great height, and require a separate tower. As the
water in these pipes is liable to become frozen in winter, objections
STATIONARY ENGINEs.
have been taken to them, and as they are
mainly raised to equalize the duty on the
engine some authorities consider a large air
vessel preferable. The pipes must be fitted
with a valve loaded to a certain pressure on the
delivery side, so that in the event of derange- H
ment from a pipe bursting, or from a diminu- ; ; ; ;
tion of pressure in the main, the engine would i
still have about the same duty to perform, as 3.3.
the water has to be forced through the passage
covered with the loaded valve before it is taken
into the air vessel, a double-beat valve being
used for that purpose. This description of
valve gives a large area for the exit of the
water, while the surface acted upon for raising
i
the valve is only a small portion of the total
area of the passages; thus less weight or pres- ;
sure on the top of the valve is required. There :
is also a blow-off valve fitted, and loaded to a ;
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Fig. 127.-Single-acting Pumping Engine with Stand-pipe Tower.


2O4. MODERN STEAM PRACTICE.
certain weight, so that in the event of any undue pressure in the
mains the water escapes, and prevents the pipes bursting. This
valve acts in a similar manner to relief valves fitted to feed pumps
for steam boilers, the water escaping into the well or reservoir from
which it is drawn.
Double-cylinder expansion engines have been successfully adopted
for water-works; where a high rate of expansion is required they
work admirably, but the complication they entail is not desirable.
For moderate power the single cylinder is to be preferred as suffi-
cient for all practical purposes, but for large power we would recom-
mend a small high-pressure cylinder working in connection with a
large low-pressure cylinder, as the strain on the machinery is not
so much felt, nor do the parts require to be of extra strength, as the
piston rods and adjuncts would require to be, were the high-pressure
steam from the boiler admitted on the top of a large piston.
We are indebted to Mr. Marten, C.E., of Wolverhampton, for the
following particulars of the pumping engines in use at the water-
works there.
The two engines at Tettenhall are single direct-action non-con-
densing engines. The cylinders are 36 inches in diameter, and
9 feet 6 inches stroke. The plunger pumps are I 3 inches in
diameter, with a lift of about 3OO feet. The steam is admitted to
the cylinder at a pressure of about 35 lbs., and is cut off at two-
thirds of the stroke. The boilers are cylindrical, two in number,
26 feet in length and 6 feet in diameter, with two tubes in each 25%
inches in diameter, and internal flues; the flame from each fireplace
passes along the tube, thence round to the front, again by the side
of the boiler next to its tube, where the two unite and pass along the
bottom into the chimney. The boilers are covered with loam or
moulding sand to a depth of about 6 inches from the top. This
substance, which should be protected by a roof from blowing away,
is found to be a very good non-conductor, little heat radiating
through it to the upper surface; it has also this advantage over
nearly all other materials employed for the same purpose, that no
condensation can take place in it within 2 or 3 inclies of the boiler
plates, since for that distance it forms a sand bath as hot as the
steam, which, in the event of a leakage, blows through it dry, and
consequently corrosive action on the plates is prevented. When
escape and condensation of steam takes place, it is detected by a
moist patch on the surface of the sand. With a material of this
STATIONARY ENGINES. 2O5
description, any portion of the top of the boiler can be uncovered
with a shovel, and
examined at once. t
For the purpose of
experiment, steam
blows at two placcs
in the boilers at Tet-
tenhall were suffered
to remain unrepaired
for a couple of years,
in order to test the
value of this covering,
and the result was
an entire absence of
corrosive action on
the plates. In the
opinion of Mr.Marten
loam sand is much
preferable for this %is:
purpose to any other %
material, provided
that it is protected by %
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a roof or covering. It
is much cheaper than -
felt, brick, or sheet %|
iron casing with air #||
space; and much r
superior to furnace
ashes, cinders, or
riddlings, which are *.
often placed over º
boilers, as these sub- *%
stances frequently
contain acids and
other chemical im-
purities, which on be-
ing brought in con-
tact with waste steam
act very injuriously
Oil wrought iron. Fig 128–Tettenhall Pumping Engines. Elevations and Plan.
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2O6 MODERN STEAM PRACTICE.
A, Steam cylinder.
B, Pump rods.
c, Steam valve.
E, Equilibrium valve,
F, Exhaust valve.
G, Crosshead.
H H, Columns,
1, Buffing pieces
K, Plug rod.
L., Wrought-iron lever
for working plug
rod & feed pump.
M, Feed pump.
N, Feed-water heater.
Fig. 129.—Tettenhall Pumping Engines, Side Elevation.

STATIONARY ENGINEs. 2O7
Fig. 130.-Tettenhall Pumping Engines. Transverse Section,

2O8 MODERN STEAM PRACTICE.
The steam, equilibrium, and exhaust valves are of gun metal, and
on the double-beat construction. Their areas are as follows:–
Steam valve,............................. 50 sq. in. = ºrth area of cylinder.
Equilibrium valve, • a s e º e s • * * * * * * * * * * * * * 50 : 9 3 = *6th 2 3
Exhaust valve, .......................... 78 , , = Tºth 5 y
The piston rod and pump rod are connected with a crosshead
working on V-slides attached to the supporting columns. The plug
rod and the valve motion are worked from a slight wrought-iron
beam under the cylinder floor, connected at one end to the cross-
head, and at the other slung to
parallel links. The feed pump is
also attached to this beam, the
water for the feed being passed
through a heater situated in the
corner of the engine house, and
formed by an enlargement of the
waste-steam pipe. This heater is
I foot 6 inches in diameter; the
feed pipe is conducted along its
centre for some distance, and oc-
cupies about two-thirds of its
area. The engine is regulated by
a water cataract, governed by a
small ratchet wheel and screw.
The number of strokes per min-
ute varies from three or four to
ten or eleven, the average speed
of piston being I 30 to I40 feet
per minute; the quantity of water
delivered per stroke is 56 gallons.
The pumps are of the plunger
type, and have the valves placed
at the top of the barrel; by this
means no air can Collect at the
top of the pump, as in ordinary
º
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Fig. 131.—Sectional Elevation of Pump.
A, Suction pipe. B, Suction-valve chest. c, Delivery- p lunger pumps for colliery pur-
valve chest. D, Plunger. E., Stuffing box poses. The area of each plunger
and gland. F, Stand pipe. wº ©
is I 32 Square inches, and the
pressure on its bottom is 130 lbs. per square inch—making a total
dead load of 17, 160 lbs., equal to a pressure of 1634 lbs. per square



STATIONARY ENGINES. 209
inch on the surface of the steam piston. These engines are
worked at a fair duty, performing about 27,OOO,OOO lbs. lifted
I foot high per minute, with a consumption of I cwt. of the
small slack in the neighbourhood; with Newcastle or Welsh small
coal they would perform a duty of 36,000,000 lbs. The pump
valves are of the ring de-
scription, rising on a central
spindle; they are made of cast
iron galvanized, beating on
wooden faces. Originally they
beat upon a mixture of lead
and tin, but this soon became
loose in the seating, causing
leakage; oak was then tried,
but the acid peculiar to this
wood corroded the cast iron,
and it had to be discontinued;
lancewood, box, and beech .
have also been tried, but no wood answers so well as holly, which
is now used for this class of valve. The area of the suction valve is
325 square inches, being about two and a half times the area of the
plunger; and that of the delivery valve is 163 square inches, or about
'one and a third times the area
of the plunger. The enlarge-
ment of the suction valve to
this extent is found to be very
serviceable where the velocity
of the plunger is likely to be
great in the ascending stroke.
The water was originally deli-
vered over a stand pipe 18O
feet high, whence it flowed by
gravitation to the town; but
now a reservoir is substituted, Fig. 133–Valve for Pump.
and the stand pipe dispensed A, Valve. B, Guide bar. c, Valve seat,
- D D, Wooden beats.
with. -
The engine at Goldthorn Hill is a low-pressure condensing beam
engine. The cylinder is 48 inches in diameter, with an 8-feet stroke.
The boilers are 30 feet long and 7 feet in diameter, with two tubes,
2 feet in diameter beyond the furnace, and 2 feet by 2 feet 4 inches
Fig. 132.-Plan of Pumps.
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14
2 IO
MODERN STEAM PRACTICE.
at the fireplace. The pressure of the steam is about 15 lbs. per
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works.
Elevations and Plan.
square inch.
To avoid the almost constant trou-
ble caused by leakage at the steam
valves on the boiler tops, from ex-
pansion and contraction of the main
range of steam pipes, the main steam
pipe should have a quadrant curve
between the boilers, so as to allow for
expansion and contraction without a
thrust sufficient to break any joints.
This arrangement is useful and effi-
cient when there is one steam pipe
leading off from between two boilers;
when, however, the steam pipe leads
off from one side, or where there is a
range of more than two boilers, it is
not applicable, and in such cases, in
the absence of packed expansion
joints, no plan is so simple and effec-
tive as the wrought-iron diaphragm
joint, consisting of a couple of circu-
lar wrought-iron plates, about two"
and a half times the diameter of the
pipe, dished out about 3 inches, and
rivetted together at the outer rim and
to flanges on the main range of the
steam pipe.
Another useful, although frequently
overlooked, point of detail in connec-
tion with the boilers, consists in lead-
ing the hot and cold feed and blow-
off into and out of the boiler through
the same pipe. This arrangement
avoids the numerous holes usually cut
in boilers for these purposes, and any
impurity which may enter the boiler
with the hot and cold feed is de-
posited near to the blow-off. In the
present instance the pipe is of wrought








STATIONARY ENGINES. 2 II
iron, and is rivetted on the under side of the front end of the boiler.
The arrangement of the valves is somewhat similar to those of a
bath, where the hot, cold, and outlet valves all take off the same
pipe. It is also important that the feed should enter the coldest
portion of a boiler, which, from the action of the currents in those
with internal flues, is just under the fire grate. When this is not
attended to the seams and rivets are apt to leak from the sudden
changes of temperature to which they are subjected.
Instead of delivering the water over a stand pipe, as origi-
nally in the Tettenhall engine, the Goldthorn Hill engine delivers
through an air vessel into two reservoirs lying near the engine,
holding together I,500,000 gallons, and raised about 20 feet above
the top lift. The reservoirs are arched over, and covered with
2 feet of soil, for the purpose of preventing vegetation in the water
and variation in its temperature. These objects are well secured,
as the water remains for months at the same temperature, and
perfectly free from all vegetable or animal impurities. The reser-
voirs are kept from being overfilled by a self-acting check valve,
which shuts against any supply beyond a certain limit; and the
man in charge of any pumping engine at a distance at once knows
when to stop work. The valve is so arranged that when the engine
ceases to work the supply from the reservoir to the town is main-
tained through the flap valves placed underneath the self-acting stop
valve. The object of a stand pipe is that the water may be always
delivered from the engine over one uniform height, and consequently
of one uniform pressure on the engine, whatever varying circum-
stances may affect the delivery after the water has once passed the
top of the stand pipe. For this purpose it is useful, but it is rather
a costly and unsightly mode of attaining what in practice is found
to be an unnecessary degree of perfection, as at a tithe of its cost
all the necessary safety can be secured by pumping into an air
vessel with a self-acting valve on the delivery side, so that, in case
of a pipe bursting, or any sudden diminution of pressure taking
place, it would be impossible for the engine to “go out of doors,”
as it is technically termed, at more than a certain regulated speed,
by the partial contraction of the area of discharge through means
of the check valve. Unless, too, the stand pipes are carefully cased
in winter they are in great danger of being frozen, and very serious
consequences have arisen from this cause. The great weight of the
column of water requiring to be set in motion from a dead stand at
2 I 2
MODERN STEAM PRACTICE.
|
A, Accumulator or
hydraulic cylinder.
B, Loaded piston.
C, Lower weights.
D, Upper weights.
E, Spiral spring.
Fig. 135.-Valve Regulator.
each stroke of the engine is
also an objection to the use
of the stand pipe.
As a substitute for these
tall stand pipes, the follow-
ing arrangement has been
adopted in the St. Peters-
burg water-works, recently
carried out by Messrs. R.
Laidlaw & Son of Glasgow.
A throttle valve or regulator
is placed so as to be con-
trolled by the pressure of
the water in the main. The
pressure acts through a
small accumulator or hy-
draulic cylinder fitted with a
loaded piston and attached
to the regulator. This loaded
piston, as it moves with
the varying pressure in the
mains, acts on the throttle
valve, and thus regulates
the motion of the engines.
A further arrangement was
made whereby the steam
would be automatically and
instantaneously shut off if
any burst took place. Fig.
I35 shows the arrangement
adopted. The lower weights
are slightly less than the
pressure on the water piston,
and thus the piston spindle
is kept in contact with the
upper weights; the steam
valve being then half open,
any increase of pressure thus
causes the upper weights
to be raised and the spiral


STATIONARY ENGINES. 2 I 3
spring is compressed and the regulating valve closed. If a burst
takes place the lower weights drop and instantly close the steam
valve.
The successful working of any pumping engine is dependent in
a great degree upon the perfection of the pump valves, which must
be so arranged as to deliver the water with ease and rapidity, and
without any concussion in closing. As an illustration of the great
practical importance of this question, it may be mentioned that when
the Cornish pumping engine was first used for water-works pur-
poses on a large scale, it was on the point of being altogether
abandoned on account of the imperfection of the pump valves.
The valves were of large area, and constructed on the old butterfly
principle, so that, under the heavy pressure at which they were
worked, the concussion caused in shutting was so violent as to occa-
sion serious alarm for the safety of the machinery and foundations.
The difficulty of constructing a valve which should present a maxi-
mum area of discharge with a minimum area of surface exposed to
the concussion of the recoiling load at the termination of each
stroke of the pump appeared for a time insurmountable, but was,
however, happily got over by the introduction of the double-beat
valve.
This valve, as already explained, has the upper area con-
tracted, and by the difference of the upper beat and the inside of
the lower one a surface is afforded for the water to act upon in
lifting and shutting the valve. The valve having two points for
the water to escape by, a very slight distance of lift gives a large
area for discharge; and the area upon which the recoiling column
descends being only the difference between the upper and lower
areas, and not the entire area of discharge as in the old butterfly
valve, forms a surface insufficient to cause any concussion. This
valve also affords, under all circumstances, a means of regulating
the pressure tending to shut the valve, whatever may be the height
of the column of water or the total pressure of the recoiling column,
by adjusting the difference of area of the upper and lower beats
inversely in proportion to the height of the column.
For the ordinary purposes of small lift pumps and colliery engines
the butterfly valve is serviceable, as there are no expensive faces to
be ground up or deranged by impurities or grit in the water, and
it can be readily repaired on the spot. For a higher class of work
there is no description of valve answers better than the double-beat
2I4. MODERN STEAM PRACTICE.
ring valve, similar to the one employed in the engines at Tettenhall
and Goldthorn Hill. Large valves of this construction, from 16 to
2O inches in diameter, answer well made of cast iron with wooden
beats; smaller valves, from 8 to 15 inches in diameter, are better
made of gun metal, working face to face, some of the latter descrip-
tion having worked for more than two years, under a pressure of
260 feet of head, without any perceptible wear. -
At the Hull water-works a special description of valve has been
adopted in one of the pumps with great success. It consists of a
ºt-lººt—a
ØS: §
º
º'0 QN4=
Sºf §es
y(0OOOVW =
º
\\ w
Fig. 136.—Gutta-percha Ball Valves on Metal Seatings.
A, Valve seats. B, Gutta-percha balls. C, Guard pieces. D, Holding-down bolt with stuffing box
and gland.
pyramid of circular seats, one above another, in each of which there
are a number of small circular beats about 2 inches in diameter,
into which a corresponding number of gutta-percha balls drop. It
is 22 inches in diameter, and works under a head of 160 feet, in
connection with a plunger pump with a direct-action steam cylin-
der. The action of this valve, as will be seen from Fig. 136, is very























STATIONARY ENGINES. 2 I 5
simple. It was substituted for the double-beat valve in use, and
immediately upon starting it lightened the burden of the engines
about 168 lbs., and has since given great satisfaction. This valve
possesses other advantages. In the first place it is much safer than
any other form of valve, as will be easily seen. Supposing a piece
of wood or other material should pass through the pump, as is
frequently the case: if the wood should be caught on the beat of
the ordinary valve, it would hold the whole valve open and let the
engine “come out” with a run, possibly causing considerable damage;
but with the small balls of this valve a piece of wood so caught
could only affect one out of fifty-six balls—so small a percentage
of the whole opening that it would merely enable the man in charge
to perceive that there was some trifle amiss by an increase of leak-
age. In the second place, the balls, being nearly of the same
specific gravity as the water, are floated open the moment the cur-
rent turns in their favour; whereas in all other valves, in addition
to the column of water to be lifted, there is also the weight of the
heavy metal valve to be opened and held suspended during each
stroke. With large valves this point becomes one of great import-
ance, as they often weigh 5 to 6 cwts, each, Again, in this valve,
whilst the area of discharge may be made fully equal to that of the
plunger, the area exposed to concussive action in closing is reduced
to the smallest possible limits, being practically the impinging force
upon one ball, the last one that shuts, or ºth part of the total area
of beating surface; this is owing to the fact that the balls do not
all rise to the same height above their seats, and consequently, as
the force of the current acts upon each ball separately, on the
cessation of motion each shuts in accordance with the height it has
to fall, and a communication exists between the water on the upper
and under side of the valve until the absolute closing of the last
ball. The result is, that although the difference in time between
the falling of the various balls must be exceedingly minute, it is
such as practically to prevent all concussion. Lastly, the valves
constructed on this plan are very easily repaired. It is only neces-
sary to keep a few spare balls ready, to be inserted in the place of
any that may become damaged; and the old ones, melted and
recast in a mould kept for that purpose, are again as good as new.
Where it is proposed to work with a high pressure of steam, cut
off so as to allow of a considerable expansion, the beam engine is
to be preferred to the direct-action engine; the latter, as a rule,
e= $
2 IO MODERN STEAM PRACTICE.
when working under a high initial pressure, is apt to start off at a
speed which jars and strains the whole of the machinery. Besides,
the speed attained by the piston as driven indoors at the beginning
of the stroke is many times greater than the average velocity per
minute, and therefore, unless all the parts are made proportionally,
the bearings very quickly wear out, and the machinery is loose at
every joint. In a beam engine, on the other hand, a very large
proportion of the initial force is absorbed in overcoming the inertia
of the heavy beam, which thus serves as a reservoir of surplus force
in the earlier part of the stroke, giving it out during the later part,
with the result that a comparatively steady velocity is maintained
throughout the stroke, much to the advantage of the whole ma-
chinery; indeed, it is only with this adjunct that expansion can be
safely carried to a very high degree. The beam, in fact, acts like
a fly wheel, storing force as required, and is attended with precisely
the same beneficial results.
For pumping a large quantity of water through an unusually
great length of main pipe, under a heavy pressure, a description of
engine may be preferred, consisting of a pair of high-pressure
expansive double-acting beam engines, coupled together at right
angles to the fly-wheel shaft. The pumps in this engine should be
of the combined bucket and plunger type. Each pump should have
an air vessel and back-flap valve, with a blow-off valve loaded to a
certain weight, so that in the event of any recoil in so great a length
of main the pumps would not burst. Along the main pipe, at each
50 feet of elevation above the pumps, a back-flap valve is required,
so that in case of any pipe bursting the whole main would not be
run dry. The leading point to be kept in view in the design and
construction of engines for such purposes is the maintenance of a
constantly uniform flow of water through the main pipe from the
pumps. This is provided for by the compound double-acting
pumps and large air-vessel accommodation, together with the
coupling of the engines at right angles. Many engineers prefer a
double-cylinder engine for conducting expansive operations; but
although in Some cases such an engine is advantageous, as for
driving machinery where great regularity of motion is a desideratum,
yet for large pumping engines the single cylinder is preferable, as
double-cylinder engines are much more complicated, and all useful
degrees of expansion can be obtained sufficiently with a single
cylinder. *
STATIONARY ENGINES. 217
The next example gives the plan of the water-works as adopted at
Berwick-on-Tweed. The works comprise two tanks for storing spring
water, one with the top water at a level of 16 feet above ordinance
and the other 12 feet higher. The upper tank, which occupies the site
of an old quarry, is 80 × 50 feet and 7 feet deep, and has three walls
built of dry rubble stones, to admit the water from the springs
SSSSSSS
§
SN
Fig. 137.-General Arrangement of Tanks, Engine and Boiler Houses, Berwick-on-Tweed
Water-works.
rising behind the walls; the wall next the river is built of water-
tight masonry in cement, with a puddle wall at the back of it. The
lower tank, which is 70 × 20 feet and 7 feet deep, has solid walls
like the large one, and receives the water from several springs, which
rise at a lower level than those stored in the upper tank. An engine
and pump and boiler, with engine and boiler house, complete the
works at the collecting ground; and a 9-inch rising main conducts








2 I 8 MODERN STEAM PRACTICE.
the water to a high-level reservoir, placed at a level of about 200 feet
above ordinance. The springs, of which there are several, are esti-
mated to yield 23O,OOO gallons in the twenty-four hours, and the
engine working ten hours per day is calculated to raise 61 cubic feet
per minute. The height being 178 feet, and the length of track
81.45 feet, with a diameter for the rising main of 9 inches, the head
Q*/
722 25'
which makes a total height of 202 feet. To calculate the horse-
power required to raise the water to the high reservoir: By the
61% x 202 x 62%
33OOO -
a fourth more for loss = 30 horse-power for the engine. It is worthy
of remark that the pressure gauge on the air vessel registers an
increase of IO lbs., which is equivalent to 24 feet of head while
I-T-I-I-I-II º
|||||||
allowed for friction was 24 feet, found by the formula h =
ordinary method we have a result of 24, and adding
Fig. 138.-Engine and Pump.
working, and when standing the pressure is reduced to that due to
the statical pressure, namely, 178 feet. - -
The engine, which is non-condensing, and is placed vertically, is

stationARY ENGINEs. 219
calculated to work with a pressure in the boiler of 40 lbs. per square
inch. The piston is 17 inches in diameter, the stroke being 3 feet,
and the number of revolutions of the crank about thirty-five. The
pump is double-acting, consisting of bucket and plunger; the dia-
meter of the barrel is 18+ inches, that of the plunger I 3% inches,
with a stroke of 3 feet. The bucket packing consists of rings of
gutta percha about I inch Square in
section, let into grooves cut in the
bucket; two holes, 3% inch in diame-
ter, are bored in the top, communicat-
ing with the grooves, the water pres-
sure being always constant presses
out the rings of gutta percha, mak-
ing them perfectly water-tight. The
valves are of the ordinary flap kind;
a large air vessel is fitted to the
pump, 3 feet 6 inches in diameter
and 14 feet 6 inches high. The mo-
tion for driving the pump consists of
a pinion on the engine shaft and spur wheel on the pump shaft,
the gearing being in the proportion of 3 to I. The fly wheel on
the engine shaft is II feet in diameter, and weighs 5 tons 12 cwts.;
a balance is placed on the spur wheel to counterpoise the weight of
the pump ram. The boilers are 26 feet long and 6 feet 6 inches in
diameter, with a single flue 3 feet 3 inches in diameter; the fire
grate is arranged underneath, with return side flues; thickness of
plates in body of boiler, 3% inch; of end plates, 3% inch. The
chimney stalk is 84 feet high, 7 feet 6 inches square at the level of
the ground, and 3 feet 6 inches square at the coping. The boiler
is fed with a small plunger pump, worked off the end of the piston
crosshead, the water being previously heated in a tank by the
exhaust steam. The engine and pump cost £950. The rising
main, 9 inches in diameter, has turned and bored joints except
where lead and yarn ones were required for sharp bends; and also
four air and four scouring plug valves with a clack valve immediately
above the air vessel and another half-way up the track. A branch
pipe leads into the lower service cistern, fitted with a self-acting
ball valve, 6 inches in diameter. The pipes cost when laid about
12s. per lineal yard. The actual work done by the engine can be
determined by means of a cast-iron measuring box placed at the
Fig. 139–Pump Bucket.

22O MODERN STEAM PRACTICE.
upper end of the pipe, with a trough having a flap valve in the
bottom for passing the water direct into the cistern if required.
By means of an indicator diagram we can calculate the amount
of work required to raise the water from the lower tank to the high
reservoir as follows:—The measuring box is 6 feet x 3 feet 3 inches X
3 feet 13% inch, and has a capacity of 60-64 cubic feet. The aver-
ages of four experiments made by the engineer for the works gave
58-25 seconds as the time required to fill the box, which represents
a discharge of 62.5 cubic feet per minute. The area of the plunger
of the pump being '9398 foot, and the double stroke 6 feet—the
engine making thirty-five revolutions per minute, which represents
I I-66 of the plunger—gives a theoretical discharge of 65.73 cubic
feet per minute, and shows a ratio between the theoretical and
actual of IOO : 95, or a loss of 5 per cent. This represents an amount
of work = 62-5 cubic feet, weighing 3906 lbs., raised 202 feet high,
which is equal to an expenditure of 23.9 horse-power. The indi-
cator diagram showed an effective pressure of 23 lbs. per square
inch, which with thirty-five strokes per minute at 6 feet, with a piston
of 224.5 square inches, is = 33 horse-power, showing a loss for fric-
tion, &c., of 27 per cent.
CONSUMPTION AND COST WITH VARIOUS KINDS OF COAL.
per Lon. per hour. per ºver per ºver
per nour. per nour.
Broomhill Nuts...... at 6/6 ... burn 3°7 cwts. ... = I7-3 lbs. ... = 602d.
Berwick Hill......... , 9/6 ... ', 2'5 , = II '7 , , = '586d.
Scremerston.......... , 9/6 ... , 27 ,, ... = I2’6 , = '63 Id.
The above table compares the consumption and cost of coal with
the actual quantity of water delivered, which is equal to an expen-
diture of 24 horse-power. If we compare the expense of working
this engine with larger ones in use at Some of the English water
works, and use the same standard—namely, the cost of raising IOOo
gallons IOO feet, which is equal to 1,000,000 foot-pounds, we find—
The Trent Water-works Company at Nottingham.............cost 287d.
Boulton & Watts, 29 horse-power, 1809, condensing,......... , 543d.
22 2 3 30% 95 5 § 9 3 ......... , 358d.
2 3 5 5 76 3 5 1828, 9 3 • * * * * * * * * > * '333d.
Berwick Pumping Engine, 1871 (high-pressure), .............., ,, .340d.
STATIONARY ENGINES. 22 I
STAND PIPES, ETC.
Stand pipes were originally introduced to equalize the weight on
the engines, and give the required pressure in the main pipes for
the town supply. The arrangement under notice was erected at
Tettenhall, and consisted of two pipes, one of them open at the top,
inclosed in a tower of brickwork, as shown in Fig. I4O.
We are indebted to Mr. Marten, C.E., for the following descrip-
tion of its action:-The engine having only steam on the under
side of the piston lifted the pump rods, and their own weight
was just sufficient to bring them down along with the plunger of
the pump if the stand pipe was only full to the junction at the top,
but it was not enough to let them force the water to the top of the
tower. When the town required all the water the engine pumped
regularly, being worked by a cataract to give the requisite number
of strokes per minute; but if the town did not take the water the
engine stood, because the rods were not heavy enough to make the
down stroke. Whenever the town drew off some water the engines
started again. The state of the water in the stand pipe was shown
in the engine house by a mercury gauge, and the engines were
regulated to keep the stand pipe full up to the junction. There
were no escape valves, because they were not needed; if by any
chance the sudden shutting of the large mains in the town, or air
returning up the main, threw the water over the top of the stand
pipe, it filled the cap of the tower and ran out at Small holes, falling
like rain, but this very seldom happened. When there is much
danger of overflow near a town an overflow pipe is fitted, which
allows the water to flow into the reservoirs from which it is pumped.
At Tettenhall there was no provision made for breaking the fall of
the water in the descending leg of the stand pipe. This want caused
much air to be carried into the mains, so that the water when first
drawn was often as white as milk with the minute bubbles of air,
but it cleared in a very short time. The chief use of the stand pipe
was to render undue pressure on the mains impossible, as there was
at first no reservoir. When a reservoir exists, however, always open
to the pumping main, it serves the purpose of a stand pipe, and
prevents any undue pressure.
In some cases, as the South Staffordshire water-works at Bromhills
(Fig. 141), the stand pipe is placed on a hill on the line of the main,
about half-way between the engine at Lichfield and the main reser-
222. MODERN STEAM PRACTICE.
voir at Walsall, and it there acts both as an air pipe and a safety
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Fig. 14o.—Stand Pipe and Tower.
A, Pipe from the pumps. B, Pipe to the town. C, Cap. D, Ladder, E, Windows.
• STATIONARY ENGINES. . 223
pipe. At Bromhills there is only one stand pipe, open at the top,
and placed in the centre of a brick tower; if it overflows the water
falls down the tower, and flows into a canal.
Mr. Marten states that he has found a 6-inch weighted valve, on
a 9-inch pumping main, do as well as a stand pipe, and it prevents
the required pressure from being exceeded. At Stourbridge a small
district near the reservoir needs higher pressure than the reservoir
gives, and a valve on the main is weighted to give the required

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Fig. 141.-Stand Pipe, &c.
pressure, the escape water passing into the reservoir. This valve
can be even made self-acting, as it does not quite close, and allows
the quantity of water to pass delivered by the engine at its ordinary
speed; and when the engine delivers the quantity of two or three
extra strokes, the pressure rises, but never beyond the 50-feet extra
head required. As the main to the reservoir is also the supply main
there is a back-flap valve on it in the same, box as the weighted
valves, which opens whenever the engine stops, and lets the reser-
voir water return. There is also a similar valve at the engine house,
about half a mile from the reservoir, which enables the engine to
send direct into the town without a reservoir or open-ended pipe;
but this plan is not adopted except in cases of repair of the main
or reservoir.
Various valves are in use for preventing the engine running away
if a main pipe bursts, and they are generally placed beyond the air
vessel when so fitted. A catch, kept open by the pressure, is some-
times used; if the pressure in the main pipe falls, the engines are
stopped by this catch preventing the steam valve from opening.
Mr. Marten states that when testing a long main he was surprised
to note the instantaneous action of the water; any alteration of the
pressure was so instantly seen at the other end that no difference
in time could be detected. On the South Staffordshire main from
Lichfield to Walsall, at every 20 feet or so of rise a back stop valve
224 MODERN STEAM PRACTICE.
is fitted to prevent the return of the water if the engine is stopped or
a pipe bursts. In the case of the latter accident it is of importance
to prevent much water escaping, as the pipe is laid for some distance
along a railway embankment formed of gravel and sand, easily
washed away. During the testing of the main one pipe burst where
there had been a chill in the casting, but so little water came out
as to do but little damage to the embankment. The engine stopped
because of the sudden drop of the pressure acting on the catch
already referred to; and the return of the water was prevented by
the back valves, even the water between the burst and the next
valve placed above being retained, as no air could get in except in
gulps at the break.
Many things which were once considered necessary to the safety
of water-works are now superseded. The constant system, or one
reservoir for the whole town, instead of each customer having one
for himself, has caused great change. Instead of the supply pipes
being led off small pipes called “riders,” they are put direct into
the main, and all the ends of the main are connected, so as to give
greater circulation to the water. The use of cisterns is discouraged
as much as possible, as they are likely to deteriorate the quality of
the water. Separate pipes to the reservoir—one to pump through
and the other to supply through—are not used, but only one pipe
for both purposes.
It often happens that the supply is obtained from a spot between
the town and the high ground where the reservoir can be made:
one pipe from the reservoir is then found sufficient, and the engine
pumps into it. If the town, as in the middle of the day, requires
all the water, it is sent direct into it; when the demand falls off, it
is partly delivered into the reservoir; if there is an extraordinary
demand, both the reservoir and engines supply the town. By this
arrangement one main answers, and it may be much smaller than
if two were used, one to the reservoir and another from it to the
town. Much of the water, also, is pumped at a less pressure than
would be needed to pump it entirely into the reservoir.
Stand pipes may be considered as among the precautionary con-
trivances once deemed requisite for supplying water to a town; but
the supply can be obtained direct from an engine as easily and
safely by properly loaded valves, although it is found a more expen-
sive plan. The engines do wretched duty, as the calls upon them
are so irregular. An engine always does best when working regu-
STATIONARY ENGINES. 225
larly at full speed, and therefore a reservoir to receive the pumped
water should be provided if possible.
When pumping under a heavy pressure it is usual to have an air
vessel to each engine on the delivery pipe beyond the pumps;
and sometimes a larger one is placed on the main pipe into which
the others deliver. Of course care must be taken that each air
vessel has its full complement of air; sufficient is usually drawn in
Fig. 142.-Air Vessels.
AA, Pumps. B B, Air vessels. cc, Sluice valves. D, Main air vessel. E, Main pipe to the town.
by the pump, and a very small hole or tap is sometimes inserted to
supply it
When more than one pump is arranged for pumping into an air
vessel, stop valves must be fitted on the delivery pipe, to prevent
the return of the water when either or both pumps are not at
work. The air vessel is of great importance, as it equalizes the flow
of the water through the main,
and less weight is required on
the top of the plunger for the P
down stroke. The capacity of
the air vessel should be about
ten times the volume of water
delivered by each stroke of the
pump. |
A relief valve should be placed
on the delivery pipe to prevent
undue pressure; it is fitted with
a lever and weight. In some Fig. 143.—Relief Valve.
examples a solid plunger is a, Solid plunger. B, Piston, c, Slotted pipe leading
adopted, having a piston and ...”. W."
rod at the top, the piston work-
ing loosely in a cylinder connected to the main by a small pipe.
The plunger A rises when the pressure increases, being larger at A
than at C, and allows the water to flow through the slots into the

15
226 MODERN STEAM PRACTICE.
reservoir from which it is pumped, thereby relieving the pressure.
The plunger falls again by gravitation, and
the piston B, acting like a cataract, prevents
the action taking place too suddenly.
The pressure valve is placed beyond the
air vessel on the main pipe; its sole use is
to prevent the plunger of the engine de-
scending too rapidly in the event of one of
the main pipes bursting. The example under
notice consists of a plunger, loaded with a
certain weight to suit the head of water; on
the bottom of the plunger a double-beat valve
is secured by a cotter, the valve working on
a seat bolted down by bolts passing through
it, and secured by lugs at the bottom of the
bent pipe and nuts at the top bearing on
Fig. 144-Pressure Valve the valve seat. At each stroke of the en-
**.*.*.*gine this valve is liſted, and consequently
F, Panch pipe from pulp. G. De were a pipe bursting the engine has still the
livery branch. w, Weight.
- same duty to perform. As has been stated,
a modification of these valves has been successfully used instead of
stand pipes.
PUMPING ENGINES FOR DRAINAGE works AND
GENERAL PURPOSES.
THE LONDON DRAINAGE SYSTEM.
The Abbey Mills Pumping Station is the largest establishment
of the kind on the Main Drainage Works, and provides, by means
of eight engines, an aggregate horse-power of I I4O, capable of lift-
ing 15,000 cubic feet of sewage and rainfall a height of 36 feet per
minute. Each of the eight engines is furnished with two boilers;
and they are contained in a cruciform building, arranged in pairs,
each arm of the cross containing two engines. The engines, as
in all the other pumping establishments on these works, are expan-
sive, condensing, rotative beam engines, but are somewhat more
powerful than those used elsewhere, the cylinders being 4 feet
6 inches in diameter, with a stroke of 9 feet. The pumps differ also
in being double-acting, a circumstance which admits of the air

STATIONARY ENGINES. 227
pump, &c., being worked from the main beam, instead of from a
Fig. 145.-Abbey Mills Pumping Engines. One-half Elevation.

228 MODERN STEAM PRACTICE.
distinct beam, as at the other stations. Each engine works two
pumps, having a diameter of 3 feet IO)4 inches, and a length of
stroke of 4% feet. The boilers are each 8 feet in diameter and
30 feet long, with double furnaces.
The engine building is divided in height into three compartments,
the lower one being the pump well into which the sewage is con-
veyed from the Low Level Sewer, the second forming a reservoir
for condensing water, and the upper one containing the eight engines
and platform overhead. The lower part of this building lies about
3 feet above the bottom of a thick stratum of clay, overlying a consid-
erable thickness of sand with water, through which the foundations
are carried by piling to a bed of firm gravel below. The boiler houses
and other portions of the work are founded upon the clay stratum
Overlying the sand. As the deep foundations are situated in close
proximity to the Northern Outfall Sewer, which is contained in an
embankment above the general level of the ground, great caution was
requisite to prevent any settlement in that sewer. The boiler house
and coal stores are built between the outfall sewer and the engine
house, so as to keep the deep excavations as far distant from the
sewer as practicable. The coal stores are built with their floors level
with the Stoke holes in the boiler house, and tramways are laid from
one to the other; this floor is only a trifle below the surface of the
ground, which is 6 feet below high water. One side of the coal
stores forms the front side of the boiler house. Tramways are laid
from the top of the coal stores to the Abbey Mill River, adjacent
to the works, where a wharf wall is built for landing coal and other
materials.
The sewage from the Low Level Sewer, before entering the pump
wells, passes through open iron cages, the bars of which intercept
any substances likely to interfere with the proper action of the
pump valves; and these cages when requisite are lifted above ground
by proper gearing, and the intercepted matter is discharged into
trucks. The sewage then passes into the wells, and is lifted by the
pumps through the hanging valves into a circular culvert of cast
iron, and then forced into any of the three culverts forming the
Northern Outfall Sewers.
It is fortunate that these works were not projected in the year
1306, when coal was first introduced into London, and was regarded
as so great a nuisance that the resident nobility obtained a royal
proclamation prohibiting its use under severe penalties; for this
STATIONARY ENGINES. 229
pumping station alone consumes about 9700 tons of coal per annum.
The expense of pumping, however, cannot be regarded as a wholly
additional item in the cost of drainage under the new system; for
the removal of deposit from the tide-locked and stagnant sewers in
London formerly cost about £30,000 per annum, and the constant
flow kept up in the sewers by means of pumping must necessarily
keep them freer of deposit, and so reduce the outlay for cleaning
them.
The Deptford Pumping Station is situated by the side of Dept-
ford Creek, and close to the Greenwich Railway Station. The
sewage is here lifted from the Low Level Sewer, a height of 18 feet,
into the Outfall Sewer. An iron wharf wall and barge bed, 500 feet
long, has been constructed at the side of the creek, and is provided
with a crane and tramways for landing coal or other materials.
There are four expansive, condensing, rotative beam engines, each
125 horse-power, and capable together of lifting IO,OOO cubic feet
of sewage a height of 18 feet per minute. These engines are Sup-
plied by ten Cornish single-flued boilers, each 30 feet long and
6 feet in diameter. The cylinders are 48 inches in diameter, with
a length of stroke of 9 feet. The pumps, two of which are worked
by an engine direct from the beam, are single-acting plunger pumps,
the diameter of the plungers being 7 feet, and the length of stroke
4% feet: one pump is worked from the beam midway between the
steam cylinder and the centre pillars, and the other midway between
the centre pillars and the fly wheel. The air, feed, and cold-water
pumps are worked by a separate beam attached to the cylinder end
of the main beam. The pump valves are of the leather-faced hanging
kind, and the sewage is discharged through them into a wrought-
iron culvert placed on the level of the Outfall Sewer, with which it
is connected by a brick culvert, which receives also the sewage from
the High Level Sewer, previously brought by gravitation under the
creek through four cast-iron pipes 3 feet 6 inches in diameter.
Both streams enter the Outfall Sewer, and are conveyed to Cross-
ness, where they are again lifted. The chimney shaft at this station
is 7% feet in diameter at the base and 6 feet at the top; its height
is 150 feet, and the furnaces draw from the sewers and the engine-
well to assist in their ventilation. The accommodation for coal is
ample, the sheds covering an area of 18,OOO feet. Gratings are
used for intercepting the larger substances brought down by the
sewers, in the same manner as at the other pumping stations.
23O MODERN STEAM PRACTICE.
The Crossness Reservoir and Pumping Station.—The sewage on
the south side of the Thames is discharged into the river at the
time of high water only; but the sewer is at such a level that it can
discharge its full volume by gravitation about the time of low water.
Its outlet is ordinarily closed by a pen stock placed across its
mouth, and its contents are raised by pumping into the reservoir,
which is built at the same level as that on the north side, and, like
it, retains the sewage, except during the two hours of discharge
after high water. The sewage is thus diverted from its direct course
to the river into a side channel leading to the pump well, which
forms the lower part of the engine building; from this well it is
lifted by four condensing rotative beam engines, each I 25 horse-
power, working direct from the beam two compound pumps, each
with four plungers. The cylinders are 4 feet in diameter, with a
length of stroke of 9 feet; they are situate at the end of the main
beam, which is 40 feet in length, the crank shaft connecting rod being
attached to the farther end, and the pump rods situated on either
side of the beam centre. The air, feed, and cold-water pumps are
worked by a separate or counter beam, fixed at one end to a rock-
ing lever, and attached at the other end to the main beam. The
cylinders are supplied by twelve Cornish boilers, each 6 feet in
diameter and 30 feet long, with an internal furnace and flue 3 feet
in diameter, set so as to have the second heat carried with a split
draught along the sides, and the third heat under the bottom of the
boiler, into the main flue leading to the chimney. The maximum
quantity of sewage ordinarily requiring to be lifted by these engines
is about IO,OOO cubic feet per minute; but during the night that
quantity will be considerably reduced, and, on the other hand, it
will be nearly doubled on occasions of heavy rainfall. The lift also
will vary from IO to 30 feet, according to the level of water in the
Sewer and in the reservoir into which it is lifted. These variable
conditions led to some difficulty in the working, but which has been
overcome by an arrangement of the pump plungers. The pumps,
which are single-acting, are placed equidistant on each side of the
beam centre, their cases being each 12 feet in diameter, and fitted
with four plungers 4 feet 6 inches in diameter. These plungers are
placed in pairs, each pair being worked from a crosshead on the
main beam, which is in two flitches for this purpose, and either
pair of plungers can be thrown out of gear. By this means the
capacity of the pumps may be varied in the proportion of one, two,
STATIONARY ENGINES. 23 I
or three, as the inner pair, outer pair, or both pairs are thrown out
of gear. The sewage is discharged into a wrought-iron trough,
:º
*-
Fig. 146.—Pumping Engines at Crossness. One-half Side Elevation.
through hinged leather-faced valves, which are suspended from
wrought-iron shackles, and fitted with wrought-iron back and front
plates. Each valve is 12 inches by 18. As has been before stated,
substances which might prevent the proper action of the valves are

232 MODERN STEAM PRACTICE.
-:/,
f
Fig. 147.—Pumping Engines at Crossness. End Elevation.
intercepted before reaching the pumps by a wrought-iron grating

STATIONARY ENGINEs. 233
placed in front of the openings to the pump well. Such substances
are lifted from the face of the grating by an endless chain with
buckets or scrapers and combs attached, working vertically in front
of and close to the grating, the teeth of the combs passing between
the bars. On the descent of the chain the buckets are overturned
and discharge their contents into a trough, from which they are
removed by manual labour.
The sewage, after being delivered from the pumps into the
wrought-iron trough, is discharged through brick culverts into the
reservoir, or, in case of need, provision is made for its discharge
through other culverts directly into the river. After remaining it,
the reservoir until the time of high water, it is discharged by a lower
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Fig. 148.—Boilers for Pumping Engines at Crossness. End Elevation.
set of culverts into the river. There are two tiers of eight openings
in each compartment of the reservoir, the upper eight for the admis-


234 MODERN STEAM PRACTICE.
sion of the sewage from the pumps to the reservoir, and the lower
eight for its discharge into the river. These apertures are all opened
and closed by pen stocks.
The reservoir, which is 6% acres in extent, is covered by brick
arches, supported on brick piers, and is furnished with weirs for
overflows, and with a flushing culvert. The height, level, and
general construction are similar to the one at Barking Creek. Over
the reservoir are built twenty-one cottages, for the engineers and
other persons employed upon the works.
The ground upon which these works are constructed consists of
peat, sand, or soft silty clay, and affords an insufficient foundation
within 25 feet of the surface. To obviate the need of removing this
vast mass of soil, and thereby reduce the expense of the foundations,
trenches were cut down to the solid earth, and the culverts on the
various levels were built as far as practicable in the same trenches,
one above the other; the lowest, leading from the Outfall Sewer to
the pump wells, support those discharging the sewage from the
reservoir, and these again support those leading from the pumps
into the reservoir. On account of the pump wells it was necessary
that the walls of the engine house should be carried down to the
depth of the gravel, independently of the nature of the ground; but
such was not the case with the boiler house. The boilers and stoke-
hole floor are supported on arches springing from walls built up
from the gravel, and the space below the floor is made available as
a reservoir for condensed water. The water from the hot and cold
wells of the engines is conveyed hither, one compartment being
used as a chamber for cooling that from the hot well, previous to
its being used again for condensing water. With the same object
of Saving separate foundations, coal stores and workshops have been
erected partly on the external walls of the reservoir and partly on
the culverts in front of them; large coal stores being also provided
in front of the boiler house and on a level with the Stoke holes, into
which the coals are brought on tramways. There is also a tramway
for the upper-level coal sheds, on the level of the tops of the boilers,
from whence the coals are shot into the stoke holes below. Tram-
ways are also laid from the coal sheds to the river, where jetties are
built for landing the coals. A wall has becn constructed along the
river frontage of the works for a distance of about 12OO feet, by
which a large portion of the “Saltings” has been reclaimed. This
wall is of brick, carried upon brick arches resting on piers formed
STATIONARY ENGINES. 235
of iron caissons filled with concrete, which are carried down to the
gravel.
The chimney into which the flues from the boilers are conveyed
is square in plan externally, 8 feet 3 inches in internal diameter
throughout, and 200 feet high; it is founded upon a wide bed of
concrete brought up from the gravel, which is here 26 feet below
the surface. The reservoir, the several culverts, and the pump wells
are connected by flues with the furnaces of the boilers, for the pur-
pose of ventilation, in the same way as at the Deptford and other
pumping stations.
The outlet into the river from the Outfall Sewer of these works
consists of twelve iron pipes, each 4 feet 4 inches in diameter, car-
ried under the “Saltings” into a paved channel formed in the bed
of the river. These pipes are connected with the Outfall Sewer by
culverts in brickwork on the land side of the wall, the numbers of
these culverts being gradually reduced and their dimensions in-
creased as they approach the junction with the large sewer.
HIGH-PRESSURE GEARED PUMPING ENGINES.
Small high-pressure geared engines may be conveniently used for
pumping water out of docks, and for other drainage purposes, being
arranged for three pumps. The connecting rod runs from the cross-
head of the piston rod, and works a cranked shaft, having a fly wheel
at one side and pinion at the other, geared into a spur wheel keyed
on a cranked shaft for the middle pump; one of the side pumps
is worked from a pin let into one of the arms of the spur wheel, and
the other pump is driven from a crank placed on the other end of
the shaft. The engine is placed horizontally, and the pumps are
vertically arranged against the side of the dock wall. When they
are needed to pump the water out of a dock in course of construc-
tion, the engine is bedded on an overhanging wooden frame, having
a strut let into the wall, or temporary pile foundation, on each side
of the frame for carrying the engine and the three throw cranks for
the pumps. The pumps are in Some instances of the plunger type,
having the plungers cast in brass; while others are simply lift pumps,
fitted with valves of india rubber working on brass gratings. There
is one suction pipe and one discharge pipe common to all the three
pumps; the former has a three-branched pipe fitted to the top, to
which are bolted the pumps, one to each branch; while the latter is
236 MODERN STEAM PRACTICE.
placed across the pumps, in communication with the valve chests,
having one vertical delivery pipe placed at the end.
THE CENTRIFUGAL PUMP."
Centrifugal pumps have been much used for pumping water out
of works in course of construction, and are recommended for their
simplicity and the ease with which they can be applied to almost
any situation. The pump, when placed in position, is driven by a
belt from the fly wheel of a portable engine. This is a temporary
arrangement; but many centrifugal pumps have been fitted up of
a permanent kind, driven by wheel gearing. When the lift is of
moderate height these pumps throw a vast body of water; and as
they are not so liable to get choked with foreign matter, they may
be used in many situations for pumping sewage with advantage.
Fig. I49 represents a pair of centrifugal pumps of the largest size
for drainage purposes connected directly to the engines, a class of
machinery brought to great perfection by the Messrs. Gwynne & Co.
of London. This description of pump is admirably adapted for
works of construction, water works, graving docks, &c., and more
especially for drainage purposes, large tracts of land having been
reclaimed by its aid. Where low lifts only are required it far eclipses
the ponderous pumping engine of the beam type.
The construction of this pump is very simple. The revolving
wheel or disc is formed of two concave plates, placed parallel with
their concave surfaces towards each other. Two saucers, placed
in corresponding positions, will give an idea of the arrangement.
Between these discs is an arm or impeller, radiating from a boss or
hollow axis, mounted on a shaft which works horizontally, vertically,
or at any intermediate angle. This impeller, which regulates the
distance between the discs, varies in breadth; its narrowest part is
at the outer edge of the discs, becoming gradually broader until
its edge intersects the inner surface of the openings for the suc-
tion. Its breadth is varied in such a ratio that the areas of any
section cut from the wheel by the surfaces of circular cylinders,
whose axes coincide with that of the shaft, shall be equal to such
other section at any distance from the centre; and these areas are
so arranged in order that the column of water or other fluid enter-
ing the wheel when in a state of revolution may have an uninter-
rupted flow from the centre to the circumference, and that the
STATIONARY ENGINES. 237
quantity received and discharged may be constantly equal. This
is considered to be essential when large bodies of water are to be
discharged, or when high velocities are required. The inner surfaces
of the discs, or the annular opening around the whole circumference,
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has an area equal to the openings at which the water is admitted
into the centre of the revolving wheel. There are two cylinders
or water passages, one on each side, with a passage for each in
connection with one suction pipe, rendering the pump extremely


































238 MODERN STEAM PRACTICE.
Compact. In one of the cylinder covers or ends there is a bear-
ing Supporting the spindle on which the wheel is fixed, in the
other cylinder cover there are a gland and stuffing box through
which the shaft for the revolving wheel passes. The suction pipe
may, if desired, be run any moderate length horizontally, and the
pump may be placed from 15 to 20 feet vertically above the water
to be raised; in most cases it is advisable to have a foot-valve at
the bottom of the suction pipe, so as to retain the water in the
pump when standing still. The delivery pipes, as seen in Fig. 149,
are fitted with self-acting flap valves, to prevent any water flowing
back on to the land when the pump is not working. The pumps are
fitted to discharge 3O,OOO gallons per minute, 12 feet high; the pipes
are 42 inches in diameter; the engines are of the horizontal condens-
ing type; diameter of cylinders 2 I inches, length of stroke 21 inches.
The action of the pump is as follows:—The pump and pipes
being filled with water, which the foot valve at the bottom of the
Suction pipe retains, the wheels or discs are coupled to the engine,
and the latter being started at a high velocity, a centrifugal motion
is given to the wheel, and to the water contained in the disc, which
is driven out into the case or receiver of the pump. The partial
vacuum thus formed in the disc is filled by the water forced up the
Suction pipe by the pressure of the atmosphere; the water entering
the disc receives centrifugal motion in the same way, and thus a
continuous stream is received into and discharged from the pump.
To prevent the water from rotating in the case, and to give it a
direction upwards to the discharge pipe, a stop or plate is placed at
the base of that pipe, reaching to the joint between the piston and
the case. The joints between the suction pipes and disc are so made
that sand, mud, or gritty matter cannot lodge near them, by which
means the wear is so reduced as to become almost imperceptible.
The following may be enumerated as the principal advantages
of the centrifugal pump:—(I.) It can be erected easily and quickly.
(2) It works with an easy rotary motion, without valves, eccentrics,
or other contrivances, which consume power in friction. (3.) It will
discharge a quantity of water greater in proportion to the power
employed than any other pump —75 per cent, being taken as an
average. (4.) It is economical in use, and of very great durability
—an important point in all machinery. (5.) It discharges a con-
tinuous and steady stream without air vessels. (6.) It is little
affected by sand, mud, grit, or other foreign matter in the water,
STATIONARY ENGINES. 239
which so rapidly destroy all other pumps. (7.) The large sizes will
admit the passage of solid bodies 6 inches in diameter without
injury, and the smaller sizes in proportion. (8.) It will pump hot
or cold liquids equally well. (9.) It requires a very light and inex-
pensive foundation, as there is no vibration while working.
A striking proof of the great superiority of these noiseless machines,
working at a high speed, over the beam pumping engine, may be
seen in the draining of the Haarlem Lake. The weight of the
pumps and valves attached to one of these latter engines was about
2OO tons, the pumps were adapted to raise about 70 tons of water
per minute a height of 15 feet when working their usual speed of
eight or ten strokes; but a centrifugal pump of the above descrip-
tion, doing the same amount of work, will weigh only 5 tons.
The Pulsometer Pump has been recently introduced with good
results in many situations where other forms of pump would have
been more troublesome to keep in order. It is a steam pump with-
out moving parts except certain valves. The operation consists in
forcing water to a height by the direct pressure of the steam, and
the lifting of the supply into the pump by the after condensation of
the same steam; this is accomplished through the medium of a ball
valve above and clack valves below, arranged in two vertical
chambers.
WINDING ENGINES.
In modern practice the use of the flat hempen ropes with these
engines has been discarded, in favour of the wire rope of a round
form. The drums and pulleys for these ropes must be of large
diameter, and the angle of the rope from the drum to the pulley on
the pit-head frame should not be too acute. Where the weight
lifted is about I ton, the thickness of rope will be about 1% inch,
and will weigh about 4% lbs. to the foot, the diameters of drum being
about 5 feet and 16 feet, and the time taken to lift through from
250 to 300 fathoms about I minute.
The engines used at collieries for winding purposes should be of
the simplest construction, strong, and free from all unnecessary
and expensive complications. With this view spur gearing has
been discarded by many first-class manufacturers, although geared
engines are still in extensive use: the object of using a pinion on the
engine shaft working into a spur wheel on the drum shaft being to
24O MODERN STEAM PRACTICE.
reduce the diameter of the cylinder and length of stroke of the
piston, and so to drive the engine shaft at a greater number of
revolutions than the drum shaft. The old type of engine most in
favour is of the beam description, vibrating on a gudgeon on pillow
blocks supported by a single column, having plain cast-iron guides,
with crosshead and link attachment connecting the piston rod with
one end of the beam; this being the simplest arrangement for giving
a true vertical motion to the piston rod. The other end of the beam
is connected to the crank shaft by a cast-iron connecting rod, of
sufficient weight to balance the piston and its adjuncts. These
rods are fitted with wrought-iron straps and brass bushes, with jibs
and keys for adjusting the brasses. The bed plate for carrying the
cylinder, main column, and pillow block for the crank shaft is cast
in one piece. When the bed plate is securely bolted down on an even
surface, with a firm foundation, this form of engine is very strong and
durable, and is generally constructed on the high-pressure principle.
Horizontal geared engines, however, have in a great measure
superseded those of the vibrating beam type. They are certainly very
compact, and when properly proportioned give great satisfaction,
notwithstanding the objections arising from their wheel gearing.
The DIRECT-ACTING. HORIZONTAL ENGINE, with the drum for
the wire rope placed on the crank shaft, may be regarded as the type
of engine to be used for the future. Simplicity is the object to be
attained, and we attain it in the direct motion of this engine simply
by giving a little more diameter of cylinder and a longer piston
stroke, with a certain number of revolutions to suit the diameter
of the drum and the speed usually allowed for running the wire
ropes. Although single engines are in daily use, they are better to
be used in duplicate, with one crank shaft, and cranks at right
angles to each other. With the latter form there is no difficulty
in starting, as is sometimes the case with single-cranked engines,
which have a tendency to stop on the dead centre, or extreme end
of the stroke, and require great attention on the part of the attend-
ant to prevent this occurring. This objection is entirely removed
by coupling the engines at right angles, the one assisting the other
in the extreme position. The perfect ease and certainty with which
these engines can be handled by means of the beautiful link motion
and double eccentrics—combined with the powerful brake on the
periphery of the fly wheel—renders the direct-acting horizontal
engine a great boon to the practical miner.
stationARY ENGINES. 24I
. . The cylinder for these engines is a plain casting, with steam and
exhaust ports suited for the ordinary slide valve: one steam port
at each end, and a central port for the exhaust. It is preferable to
fit a cover at each end, more especially for large diameters, as the
boring bar requires to be of a large size to bore out truly these long
º: a- -N. @–t
ºs-ºf-Hº@, iſ ºf
- * © 39E9E
+
> ***-*.. **** > *s-
lº.;3,9; Šºšiii.3:
*.*
Fig. 15o. - Colliery Winding Engines. Side Elevation and Ground Plan.
cylinders free from vibration, and the hole for the bottom bush in
the stuffing box on a solid end is too small in diameter for an
ordinary sized boring bar. There is a deep stuffing box on each
cover, fitted with a gland in the usual manner. The piston rod
passes through both these boxes, an arrangement which takes part


16
242 MODERN STEAM PRACTICE.
of the weight off the piston on the end glands, the piston rod acting
as a round beam loaded at the middle when the piston is at half
stroke; by this means the action of the piston has not so much
tendency to wear the cylinder oval. Trunks or hollow pipes have
been introduced in some classes of blowing engines to remedy this
evil, inherent in all horizontal engines of very large size; and when
properly proportioned they have given good results. The cylinder
is cast with brackets on the bottom half for bolting it down on the
bed plates; of course these palms or brackets should be nearly in a
line with the strain, or a little below the centre line of the cylinder.
Joggles are cast on the bed plate to embrace the brackets, and by
this means end keys are fitted and driven in tightly, thus taking
the shearing strain off the bolts. By attention to these details secure
and firm work is obtained, more especially for high-pressure engines,
where the succession of shocks from the high steam pressure used
has a great tendency to shake the cylinder and loosen the fittings
if not properly joggled to the bed plate. Indeed, for fast-going
engines of the high-pressure type, the repeated shocks received on
the end of the cylinder necessitates the use of wrought-iron stays
to bind the cylinder and bed plate firmly together; some makers
even casting the cylinder along with the bed plate, which effectually
secures this object. *
The steam valve is an ordinary D one, and should be fitted with
packing rings on the back, bearing on the valve-casing cover. Some
makers, however, prefer a small piston working in a short cylinder
placed on the valve-casing cover, the piston being connected to the
valve by means of a vibrating link. Some such contrivance is
absolutely necessary to take the back pressure off the valve; and
the former method does so by reducing the area on the back of
the valve—that is to say, the rings are made steam tight, and the
surface exposed to the steam in the casing is reduced; while by the
latter method the valve is drawn, as it were, off the face with a
certain force applied by means of the piston, and which being
received on the pins of the vibrating link, renders it comparatively
easy to move the valves by hand, just as any heavy weight is easily
moved when suspended by a chain. The valve casing is sometimes
cast on the cylinder; but many prefer it to be separate, and secured
with bolts, as in this case the facing for the valve is more readily
planed, and afterwards scraped to a true surface. The usual
stuffing box is cast along with the casing, with brass bush and
STATIONARY ENGINES. 243
gland, and it should have a brass guiding socket at the other end
for taking the valve spindle, which passes through a tube cast along
with the valve, and to which it is secured by means of a nut and
jam nut at each end. Some makers dispense with this guide, and
attach the rod to the valve by a screwed part at its end, having a
nut let into the valve, with a jam nut to lock it securely when the
valve is properly set.
The valve is actuated by double eccentrics and link motion.
The eccentric sheaves are of cast iron, of the usual construction,
and may be cast all in one piece, or have the means of taking them
off the shaft without disturbing the main parts of the engine. The
straps should be cast in brass, or they may be forged on the eccen-
tric rods, and lined with strips of brass rivetted on. The link,
suspension rods, weigh shaft, and reversing handle should be made
of wrought iron, and all the working pins case-hardened; and the
sliding block for the link should be of steel. All the bearings for
the weigh shaft should be bushed with brass, and the whole motion
adjusted in a strong and substantial manner.
The starting handle should be a plain lever, fitted with quadrant
and catch for holding the link in position. The starting platform
should be placed so as to command a good view of the pit head.
Its position depends, of course, on the method of fitting up the
machinery, but in ordinary cases the platform may be arranged at
the back of the winding drum, and of sufficient height to see well
over it. In this position, when the fly wheel is placed at the centre
of the engine shaft, the friction strap and hand gear for working it
is greatly simplified, and the attendant has the two important handles
for reversing and applying the friction brake in a direct line with
the pit head. The handle for working the stop valve of the equili-
brium type should be placed here likewise, on the centre of the
steam pipe between the two engines. The handles are, however,
at times arranged on the outside of the left-hand engine looking
towards the pit head, with a cross shaft, as in the former method,
for the reversing gear placed underneath the bed plates or above
them, supported at the end and middle with suitable pillow blocks.
On this shaft the lifting arms are fitted, with a weight arm at the
centre of the shaft, or between the end and middle pillow block,
having a suitable weight, which may be placed on the starting
handle, for balancing the links and rods, and thus easing the labour
of starting and reversing the engines. The handle will of course
244 MODERN STEAM PRACTICE.
suit almost all attendants when arranged for the right hand. The
lever for the brake is worked by foot; it should be of great length,
and so placed that the attendant can press it with his left foot
whilst he holds the reversing handle. The brake lever must, of
course, be arranged horizontally, and fitted with a cross shaft and
short lever at the end for taking the brake strap of wrought iron
lined with blocks of wood. The shaft is supported on three pillow
blocks, and is fitted with a weighted lever, the weight being suffi-
cient to balance the long foot lever, which should have a suitable
stop to keep it always at a convenient height for treading upon.
Many engineers are of opinion that it would be better to fit a hand
lever and rod to the long brake arm, instead of pressing on it with
the foot; but it must be borne in mind that both hands may be
required at times to lift or depress the link motion, and the foot
can be applied to the brake when the engine requires to be sud-
denly stopped. In other examples the long brake handle is placed
above the floor of the engine room, the engineman moving it by
hand, and the handle is kept up by a catch cast on a suitable cast-
iron column: there is another catch placed on a nut worked by a
screwed rod and wheel, supported by the column. The nut can be
adjusted at pleasure to suit the wear of the wooden friction blocks.
When the handle is depressed and sprung under the catch the
blocks are pressed against the friction wheel, and when the friction
requires to be increased the wheel on the screw rod is turned by
hand, which firmly locks the friction blocks.
The piston for all horizontal engines should be of the strongest
and lightest construction possible, fitted with a single packing ring,
and the usual junk ring. The packing ring may have steel springs
between it and the body of the piston; but some makers prefer a
plaited gasket. The junk ring is bolted to the piston with screwed
bolts and nuts recessed in the body of the piston. Another form
of piston largely used for high-pressure engines is a plain casting,
turned on the rubbing surface, and recessed for light steel springs.
This is certainly the simplest form of metallic packed piston; and
when it is supported by means of the piston rod passing through
stuffing boxes at each end of the cylinder, it works admirably even
for large diameters. The method of connecting the piston to the
rod is by forming a coned part at the middle of the rod with a
corresponding cone turned in the piston, which is secured by a
cotter passing through the body of the piston, as in the ordinary
STATIONARY ENGINES. 245
packing-ring system; but when the piston is cast solid, and indeed
for all pistons, it is preferable to cut a screw on the rod at the
small end of the cone, which is fitted with a nut for pressing the
piston firmly on the cone; and to prevent the piston turning round
in the cylinder, as it may do in course of time, a small short key is
let into the rod, having a corresponding part cut in the piston for
its reception.
The crosshead and gudgeon for the connecting rod is of wrought
iron, suited for single or forked ends as may be desired; the hole in
the crosshead for the piston rod is bored out slightly tapered, the
rod being turned to suit, and secured with a cotter passing through
them both. Holes should be drilled at the small end of the cotter
for passing a split pin through, to keep it from shaking loose. The
holes for the gudgeon in the jaws of the crosshead are bored quite
parallel, and the gudgeon, being accurately turned, is driven through
tightly, and secured with a key. The gudgeon can be of a less
diameter at the ends for taking the guide blocks, and of sufficient
length at one end for fitting the eye of the feed-pump plunger to it.
The motion bars for guiding the crosshead in a direct line with
the piston rod are of cast iron. The bottom bars are generally cast
along with the bed plate, but they sometimes form separate castings,
which require to be fitted to the bed plate; while the top bars are
generally made—so that the gear can be adjusted—with thin Strips
of metal between them and the bottom bars, which can be reduced
in thickness as the guide blocks wear. In this arrangement the top
bars are secured to the bottom ones with bolts at the ends, the same
bolts securing the bottom bars to the bed plate; but in some cases
the bottom and top motion bars are cast in one piece, and fitted
and bolted down on the bed plate. These guiding bars must be
accurately planed, and also the guide blocks, which are cast in hard
brass. Sometimes cast-iron blocks are adopted, in which case the
rubbing surfaces are filled in with white metal, recesses being
left in the casting for that purpose; plain cast-iron blocks, however,
answer very well, when lubrication is properly attended to—that
being a most important point in all rubbing surfaces. Oil cups
should be cast on the top motion bars, and fitted with proper covers
to exclude grit, with siphon pipe and wick to supply the oil drop
by drop.
The connecting rod is of wrought iron, turned from end to end,
with oblong pieces at the ends accurately planed, and fitted with
*
246 MODERN STEAM PRACTICE.
wrought-iron straps and jibs and keys for adjusting the brass
bushes; suitable lubricating cups are fitted to the straps.
The main cranks are of cast iron, but most engineers would
prefer them of wrought iron, as they are much stronger and better
adapted for engines subjected to severe shocks. They are usually
bored out and shrunk on the shafts hot; but when they are forced
on cold with an hydraulic ram the material is not so much strained,
while the holding power is equally good. The cranks are further
secured with a single key, fitting into a recess planed in the shaft
and slotted out in the crank eye. The crank pin is slightly tapered
in that part fitting into the hole in the crank, and is forced on and
then rivetted at the end, a part being turned out for this purpose;
this makes very secure work. In some recent examples the cranks
are formed of discs of cast iron, with a side flange on the circum-
ference of the disc, strongly ribbed to the boss at the centre. This
plan balances the engine better than the single crank arm. The
crank pin is secured by means of a nut and feather or key on the
pin.
The main pil/ow blocks are separate castings, fitted with brasses,
and caps arranged at an angle, so that the brasses are adjusted in
the direction of the greatest strain. The bottom of the blocks are
planed, as also the fitting strips on the bed plate, which has extra
strong joggles cast on it for driving in wedges, thus taking the
shearing stress off the pillow block holding-down bolts.
The Öed plate is a strong frame of a box section, open at the
bottom; it is tied at the ends and at the middle in the casting, and
should be strengthened with cross feathers between the sides, having
all the necessary joggles and fitting strips for the cylinder, pillow
block, pumps, and other minor fittings. There should be at least
four large holding-down bolts on each side of the frame, passing down
through holes left in the foundation, and secured on the under side
with a plate and key for each bolt. The foundations should con-
tain suitable man-holes, so that these bolts can be adjusted at any
time. In some instances the plates at the bottom of the foundation
are carried across, embracing two bolts; by this means a foundation
of brickwork laid in cement is firmly bound from top to bottom.
When brick is used for the foundation it is preferable that a layer
of stone-work or balks of wood be placed on the top, for the main
bed plate to rest on.
The main shaft of the engine should be of wrought iron, and all
STATIONARY ENGINES. 247
the bearings and raised parts for the drum, fly wheel if so fitted,
eccentrics, and other minor details, should be accurately turned;
while all the eyes of the various fittings should be bored out to
the exact size, and held by means of keys bearing on a flat part of the
shaft, keyways being cut in the parts. This is by far the cheapest
and best mode of hanging the drum and centre pieces, fly wheel,
&c.; the old mode of hanging these fittings with a number of keys
in each is not to be commended, and has now become obsolete.
The feed pump is of the plunger type, and is bolted down on
the top of the bed plate at the end nearest the main crank shaft.
It is desirable that the plunger should be of brass or Muntz metal,
connected by means of a wrought-iron rod to the end of the gudgeon
for the crosshead—an eye is forged on this rod, and accurately
bored out to take the end of the gudgeon, and held in position with
a set screw. When the pump is placed well back, the plunger is
better balanced at the extreme IN stroke, as there is a considerable
distance from the pump gland to the centre of the crosshead while
in that position; and the plunger by this arrangement is not so
liable to droop, as it would do were the crosshead working quite
close up to the pump gland. The suction and delivery valves and
seatings are of brass, fitted into cast-iron valve chests; an escape
valve should also be fitted, loaded with a certain weight, so that
when the attendant shuts the feed valve on the boiler, the water is
forced past the escape valve, and finds its way by a pipe connection
into the pond or cistern from which the supply is drawn. An air
chamber should be fitted to some convenient part of the feed pipe,
as by this means the flow is more uniform, and tends to lessen the
vibration in the pipes when the engine is working at full speed.
As these pipes are sometimes subjected to the influence of hard
frost, the engine rarely going all night, they should be properly
clothed and protected with a non-conducting material; and a small
plug tap should be fitted, so that all the water may be run off
between the pump and feed valve placed on the boiler: these pre-
cautions taken, there is no fear of breakage occurring, as has too
often been the case otherwise; for when an engine is started in the
morning with the water in the feed pipe frozen a fracture must
take place. In many arrangements the ſeed pump is dispensed
with, the boilers being fed with a separate steam pump. The steam
pipes must also be protected with felt and canvas sewn over, to
prevent condensation The exhaust pipe (when the waste steam
248 MODERN STEAM PRACTICE.
is blown up the chimney) should be trapped at the end, by leading
it into a cast-iron cistern, fitted with a separate pipe into the
chimney, having a bend at the end for directing the waste steam
vertically; by this means much of the moisture is got rid of, being
retained in the cistern and run off by a suitable overflow pipe. In
this way the chimney is kept comparatively dry, and consequently
less liable to the deterioration caused by a blast of steam and water
blown into it. Some engineers prefer blowing off the waste steam
directly from the cylinder by a vertical pipe passing through
the roof of the engine house. By such an arrangement there is, of
Course, no steam blast to injure the chimney; but, on the other
hand, we lose its valuable aid in urging the fires, by causing a
partial vacuum in the chimney, which tends to supply through or
between the fire bars the necessary quantity of oxygen to effect
complete combustion.
The drums for the round wire ropes must be of large diameter.
They are of two kinds, conical and parallel; with the conical the
strain on the engines is better regulated. The lift is taken on the
smallest diameter, and the rope unwinds for the empty cage from
the largest diameter; consequently the latter balances in a measure
the ascending cage fully loaded, which is lifted slowly, throwing
less strain on the machinery. The drums are constructed of light
cast-iron wheels, each with eight strong arms, and arranged for
bolting together in two halves; a side flange is cast on to receive the
wooden battens, to which they are securely bolted. For the conical
drums there are two wheels of the same diameter, one at each end,
with flanges bevelled according to the hollow given to the cone,
and a smaller wheel is placed between them, having a flat rim; the
wood is laid quite flat on the inside, and for the outer diameter it is
cut to the cone required. The wire ropes are put on one above
and another below the drum, and are wound from its longitudinal
centre, the cone increasing to the ends at each side. The side and
middle sheaves are keyed on the shaft similarly to an ordinary
fly wheel, and should be fitted with wrought-iron rings, shrunk on
the outer circumference of the bosses. It is preferable to fit a fly
wheel close up to the main bearing; it should be of sufficient weight
for the engine, and made of extra strength in the arms, as the
brake is generally applied on the periphery.
The most approved form of brake consists of wooden blocks
fastened to wrought-iron hinge pieces, vibrating on pins and joints,
STATIONARY ENGINES. 249
secured to the floor in the fly-wheel pit. There are two fitted
under the wheel at each end. On the vibrating centre or fulcrum
of the long brake lever, a shaft carried on suitable bearings has a
double-ended short lever keyed on it, fitted with eyes and pins;
from these joints two side rods pass along, one on each side of the
fly wheel, and are secured to eyes on the wrought-iron pieces for
taking the friction blocks. Both brakes are so fitted, and with a
movement of the long lever the off-brake is drawn against the
periphery of the fly wheel, while the near one, fitted with short rods,
transmits a compressive strain, which of course the short connecting
links are better calculated for. With parallel winding drums the
arrangement is somewhat different. The drums have two side
sheaves for each; the two centre ones are placed sufficiently wide
apart to take a strong ring which is fitted to the skeleton sheaves,
this serving as a brake wheel, which in this arrangement is acted
on by a strap lined with wood placed underneath it, fitted with
suitable levers and shafts. Some authorities consider that this
brake wheel is not so well placed as in the former example, for the
strain acting on the centre of the shaft between the two engines
tends to throw undue stress on the shaft. But we must not lose
sight of the fact that when a separate fly wheel is used, placed at
the side of the drum, the adjoining bearing has more duty to per-
form, and it may be concluded that with extra strength given to
the shaft, to resist the pressure of the brake, the intermediate brake
wheel can be used with advantage, equalizing the wear on the
bearings, which is an important consideration in coupled engines.
In some examples where steam pumps are fitted, instead of the
usual feed pumps, thus simplifying the engine considerably, the feed
water is heated in its transit to the boilers by passing through a
number of small tubes fixed in plates, inclosed in a cast-iron cylinder;
the exhaust steam enters this cylinder, surrounds the tubes, and
transmits its heat to the cold water passing through them. Some
engineers blow the exhaust steam into a receiver, and the cistern
placed at the end of the exhaust pipe for collecting the condensed
water is a similar contrivance: the steam is blown over the surface
of the water, which becomes thoroughly heated. Of course the
steam that is not condensed is blown up the chimney in either of
those feed-water heaters. In the former plan there is no trouble
attending the operation, as the-feed water is simply passed through
the small tubes in its transit from the feed pumps; but the latter
25O MODERN STEAM PRACTICE.
*
requires attention to keep the water in the cistern at the proper
level, and in many situations the water would require to be raised
by a separate pump, or the cistern placed low enough to admit of
the water running in from an adjoining pond. -
We give a Plate of a Winding Engine of approved construction,
erected in 1881 for a pit belonging to the Benhar Coal Company,
at Niddrie near Edinburgh. -
BLOWING ENGINES.
OVERHEAD-BEAM BLOWING ENGINE.
We will now consider that form of engine used for blowing air to
the furnaces for melting iron ores, technically termed the “blowing
Fig. 151.-Blowing Engine. Side Elevation.
engine.” This engine delivers the air into a receiver, the pressure
varying from 2 to 4 lbs. per square inch, or a mean of say 3% lbs.,
that being the pressure on the large piston of the blowing cylinder.

;#:i
A A
B B
CC
D D
E. E.
FF
H. H.
I
Cylinders.
Cylinder Covers and Stuffing-box Glands.
Piston Rods
Prolongation of the Piston Rods.
Steam Valves.
Exhaust Valves.
Valve Casings.
Double Eccentrics and Link Motion.
Suspension Link.
Weigh Shaft.
Lifting Rod in communication with the
Starting Handle.
Starting Handle.
Handle for Stop Valve.
Shaft for Stop Valve.
Lever Handle for Brake.
Shaft for Brake Gear.
Brake Blocks (of wood).
Fly Wheel or Drum.
Turned Parts for Brake Blocks.
LONGITUIDINAL
Diameter of Cylinders, 3 ft. 4 in.
Length of Stroke of Pistons, 5 ft. 6 in.
Diameter of Winding Drum, 18 ft.
SECTION,
{
H
R R Crossheads and Gudgeons.
s's Connecting Rods.
TT Wrought-iron Cranks.
U U Wrought-iron Crank Shaft,
v v Sole Plates.
ww Pillow Blocks.
xx Motion Bars.
Y Y Stop Valve and Cteam Pipe.
z Exhaust Pipe.
z’ Foundation of Concrete.













STATIONARY ENGINEs. 25 I
A variety of forms of blowing engines are now in use, viz. the
beam, the side-lever, the vertical, and the horizontal, which we will
notice in succession. .
The high-pressure beam engine has been largely used for blowing
purposes. Its main beam is cast in two halves, held together by
distance pieces; the steam cylinder is placed at one end of the
beam, and the blowing cylinder at the other. The connecting rod
and crank shaft are placed between the steam cylinder and the
main centre of Oscillation of the beam, and the cold water and
feed pumps between the blowing cylinder and the main centre of
oscillation.
The steam cylinder is a plain
casting, with oblong branches
at the top and bottom for the
steam ports, which are made
as short as possible. When
the stroke of the piston is long
it is desirable to have the
steam valves so arranged that
the cubical capacity of the
passages on the cylinder side
should be as Small as practi-
cable, by which means much
steam is saved at each stroke,
as compared with Some ar-
rangements where the pas-
sages extend from the top to
the bottom of the cylinder. A Fig. 152.-Steam Cylinder and Cover.
square base is cast along with a Cylinder on, Steam ports. c. Cone plug. D, Cover.
the cylinder, having a hole in *...*
the centre for the boring bar to
pass through, which is afterwards filled up with a plug or cover. Part
of the base is hollowed out on the opposite side from that of the
steam ports, to give the necessary clearance for the main connecting
rod. The body of the cylinder has suitable belts cast on, and also
a projecting moulding near the top for supporting the platform.
The cylinder is firmly bolted down at each corner of the base plate
with long bolts, passing down through holes left in the foundations,
and secured at the under end with plates and cotters; these beam
plates extend across the structure from hole to hole. A cast-iron

252 MODERN STIEAM PRACTICE.
plate is laid down on the top of the foundation, having fitting
strips for correctly adjusting the vertical line of the cylinder, cor-
responding strips being left on its base for that purpose. This
makes a thoroughly good fixture, as these foundation plates spread
over a large surface of the stone or brick work, and the action of
the steam in the cylinder and motion of the working parts have
not so much tendency to abrade the stone and loosen the founda-
tions. The cylinder cover is generally an open casting, and should
be turned on the face; the surface is made steam tight by Scraping
the faces on the cover and cylinder, and interposing a thin coating
of red lead at the joint. A brass bush is fitted at the bottom of
the stuffing box, and also in the cast-iron gland. The flange of
the stuffing box has a raised part round the edge, to prevent the
oil or other lubricant from flowing over and dirtying the cover.
The cover is turned all over the exterior, and should be finished
bright, as it is then much more easily kept clean. The bolts for
the gland should be cut with a square thread, and have Square nuts,
as hexagonal nuts are not nearly so good for parts requiring such
frequent adjustment. -
The piston is of the usual description, and made very heavy;
§%
In
§ §§§
Fig. 153.−Piston for Steam Cylinder.
Z
%
Ż
A, Coned part for the piston rod. B, Junk ring. C, Metallic packing ring.
indeed, some engineers cast the body solid, with a view to balance
the large blowing piston at the other end of the beam. The pack-
ing ring should be in one piece; some use two rings, but this is not
required, and is decidedly objectionable, from the fact that there are
then four faces to be kept steam tight, whereas with one ring there
are only two. The narrow junk ring is accurately turned on the
fitting strips and corresponding parts on the piston, and is made
steam tight by Scraping the surfaces. The holding-down bolts are
screwed into nuts recessed into the body of the piston in the usual
manner. The piston rod is secured to the piston by means of a
coned part turned on the former, with a corresponding cone on the
latter, through which a cotter passes and tightly forces the piston
on the coned part of the rod. A better plan is to fit a nut on the







STATIONARY ENGINEs.
253
- top of the piston, having a screwed part on the piston rod, in which
case a recess needs to be leſt in the cylinder cover for the nut to
pass into, as the piston works closely up to the under side of the
cover and down to the bottom of the cylinder,
34 inch of clearance being quite sufficient be-
tween the piston and the end of the cylinder at
the top and bottom.
The valves are of the piston description,
fitted with metallic packing rings and junk
rings, similar to the main piston; and they
work in short cylinders placed in the nozzle
chest and bolted to the main cylinder. These
cylinders are cast with oblong ports, the bars
lying at an angle; by this means the rings
on the valves work more
evenly, and are not so
liable to form ruts as they
would be were the bars
placed vertically. These
valve cylinders are pro-
perly secured in the cas-
ing, which is bored out
Each valve is connected
fitted with a nut.
ſ * _{*
Fig. 155. — Nozzle Chest for
-ºl
N
|
º
*
|
Fig. 154.—Piston Valve and
Cylinder.
A, Piston valve. B, Metallic
packing rings. C, Valve rod.
D, Cylinder for valve.
E, Slot holes.
for their reception.
with a rod passing
C A. C through the centre of the piston, and secured
with a collar on the rod and a screwed part
The nozzle chest is arranged with one central
pipe, fitted with an expansion joint, and branch
pieces at the top and bottom for bolting to the
branches on the main cylinder of the engine,
as well as with the main steam branch located
at the top, so placed as to pass well under the
beams for supporting the platform. The steam
from the boiler is admitted into the central
nozzle between the valves, while the exhaust
Steam Cylinder. takes place on the top edge of the top valve
* ºn Pipe "ºlº and the bottom edge of the bottom valve; the
cylinders. C C, Exhaust
pipes. D D, Expansion joints. Steam from the top passing through pipes on
each side of the central pipe, which are like-
wise fitted with expansion joints. The exhaust steam from the top










254 MODERN STEAM PRACTICE.
of the cylinder passes down these pipes on each side, and they are
- connected to a cross pipe at the bot-
tom, which carries away the steam
from both ends of the main cylinder.
Two branch pieces are generally cast
on the cross pipe, for the convenience
of carrying away the exhaust on
either side, as may be determined on;
of course one of them has a blind
flange when completed. A cover is
fitted to the top nozzle chest, and one
to the bottom chest, the latter having
a short pipe turned on the exterior
surface.
The valve spindle passes down this
Fig. 156.—Stoup and Links for Valve Motion. pipe, and is connected to a solid end
A, Valve rod. B, Stoup. c. Guide pipe, on another pipe (technically termed
D, Strap. E, Side link.
- the stoup), by means of a coned hole
on the end of the pipe and a corresponding cone turned on the
valve spindle, fitted with a nut on the
end of the rod. On the top of the
stoup a stuffing box and gland is ar-
s
SS
N
§
#
N
NS
S
N
i
§
t
§
N:
N
º
%
ZZ
Ø
%
º B TI ranged, which makes it steam-tight
on the pipe that is bolted to the cover.
A. - - º
}^7 ºf ----------------------, A wrought-iron strap with two side
{ ::::::::::::::: ...}} pins is fitted on the stoup; these pins
`------- ~ ºf take side rods passing downwards to
P the pins on the levers of the weigh
E=- shaft.
The wiper shaft is supported at
both ends on bearings, and is fitted
! F----------------j with a strong cast-iron lever, having
,--------. ; ------------------, a pin for taking the eccentric rod,
: *-* with other two levers for the rods
connected to the stoup for working
the valves. A back balance lever,
Fig. sº-wiper shaft and Lever, for valve fitted with a suitable weight for bal-
Motion.—A, Wiper shaft. B B, Levers for valve. ancing the valves, is also provided
C, Balance lever. D, Eccentric lever. e. e y º y
and this is cast along with one of the
levers for the stoup connection; while a socket is left on the double



















STATIONARY ENGINES. 255
lever for the eccentric rod for the starting handle. These levers
should be made very strong and well feathered, and may be cast
along with the shaft, at least those for the stoup and balance
weight, but the eccentric lever should be made a separate casting
for adjustment. As the strain is light a cast-iron shaft and levers
may be adopted, when the weigh shaft is placed under the floor of
the engine house out of sight; but a preference ought to be given
to wrought iron in all valvular arrangements, as the material is
better adapted for any sudden strain, even although balance valves
are adopted.
The valves are actuated by means of an eccentric and rod. The
Fig. 158.—Eccentric and Rod.
A, Eccentric sheave. B, Eccentric rod and strap. c, Gab end.
eccentric sheave is so arranged that it can be put on and taken off
the main crank shaft without disturbing any other detail, and is
secured on the shaft with a key, as these engines only require to
be worked in one way. The eccentric rod is of wrought iron; one-
half of the strap is forged on with suitable lugs, and the other half
has lugs forged on for bolting the hoop together, with a single bolt
and nut for each lug. The rubbing surfaces are of brass, rivetted
to the strap, and then accurately turned to suit the sheave. The
lugs on the strap do not fit closely together, so as to adjust at any
time the rubbing surface. Suitable mechanism for lifting the
eccentric out of gear when starting the engine should be arranged.
This may be worked in a variety of ways; with hand levers, or
with a foot lever and rod attachment, which the attendant can press

256 MODERN STEAM PRACTICE.
on with his foot while his hands are free to move the steam regu-
- - - - - - - - - - - - - - - - - - - - - - - w - - - - - - - * * *
Fig. 159. –Bottom of Blowing Cylinder.
A, Bottom. B B, Valve openings. C,Discharge
passage.
lating valve and hand lever, which is
placed in a socket on the gab lever
secured to the weigh shaft. This valve
gear and mechanism for working it is
very simple, and suits admirably for
engines fitted with a crank shaft and
fly wheel.
The cylinder for the air consists of
a round barrel with flanges at the
ends, truly bored out and the flanges
faced; it is bolted down on a square
base, which has nine openings for ad-
mitting the air into the cylinder, and
one large opening for its exit. The
former openings are fitted with flap
valves, made of an elastic material,
and backed with suitable wrought-iron plates; while the non-return
NS: H–lº NN
§§. S
SS- SSSSSSSSSSSSI-RSSN-SS
N
Fig. 16o.—Cover and Valve Boxes for Blowing
- Cylinder.
A, Cover. B B, Valve openings. C, Valve chest.
D D, Discharge valve openings.
valves for the bottom are fitted on
the passages for taking away the air
under pressure. The base is securely
bolted down with one large bolt at
each corner, passing through holes
left in the foundation to the girder .
plates at the bottom, and the bolts
are secured with keys bearing on
these plates; thus the foundation is
firmly bound together with plates at
the top and bottom similar to the
steam-cylinder end. -
The cover for the cylinder is fitted
with a packing box and gland for
the piston rod, and has three open-
ings for the admission of the air, and
five smaller openings placed inside
of the branch cast on the cover for
the exit of the air. The former are
fitted with valve boxes, which are
bolted down on the cover, and have
a door fitted to the top of each box. There are four openings



STATIONARY ENGINES. 257
in each, and the valves are arranged nearly in a vertical position,
hinging from the top; while the valves for the exit of the air are
| | | || T A
I J -
%
|ſ
Fig. 161.--Top Chest for Blowing Cylinder. Fig. 162.-Bottom Chest for Blowing Cylinder.
A, Top chest. B, Passage on the cylinder cover. A, Passage for cylinder. B, Bottom chest.
placed quite flat on the cover, and are secured—as all these valves
are—with bolts and nuts, having a narrow strip of plate for the nuts
to bear on at the hinge.
The top and bottom chests for taking away *-*
the air are formed of separate plates bolted .
together like a tank, and the joints rusted with { |
a cement made of fine cast-iron borings, sal -
ammoniac, and sulphur. The proportions used
for this cement are—sal ammoniac, 2 parts;
flower of Sulphur, I part; cast-iron borings,
2OO parts. It requires some time to set, and
makes a first-rate joint. The top chest is
bolted to the flange cast on the branch, and
the bottom one is let into the socket cast on
the base plate and then rusted up, and is fitted
with an inclined plate between the socket and
the bottom discharge chest—this plate having B
four openings for the non-return valves. The 2. N
top and bottom chests are connected by means
of a circular column, securely bolted at the top ºpianº Air
tº e º tº e º Chests for Blowing Cylinder.
and properly jointed, no expansion joint being, pºems, pipe. B, Loose ring.
required. The pipe for leading the air to the
wrought-iron receiver is fitted to the bottom chest, the line of
piping being circular.

17
258 MODERN STEAM PRACTICE.
The piston for the blowing cylinder should be light, yet strong.
It is fitted with a narrow junk ring for pressing down the packing,
- and held down with bolts and
nuts let into the piston. The
biston rod has a cone fitting into
a corresponding cone in the pis-
ton, and is secured with a plain
cotter passing through the boss
of the piston and rod.
C We will now consider the de-
tails for actuating the pistons of
the steam and air cylinders simul-
taneously. The main beam is
cast in two halves, and held together by cast-iron distance pieces
with flanges for bolting to the halves. All the holes for the main
gudgeons should be accurately bored out, and the gudgeons turned
to fit. The one for the main connecting rod has collars turned on
it, and should be placed in position before the beams are bolted
* * * * * * N N * * * * * *
N N N &
§ Tº-T
§ SS SNSSSSSSSSSSS
N
N
SSSNSNS §
Fig. 164.—Piston ſor Blowing Cylinder.
A, Piston, B, Junk ring. C, Packing space.
Fig. 165.—Main Beam.
A, Beam. B, Steam cylinder end. c, Air cylinder end. D, Boss for connecting-rod gudgeon.
together; all the other gudgeons, excepting those for the feed and
cold water pump, have the journals on the outside of the beam,
and can be put in at any time; they are held in position with
keys. Some engineers prefer fitting four keys on the main gud-
geons, the hole being left larger, and after the keys are fitted lead
is run in, filling up the space; but this does not make such good
work as boring out the hole the exact size. For heavy cast-iron
beams of all descriptions, neat wrought-iron hoops should be shrunk
on the main boss, thereby binding the part that takes the whole
strain that is transmitted through the beam.
The pillow blocks are of the usual description, fitted with brasses,





STATIONARY ENGINES. 259
& which are secured by means of covers and bolts; a broad base is
cast on the pillow block, and bolted at the ends to the spring beam,
f \
Fig. 166.—Pillow Block for the Gudgeon of the Main Beam.
A, Pillow block. B, Boss for holding-down bolt.
while the large central bolt passing down through each column also
passes through a hole in the spring beam and base of the pillow
blocks, the nut bearing on the top of the base plate—thus firmly
bolting the pillow blocks, spring beam, entablature, and columns
together.
The spring beam is a light frame of cast iron running the entire
length of the engine house, and is built into the walls at the end.
The part inclosing the beam is formed as a half circle at the ends,
and in long spring beams a cross beam runs across the engine
house at each end, and is built into the side walls. The spring beam
proper ends at this cross beam, but its continuity is maintained by
bolting girders to the ends, which are built into the walls; these
and the cross girders are placed in mainly to support the spring
beam and carry the floor. In some cases stone flags are laid down,
but open cast-iron foot plates are preferable, and when neatly
executed give a light and airy appearance to the engine room.
When the engine is under repair, heavy weights must not of course
be placed on such a floor. Planking should be laid down on the
top of the beams which run across the engine room for carrying the
cast-iron floor plates; they should be made with thin raised parts,

26O MODERN STEAM PRACTICE.
with side flange pieces. By this means the floor plates are sup-
ported, and kept slightly apart from one another in the length of
Hº-su-H =
D - D
Fig. 167.—Spring Beam.
A, Spring beam. B, Cross beam. cc, Pillow-block seats. D D, Bosses for holding-down bolts.
the building, but across the building they are simply placed end
to end. - - - -
The entablature placed between the spring beam and the top of
the columns runs across the building, and is built into the side walls,
and securely joggled and bolted to the spring beam. It is best to
form the entablature in two pieces, which are placed a short dis-
tance apart, and are hollowed out to take a projection cast on the
top of each column. All these longitudinal and cross beams are
supported by two columns, which rest on cast-iron plates laid on

STATIONARY ENGINES. 261
the top of the foundation; each column is bolted down with one
central bolt passing down to the bottom of the foundations, and a
cross plate takes both of the bolts, which are secured at the ends
º
||
|| ||
F- -
)
I
-,
|--
H
JE
*d
Fig. 168.—Pillars and Entablature.
A, Pillar. B, Recess for bolt heads. C, Entablature. D D, Hollows for pillars, E, Wall box.
with proper keys, like all the main holding-down bolts for the
cylinders and crank-shaft arrangements.
The pillow blocks for the crank shaft are fitted with thick brasses
and strong caps and bolts, and at the crank end a plate is laid
down, butting against the steam cylinder and central pedestals of
the foundation. This plate has fitting strips cast on it with the
necessary joggles for fitting and Securing the blocks at the ends;
holes are also cast in it for bolting the pillow block to, and for the
º

262 MODERN STEAM PRACTICE.
holding-down bolts which pass down through the foundation. At
EG O 5-
Fig. 169.-Pillow Block for Crank Shaft.
A, Pillow block. B, Bed plate.
the other end of the crank shaft a plate is let into the side wall, a
proper arch being formed in the wall for its reception.
The cramé shaft and crank
are of wrought iron, the latter
being bored in the main eye,
somewhat smaller than the
part of the shaft where it is
shrunk on. The crank is
slightly heated for that pur-
pose, it is then slipped on the
shaft, and cold water poured
over it, thus shrinking it
tightly on. The shaft should
be only a very little more in
diameter than the eye, as
when too much is allowed it
is apt to strain the material
and weaken the eye. The
crank and shaft should have
a keyway cut prior to the
operation of shrinking on, and when it is cleaned out quite smooth
'* * * * * * *, * * * * * * *
Fig. 17o.—Main Crank.
A, Crank, B, Crank pin rivetted in.


STATIONARY ENGINES. 263
and fair the key is driven tightly in with a few strokes of a sledge
hammer, and then cut off and filed quite smooth at the ends. The
crank pin is held firmly in its eye by heating the eye and driving
the pin in with a hand hammer, and then pouring water over it, the
eye contracting and firmly binding the pin, which is then rivetted
over at the end, a part being turned out in the pin for that purpose.
The main connecting rod is generally of wrought iron. turned
from end to end, except
the square parts for tak- Sº
ing the straps, which are
fitted with brasses, having
a jib and key, with a screw
turned on the key, which
passes through an oblong
hole in the bent part
formed on the jib, the
screw being fitted with a | ºrſ
nut on each side of the * º
jib. The rod is finished º
bright all over, or at least S- %ź
it should be turned all Fig. 171.—Connecting Rod.
over and painted. Some A, Body of rod. *. * §: and cotter. D, Brasses.
connecting rods for the 2 *-* * * *H*e
blowing engine are made of oak, with wrought-iron straps on
each side, well bolted and hooped, and a metal piece at each end
securely bolted through the straps; this piece is for the brasses to
abut against. The latter are held in position with jibs and keys.
Although this form of connecting rod has not such a handsome
appearance as the metal one, yet it answers the purpose very well.
There is but little strain on it, as it merely (in connection with the
crank) changes the reciprocating motion of the pistons,—in fact, it
should just be made stiff enough to resist the strain at the dead
centre, as it is termed, elsewhere it merely imparts motion to the
fly-wheel shaft. It must be borne in mind, however, that a wrought-
iron connecting rod balances the heavy piston of the air cylinder
much better than one made of lighter material.
For convenience of transportation the fly wheel is built up in
segments. Its central part is cast in one piece, and suited for eight
arms, each arm having its segment cast along with it. These seg-
ments are dovetailed into one another at the joinings, and then






264 MODERN STEAM PRACTICE.
-
firmly secured with oak and thin iron wedges; the same mode of
fastening the arms into the central part being adopted. Of course
sº
N
Fig. 172.—Fly Wheel.
a, Boss. B, Wedging space for arm, c, Arm. D, Rim. E, Dovetail at end.
there are other ways of fastening with bolts and nuts, used for fly
wheels for general purposes. The boss is keyed on the shaft with
a number of keys; but it is preferable to bore out the eye the same
diameter at the raised part of the shaft, where it is fitted on with
four keys, and a wrought-iron hoop should be shrunk on each side
of the boss; by this means the keys can be firmly driven home
without danger of splitting the boss, although there is not much
risk of this when the metal is properly proportioned and care is
taken to fit the keys; they should in the first instance be driven
with a hand hammer until nearly home, with the surface bearing
all over and filed quite smooth, then a few blows with a large
hammer are given to complete the operation.






STATIONARY ENGINES. 265
The piston rods of both cylinders are connected to the beam by
Fig. 173.-Crosshead.
A, Cast-iron crosshead. B, Gudgeon. C, Collars. D, Piston rod. E, Jib and cotter.
cast-iron crossheads and wrought-iron side links, and the vertical
A, Main link. B, Distance pillar. C, Jibs and cotter. PP, Plates. E, Back link,
F, Cotter for brasses. .


266 MODERN STEAM PRACTICE.
line is attained with the ordinary parallel motion, having fore and
back links, parallel bars, radius rods, and cross gudgeons for the
back links. The cast-iron crossheads are turned all over, and are
secured to the piston rods with jibs and cotters; on each side a
cast-iron ring and thin brass collar is laid on the gudgeon, which
is secured with a key at each end; the outside bearings are for
the main links, while the large eye of the parallel bar is placed
between the main links and the brass washers.
The main links (Fig. 174) are plain wrought-iron straps, fitted with
brasses at the top and bottom, having a distance column between
them, bearing on wrought-iron plates fitted between the flanges of
the brasses at the bottom of the top pair and at the top of the bottom
pair; these brasses are held in position with two jibs and one key, a
screw bolt being formed on the bottom jib, fitted with two nuts, one
on each side of the eye formed on the end of the key, an elongated
hole being made in the eye. The straps in some cases are turned
all over on the Outside, and oil cups formed on their tops; when got
Fig. 175.—Bull's Eye and Cross Shafts for Parallel Motion.
a, Cross shaft for cold-water pump rod. B, Bull's eye for cold-water pump rod. C, Cross shaft.
up in first-class style they add greatly to the beauty of the engine.
The back links are two plain round rods; the one for the steam
cylinder has eyes forged on the ends, fitted with brasses held by a
single key, and the one for the air-cylinder end has an eye at the
middle for taking a bent cross bar, to which the cold-water pump
rod is secured. The bottom bar has an elongated eye at the middle
for the rod to pass through, the cross bar for the back link of the

STATIONARY ENGINES. 267
steam-cylinder end being quite plain. The parallel bars are fitted
to the crosshead and to the cross bars on the back links, the brasses
being adjusted with a single key;
the radius rods are similar, and \ |
work on a pin fitted to a bracket
which is secured to the spring
beam at the cylinder end, and
the other eye takes the cross bar
for the back links. In setting out
this parallel motion, the length
of the links from centre to centre
is one-half of the piston stroke;
N A /
[]| ||
Fig. 176.-Bracket for Parallel Motion.
A, Bracket. B, Pin secured with nut.
the centre for the back links on the beam is equidistant from the
end of the beam and the centre of vibration. The parallel and
radius rods are exactly this length
from centre to centre, or the dis-
tance from the back-link centre to
the end centre of the beam; the
true line of the piston rods being
one-half of the versed sine of the
chord contained by the full arc
delineated by the travel of the
beam, taking the distance from the
end centre to the centre of vibra-
tion as the radius.
The cold-zvater pump is a plain
open barrel, fitted with a suction
valve of leather, stiffened with
wrought-iron plates at the top
and bottom, rivetted through and
through, and hinged on a separate
conical valve seat. A cross bar,
having an eye at the top, is fitted
for holding down the leather, and
for drawing out the valve and
seating; this is secured to the
latter by a cotter passing through
the shank forged on the cross bar,
º
>
:
s
=
Fig. 177—Parallel and Radius Rods for Parallel
Motion. - A, Parallel rod. B, Radius rod.
the cotter bearing on the under side of the web cast along with
the seating. The bucket is fitted with a valve of a similar descrip-



268 - MODERN STEAM PRACTICE.
tion. The packing of the bucket is a plaited gasket, or gutta-
percha rings may be adopted, and kept to the circumferential sur-
face of the barrel by the hydraulic pressure of the water, a small
hole being bored at the top in communication with the recesses
left in the bucket. The pump rod is connected to the cross shaft
placed at the centre length of the back link, passing through an eye
formed on the shaft at the bottom end. The water is pumped into
a cistern provided with an overflow pipe, the exhaust steam passing
over the surface of the water and then escaping through another pipe
into the atmosphere; by this means
the feed water is heated before it is
forced into the boiler by a plunger
pump, the rod for working it being
connected directly to the beam by a
gudgeon passing through it, and to the
plunger with a pin joint. The valves
and their seatings are of brass; and
a relief valve should be fitted, loaded
with a weight, to return the water
into the well or pond from which it is
drawn by the cold-water pump. This
of course is only required when a re-
gulating valve is placed on the boiler;
but should the valve for regulating
the supply to the feed pump be placed
on the suction pipe, a relief valve may
be dispensed with. In either case,
fº however, it is desirable to have one
Fig. 178.-Feed Pump. fitted close to the pump, so that in the
a Pump. , , Plunger. C. §§ctiºn valve event of the water in the feed pipes
D, Delivery valve. E E, Brackets. e e tº e
freezing the line of piping may not
be damaged; and to guard against this evil, a small plug tap
should be fitted to the line of feed pipes, and so placed that all the
water may be run off between the check valve on the boiler and
the pump.
The steam-regulating valve fitted to the nozzle chest should be
placed so that the attendant can reach it easily when starting the
engine. It consists of a sluice valve of brass, fitted on a cast-iron
face, accurately planed and scraped to a true surface,—the valve
chest being fitted with two covers to facilitate the operation of
sº
%
ſº





STATIONARY ENGINES. + 269
scraping truly. One of these covers is fitted with a packing gland
for the valve rod, which is actuated with a lever handle having a
stud fitted to the
valve box, with a
joint and pin for
taking the starting NS
handle. The valve ==
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rod is secured to - %
the valve with a
pin passing through two snugs cast on the
valve, and has a slot crosshead keyed on the
outside, which the handle passes through.
The arrangement of the boilers for this
engine is described in the section treating on
boilers (p. 39). Three egg-ended boilers
were supplied, each 38 feet in length and
5 feet 7 inches in diameter. tº
In some examples of blowing engines erec- Fig. 79–steam regulating valve.
ted at the Dowlais Iron Works the general a, Valve chest B, Valve
arrangements are the same as the foregoing. c, Handle.
The beam is supported on a wall carried up from the foundation,
with a cast-iron wall box on which the pillow blocks are fitted.
This pedestal is secured by long bolts and nuts passing through a
plate at the bottom of the foundation; these bolts, passing from the
top to the bottom, firmly bind together the lever wall. The pillow
blocks are securely bolted and joggled to the wall box, and are fitted
with brasses, but there are no caps, the brasses being held down
with jibs and cotters passing through the sides of the pillow-block
frame. Wooden spring beams are substituted instead of cast iron;
they are let into the box on the lever wall, and pass along to the
end walls of the engine house; transverse beams also are secured
to the longitudinal ones for supporting the flooring. The beam is
fitted with parallel motion, the main links taking the crosshead of
the piston rods being placed between the beams, as are also the
back links. The parallel bars and radius rods are fitted outside
of these, the latter taking a pin on a cast-iron bracket bolted to
the spring beam.
The steam cylinder in this example (Figs. 18O, 181) is 55 inches
diameter, stroke of piston I 3 ft.; number of strokes per minute, 20;
steam pressure, 60 lbs. per square inch. An ordinary slide valve
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27O - MODERN STEAM PRACTICE.
worked by an eccentric is fitted, having a gridiron expansion valve,
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are formed in one casting, each having a separate cover; they are

STATIONARY ENGINEs. 271
- placed at the bottom of the cylinder, with a connecting pipe fitted with
an expansion joint, forming the passage to the top of the cylinder.
A separate slide valve is also fitted for starting the engine, which is
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Fig. 18r.—Blowing Engine at the Dowlais Iron Works. End Elevation.
worked by hand; but the main slide valve has the ordinary eccentric
motion, with weigh shaft side rods and crosshead overhead, the
valve rod being guided at the top by a stud placed on the passage
between the top and bottom of the cylinder. The valve rod passes




272 MODERN STEAM PRACTICE,
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through a stuffing box on the under
side of the valve casing. The
expansion valve rod also passes
through stuffing boxes at the top
and bottom, and may be actuated
by an eccentric or cam motion.
The pedestal for bolting the cylin-
der to rests on massive frames of
cast iron, and is raised somewhat
above the line of the crank shaft;
the castings under the cylinder
weigh 75 tons, and the foundations
contain IO,OOO cubic feet of lime-
stone in large blocks; thus securing
a firm bedding for the machinery.
When the main parts of such heavy
castings can be run from Smelting
furnaces where the engine is to be
fitted up, of course cast iron is
largely used; but where transport
is necessary recourse must be had
to the usual mode of building the
foundations with stone or brick-
work laid in cement.
The cramé is of cast iron, but the
shaft is better of wrought iron, al-
though many cast-iron ones are
in use. The pillow block for the
crank end rests on one of the
frames to which the cylinder pe-
destal is bolted; the other end of
the shaft passes through the side of
the engine house, and is supported
by a pillow block resting on a mas-
sive wall plate.
The fly z0/zeel is 22 feet in dia-
meter, weighs about 35 tons, and
\ is fitted up in segments in the usual
manner, the arms being fitted into
D, Slide valve. E, Expansion valve. F, Small valve for moving the engine.









STATIONARY ENGINES. 273
a large centre piece, and securely dovetailed into the rim at the
extreme diameter.
The main part of the connecting rod is of oak, strapped with
wrought iron from end to end, well bolted together, and in addition
secured with a strong hoop shrunk on at the middle. Blocks of cast
iron are fitted to the ends of the rod for the brasses to bear against,
the blocks being bolted through and through the straps; and as both
ends of the rod are forked, the brasses are adjusted with deep jibs
and keys. The top end is placed between the beam, as in the
previous example.
The beam has a total length of 40 feet between the outside
centres, and is so arranged as to give a stroke of I 3 feet to the
steam piston and I2 feet to the air piston. It is cast in halves, each
half weighing 16% tons, the total weight on the centre gudgeon,
including all the minor details, being about 44 tons. The wall for
supporting the beam and its adjuncts is 7 feet in thickness, built of
stone accurately dressed; the pedestal on which the main pillow
blocks rest is bolted down with twelve bolts, 3 inches in diameter,
taking a wall plate, the extreme breadth of the lever wall, placed
below the level of the floor, for the blowing-cylinder end.
The blowing cylinder is 144 inches in diameter, stroke I2 feet; and
as the piston makes twenty double strokes per minute, the quantity
of air discharged is nearly 54,283 cubic feet per minute, delivered at
a pressure of 3% lbs. per square inch. The area of the entrance
valves is 56 square feet, and that of the delivery valves I6 square
feet. The cylinder is cast in two pieces, and is bolted down to the
bottom plate, which is strongly ribbed in the casting, and arranged
with a suitable number of openings for the air flap valves. This
bottom plate is supported on pillars of cast iron at convenient
distances all round, which are stepped on a massive cast-iron plate
resting on the top of the foundation, and to which it is bolted with
long bolts passing down through the foundations, and secured at
the bottom with keys bearing on a wall plate built into the stone-
work. The cover is fitted with valve boxes, as in the previous
example, the flap valves beating against the angular sides of the
boxes. The boxes are fitted with covers at the top, through which
the inside of the cylinder may be inspected. There are also fitted
at the top and bottom large entrance valves, placed vertically
immediately over and under the discharge passages. The non-
return or discharge valves are placed in a line with and immediately
18
274 MODERN STEAM PRACTICE,
opposite the large entrance valves, and are fitted to the discharge
chambers. The discharge pipe is 5 feet in diameter, it is carried
I40 yards in length, and acts as a capital regulator, providing a
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Fig. 183.—Vertical Section of Blowing Cylinder.
A, Cylinder. B B, Bottom valves. cc, Top valves. D, Top discharge valves. E, Bottom discharge valves.
F, Discharge pipe. G, Pillars for supporting the bottom plate of the cylinder.
uniform blast to the furnaces, the engine being calculated for Sup-
plying a blast to eight furnaces, whose diameters across the boshes
vary from 16 to 18 feet.
Eight boilers are supplied, of the Cornish description, each 42 feet
long and 7 feet in diameter, with a single flue, 4 feet in diameter,
running from end to end. The length of fire grate is 9 feet—which
is too long to manage properly.
SIDE-LEVER COMBINED BLOWING ENGINES.
High and low pressure combined engines have been successfully
adopted for blowing furnaces. The side levers, two in number, are
placed one on each side of the steam cylinders; the high-pressure





STATIONARY ENGINES. 275
.. cylinder being at one end, and the low-pressure cylinder at the
other end. The blowing cylinders are placed overhead, and rest
on stone pedestals built up from the foundation. The engine house
. . * * ~ * * ~ * * . . *
* * * ., “ . . * *, *.* -- r <^*,
Fig. 184—Side-lever Combined Blowing Engines, by Wilson of Patricroft.
is about 75 feet long, 60 feet wide, and 72 feet in height, and con-
tains three pairs of engines. *.
The high-pressure cylinder is 45 inches, and the low-pressure one
66 inches in diameter; the blowing cylinders are each IOO inches
in diameter; and the length of stroke for all the pistons is 12 feet.

276 MODERN STEAM PRACTICE.
Cornish valve gear, arranged for double action, is fitted to both of
the steam cylinders. The steam, after doing duty on the top of
the high-pressure piston, expands on the top of the low-pressure
piston (and vice versö), and then exhausts into the condenser; it
will therefore be understood that two steam valves and two exhaust
valves are fitted to each cylinder. The hand gear is placed on the
low-pressure cylinder, and is connected by rods running below the
flooring to the gear for the high-pressure cylinder; the attendant,
therefore, from one platform can actuate by hand all the eight valves;
or, in other words, the movement of the one set of gear for the
steam valves of the one cylinder controls the movement of the
steam valves of the other cylinder—the exhaust valves acting in the
same way. Thus it will be seen that, with a steam and exhaust
valve fitted at the top and bottom of each cylinder, the action will be
as follows: Supposing steam from the boiler is acting on the bottom
of the high-pressure cylinder, forcing up the piston, the lower
exhaust valve and top steam valve are shut and the top exhaust
valve open, while the top steam valve on the low-pressure cylinder
is open and the top exhaust shut; thus the steam expands from
the top of the small cylinder into the large one, at the same time
the exhaust valve for the under side of the low-pressure cylinder is
open to the condenser, the bottom steam valve being shut. The
reverse of this takes place on the downward motion of the high-
pressure piston. Thus the high-pressure piston is raised and
depressed by steam direct from the boiler, while the low-pressure
piston is raised and depressed by the exhaust steam from the high-
pressure cylinder. An additional benefit accrues from the final
condensation of the steam, as the top and bottom of the cylinder
are in alternate communication with the condenser; power is thus
gained and fuel economized. The arrangement of the Cornish
valve gear may appear complicated when applied to one engine;
but it must be remembered that this complexity consists merely
in an increase of parts, as the whole of the gearing is joined together
and works in unison.
The main side levers have a length of about 38 feet from centre to
centre, and each weighs upwards of 20 tons; they are connected to
the crosshead of the piston rod, common to both cylinders, by side
rods. The vertical motion of the piston rods and crosshead is main-
tained by cast-iron guides, the distance from the top of the steam
cylinders to the bottom of the blowing cylinders being about 17 feet.
STATIONARY ENGINEs. 277
The air pump is worked by means of a crosshead with connecting.
rods from the side levers; the -
plug rod for the valve me-
chanism is a continuation of
the air pump rod, guided at
the top with a bracket fitted to
the nozzle chest. It is essen-
tial for this class of engine to
have a travelling crane fitted
Overhead, so as to lift the pis-
tons, &c., for inspection or
repair.
VERTICAL BLOWING ENGINES.
Another example is the
vertical direct-acting high-
pressure engine, which differs
materially from the foregoing
in having no side levers or
beams. The blowing cylin-
ders are placed on the ground
floor, four strong cast-iron
pillars are securely fitted, one
at each corner, and carried up
to the top of the house, with
cross girders for carrying the
steam cylinder and fly-wheel
shaft. The blowing cylinder F F
is IO8% inches in diameter,
and the steam cylinder, placed
overhead, is 47% inches in
diameter; the stroke of each D
is 6 feet 63% inches. The fly-
wheel shaft is 25 feet IO inches
above the floor of the engine,
and the total height from the Fig. 185.-Vertical Blowing Engine at the Creuzot Iron
Works, dep. Saône-et-Loire, France.
base to the centre of the crank A, Blowing cylinder. B, Steam cylinder c, Crank shaft
shaft is about 44 feet 3 inches D, Fly wheel. E, Bottom of air cylinder. FF, Pillars.
The crank is connected by a rod to a crosshead working in guides,


278 MODERN STEAM PRACTICE.
taking the rod for the steam piston, which passes down through
a stuffing box at the bottom of the steam cylinder, and is con-
nected to the piston for the blowing cylinder. This class of
blowing engine has a fly wheel; the valve gearing is worked from
the fly wheel shaft, spur wheels being used to drive a cam shaft
which actuates equilibrium valves. The steam is admitted into the
cylinder at a pressure of 60 lbs. per square inch, and is cut off at
N/TNº.
Fig. 186.—Table Blowing Engine.
A, Blowing cylinder. B, Steam cylinder. C, Crank shaft. D D, Fly wheels. E, Air valve.
FF, Eccentrics for air valve, G, Eccentric for steam valve. H, Steam valve. I I, Side rods.
K, Crosshead. L, Guides. M. M., Air pipes.
about one-fourth of the stroke; the number of revolutions of the
crank shaft is about fifteen. The inlet and exit valves for the
blowing cylinder are arranged on the cover and bottom of the
cylinder; small flap valves are used, one-half of the area being for
the inlet, and the other half for the exit of the air, which is
delivered at a pressure of about 3 lbs. per square inch, and the
quantity is about 90 per cent. of the cubical contents of the cylinder
at each stroke, - -

• STATIONARY ENGINES. 279
Vertical Table Engine.—We shall now notice the kind of blowing
engines called “self-contained,” that is, those erected on one bed plate
carrying the whole of the engine. Of this class are the vertical table
engines, which are constructed for easy transport, all the parts being
as light as possible (Fig. 186). The blowing cylinder stands on a
pedestal bolted to the bed plate. The diameter of the cylinder is 30
inches; stroke of piston 2 feet 6 inches, making 80 strokes per minute.
These engines being small, a greater number of them must of course
be provided; and when large sizes are adopted the weight of the
various parts becomes a serious matter. The piston of the blowing
cylinder is packed with hemp, with a junk ring to press it a a
down. The openings for admitting the air into the cylinder
are formed on the circumference at the top and bottom; a ſº
projecting flange is cast on at the top and bottom, the bars ºf
between the opening being inclined, similar to the piston-
valve arrangement already described. The valve is of the
annular description, encircling the whole cylinder from top
to bottom; the rubbing surfaces are formed of brass rings
accurately bored out. The body of the valve is formed of thin
wrought-iron plates, securely fastened with a number of small bolts
to two cast-iron rings, which are bored out inside for the reception
of the brass packing rings. These rings fit the recesses in the
cast iron and face on the cylinder without any other packing; and
as they are cut through the wear can be adjusted with a thin slip
of metal or paper, and then properly secured with bolts, although
there is but little wear with this description of valve, owing to its
being perfectly balanced. The air from both ends of the cylinder
passes into the annular space between the cylinder and the valve,
from which it escapes by two pipes, placed opposite each other,
with flanges for jointing them to the cylindrical part of the valve.
The pipes at the other end slide on a vertical surface prepared for
them ; the motion is small, as the pipes are long, and the vertical
motion of the valve is not great. The valve is driven by two
eccentrics, one on each side of the cylinder, with rods taking pins
fitted to the top cast-iron ring. The steam cylinder is placed
on the top of the blowing one, and is fitted with a common valve,
with sufficient lap to cut off the steam at one-half of the stroke.
The piston-rod crosshead is fitted with two connecting rods taking
the cranked shaft, the crosshead working in suitable guides. Two
Fig. 187.1
i Section of Air Valve. — A, Valve. B, Plate for connecting valves.

28O MODERN STEAM PRACTICE.
fly wheels are fitted, thus less diameter is required for a given
weight, and it is found desirable to limit the weight to I ton. When
the means of transport is difficult no part of the engine should
exceed this weight. These engines do not require massive and
expensive foundations; they can rest on balks of timber with merely
a few bolts to hold them down. They can also be driven at a high
velocity, owing to the action of the valve preventing all blow and
jar in the working, when the lap and lead are properly adjusted:
a pair of them can be worked together, the cranks being at right
angles to each other, causing great uniformity in the flow of the
blast, and no regulator is required. A pair of these engines, with
a piston speed of 400 feet per minute blowing 36OO cubic feet of
air, make a very compact arrangement for small-power blowing
engines.
HORIZONTAL, BLOWING ENGINE.
Horizontal high-pressure blowing engines have been extensively
used. In the following example (Fig. I88), which is one of the largest
description, the diameter of the steam cylinder is 4 feet 3 inches,
with a stroke of 9 feet. The blowing cylinder has a diameter of
IO8 inches, and the length of stroke is the same as for the piston of
the steam cylinder, the number of strokes being about twenty-two,
giving a total speed of 396 feet per minute.
The steam valves (Fig. 189) are of the piston type, which are very
generally used for blowing engines, because they are perfectly
balanced, and therefore suffer little wear and tear, which is a great
desideratum with engines requiring to go day and night for a length-
ened period. The valves are cast together with a pipe connection,
each piston is packed with a single ring, which is kept up to the
working face by a spring; the junk rings are each secured with a
single nut having a thread cut on the valve spindle, which is central
with the valves. The valve casing is a circular casting; the steam
is admitted between the valves, and the exhaust takes place at both
ends. The valves are arranged so as to make the steam ports as
short as possible; and there is an annular ring round the piston, to
give free entrance and exit for the steam all round the circumfer-
ence of the valves. The valve rod passes through stuffing boxes at
both ends of the casing, and as the valves are placed at the side of
the steam cylinder, the motion for working them is direct, a plain
STATIONARY ENGINES.
281
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282 MODERN STEAM PRACTICE.
eccentric and rod being adopted, having a joint placed close up
to the guide block for the valve rod, carried up considerably
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Fig. 189.-Steam Valve for Horizontal Blowing Engine.
A, Valve. B, Valve rod. C, Packing ring. D, Connecting pipe.
beyond the stuffing box, thus lessening the length of the eccentric
rod.
The steam cylinder (Fig. 190) is of the ordinary description, with
projections cast on for bolting down to the bed plate. It is provided
with a cover and stuffing box at each end, through which the piston
rod passes, with recesses for the nut and collar that secures the piston
to the rod. The piston should be as light as practicable, and its
ends strengthened with ribs in the casting; the packing is metallic,
held up to the face with a number of short flat springs; the junk
ring is bolted down with bolts and nuts recessed in the piston in
the usual manner. To prevent radiation the cylinder and valve
casing are covered with felt and wood lagging; and straps of
wrought iron or brass are used to bind securely the wooden strips
placed over the felt. The main crank is of cast iron, and is con-
nected to the piston rod by a wrought-iron rod, with straps, jibs,
and keys at both ends, having a wrought-iron crosshead and gud-
geon with blocks working in cast-iron motion bars; thus one end
of the piston rod is truly guided, while at the back end it takes a
crosshead working into a slipper guide, to which the piston rod for
the blowing cylinder is securely cottered.
The blowing cylinder (Fig. I91) is a plain casting, with side flanges
for bolting it to the bed plate which runs the entire length of the









STATIONARY ENGINES. 283
engine. The piston rod passes through both ends of the cylinder,
and is guided with crossheads and slipper guides, as already ex-
:
plained. The diameter of the piston rod is greater than that for
the steam cylinder, which tends to carry up the piston. Some

284
MODERN STEAM PRACTICE.
engines of this class have a trunk passing through both ends in a
similar manner, by which means more bearing surface is obtained
for carrying up the piston, it being supported as it were with a
tubular beam,_thus reducing the wear and tear in the cylinder.
The air valves are arranged in the covers, and consist of round
Fig. 191.-Blowing Cylinder and Cover.
discs, working on suitable grat-
ings, with guards to limit the lift.
The valves for the entrance of
the air are placed centrally round
the stuffing box for the piston
rod, that part of the cover being
strongly ribbed in the casting;
and an annular chamber is cast
round the circumference of the
cover, which is fitted with valves
of the same description for the
exit of the air, a large opening
being left at the bottom, in con-
nection with the main pipes, &c.,
to the furnaces. Small covers
are fitted for the convenience of
inspecting the exit valves.
This engine is used to blow air
to two furnaces; the area of the
blowing piston is 63'O72 Square
feet, and it discharges 24,976
cubic feet per minute. As ample
rubbing surface in all the work-
ing parts has been well consi-
dered, this engine has been found
to be very economical in the
matter of repairs. The diameter
of the fly wheel is about 21 feet;
and as the whole of the ma-
chinery is built up on one frame,
from end to end, the foundation is laid in brickwork, with about
2 feet of stonework on the top.
This class of engine is certainly
the cheapest that can be supplied for heavy work; and the engine
house need not be so large as for the overhead-beam arrange-
mentS.

'STATIONARY ENGINES. 285.
ROLLING-MILL ENGINES.
Engines for driving rolling mills, &c., should be made strong, as
they require to run for weeks without stopping. The examples
shown in Figs. 192 and 193, of engines erected at the Dowlais Iron
Works, are unusually strong. Cast iron is largely used in their con-
struction. They are of the high pressure kind, coupled at right
angles to each other.
The steam cylinders are 45 inches in diameter, with a stroke of
Io feet, making 24 double strokes per minute. Each cylinder has
a common slide valve of brass, worked by an eccentric on the main
shaft. The expansion valves are of the gridiron sort, worked by a
cam on the main shaft, the steam being cut off at about one-third
of the stroke; an arrangement is made for throwing these valves
out of gear when the engines are doing heavy work. Each engine
is fitted with a small slide valve to be worked by hand, for the
purpose of starting and reversing.
The framing under the engines and machinery is of cast iron,
and consists of four lines, each 75 feet long, I2 feet high, and
21 inches wide, the whole weighing about 850 tons. The whole
engines are thus self-contained,—a very important point in this
class of engine.
Each beam is in two parts, each part weighing about 17 tons,
making the total weight of the beam when complete about 37 tons.
The two beams are supported upon eight columns, 24 feet long
and 2% feet in diameter, securely fastened at the bottom in deep
jaws cast upon the framing. Upon the top of each group of four
columns is a large and heavy entablature plate, which carries the
pillow blocks for the main gudgeons. Each column passes through
the entablature, the bosses at the junction being 24 inches deep;
these are bored out, and the tops of the columns turned, so as to
insure a perfect fit. The pillow-block brasses are secured and
tightened up by wrought-iron keys in the jaws of the pillow blocks,
which are bolted down on the entablature, and further secured with
joggles and keys.
The connecting rods are of oak, with wrought-iron straps; an
experience of forty years having proved that such rods are the
best, and more easily kept in repair than cast-iron ones, which are
286
MODERN STEAM PRACTICE.
liable to break, while wrought-iron rods are much heavier.
The
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oak rod, strapped with wrought iron, is better calculated to stand


STATIONARY ENGINES. 287
the severe and sudden strain, as the material possesses an elasticity
which tends to lessen the shock.
The driving-wheel shaft is of cast-iron, 24 inches in diameter;

288 MODERN STEAM PRACTICE.
the fly-wheel shaft is also of cast iron, with bearings 21 inches in
diameter. The diameter of the driving wheel is 25 feet at the pitch
line; the pitch is 7
inches, and the width
of the teeth 27 inches.
The diameter of the
spur wheel or pinion
on the fly-wheel shaft
is 6 feet, and the teeth
are strengthened by a
flange running up to
their points on each
side. The fly wheel
on the mill shaft is
Fig. 194.—Details of Fly Wheel, Framing, and Pinions. 2 I feet in diameter,
A, Fly wheel, showing mode of fastening. B, Frame, showing mode and weighs about 3O
of fastening, c, Pinions.
32;
- tons; it makes up-
wards of IOO revolutions per minute. The whole of the fastenings
both of the wheels and framing are of dry oak and iron wedges.
The blowing engines of this firm, described in the preceding
pages, are of 650 nominal horse-power, and weigh about 3OO tons,
including the bed plate; the pair of rolling-mill engines are of
IOOO nominal horse-power, and contain about IOOO tons of metal,
or I ton per nominal horse-power. This is very nearly double the
ordinary proportion, but it is the practice of this firm to make their
engines very strong, so as to avoid if possible the need of stoppages
of the works caused by a break-down of the machinery. The steam
for the rolling-mill engines is supplied by six Cornish boilers, each
44 feet long and 7 feet in diameter, with a 4-feet tube. The whole
of the plates are best Staffordshire, ºr inch thick; the total weight
of the boilers is about I2O tons.
These engines can drive one rail mill capable of turning out
IOOO tons of rails per week, another mill capable of making 700 tons
of rails or roughed-down per week, and one bar or roughing-down
mill, capable of making 200 tons per week; thus turning out a
total of about 2000 tons of iron per week. Two blooming mills
with three high-rolls and two hammers, are also worked by the
same engines. The saws and small machinery are driven by
separate engines, as also the punching and straightening machines.
The roofs cover a space of 240 feet by 2 IO feet, and are formed of





STATIONARY ENGINES. 289
corrugated black plates, No. 14 wire gauge in thickness. The spans
are 50 feet, the roofs being supported upon lattice girders of an
average length of 45 feet. The position of the columns is shown
on the ground plan, Fig. 195; and it will be observed that the entire
Tºg
vºr
;
Tº “T H H
-º-

&
gº
H|
[[T]
i H. H. [EE H
l -
A— -
Fig. 195.—General Arrangement of Rolling Mill. Ground Plan.
mill floor is free from obstruction. The flooring is of cast-iron
plates, I inch thick.
It had long been felt that the power of rolling wrought iron of
large section and great lengths had not kept pace with the require-
ments of engineers, who were frequently hampered in their designs
by the impossibility of obtaining iron of sufficient dimensions. For
engineering works of any magnitude bars of great length, consider-
able width, and moderate thickness are often required; and in the
ordinary mode of rolling, the length and width of the bar are
measured by the power of the engine and the time occupied in
rolling. It is obvious that to finish a bar quickly it is necessary
- 19
29O MODERN STEAM PRACTICE.
that it should be rolled in two directions to prevent delay; and
long and heavy bars can be thus rolled only by an engine of enor-
mous power, such as the large combined engines we have described.
A simple arrangement of rolls for working in two directions has
been adopted, by which means large bars of thin section are finished
>
>.
* * * * * * * * : * ~ * > *_^* * * : * ~ * * : * = a s
*
O
/.
~,
f
i
*
Fig. 196.-Arrangement of Rolls for rolling in two directions.
A A, Rolls driven from fly-wheel shaft. B B, Rolls driven from the fly-wheel shaft by a pair of
wheels C C, Fig. 194.
in one heat, as it is impossible to get such large bars into the fur-
nace to re-heat. In ordinary rolling so much time was lost in
bringing back the bar over the top of the rolls that it was found
impossible to make the larger sizes required for modern work, and
the plan was therefore adopted of having a second pair of rolls
running in the opposite direction, placed at the back of the first
rolls, as seen in Fig. 196, the lower one of the second pair being
raised just enough above the upper one of the first pair to clear
the bar in coming through, and the bar is passed back through the
second rolls, and then through the third, fourth, and fifth rolls as
may be required, as shown by the figures in the engraving. By


ROLLING MILL ENGINES. :
A High-pressure Cylinder. N Small Engine for Starting and Reversing. | O
B Low-pressure Cylinder. - o Starting Handles. * * - - - º
B' Steam Receiver. P Main Framing. --- -.
c c Piston Valves. Q Pillar Blocks with Steel Covers. |
D D Valve Chests, R Slide Bars.
E Valve Spindles. s Side Framing. |
F F Pistoms and Rod. T Oval Boss with Steel Hoop for securing Side Framing.
G Crosshead. - U Sole Plate. y
H Connecting Rod. v Auxiliary Slide Valve.
I Crank Shaft. w Escape Valves.
k Crank Discs. x Steam Pipe.
L. Double Eccentrics and Link Motion. Y Stop Valve. t
M. Weigh or Reversing Shaft. z Platform. LONGITUDINAL SECTION.
T
2
8
4.
O
t
#
3
#
5
#
& § Tº 11 12 feet.
| M |
HALF PLAN SECTION.
compound REVERSING ROLLING MILL ENGINES, STEEL COMPANY OF SCOTLAND'S WORKS AT HALLSIDE, NEAR GLASGOW.
CONSTRUCTED BY MESSRS. MILLER & CO., COATBRIDGE. &
















STATIONARY ENGINES. 29I
this means much time is saved over the ordinary method, with
the additional advantage of being able to manufacture bars up
to 60 feet long, for deck beams and keels of iron ships, in one
length without a weld, which can only be effected by having a high
speed of the rolls so as to complete the work before the bar gets
too cold. Reversing gear has been used for the rolls, but it is
, not to be recommended for them when running above forty-five
revolutions per minute, on account of the violent shock in reversing
the motion at a higher speed. To roll the length required for the
above purposes the speed at the Dowlais Iron Works is nearly
three times as great, the ordinary rolls running at I2O revolutions
per minute, and the others for large sections at I IO revolutions,
the rolls being of the full size—21 inches in diameter.
COMPOUND REVERSING RAIL MILL ENGINES,
AT HALLSIDE STEEL WORKS, NEAR GLASGOW. (SEE PLATE.)
“The engines are of the compound direct-acting horizontal type,
and have two high- and two low-pressure cylinders, whose diameters
are respectively 3 I inches and 50 inches, while the length of stroke
is 5 feet. They act directly on the rolls, by which arrangement
there is obtained a very high speed in the rolling operation with a
comparatively limited speed in the engines, the latter making from
fifty and sixty revolutions per minute. In each case the high-
pressure is placed in rear of the low-pressure cylinder, with which
it is connected by means of an intervening receiver. Laid upon
a bed of hard and tough blue clay, the foundation of these engines
—the total weight of which is some 3OO tons—consists of a solid
mass of Portland cement concrete, I2 feet or I4 feet in thickness,
and weighing between 500 tons and 600 tons. To this foundation
is fixed the soleplate, which weighs about 60 tons, and carries the
two pairs of cylinders, as also the two main frames. The latter,
which are of the box form, are, as will be seen in the Plate,
arranged so as to form a direct connection between the low-pressure
cylinders and the crankshaft, while the pedestals for the crankshaft
bearings are cast solid with them. Under each crankshaft bearing
the frame has a strong foot, which is not only bolted down to the
soleplate by two holding-down bolts, but which has in addition on
292 MODERN STEAM PRACTICE.
each side oval bosses, on which there are shrunk steel hoops for
tying down the central part of the foot to the soleplate; while the
ends are keyed in between strong snugs cast on the same plate.
Each crankshaft bearing
is provided with four
brasses, one above and
One below, and one on
each side. The fore and
aft parts are fitted with
movable wedge blocks
which take up the wear,
these blocks being pro-
vided with slotted eyes,
and being suspended by
means of bolts, which
are flat-headed, but of a
circular form. The top
brasses are adjusted with
set screws, and both they
and the bottom brasses
are held in position by
the top cover, which
bridges over the opening
in the frame. On each
side of this opening there
is a strong dovetailed
projection over which the
Cover is placed. Itself a
strong steel forging, this
cover is most securely
keyed in position, in ad-
dition to which it is
bolted down hard and
fast. The arrangements
:
:
|
just noticed result in the most rigid connection being effected
between the fore and aft portions of the engine framing. Be-
tween the crankshaft bearings and the guide bars the frames have
cast on them horn-like brackets, through which pass stay bolts
carrying suitable distance pieces, thereby securing at this part
of the framing an amount of rigidity quite equal to that which

STATIONARY ENGINES. 293
exists in the anterior portion. Inside the main frames there are
fixed the slide bars, which are adjustable, top and bottom, for
the purpose of taking up the wear. The upper one is made plane
throughout, but the lower one is of a trough shape. They are
made of the best forged steel, as, indeed, are all the working parts
of the engines.
The high-pressure cylinders are each fitted with a liner, the
space between this and the cylinder casting proper forming a steam
jacket; the low-pressure cylinders, however, are not jacketted. At
their forward ends each of the low-pressure cylinders is solid, and is
provided with a bracketted flange where it is in contact with the
main frames; and connection between the frames and the cylinder
ends is effected by means of bolts, no studs being used.
The valves of these engines are of the double-piston type. The
steam ports in the valve casings have triangular openings into the
valve cylinders, the valve pistons having a 9% inch stroke, and
being fitted with broad packing rings which are furnished with
cylindrical springs of a V shape. A tight-working piston is thereby
obtained, no escape of steam having been observed at any pressure
yet employed. The object aimed at in employing this type of
valve was to relieve the valve motion of the severe tear and wear
resulting from the use of unbalanced flat-faced valves.
The valve casings are placed on the sides of the cylinders in
order that they may be easily got at for inspection or in case of
repairs being necessary. The receiver formerly mentioned as inter-
vening between the high- and low-pressure cylinders of each engine
is immediately underneath the valve casings, and serves to catch
up any water that might otherwise enter the cylinders. The valve
spindles are of steel, and are jointed together by means of a box
coupling provided with cotters—an arrangement which allows of
the pistons and spindles being easily withdrawn for repairs and
replaced in position.
Steam is admitted into the high-pressure cylinder by the piston
valve entering between the pistons of the valve, and exhausting at
each end into the receiver. The distribution of the steam into the
low-pressure cylinder is similarly effected by its valve, the steam
entering at the middle of the valve, and exhausting at each end as
before. On the top of the low-pressure valve casing there is placed
a small auxiliary slide valve, which is worked from the link motion
of the main valve, and is in direct communication with the steam
2.94. MODERN STEAM PRACTICE.
of full boiler pressure, so that in the event of the rolls failing at any
time to ‘bite' when the ingot or bar in process of rolling is about
to enter, the driver can at once admit steam at full pressure direct
from the boilers upon the pistons in the low-pressure cylinders, and
turn it off instantaneously when the desired, effect is accomplished.
The valve just referred to consists of a D-slide working on the face
of a grid plate having openings similar to the valve ports, and
serving the purpose of a shut-off valve as well as a slide valve. The
motion of this valve is governed by the general link motion of the
engines, thereby insuring that there shall never be any uncertainty
as to the admission of the steam pressure on the proper side of the
piston. Both high- and low-pressure cylinders are provided at each
end with spring escape valves.
The crankshaft, which weighs IO)4 tons, is a fine steel forging,
and extends from the coupling to the mill to the right-hand engine,
or engine furthest from the mill. *
The crankshaft bearings are 18 inches in diameter, as are also
the Crank-pins.
The several levers by which the operation of starting, reversing,
&c., are controlled, are all within a few inches of each other, and
there is nothing to intercept the driver's view of what is going on
at the rolling mill, in front or in rear, or of the whole surface of the
engines. The engines are started and reversed by the aid of a small
steam cylinder provided with cataract regulation.
The engines we have been describing drive a 26-inch mill. They
are worked with steam at 120 lbs. pressure, and are capable of
easily developing 3OOO horse-power.
The steam for driving the engines we have been describing is
supplied by boilers of the locomotive type, these being three in
number. tº
The boilers have barrels 6 feet 2% inches in diameter, and each
contains 336 tubes, 2% inches in diameter by 12 feet long. The
tube surface in each boiler is thus 2640 square feet, while the firebox
surface is 17 I }% square feet and the firegrate area 30 square feet.
The fireboxes are each provided with a longitudinal mid-feather;
and in each case the roof of the inside firebox is stayed direct to
the casing by steel stays. The two front rows of these stays are
arranged with their upper ends in sockets, so as to allow for the
expansion and contraction of the tubeplate of the firebox. Arrange-
ments are made for a firebrick arch resting on angle-irons. No
STATIONARY ENGINES. 295
brick setting is required for the boilers, which are, instead, set on
cast-iron frames, which serve as stands on each side of the firebox
and smokebox, in this way again giving allowance for freedom of
motion during expansion and contraction. Each boiler is supplied
with a couple of Cockburn's 2% inch diameter open-flow pendulum
valves, each of which is loaded to a working pressure of I2O lbs. per
square inch. Prior to delivery the boilers were experimentally sub-
jected to a water pressure of 250 lbs. per square inch, while they
were also tried under steam to the pressure just mentioned They
have already proved themselves to be excellent steam raisers.
Practically the whole of the material of these boilers is steel; the
principal exception being that of the tubes, which are of iron."
THE CORLISS ENGINE.
An engine combining economy of working with a moderate first
cost must ever be of primary importance. The distribution of
steam effected by the ordinary slide valve actuated by the single
eccentric has, after long trial, been found to yield unsatisfactory
results; many ingenious improvements have been adopted, and
amongst these is the “Corliss’ liberating valve gear, named after
the inventor.
The characteristic features which are common to all the forms of
liberating valve gear may be thus briefly stated:—The steam is cut
off almost instantaneously by the agency of some force suddenly
called into play, such as a falling weight or the recoil of a distended
spring, the cut-off being regulated to the amount of work the engine
has to perform directly by the controlling agency of the governor
and the cut-off gear. The Corliss engine has separate pairs of
steam and exhaust valves, or altogether four for each cylinder.
They are of the cylindrical type; the lower of them, or the exhaust
valves, are wrought directly from the eccentric by means of a disc
plate and levers connected with the valve spindles; they remain
open during the whole period of the stroke, and are not affected by
the cut-off gear. The steam valves are likewise wrought from the
disc plate by levers, which open the valves at first, and so distend
a steel spiral spring whilst the steam is being admitted, till on the
* For the description and plate we are indebted to Engineering, vol. xxvii.
296 MODERN STEAM PRACTICE.
lever reaching a certain position it is tripped up by a peculiarly-

..STATIONARY ENGINES. 297.
shaped toe-piece liberating the spring, which by its recoil instantly
closes the valve. To guard against the damage that might
possibly arise from the too violent impact of the spring, it is closed
in a dash pot or vessel, to which the air is admitted by Small
holes, but prevented from escaping freely, and which forms a
cushion to check the impact of the spring and bring it gradually to
rest. The governor is connected with the cut-off gear by levers,
by which the point where the lever is tripped may be altered as the
cut-off requires to be hastened, or delayed according to the power
required from the engine. No throttle valve is therefore employed
to wire-draw the steam, and by a fall of pressure (involving a direct
loss of energy) to vary the power given out by the engine; but the
better expedient is adopted of supplying exactly the quantity of
steam required to perform the work. With what efficiency this
arrangement answers will be best gathered from the following
instance:—In a spinning factory a cogged wheel was instantaneously
stripped, the resistance portion of the work which it drove was thus
suddenly removed; but so perfectly did the engine draw the reduced
quantity of steam that on examination not a single thread was
found to be broken. Pumping machinery also affords another
instance, as not even the breaking of a spear rod sensibly affects the
speed of the engine. -
As has been already stated the Corliss engine has separate steam
and exhaust valves. Not to mention the good results in the work-
ing of the engines which are due to this arrangement, the separate
valves effect a direct economy, as each valve is kept at a constant
temperature, and the steam that enters through them directly from
the boiler is not cooled down as it would be if it entered through
the same passage by which the exhaust steam had previously
escaped, neither is the exhaust steam again re-heated by contact
with the hot steam valve; we have thus a direct saving of heat,
which in an ordinary slide-valve engine would be lost. The steam
lost by clearance when performing work is with these valves reduced
to a minimum. To test thoroughly the actual working of this
engine the indicator must be summoned to our assistance; and the
diagrams obtained from it will enable us to judge to what extent
the theoretical diagrams, or those that give the maximum amount
of power from a minimum consumption of steam, agree with those
realized in practice. The conditions necessary to insure the maxi-
mum of efficiency may be thus briefly stated:—(1) The ports must
298
MODERN STEAM PRACTICE.
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be fully open during the whole period for the admission of steam.






STATIONARY ENGINES. 299
(2) The cut-off must be rapid. (3) The back pressure must be a
minimum. (4) The steam must be admitted into the cylinder at
its full boiler pressure until the point of cut-off is reached. In the
Corliss diagrams these conditions are strictly fulfilled. The admis-
'sion of steam is indicated by a nearly perpendicular line, Figs. I98
and 199, and the cut-off must, with the means employed, be practi.
cally instantaneous. The diagrams exhibit a remarkably small back
pressure; this result, along with the constancy of pressure main-
tained until the point of cut-off is reached, is accounted for by the
large area that can be given to the steam and exhaust passages, as
the valves employed are of the whole breadth of the cylinder.
In ordinary engines a large expenditure of power is required to
move the valves; this loss of power is saved in the Corliss engine,
as one man with an ordinary starting bar can move the valves of
a IOOO horse-power engine against the full pressure of steam. As
every part of the engine is readily open to inspection, no difficulty
is experienced in examination, and repair of any of the parts
requiring it; but in practice the wear is found to be very slight.
The Corliss engine is economical in the matter of fuel, its con-
sumption being at the rate of 2% lbs. per horse power per hour, as
proved by experiment, a result that must go far to recommend it
to the favourable notice of manufacturers requiring steam-power.
HIGH AND LOW PRESSURE COMBINED BEAM
ENGINE.
The high and low pressure combined beam engine is much used
where great regularity of motion is required, more especially for
driving spinning machinery. This regularity of motion is due to
the steam expanding from the top of the high-pressure to the
bottom of the low-pressure cylinders, and vice versa, by which the
jerk at the commencement of the stroke of the piston is not so
much felt as in ordinary engines receiving the full force of the
steam on one side of the piston. The example illustrated, Fig. 200,
consists of a pair of engines, coupled at right angles, for driving the
machinery at the Royal Gun Factory at Woolwich. The diameter
of the fly wheel is 22 feet at the pitch line, the breadth of the teeth
I2 inches, and the pitch 3 inches, gearing into a pinion 4 feet
6 inches in diameter.
3OO MODERN STEAM PRACTICE.
Speed of the engine shaft, .......... e e s & sº e s e º e º e s e e s a 21 revolutions per minute.
Do. second shaft............. . . . . . . . . . . . . . . IO2 99. 9 y
Do. third shaft................... e.g. * * g g g g s e. e. I5O 3. 95
The total length of the shafting is about 932 feet, in parallel lengths,
the diameter of the pinion shaft being 8 inches, and that of the
M S -- .
*"... •
Fig. 200.—High and Low Pressure Combined Beam Engines of 8o horse-power collectively.
A, High-pressure cylinder. B, Low-pressure cylinder. C, Condenser and cistern. D, Cold-water
pump. E, Governor and feed-pump rod. F, Spring beam. G, Main beam. H, Crank
shaft. 1, Pinion shaft. K, Entablature. L, Columns. M, Stone pedestal. N, Foundation.
smaller line of shafting 3 inches at the end. The diameter of each
high-pressure cylinder is 15% inches, stroke of piston 4 feet 6 inches;
and the diameter of each low-pressure cylinder is 3 I inches, with a
piston stroke of 6 feet. The valve mechanism for those engines has
already been described, p. IO2, Fig. 5 I. The diameter of each air
pump is 2 I inches, with a stroke of bucket of 3 feet. The crank
shaft is of cast iron, the journals being IO inches in diameter and
I5 inches long, and the crank pins 5% inches in diameter and
7% inches long. There are three large boilers, 35 feet long and
7 feet in diameter, with two inside furnaces, and flues running the
entire length, 2 feet 6 inches in diameter, with return wheel flues of
brickwork. The steam pressure is 40 lbs. per Square inch, and the
thickness of the plates is as follows:— jº
Shell.................... }% inch thick. Flues................... 3% inch thick.
Ends.................... 38 93. Rivets.................. 34 inch in diameter.

STATIONARY ENGINES. 3OL
RULES FOR PUMPING ENGINES.
Horse-power—The standard fixed upon to represent the work
of one horse is 33,000 lbs. raised I foot high in one minute. To
find the horse-power, the quantity of water to be raised is reduced
to lbs. and multiplied by the height in feet, and the product divided
by 33,000 expresses the horse-power. A gallon of water weighs
exactly IO lbs., thus any number of gallons can be expressed in
lbs. by adding a cipher. Hence the following formula:
Gallons to be raised per minute x Iox height
33OOO
= horse-power.
But in practice about one-fifth must be added for the friction of the
engine. Examples:– -
Supposing IOOO gallons of water per minute is required to be
pumped through a line of piping to a height of I2O feet, and the
allowance made for the friction in the pipes is equivalent to a head
of water of 150 feet: required the horse-power. Thus we have—
Gals. per minute. Lbs. Height in ſeet.
IOOO_X_IO × I5O . . .
33OOO = 45'45
to which add ºth for the friction of the engine = 9'09
54'54 horse-power.
Again, supposing 1,440,000 gallons of water is required to be
pumped up in the 24 hours the same height, we have—
Lbs. raised
- 1 foot high per
Gals. in 24 hours. Lbs. Height. minute = H.P. mins. hours.
I,440,000 × IO x ISO -- 33OOO x (60 x 24) = 45°45
adding as before #th for friction of the engine.................. = 9'09
54'54 horse-power.
Another method gives the horse-power as follows:—
Gals, in 24 hours. Height. Constant.
I,440,000 × I5O + 4,752,OOO = 45°45
- #th added = 9.09
54'54 horse-power.
Supposing the quantity is given in cubic feet to be delivered in
the 24 hours, at the same height as before, we have—
3O2 MODERN STEAM PRACTICE.
Weight Lbs. raised
Cubic feet of a cubic Height I foot high per
in 24 hours, foot in lbs. in feet, minute = H. P. mins, hours.
230,400 x 62’5 × I50 + 33OOO × (60 × 24) = 45°45
#th added.................. = 9'09
54'54 horse-power.
The power required to raise water to any height is as the weight
and velocity of the water. Hence the following rule: Multiply the
perpendicular height of the water in feet by the velocity in feet, by
the square of the pump's diameter in inches, and then by 34I (the
weight of a column of fresh water I inch in diameter and I2 inches
in height), dividing the product by 33,OOO; the quotient gives
the horse-power, to which must be added one-fifth for friction,
and say one-fifth for loss, or two-fifths in all. For water-works'
engines 20 per cent. is allowed for friction, &c., and about 50 per
cent, for contingencies, making a total of 70 per cent, additional
power. -
When the diameter of the pump and velocity of the water are
given, to find the quantity discharged in gallons or cubic feet in
any given time. Multiply the velocity of the water in feet per
minute by the square of the pump's diameter in inches, and by
‘O34 for imperial gallons, or 'OO5454 for cubic feet, and the product
will be the number of gallons or cubic feet discharged in the time
nearly.
When the length of stroke and the number of strokes are given,
to find the diameter of the pump and the horse-power that will
pump or discharge a given quantity of water in a given time. First,
multiply the number of imperial gallons of water to be discharged
in the given time by 353, or the number of cubic feet by 22O1, and
divide the product by the velocity of the water in inches; the
square root of the quotient will be the pump's diameter in inches.
Second, multiply the number of gallons per minute by IO, or the
number of cubic feet by 62'5, and by the perpendicular height of
the water in feet, divide the product by 33,000, then add 4th to the
quotient, which will give the horse-power required. Example:–
Supposing 3,000,000 gallons of water is required in the 24 hours,
the stroke being IO feet, making 12 strokes per minute—
Gals. in the 24 hours. mins.
3,000,000 + 1440 = 2083 gallons per minute.
Strokes
Constant. Stroke. per min.
‘O34O9 × IO x I2 = 4'09 divisor,
STATIONARY ENGINES. 3O3
Gals. per min.
2083
4."O9 &
One-fourth more than the above is usually allowed for waste.
= V 509'2, the square root of which is 22-6 inches, the diameter of the pump.
Again, supposing the number of gallons per minute is required—
Square of the Strokes
Constant, pump's dia. Stroke. per min.
'o64O9 × 509'2 x Io x 12 = 2083 gallons per minute nearly.
To find the stroke of a pump:—
Square of the Strokes
Constant. pump's dia. per min.
'o64O9 x 5092 × I2 = 208:2 divisor.
Gals. per min.
2083
zºg. = 10 feet stroke of pump nearly.
Pumping water out of floating and other docks. – Given the
quantity in tons of sea water (35 cubic feet to the ton), the height
to which it is raised, and the time in hours that is allowed to dis-
charge it, to find the horse-power. Divide the quantity in tons by
the number of hours, which gives the quantity to discharge per
hour, and this divided by 60 gives the quantity to discharge per
minute; then take I.47 as the third divisor (147 tons=33,OOO lbs.,
the weight raised I foot high per minute), which gives the horse-
power required to raise the total quantity I foot high: multiply
this sum by the height at which the water is discharged, and the
quotient is the horse-power required to discharge the whole amount
in the given time, -to which must be added the loss from friction
and waste.
To find the diameter of pump required to discharge a given
number of tons of sea-water in a given time, with a certain velocity
(the usual speed of pump bucket being 160 feet per minute). Mul-
tiply the quantity by the constant 35, and divide the product by
the speed multiplied by the time in hours, and then by 60 for
minutes; the quotient is the pump area in square feet, which can
be subdivided by the number of pumps that are adopted.
Method for finding the horse-power of single-acting pumping
engines—Thus supposing the water is pumped into an air vessel
to a height of 252 feet, and making an allowance for the friction in
the pipe—say a total height of 285 feet—the diameter of the plunger
being 23 inches and the stroke IO feet, making Io strokes per
minute, we have as follows:
3O4. MODERN STEAM PRACTICE.
Area in sq. feet.
I)iameter of the plunger, 23 inches = 2:8852
Weight in lbs. of
Plunger area. Lift in feet. 1 cubic ft. lbs.
2.8852 x 285 x 62’5 = 51392
Now allowing #th to overcome the load on the air pump and the
friction of the engine, we have:
Load on the Length of Strokes
piston in lbs. stroke. per minute.
61670 × 10 × Io = 6167ooo
6167000
= 186 horse-power nearly.
33OOO
Approximate rule for power of Cornish engine.—A simple rule used
by some engineers for calculating the quantity of water delivered from
a given pump is as follows:—Let D = the diameter of the pump, then
D tº e e
†: represents the quantity of water in gallons delivered per I foot
stroke of pump nearly. Let S= the speed of the plunger of bucket
D2
3O
Let L = the lift in feet, and the horse-power will be thus obtained:
L IO (s
33OOO
= 16, stroke of pump-7.5, number of strokes per minute = 7.5,
lift = 190 fathoms = I 140 feet.
per minute, then S += the number of gallons delivered per minute.
D2
...). The following is an example:—Diameter of pump
Diameter of pump. Speed.
I6 × 16 :* = 8.5 x (7.5 × 7.5) = 478 gallons per minute.
1140 x 10 × 478
33OOO = 165 horse-power nearly.
The work done =
This rule evidently allows for waste in the pump, but one-fifth
must be added to the sum for the friction of the engine.
To find the area of cylinder required to perform a given amount
of work-We may consider the mean pressure in the cylinder as
from 14 to 15 lbs. per square inch, and the velocity of the piston
from 80 to 85 feet per minute. It must be remembered that the
pressure per square inch is derived from the actual water load
divided by the area of the piston, and that one-fifth more power
must be allowed for friction. Thus the pressure multiplied by the
velocity equals so many foot pounds, which may be taken on an
average as IOOO. Therefore we divide the number of lbs. of water
raised I foot high by IOOO, and the quotient is the area of the
cylinder in square inches. For example:—Suppose it be required
STATIONARY ENGINES. . 3O5
to find the diameter of a cylinder of a Cornish engine sufficient to
raise 7,000,000 gallons of water 120 feet high in 24 hours. Multi-
ply the number of gallons by Io (the weight in lbs. of a gallon of
fresh water), and then by the height; divide the product by the
number of hours reduced to minutes, and the quotient gives the
number of lbs. raised 1 foot high per minute, which divided by IOOO
gives the area of the cylinder. Thus:
7oooooo x 10 x 120
I44O
which equals 86 inches diameter nearly; to which must be added
an allowance for the friction of the engine. The divisor used may
vary, owing to the pressure and velocity, and on this account three
eminent firms have used in their practice 926, 1 II 3, and I 140
respectively; but the average of a number of Cornish engines
1s 77 I.
Steam valves for Cornish engine:—
= 5833333 + IOOO = 5833,
The steam valves............... = #ith to ºth of the cylinder area.
The equilibrium valves........ = ºth to ºth 3 * 5 y
The exhaust valves............. = ºsth to #5th 5 y y 5
To find he duty of an engine.—Supposing an engine required
3 lbs. of coal per indicated horse-power per hour, it is required to
find the duty performed by I 12 lbs., or a cwt. of coal. The horse-
power being 33,000 lbs. raised I foot high in a minute, or I,98O,OOO
lbs. raised I foot high in an hour—then by the rule of three we have
*
lbs. hbs. lbs. lbs.
3 : 1980OOO :: 112 = 7392OOOO
raised I foot high by a cwt. of coal per hour. Formerly the duty
was estimated by the bushel of coal, weighing 94 lbs., but it is
considered most convenient to adopt the I I2 lbs. measure. The
average duty of Cornish engines may be taken at 60,000,000 lbs.
raised I foot high in one hour by a bushel of coal weighing 94 lbs.,
or 71,489,361 lbs. with a cwt. or II 2 lbs.
The power required to overcome the friction of water through pipes.
—When water is required to be pumped through a long line of
piping an allowance is generally made for its friction in transit. The
quantity of water in cubic feet per minute, and the diameter and
length of the line of piping being given, multiply the square of the
quantity in cubic feet by the length of the piping in feet, and divide
the product by the constant 22 for pumping engine, multiplied by
the fifth power of the diameter of the piping. Thus, supposing
20
3O6 MODERN STEAM PRACTICE.
61 cubic feet of water requires to be forced to a height of 178 feet,
the length of the piping being 81.45 feet and the diameter of the
pipe 9 inches, we have—
Cubic feet. Length of piping.
61 × 61 = 3721 × 8145 = 30307595
22 × (9 × 9 × 9 × 9 × 9) = I299078 T
as the additional height to be allowed for the friction, or say 24 feet
in round numbers; thus 24 feet added to the height the water
requires to be pumped equals 202 feet: then calculate the horse-
power by the ordinary method, namely:
Cubic Weight of a
feet. Height. cubic foot.
61 × 20.2 x 62’5
33OOO
23.2 feet,
= 23:3 horse-power,
to which add one-fourth for loss, and the product is 29 horse-power
nearly, irrespective of the friction of the engine.
Formula to find the extra height to allow for friction according
to the above:-
Q* /
H = ±,
where Q is the quantity in cubic feet per minute, l the length of
the line of piping, and d the diameter of the pipes.
Formula to find the horse-power required to overcome the friction:
__Q* *
T 14ozº’
P represents the horse-power necessary to overcome the friction,
Z the length of the pipe in inches, Q the quantity of water to be
delivered in one second in gallons, and d the diameter of the pipe
in inches. The formula reads, that the cube of the quantity in
gallons per second must be multiplied by the length of the line of
piping in inches, dividing the product by the constant 140 multi-
plied by the diameter of the piping into the fifth power.
Delivery of water in pipes.—The formula is:
_VD’ D = '538 5 LX w.
W = 4.72 L H
V;
where D equals the diameter of the pipes in inches, H the head of
water in feet, L the length of pipe in feet, and W the cubic feet of
water discharged in a minute.
Pſawksley's formula.-This formula is:
5 /7-5-7- Fºr ETSV5 TF
D=*Vº g-Vºß,
STATIONARY ENGINES. 307
where G equals the number of gallons delivered in an hour, L the
length of pipe in yards, H the head of water in feet, and D the
diameter of pipe in inches.
Weight and measurement of water:—
1 cubic foot............................................ = 62.5 lbs. avoirdupois.
1 cubic inch........................................... = 'og617 93.
I gallon ................................................ = 10' 22
A column I2 inches high and I inch square... = 434 3 J.
A column I2 inches high and I inch diameter = 341 22
A cylindrical foot.................................... = 49' I 3 y
A cylindrical inch.............................. = 'o2848 92
II 2 imperial gallons............................... = I cwt.
224 imperial gallons............. . . . . . . . . . . . . . . . . . . . . . = I ton.
I’8 cubic feet......................................... = I cwt.
35’84 cubic feet...................................... = I ton.
I cubic foot........................................... = 6% imperial gallons.
I cylindrical foot............... ............. = 5 9 3 33
To find the thickness of pipes for conveying water.—Multiply the
constant OOOO54 by the head of water in feet, and then by the
inside diameter of the pipe in inches, to which add 3% inch for
pipes less than I2 inches, 9% inch from 12 to 30 inches, and 5% inch
from 30 to 50 inches internal diameter, and the result gives the
thickness. Thus, supposing the head of water was 6OO feet and
inside diameter of the pipe I 5 inches,
‘OOOO54 × 600 x 15 = OOO'486OOO + 5 = 98,
or nearly I inch as the thickness.
PROPORTIONS OF SOCKET FOR STANDARD PIPES FOR WATER SUPPLY.

*P* | Thiºn. ºf Tºrº jº,
inches. inch. inches. inch. inch.
3 i’s 3# # #
4. *; 3# #s #
ź # 3# is *
S. J -1 75 T5
7 § 3} # +'s
8 #s 3# # #s
9 is 4. * #
IO # 4. # #
I I # 4. # #
I 2 Hºs 4. # #
I4. § 4. # #
To find the weight of cast-iron pipes.—To find the weight of a
lineal foot, square the outside and inside diameters, and find the
difference, then multiply the result by 2:45 lbs., which is the weight
of a circular bar I inch diameter and I foot long. Supposing the
pipe is 22 inches diameter outside and 20 inches diameter inside,
3O8 MODERN STEAM PRACTICE.
(22 × 22) = 484 – (20 × 20) = 400 = 84 x 2:45 = 205.8 lbs. nearly.
Two flanges are generally reckoned equal to 1 foot of pipe.
Pipes for pit pumps.—The most approved form of joint for pit or
pump stand pipes is the Spigot and faucet, with a turned face on
the flanges for making the joint, which is done by a ring of wrought
º
Fig. 200 A.—Pipes for Pit Pumps.
A, Bottom pipe. B, Top pipe. C, Spigot. D, Faucet. E, Ring of wrought iron. F, Flange.
G, Brackets. H, Bolt and nut. I, Holes. K, Faces for joint.
iron covered with plaiding steeped in tar, and securely bolted
together by means of the flanges and bolts. The spigot is accur-
ately turned a little less in diameter than the faucet, which is
bored out for its reception. The flanges are strongly bracketed
to the body of the pipe, and the holes for the bolts are made
slightly oblong. The length of the pipe is generally about 9 feet
over the flanges, and the body is strengthened with two or more
raised rings cast on.








STATIONARY ENGINES. 309
Horse-power of an engine—The horse-power of a condensing
beam engine may be found theoretically by calculating the mean
pressure taken from the steam pressure adopted and the point of
cut-off determined on, allowing 12 lbs. per square inch as the amount
to be derived from the vacuum. Hence,
Area of cylinder in sq. in. x total pressure per sq. in. × velocity of piston in feet per minute
33000 ..”
gives the horse-power the engine will work up to, adding to this an
allowance of about one-fifth for friction.
Diameter of cylinder and length of stroke.—To find the diameter
of cylinder for a given horse-power, we must first find the number
of square inches to the horse-power, at the speed determined on,
by dividing the constant 33,000 by the total pressure (adding one-
fifth for friction) multiplied by the velocity of the piston in feet per
minute. Thus,
33OOO ſº
Total pressure x velocity of piston in feet perminuteſ
and the product multiplied by the total horse-power will give the
full area of the cylinder in square inches. Where great exactness
is required, add one-half of the area of the piston rod, then by the
table of areas the diameter is easily ascertained. The stroke of the
piston ranges from 2 to 2% times the diameter of the cylinder.
Speed of piston (varying with the stroke):—
2 ft. O in. stroke= 160 feet per minute. 4 ft. 6 in. stroke=207 feet per minute.
2 6 2 3 F I7o 5 * 5 O 53 = 2 I 5 3 5
3 O , , = 18O 3 3 6 O , , = 228 3 3
3 6 , , = 189 3 3 7 O ; , F245 5 y
4 O , , = 2CO 3 5. 8 O , , = 256 32
Opening of port by valve.—The opening of the port by the valve
is found by multiplying the area of the cylinder in square inches
by the speed in feet per minute, dividing the product by the con-
stant IO,OOO. The port should be made in excess of this, so as to
give a free exhaust; the breadth depends on the length of the port,
one-twentieth of the area of the cylinder may be allowed in all
cases. For the exhaust port multiply the area of the supply port
by I'5, and for the length of port multiply the diameter of the
cylinder by 6.
3IO MODERN STEAM PRACTICE.
RULES FOR THE BEAM ENGINE.
The beam.—The length of the beam should not be less than
three times that of the stroke, and its breadth one-half of the stroke;
for the breadth at the ends multiply the breadth at the middle by 4.
To find the thickness of web at the centre multiply the total pres-
sure on the piston—i.e., steam and vacuum—by one-half of the
length of the beam in inches, and divide the result by the constant
5oo into the depth in inches; the quotient is the sectional area in
square inches for cast iron.
Wrought-iron tubular beams:—
= length........................................... 28 feet 8 inches.
d = depth............................................ 5 , 6 , ,
a = area of bottom flanges....................... 56-67 square inches.
C = constant......................................... 8o
W = breaking weight in tons; hence
W – 56-67 × 5.5 × 8o. = 870 tons,
28.66
as the breaking weight in the middle. The load on the beam being
from 85 to 90 tons, we may safely consider the ratios of strength
as 870 : 90, or nearly IO to I. The thickness of sides for a beam of
the above dimensions is 3% inch, supported between the flanges
with T-iron over the joints, and corresponding strips outside; upper
and lower webs or flanges 2 feet wide, with four plates in each,
34 inch thick, rivetted to the sides with double angle iron. The
centre boss is cast with a plate, which is rivetted to the sides; the
end and intermediate bosses have also cast-iron plates. Instead of
the box form of beam, the side plates are sometimes made of
sufficient strength, having no angle irons at the top or bottom, but
merely secured with bolts and nuts, and sometimes rivetted to the
cast-iron bosses. The diameter of the main gudgeon is generally
one-fourth of the diameter of the cylinder, and for the piston-rod
gudgeon divide the cylinder diameter by 6:5; or they may be cal-
culated taking them as round beams loaded in the middle.
To find the versed sine described by the beam of an engine.—Divid-
ing the Square of the stroke of the engine by 8, multiplied by the
radius of the beam, gives the versed sine nearly, viz., S*-i- (8 × R)=
versed sine.
Air pump and condenser.—The air pump has generally a stroke
STATIONARY ENGINES. 3 II
of one-half of the travel of the steam piston. To find its cubical
contents, divide the cubical contents of the steam cylinder by 4:3.
When the stroke of the pump equals one-half that of the steam
piston, to find the diameter of the pump, in usual cases, multiply
the diameter of the cylinder by 7. The cubical contents of the
condenser should be about twice the capacity of the air-pump.
Cold-water pump and injection water—To determine the size of
the cold-water pump we must first ascertain the quantity of water
required for condensation. This is found by multiplying the tem-
perature of the steam by 'OO34; or approximately O'8 cubic foot, or
5 gallons, are required per nominal horse-power. Multiply this
number by the nominal horse-power of the engine, and then by the
constant 22OO; divide the result by the velocity of the pump bucket
in inches per minute, and the square root of the quotient is the
diameter of the pump. When the stroke of the pump is one-half
of that of the steam piston, the usual diameter allowed for the pump
is found by multiplying the diameter of the cylinder by O-3. The
area in Square inches of the injection valve should be from Hoth to
+3th the number of cubic feet in the steam cylinder.
The feed pump.–To find the water required to be delivered by
the pump, multiply the cubic contents in feet of steam in the
cylinder for an entire revolution by the number given in the table
of cubic inches of water required to raise a cubic foot of steam at
the desired pressure, and the result will give the contents of a
single-acting pump in cubic inches; a little more may be allowed
for waste, &c., but when the steam is cut off, soon in the cylinder
no additional allowance will be required.
TABLE OF THE PROPORTION OF WATER TO STEAM.
Pressure of steam Cubic inches of water Pressure of steam Cubic inches of water
per square inch. in a cubic foot of steam. per square inch. in a cubic foot of steam.
I 2- I ‘O99 45 F. 3'7OO
5 - I 350 50 = 3.981
IO == I-658 55 - 4'256
2O - 2-258 6o - 4°535
25 F 2°552 65 F. 4'812
3O - 2°842 7o = 5 O52
35 - 3' I 30 75 - 5-317
4O == 3°415 8o - 5-650
The diameter of the valves is found by multiplying the diameter of
the plunger by O-6.
Piston rod and connecting rod—To find the diameter of the piston
rod for compressive strain, multiply the area of the cylinder by
312 MODERN STEAM PRACTICE.
the steam pressure, and divide by 2240, which gives the area of the
rod; and for tensional strain divide by 40OO, which gives the area
at the weakest part. These proportions will be sufficient for all
the parts subjected to direct strain. The area of the connecting
rod straps equals the area of the piston rod; the thickness of the
Strap at the keyways must be more according to the area cut out
for the key. The depth of jib and cotter equals two-thirds of the
diameter of the connecting rod at the ends; the thickness of the
jibs and keys equals one-fourth of the rod at the ends; taper of the
key equals 9% inch to the foot; keyway from end of butt equals the
breadth of the jibs and cotters.
Crank shaft.—To find the diameter of the crank shaft when
made of wrought iron, multiply the length of the crank in inches
from centre to centre by the total pressure on the piston, and divide
the sum by 1266; the cube root of the quotient will be the diameter
of the shaft.
Crank of wrought iron.—The diameter of the crank pin will be
found by multiplying the diameter of the cylinder by 16; for the
length of the pin, multiply the diameter of the cylinder by 22.
The diameter of the eye for the crank pin is twice the diameter of
the pin. The length of the boss at the shaft is equal to the diameter
of the shaft; and for the thickness of the metal around the shaft
multiply the diameter of the shaft by '37. The breadth of the web
at the crank-pin end and journal is three-fourths of the diameter of
the respective bosses, and its thickness is five-eighths of their width.
These proportions are for low-pressure engines, with a steam pres-
Sure of 30 lbs. or so per Square inch.
Crank of cast iron.—The diameter of the crank pin is the same
as for wrought iron, and also the length of the pin. The diameter
of the eye for the crank pin is two-and-one-half times the diameter
of the pin. The length of the boss at the shaft equals the diameter
of the shaft, and its diameter is twice the diameter of the shaft.
The breadth of the web at the crank pin and journal bosses is
three-fourths of the diameter of the respective bosses, and its thick-
ness is one-half of the diameter of the shaft, with a feather at the
back tapering from the large boss to the crank-pin boss, in thick-
ness one-half of that of the web. - -
Fly wheel—The diameter of the fly wheel is generally from three-
and-a-half to four times that of the stroke of the engine. The
velocity of the periphery should always exceed the velocity of the
STATIONARY ENGINES. 3I 3
periphery of the stones of a flour or other mill, to prevent back
lash. To find the weight of the rim in cwts, multiply the constant
1366 by the horse-power of the engine, and divide the product by
the mean diameter multiplied by the number of revolutions per
minute, and the quotient is the weight. To find the thickness of
the ring when the breadth is given, in the first place find the area
of the ring in square inches, then divide the weight in lbs. by the
area multiplied by 263, and the quotient is the thickness in inches.
The breadth of the rim for large wheels is generally ºrth of the
diameter of the wheel, to Hºrth for small wheels.
The governor—The point of suspension of the arms should be
as near the centre of rotation as possible, and the working angle
should never exceed 45°; the diameter of the balls varies from
4 to 9 inches. To find the number of revolutions, divide 375 by
the square root of the pendulum, or vertical distance from the point
of suspension to the working plane of the centre of the balls, and
one-half of the quotient will be the number of revolutions required.
When the revolutions are given, to find the length of the pendulum.
Divide 375 by twice the number of revolutions per minute, and the
square root of the quotient will be the length required; or other-
wise, divide the constant 1875 by the square root of the pendulum,
which will give the number of revolutions. Thus, supposing the ver-
tical height is 36 inches, the square root = 6 inches, we have—
tº = 31-25 revolutions.
Given the number of revolutions, to find the length of the pendulum
from the centre of the working plane of the balls to the centre of
suspension. Divide 1875 by the number of revolutions, and the
square of the quotient will be the length of the pendulum:
I87 - 5 e
; = 6*= 36 inches long.
Formula for safety-valve levers:—
Weight or pressure on the valve x distance of valve from stud
Total length of lever from stud
(I)
= weight.
(2) Weight or pressure on the valve x distance of valve from stud
Weight
= total length of lever,
) Weight on lever x total length of lever from stud
Distance of valve from stud
= total pressure on valve.
(3
3I4 MODERN STEAM PRACTICE.
This is when the valve is between the stud or pin and the weight
on lever. When great exactness is required, subtract the weight
ſº (
[T] -
ŞXS$º
#2% ºf
Fig. 2008.-Safety Valve, with Lever and Weight.
A, Stud. B, Weight. C, Valve.
of valve and the effective leverage or weight of lever from the total
(steam lbs) pressure on the valve. Examples:–
Supposing the pressure of the steam in the boiler is 30 lbs. per
square inch above the pressure of the atmosphere, giving a total of
288-61 lbs. on the valve—and the length from A to B is 35 inches,
and from A to C 3% inches—we have,
288.6 × 3.5 = weight on B = Say 28:86 lbs.,
A B = 35
288-6 × 3.5 p c. - •y r* :
B = 2S-86 = B from A = Say 35 inches,
*::: = total pressure on the valve = 288-6 lbs.,
which gives the total load on the valve; to be more accurate, the
weight of the valve and the effective leverage must be subtracted
from 2886, the total (steam lbs.) pressure on the valve.
WATER-PRESSURE - ENGINES.
In 1846 the first hydraulic crane was erected at Newcastle-on-
Tyne, for discharging ships, the supply of water being obtained
from the mains connected with the town service reservoirs. After-
wards one was erected at Liverpool, and another at the new dock
at Grimsby. The Liverpool crane, like the Newcastle one, was
supplied with water from the town mains; but at Grimsby a tower
was built with a tank into which the water was pumped by a steam
engine. In the former cases the irregularity of pressure consequent






STATIONARY ENGINES. 3 IS
on the varying drain upon the pipes for the ordinary consumption
proved a serious disadvantage; but this drawback was not experi-
enced at Grimsby, where the tank upon the tower furnished an
uninterrupted supply. In the absence of a natural head of water,
with pipes laid for conveying it to a lower situation, the erection of
water towers was a serious obstacle in extending the principle of
the hydraulic crane, and engineering ingenuity resorted to another
form of head, which possesses the advantages of being applicable
at a moderate cost in nearly all situations, and of lessening the
size of the pipes and cylinders by affording a pressure of greatly
increased intensity. The apparatus by which this is effected has
been named the “accumulator,” because of its accumulating the
power exerted by the engine in charging it. The accumulator is
in fact a reservoir giving pressure by load instead of by elevation,
and its use is to equalize the duty of the engine in cases where the
quantity of power to be supplied is subject to great and sudden
fluctuations. In the application of water-pressure machinery, where
an artificial head of water has to be obtained, the real source of
power is the steam engine employed in pumping the water into the
accumulator, and the water acts simply as a convenient means of
storing up the power of the engine, and applying it whenever
wanted at the distant points where the work has to be done. We
may take as an example of this the Victoria Docks in London,
where the area over which the power is extended is so great as to
require 4 miles' length of mains to convey the water to the several
cranes, hoists, and to the lock-gates. -
In Hastie's variable water-power engine the quantity of water is
regulated to the work done automatically. There are two or more
Oscillating cylinders rocking on trunnions at their lower ends, the
pistons being solid plungers, and centered on a crank pin which is
free to move in a slide, so that the throw becomes variable according
to the demand on the engine.
THE ACCUMULATOR.
The accumulator consists of a large cast-iron cylinder A (Fig. 201),
fitted with a plunger B, from which a loaded case C is suspended to
give pressure to the water injected by the engine. The load upon the
plunger B is usually such as to produce a pressure in the cylinder
equal to a column of water I 500 feet in height, and the cylinder is
316 MODERN STEAM PRACTICE.
made large enough to contain the quantity of water which can be
required from it at once by the simultaneous action of all the
i- Š hydraulic machines connected with it. If, how-
3.33: ever, the engine pumps more water into the
accumulator than the hydraulic machines re-
quire, the plunger rises and makes room in the
cylinder for the surplus; and when, on the other
hand, the Supply from the engine is less than
the quantity required, the plunger with its load
"> descends and makes up the deficiency out of
: the store. The accumulator serves also as a
| regulator to the engine, for when the plunger
, rises to a certain height it begins to close the
, “ , ” ** throttle valve in the steam pipe, so as gradually
...] [... to reduce the speed of the engine, until the
* . . . . . , , descent of the plunger again requires an increase
- of power. The introduction of the accumulator
É removed all the obstacles to the extension of
à water-pressure machinery, which has been now
practically tested in nearly all the principal
docks and in many of the government establish-
J.Lº ments in this country. This class of machinery
Fig. 20.—vertical section of has also been adopted in many of the principal
º: railway stations, not only for Cranage, but also
for working turntables, traversing machines,
waggon-lifts, hauling machines, &c. It is also extensively used for
raising and tipping waggons in the shipment of coal, for opening
and closing bridges, and for many other purposes.
PUMPING ENGINE FOR CHARGING THE ACCUMULATOR.
The most approved form of the pumping engine for charging
the accumulator is that of two high-pressure cylinders fixed hori-
zontally, with double-acting pumps directly connected with the
piston rods; the form of pump being the solid bucket and plunger
system. In the arrangement shown (Fig. 202) the OUT stroke of the
pump forces the water contained in the annular space surrounding
the plunger E into the accumulator, while a further supply of water
enters behind the piston F through the suction valve G. In the
IN stroke the water behind the piston is discharged through the

STATIONARY ENGINES. 317
delivery valve D, half of it passing round into the annular space on
the other side of the piston, the remaining half being forced into
the accumulator. As the area of the plunger E is exactly half that
of the piston F, each stroke of the pump delivers the same quantity
of water into the accumulator. Much difficulty has been experi-
enced to secure proper joints for the pipes of hydraulic machinery;
1]O plan appears to stand so well as a small ring of gutta percha
II
Y!%
D -
% Z%
(2a–. - TTTºº &
E
*-i-º-º-
OC)
Tºnºſº
Clºt
% %
Ø
Fig. 202.-Longitudinal Section of Force Pump.
D, Delivery valve. E, Plunger. F, Piston. G, Suction valve. J, Gutta-percha ring joint.
compressed into a recess formed on the end of one pipe, with a
projection on the adjoining pipe accurately turned to fit the recess,
like a spigot and faucet. --
Rivetting, both of boilers, girders, and shipwork, is now in many
cases carried out by hydraulic pressure through the action of
accumulators, loaded as high in some cases as I 500 lbs. per Square
inch, india rubber or flexibly jointed metal pipes being used to
convey the water to the working parts.
wATER WHEELs.
Water wheels may be classed as vertical and horizontal, of
these the vertical class may be subdivided into undershot, overshot,
and breast wheels, whilst the turbine form represents the horizontal
class. The undershot wheel is simply the old form of water wheel,
made of wood, with radial float-boards, on which the water
presses as it flows past. The efficiency or ratio of the useful to the
total work is small in such wheels, being only about $. In the over-
shot or breast wheel the water is led on at or near the top, and the
floats are made of a bucket form; the weight of the water is in
this manner taken advantage of as well as the impulse due to velo-
city. The efficiency of such wheels is about 4%; to #.
The turbine form of wheel is very suitable for high falls where a
great velocity of flow can be obtained, and is not affected by “back-





318 . MODERN STEAM PRACTICE.
water" as the vertical wheels are. There are several forms of such
wheels, depending upon the direction in which the water is allowed
to impinge upon the vanes or blades. These vanes are curved, and
it is of importance that the water should be directed upon them in
such a manner as to cause as little shock as possible; the propelling
action being due to the pressure and reaction on the vane due to the
gliding of the water along its surface. Curved vanes are found in
this manner to be more efficient than flat surfaces, their surfaces
being in the direction of the resultant of the lines of motion of the
jet and vane. Turbines are now largely used on natural falls,
notably so in America and in France and Switzerland.
HYDRAULIC CRANE,
Of the various applications of water pressure, the most com-
mon is that of a hydraulic press with a set of sheaves used in the
inverted order of blocks and pulleys, with the object of obtaining
an extended motion in the chain from a comparatively short stroke
of piston. The general arrangement of the machinery for working
such a crane may be described as follows:—The pressure cylinder A
(Fig. 203) is fixed horizontally below the surface of the ground in a
chamber at the foot of the crane, and is fitted with the ram B, carry-
ing the pulleys C at its outer extremity. The lifting chain is made
fast at one end to the cylinder A, and passes alternately round the
movable pulleys C and the pulleys D at the inner end of the cylinder;
and is then led round the guide pulley E up to the crane post F,
and along the jib to the load. The motion of the lifting chain is con-
trolled by means of the handle G, acting upon the inlet and outlet
valves, which are kept closed by the weights H and I; by opening
the inlet valve H (Fig. 204) the water is let into the cylinder A from
the pressure pipe J, and acting on the plunger raises the load; by
opening the outlet valve I the water escapes from the cylinder into
the exhaust pipe K, allowing the load to descend. The travel of
the ram B in the outward stroke is prevented from exceeding the
proper limit by the pulley block C coming in contact with a stop
connected with the handle G, which closes the inlet valve H, and
prevents the load from being lifted too high. The return stroke of
the ram is effected by the load suspended from the chain; and in
the absence of any load, a small supplementary ram L is employed
to force the main ram B back, the slack chain being made to run
out by the permanent weight M.
STATIONARY ENGINES. 319.
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Fig. 203.—Hydraulic Crane. General Arrangement of Machinery.
Pressure cylinder. B, Ram. c and D, Pulleys. E, Guide pulley. F, Crane post. G, Handle
for valves. H and 1, Weights. J, Pressure pipe. K, Exhaust pipe. L, Supplementary
valve. M, Permanent weight. No, Cylinders and plungers for turning the crane.
A,
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Fig. 204.—Cylinder and Valves for Double-power Hydraulic Crane.
E, Piston, F, Valve chest. H, Inlet valve. I, Outlet valve.
M, Waive. N, Relief valve.
A, Cylinder. B, Ram. C and D, Pulleys.
J, Pressure pipe, K, Exhaust pipe. L, Valve for higher power.






- 32O MODERN STEAM PRACTICE.
To meet the variation of load it was formerly the practice to
combine three of the pressure cylinders so as to act either sepa-
rately or collectively upon the lifting chain; but a variation of power
is now obtained with a single-bored cylinder, fitted with a combined
piston and ram, as follows:—A (Fig. 204) is the cylinder, fitted with
the piston E and ram B; the water from the accumulator enters the
valve chest F through the pressure pipe J and the inlet valve H.
For the lower power the water is admitted to both sides of the
piston E by opening the valve L, in which case the power exerted
and the water expended are proportionate to the area of the ram B.
For the higher power the valve L is
closed and the valve M opened, so
that the front side of the piston E is
thrown open to the exhaust K, and
the result, both as regards power
and expenditure, is then propor-
tionate to the full area of the pis-
Fig. 205.—Deta... of Valves for Cylinder of Double- ton E. It is seldom necessary to
power Hydraulic Crane. — F, Valve chest, have more than these lower and
H, Inlet valve. 1, Outlet valve. L, Valve for * tº
higher power. M., Valve. N, Relief valve. higher powers; but where a third
or less power is required, a smaller
ram is used with the other. For lowering the load the valves H and
M are closed and the outlet valve I opened, allowing the water to
escape from the cylinder A into the exhaust pipe K; at the same
time the valve L is opened to allow the water to follow up the piston
in the inward stroke. The packing of
the solid piston A is held in position by
means of a ring of metal B, and secured to
the piston by stud bolts and nuts, and
consists of a cupped leather washer C,
Fig. 206.-Piston and Cupped Leather which is pressed against the side of the
for cylinder of Double-power Hy- cylinder by the hydraulic pressure.
draulic Crane.—A, Piston, B, Ring ſº te º
with bolts. C, Cupped leather. In hydraulic cranes the power is applied
not only for lifting the load, but also
for swinging the jib, which is effected by means of a rack or chain
acting on the base of the movable part of the crane, connected
either with a cylinder and piston, or with two single-acting cylinders
applied to produce the same effect by alternate action; as shown,
the two cylinders N and O (Fig. 203) are fitted with rams, working
by a chain passing round the base of the crane post F. The motion
Z%2


. STATIONARY ENGINES. 32 I.
is controlled by means of a slide valve worked by a handle situated
alongside the handle G, so that while the water is admitted to one
cylinder the other is open to the exhaust. The travel of the rams
is limited by means of a tappet rod connected with the handle of
the slide valve, whereby the crane is prevented from being turned
round too far. Small hydraulic rotary engines have been intro-
duced for working cranes, and in many cases they can be easily
attached to existing hand cranes.
The absence of any sensible elasticity in water renders the motions
resulting from its pressure capable of the most perfect control by
means of the valves which regulate the inlet and outlet passages;
but this property, which gives so much certainty of action, tends to
cause shocks and strains to the machinery by suddenly resisting
the momentum acquired by the moving parts. Take, for example,
the case of a hydraulic crane swinging round with a load suspended
from the jib.: the motion being produced by the water entering
into one cylinder and escaping from the other, it is obvious that if
the water passages be suddenly closed, the ram, impelled forward
by the momentum of the loaded jib, but met by an unyielding body
of water deprived of outlet, would be brought to rest so abruptly
as to cause in all probability some damage to the machine. So
also, in lowering a heavy weight, if the escape passages were too
suddenly closed, a similar risk of injury would arise from the sudden
stoppage of the weight. But these liabilities to injury are effectually
removed, in the case of a single-acting cylinder, by fitting a relief
valve in connection with the water passages, consisting of a Small
clack valve N opening upwards against the effective pressure, so as
to permit the pent-up water in the cylinder to be forced back into
the pressure pipe, whenever it becomes subject to a compressive
force exceeding the pressure given by the accumulator; and in
the case of a double-acting cylinder fitted with a piston and slide
valve, or where two single-acting cylinders with rams working
alternately are controlled by a slide valve—as in the instance of the
cylinders N and O—for turning the crane, relief valves are fitted in
connection with the slide valve. These consist of four small leather
flap valves (Fig. 207), with metal pieces at the top and bottom. The
passages PP communicate with the pressure pipe. J, and the pas-
sages E E with the exhaust K. When the slide valve is moved in
the direction of the arrow the pressure is first cut off from the
port R by the top of the valve, the port S being still open to the
3-l.
322 MODERN STEAM PRACTICE.
exhaust K; at the same instant the flap valve T opens upwards
-- and allows a small quantity of water to pass
from the exhaust K into the port R to follow
up the ram until brought to rest. When
the slide valve arrives at the central position
Nº "s. as shown, the port S is closed to the exhaust,
SN3:
tº and the pressure in it being increased by
=:
ES$g the further motion of the ram before it is
completely stopped, the second flap V is
raised, and a small quantity of water forced
back into the passage P communicating with
the pressure pipe J. When the slide valve
is moved in the opposite direction, the two
remaining relief valves are brought into ac-
re, Exhaust passages. I pressure tion in the same manner. By these means
pipe. K, Exhaust. P, Pressure all risk of concussion is avoided, and per-
passages. R and S, Ports. º e e
fect control over the machine is combined
with great softness of action.
ŽR&S
in
§
º
º
S
s
Fig. 207.-Section of Slide Valve &
Relief Valves ſor Hydraulic Crane.
DOCK GATES.
The method generally adopted for opening and closing dock
gates by means of hydraulic pressure consists in applying to each
gate a pair of cylinders with rams and multiplying sheaves, similar
to those used for the hoisting apparatus in hydraulic cranes. One
of these cylinders opens the gate and the other closes it; and the
whole of the machinery is placed in chambers beneath the ground.
The water is admitted from the pressure pipe J to the cylinder A
(Fig. 208) through the inlet valve H by means of the handle G; the
same motion of the handle also opens the outlet valve of the other
cylinder B. The opposite motion of the handle G opens the outlet
valve I, allowing the water to escape from the cylinder A into the
exhaust pipe K, and at the same time admits the pressure to the
cylinder B. A stop M connected with the handle G prevents the
ram from travelling too far in the out stroke, by closing the inlet
valve; and the return stroke of the ram is effected by means
of the weight L. This arrangement has been applied to several
of the London and Liverpool Docks, as well as to some others
throughout the country.
In Fig. 209 we give an engraving of the general plan of a

STATIONARY ENGINES.
323
dock entrance which has been adopted in some instances, and
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found to answer extremely well. Instead of connecting the hauling
cylinders with each gate, a line of shafting A, driven by a small



324 MODERN STEAM PRACTICE.
water-pressure engine B, is laid beneath the surface of the ground, ,
parallel with the coping on each side of the entrance, and by means
of clutches is thrown into or out of gear with each gate crab. . A
Pressure
Fig. 209. — Arrangement for Lock-gate Machinery.
A, Shafting. B B, Pressure engines. C C, Capstans.
wire from the engine extends the whole length of the snafting, so
that the engine can be regulated from the point where the work
has to be done. A more recent method is to attach a separate
engine to each crab, and also to the sluices; and in some instances
these engines have been fitted to existing machines without inter-
rupting the traffic. The rapidity with which dock gates can be

STATIONARY ENGINES. 325
opened and closed by these appliances is limited only by consider-
ations of safety to the gates, the time taken in actual practice
being about two minutes. In nearly all the cases in which hydraulic
pressure has been applied for the moving of dock gates, it is also
used for opening and closing the levelling shuttles, and in many
cases also for working the capstans. The former purpose is effected
by the direct application of a cylinder and piston fixed above the
shuttle: and the latter is accomplished by throwing the capstan C
into gear with the shafting A.
WATER-PRESSURE ENGINES FOR DOCK GATES, &c.
These engines consist of a combination of three oscillating cylin-
ders, working cranks inclined I2O" to one another. The cylinders A
(Fig. 2 IO) are fitted with plungers B, instead of pistons, and are there-
fore only single-acting. The slide valves V are worked by the oscil-
lation of the cylinders, communicated through the levers L. When
the back end of the cylinder is depressed, the slide valve is lowered,
and allows the water to enter from the pressure pipe P through the
pipe C to the cylinder, where it acts upon the plunger in the out
stroke; and in the return stroké the back end of the cylinder is raised,
the cylinder port C is closed to the pressure pipe P, and open to
the exhaust E. A small relief valve is fitted to the cylinder pipe C,
opening against the pressure, which prevents any shock when the
communication with the exhaust is closed at the end of the return
stroke. These engines have occasionally been made with pistons,
so as to be double-acting; but for the great pressures employed
where accumulators are used, the single-acting arrangement with
plunger is preferred. It will be observed that with the arrange-
ment of cranks dividing the path into three equal parts, there is no
liability of the engine stopping on the “dead centre,” as it is termed,
the one crank assisting the other over the extreme points.
In working swing bridges by means of water pressure, a central
press is generally applied to lift the entire bridge clear of its
supports, and it is then turned by an application similar to that
used for swinging a crane. An example of a swing bridge on this
principle is seen at Wisbech, having an opening of 85 feet, arranged
for a double roadway in one leaf, weighing about 450 tons. The
power is derived from an accumulator charged by a hand force
pump, and notwithstanding its great length and weight the bridge
326 MODERN STEAM PRACTICE.
§§ Sº §
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Fig. 210.-Water-pressure Engine.
AA, Cylinders. B B, Plungers. C, Pipe to cylinder. E, Exhaust pipe. L, Lever for working slide
valve. P, Pressure pipe. v, Slide valve.

















STATIONARY ENGINES. 327
can be lifted and turned in less than two minutes. The plan of
using an accumulator charged in this way has been adopted for a
railway drawbridge near Caermarthen; and it can be applied to
many other purposes requiring a concentrated exertion of power
with intervening periods of inaction.
One application of water pressure with an accumulator, for the
purpose of rapidly lifting or lowering heavy loads, calls for special
notice because of its growing importance. We refer to vertical
hoists at the landing stations of steam ferries, where the traffic of a
railway is required to be passed over a river or estuary not spanned
by a bridge. The traffic of the Aix-la-Chapelle, Düsseldorf, and
Ruhrort Railway is by this means shipped and unshipped at the
ferry across the Rhine; and such is the rapidity and facility of the
operation that a train of twelve coal waggons, weighing collectively
133 tons, can be transferred from the deck of the steamer to the
railway, a height of about 20 feet, in twelve minutes. Each hoist
lifts two waggons at a time, and raises its load in ten or twelve
seconds. These hoists are so arranged as always to accommodate
themselves to the level of the boat, and also to stop at the exact
level of the railway.
WATER POWER FROM NATURAL FALLS.
Having said this much on that branch of the subject which
embraces the two principles of accumulation and transmission of
water power, we will now notice the applications of water pressure
as derived from natural falls. When the moving power consists of
a natural column of water, the pressure rarely exceeds 250 or 3OO
feet; and in such cases, to produce rotary motion, a pair of cylin-
ders and pistons are employed, with slide valves resembling in some
measure those of a high-pressure, engine, but having relief valves
to prevent shock at the return of the stroke. Where the engine is
single-acting, with plungers instead of pistons, as in the water-
pressure engine already described, the relief valves are greatly
simplified, and indeed are reduced to a single clack in connection
with each cylinder, opening against the pressure, as the relief valve
in the valve chest of the hydraulic crane. The water engines
erected at the lead mines at Allenheads, in Northumberland, pre-
sent an example of the utilization of natural falls in this country.
These engines are used for the various purposes of crushing ore,
328- MODERN STEAM PRACTICE.
raising materials from the mines, pumping water, giving motion to
machinery for washing and separating the ores, and driving a saw-
mill and the machinery of a workshop. Small streams of water,
which flowed down the steep slopes of adjoining hills, have been
Collected into reservoirs at elevations of about 200 feet, and pipes
have been laid from them to the engines. Water-pressure machin-
ery is invaluable in such a hilly district, where steam power is
almost impracticable in a commercial point of view, from the great
cost of conveying coals to the works.
An application of hydraulic machinery in situations where falls
of sufficient altitude for working water-pressure engines cannot
be obtained has been carried out at these mines, which deserves
special notice. For the purpose of draining an extensive dis-
trict, and searching for new veins, a drift way or open level nearly
6 miles in length was cut. This drift way runs beneath the
valley of the Allen, nearly in the line of that river, and upon
its course three mining establishments have been erected. At
each of these power was required for the various purposes already
mentioned, and it was desirable to obtain this power without re-
sorting to steam engines. The river Allen was the only resource,
but its descent was not sufficiently rapid to permit of its being
advantageously applied to water-pressure engines; it abounded,
however, with falls suitable for overshot wheels, and it was deter-
mined to employ the stream, by means of such wheels, in forcing
water into accumulators, and then transmitting by pipes the power
thus stored to the numerous points where it was required. In this
arrangement intensity of pressure takes the place of magnitude of
volume, and the power derived from the stream, assumes a form
susceptible of unlimited distribution and division, and capable of
being utilized by small and compact machines. º
A somewhat similar plan is also.adopted at the coaling establish-
ment for the navy at Portland Harbour. The object in this case
is to provide power for working hydraulic cranes and hauling
machines for coaling war steamers. A reservoir on an adjoining
height affords an available head of upwards of 3OO feet; but in
order to diminish the size of the pipes, cylinders, and valves con-
nected with the machinery, and also to obtain greater rapidity of
action, a hydraulic pumping engine and accumulator are interposed,
so as to intensify the pressure and diminish the volume of water
acting as a medium of transmission.
. STATIONARY ENGINES. 329
HYDRAULIC MACHINERY FOR WAREHOUSING GRAIN
AT THE LIVERPOOL DOCKS.
The dock around which the blocks of warehouses on the Liverpool
side of the river are situated, shown in the general plan Fig. 2 II,
is 570 feet long, 230 feet broad at one end, and 180 feet at the other.
Three sides of it are occupied by separate blocks of warehouses,
Connected by wrought-iron bridges. The blocks on the east and
west sides are 650 feet long and 70 feet wide, and that on the north
end is the same width and 185 feet long. Each block contains five
stories, as shown in the transverse section, Fig. 215; above the fifth
or top storage floor, and partly in the roof, is placed the machinery
floor; and below the quay level are wells and arched subways for
the reception of the underground machinery. There are five dis-
charging berths for large vessels, one at the north block and two
each at the east and west blocks; and additional accommodation is
provided for small vessels. In the centre or north block is placed
the steam engine A, of 370 horse-power, which in addition to
driving the whole of the machinery in the warehouses, supplies
power for working the lock machinery and the bridges. These
consist of two bridges of 60 feet span and one of 50 feet, twelve
Sluices, ten powerful ship capstans, and twenty-four machines for
Opening and closing the lock gates.
The principal processes required to be performed by the machin-
ery in the warehouses are:—Discharging grain in bulk direct on to
the quay or into the warehouses;—hoisting grain in bags or casks
on to the quay;-discharging ordinary merchandise direct on to
the quay or on to any floor in the warehouses, and loading out-
ward-bound vessels;–lifting and lowering sacks or other merchan-
dise. On platform elevators and jiggers, to or from any floor;--
elevating, screening, weighing, and distributing grain in bulk, and
Conveying it to and from all parts of the warehouses, and outwards
for delivery into ships or waggons;–and transferring grain from
one part of the warehouses to any other part. -
The two accumulators which generate the water pressure employed
as the medium for conveying power to the machinery are situated
at C C in the general plan Fig. 2 II, at each end of the centre or
north block of building; and between the west block and the river
entrances a large auxiliary accumulator is placed. The two accum-
ulators in the north block are each weighted with a load of 70 tons,
330
MODERN STEAM PRACTICE.
acting on a ram I7 inches in diameter, with a vertical ran
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feet; and the auxiliary accumulator is loaded with IOO to
ll ſ f














STATIONARY ENGINES. 33 I
3 inches in diameter, and wrought-iron branch pipes convey it
from the mains to the several machines. In order to economize
the consumption of water, which is obtained from the town supply,
return pipes are laid to conduct the exhaust water from all the
machines back again into a well in the engine house, from which
the pumps draw their supply; and thus the same water is used over
and over again. The steam engine for supplying the accumulators
is situated on the quay level at A, with its boilers at B; it is a hori-
zontal high-pressure engine with two steam cylinders, and the
plungers of the double-acting force pump are attached directly to
the piston rod. The engine is made in duplicate in all its parts,
to admit of either side being worked separately in case of need.
Double-acting lift pumps are provided for raising the supply and
the return water from the storage well into a settling tank above
the level of the engine, from which the forcing pumps draw their
water. The engine is capable of forcing 209,350 cubic feet of water
per minute against the accumulator pressure of 700 lbs. per Square
inch.
A number of experiments were made for the purpose of ascer-
taining the best means of conveying the grain horizontally from
one part of the warehouses to another. The common method by
means of revolving screws was first tried, the experiments being
conducted at a brewery fitted up with this class of machinery.
The screw employed was 12 inches diameter and 4 inches pitch,
made in lengths of about 12 feet from bearing to bearing; the
space between the screw and the fixed casing in which it revolved
was 94 inch. At sixty revolutions per minute, which was found to
be the maximum effective speed, this screw discharged the grain at
the rate of 634 tons per hour, and required a power of O'O4 horse-
power for every foot run. The sectional area of the body of grain
propelled was 49 per cent. of the whole transverse area of the screw.
At a higher velocity than sixty revolutions the grain was simply
carried round, and not propelled forwards at all. With a screw,
afterwards tried, of 12 inches diameter and 12 inches pitch, driven
at seventy revolutions per minute—the most effective speed—34 tons
of grain per hour were discharged, and the power required to drive
the screw was O'I25 horse-power per foot run, or 37 per cent, less
than in the case of the previous screw for the same delivery of
grain. The sectional area of the grain in motion was 72 per cent.
of the whole area of the screw. The saving in power in this case
332 MODERN, STEAM PRACTICE.
was owing to a better construction of parts, as well as the quick
pitch. The effect upon the grain itself was very marked: with the
first screw it was propelled without any appreciable agitation, but
with the quick-pitched screw it was rubbed and polished, and
thereby improved in marketable value.
In order to overcome the objections experienced with this screw,
and to improve still further if possible the conditioning of the grain,
trials were made with screws contained in revolving casings. A
preliminary experiment was made with a 6-inch screw, 6 feet long,
with 2 inches pitch and a depth of blade of 2% inches; a portion of
the casing was perforated so as to act as a screen, which it did
effectually. A second trial was then made with a 30-inch screw,
calculated upon the result of the preliminary screw to discharge at
the rate of 50 tons per hour. The length of this screw was 18 feet,
and its pitch I 2 inches, or #ths of the diameter. The body of the
screw was properly balanced, and revolved upon finely adjusted
rollers, carried in cast-iron frames. A third experiment was made
with a screw 12 inches in diameter and I2 inches pitch, only with
the view of ascertaining the effect of the quicker pitch. The results
of these trials were as follows:—
The 6-inch Screw discharged per minute, at 60 revolutions, o'47 cubic foot of wheat.
Do. do. 8o 2 3 o:6o 5 3
Do. do. IOO 25 O'50 33
Do. do. I4O 39 o'OO (no delivery).
Showing that, as the grain in this class of screw is propelled for-
wards by gravity, centrifugal force comes into action at high speeds,
and stops the discharge. With the 30-inch screw a speed of thirty-
six revolutions per minute was found to be the most effective. At
this speed the grain was carried up on the rising side of the screw
about 5 inches above the centre of the casing, and the discharge
was 63% cubic feet, or about 80 tons of wheat per hour, which was
a much higher duty than had been calculated upon. The power
required was O:40 horse-power per foot run; and the sectional area
of the body of grain was 36 per cent. of the whole area of the
casing. The 12-inch screw, driven at the same speed of thirty-six
revolutions per minute, gave IO tons of wheat per hour, with a
sectional area of only 17 per cent. The pitch of #ths of the
diameter proved the most effective of those tried. The use of these
screws with revolving casings was highly advantageous to the grain,
which became well rubbed and polished; and they also obviated
STATIONARY ENGINES. & 333
the principal objection experienced with the screws in fixed casing,
which harboured dirt and caused the grain to be injured by the
action of the screw blades revolving within it. The great power
necessary to drive the screw with revolving casing was found, how-
ever, an insuperable objection to its adoption upon a large scale.
The long distances over which grain had to be conveyed hori-
zontally in the warehouses, amounting collectively to 7000 feet, or
about 1% mile, and the power required for conveying it even with
the best form of screw, rendered it expedient to seek some other
mode of transport requiring less power; and recourse was therefore
had to endless travelling bands. After a few preliminary trials
with small canvas bands, experiments were made with a flat band
I2 inches broad, constructed of canvas and india rubber. In work-
ing out this arrangement the first point to ascertain was the highest
speed that could safely be used with different kinds of grain. A
speed of 8 feet per minute was found to be the maximum for oats
and other light grain; and at this speed even bran and flour can
be conveyed without any portion being blown off by the resistance
of the air in the passage of the band. A speed of about 9 feet per
second can be reached with heavy clean grain, and a still higher
speed with peas; chaff is blown off at a speed of about 9 feet per
second. The quantity of grain discharged by the 12-inch band,
travelling at a speed of 8 feet per second, was about 35 tons per
hour. Further trials were then made with a band 18 inches broad,
formed of two plies of stout canvas, covered with vulcanized india
rubber; and this pattern was subsequently adopted for permanent
use. The band was made continuous, extending over a distance
of 37 feet, and was supported on plain cylindrical carrying rollers,
fixed at intervals of 6 feet apart. The rollers were made of wood,
with wrought-iron spindles revolving in bearings of white metal,
and lubricated with hard grease. The band was driven by shaft-
ing, and provided with a self-tightening apparatus similar in con-
struction to that finally adopted in the warehouses, consisting of a
heavy tightening pulley suspended upon the band, and sliding
vertically between guides. The maximum quantity of heavy grain
conveyed by an I8-inch band is at the rate of about 70 tons per
hour, and the power required to drive the band when working at
this rate is equal to about ool A horse-power (ºth) per foot run.
The grain has no tendency to fall off the band, and indeed it is
surprising to see separate grains at the edge of the band remain
334 MODERN STEAM PRACTICE.
steadily in position whilst passing over the carrying rollers at the
highest rate of speed. Comparing the amount of power required
to convey a stream of grain at the rate of 50 tons per hour through
a distance of IOO feet, by means of the common screw in stationary
casing, the tubular screw with revolving casing, and the travelling
band 18 inches wide, the following are the results:—
With the common screw......................................... 1838 horse-power.
35 tubular screw........................................... 25'OO 2 3
9 3 18-inch travelling band..................... * * * * * * * * * * I "O2 5 y
This shows the great superiority of the band over the screws in
economy of power. -
For the purpose of passing the grain off at any point on either.
side of the main travelling bands, several contrivances with air-
blast and brushes driven from the band itself were tried, but with
indifferent success; both methods were objectionable on account of
raising dust, and the friction of the brushes proved injurious to the
band in course of time. The idea then occurred of diverting the
stream of grain by means of an upward deflection of the carrying
band, which would throw it clear from the band into the air for a
short distance, and in falling it would be caught and led off by a
spout to either side as required. This plan proved successful, and
has been extensively adopted in connection with the use of the
endless travelling bands for carrying grain. The throwing-off
apparatus is shown in Fig. 212. It consists of a couple of wrought-
iron rollers B B, centred in gun-metal bearings in a rocking frame C,
which is hung in a movable carriage D running upon the timbers E
of the wooden framing that supports the travelling band II. The
carriage is moved to any position along the length of the band
where the grain is required to be discharged, and is then secured
by the wedges FF and the clamping screw G. The rocking frame C
is rotated in either direction by means of the screw and worm
wheel H, so as to bring the pair of rollers B B into action at the
proper position for throwing the grain off in the direction in which
the band I is running; and the rollers are turned back into the
horizontal position so as to be clear of the band when the carriage D
is required to be moved to another position. A curved spout K is
attached to the carriage D for catching the stream of grain in its
fall, and leading it off on either side of the band I. No difficulty
is experienced in keeping the grain on the band; but it is found
necessary to let it fall upon the band from a feeding hopper through
STATIONARY ENGINES. 335
a spout rather less than half its breadth, and set at an inclination
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of 42%, so as to give the falling grain a horizontal velocity nearly
equal to that of the band. The fine dust and grit thrown off with


MODERN STEAM PRACTICE.
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STATIONARY ENGINES. 337
protected from injury at such places. As the flow of various kinds
and conditions of grain through the spout from the hopper varies
considerably, it is found desirable to place a pair of oblique side
rollers at the point where the grain falls upon the band, in order to
give it a slightly hollow form, and so prevent the grain from
spreading. In passing heavy quantities of grain along the bands
to great distances it has also been found expedient to apply at
intervals pairs of these oblique side rollers, which are carried on
movable frames that can be set at any required spot.
The cross bands J J (Fig. 213), for conveying the current of grain
in a direction at right angles to the main bands, are driven from the
lower or return half of the main band, which is passed half round
a driving roller R, at each of the cross bands; and the motion is
communicated from this roller to the cross bands through a pair of.
mitre wheels S, having a clutch T for throwing the driving shaft in
and out of gear. The cross bands or other machinery, such as the
centrifugal distributing fan, can also be driven by depressing the
return half of the main band by a roller carried in a rocking frame
So as to bring the band well into contact with a fixed roller situated
underneath, which can then communicate the required motion for
any purpose; and this simple mode of taking off power from the
main bands has proved of service in many ways.
A revolving fan for spreading the grain over the floors of the
warehouses, and, for ventilating it and improving its condition, has
been used with success. This fan is carried upon an upright shaft,
driven from the main band by the same arrangement as that
described for driving the cross bands. As the band is required to
travel in opposite directions, the fan is made with straight radial
vanes, to allow of its revolving in either direction. The grain is led .
by a spout on to the top of the fan, and to avoid the separation of
heavy and light particles in the mass, and to spread it as evenly
over the floor as possible, the body of the fan has a conical form,
the alternate blades being made of a different length and shape, as
shown in the enlarged view, Fig. 2 I4. A hinged tongue is placed
in the end of the delivery spout above the fan, and the discharge of
the grain can be directed to any particular spot by turning this
tongue round in the required position. The fan is placed 9% feet
above the floor, and at its usual speed of 250 revolutions per minute
it deposits the grain in a circle of 45 feet diameter.
Five hydraulic cranes for discharging cargo are fixed in-towers
22
338 MODERN STEAM PRACTICE.
specially constructed in the warehouses, as shown in Fig. 215. These
cranes are fitted for raising grain in tubs containing 2 I cwts, each,
at a rate of 50 tons per hour under the most favourable conditions;
and they are also employed for
landing sacks, casks, and other
merchandise on to the quay, or
to any of the warehouse floors.
The lifting chain has an extreme
range of 130 feet, and the jib an
extreme projection of 24 feet be-
yond the quay; a traversing mo-
tion of 7% feet is given to the
foot of the jib, but this is only
required for the largest class of
vessels. The motions are all ef-
fected by hydraulic power, under
the control of one man stationed
on a platform in the tower. The
grain is filled into tubs in the
hold of the vessel, and to find the
best form for these tubs has been
matter of some difficulty. The
first form used was the ordinary
tipping tub, which has by long
experience been found to answer
best for the discharge of coal,
salt, gravel, &c. The next form tried required no tipping, but was
fitted with a cone to deliver the grain through the bottom. The
form that proved on the whole most satisfactory also requires no
tipping, and is fitted with a butterfly valve in the bottom; when the
tub is in position for emptying into the upper receiving hopper P,
this valve is opened by a lever from the platform on which the
man is stationed to work the crane. The time required by this tub
for emptying itself depends on the kind and quality of the grain
which it contains: with wheat in good and dry condition it is five
seconds, with barley seven seconds, and with Indian corn from
nine to ten seconds. - -
The hopper P (Fig. 216), into which the grain lifted by the crane to
the top of the warehouse is dropped from the tub, holds about 8 tons,
and from this hopper the grain is diverted into two streams, and
Fig. 214.—Distributing Fan.


STATIONARY ENGINES. 339
f
N, Distributing fan, o, Crane.
P, Upper receiving hopper.
o, Band. R, Receiving hopper.
s, Weighing hopper.
T T, Distributing hoppers.
uu, Spouts. v., Arched subway.
w, Elevator. x, Filling hopper.
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Fig. 2x5.—Transverse Section of Warehouse, showing Hoisting Gear, &c.







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34O MoDERN STEAM PRACTICE.
allowed to flow through the spouts fitted with regulators on to two -
18-inch inclined bands Q, driven by one hydraulic engine. One of
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crane, but two are employed to spread it out more, and to separate






STATIONARY ENGINES. 34. I
the dust from it when required. This separation is effected by an
inclined flap fixed in the inner receiving hopper R, into which the
two bands Q convey the grain from the outer hopper P. From the
hopper R the grain is allowed to drop through the valve into the
1-ton weighing hopper S; after which it is delivered, by a simple
arrangement of doors in the bottom of the weighing hopper, to
either side of the distributing hopper T, from whence it passes on
to one or other of the 18-inch bands II which traverse the entire
length of the warehouses. The man stationed at the weighing
machine S regulates the flow of grain from the several hoppers,
and records the quantity passed.
Two main lines of 18-inch bands, made to run in either direction,
are necessary for the convenient working of these warehouses. A
vessel, for instance, lying at the west block of the warehouses may
require her cargo deposited at either end of that block, or at any
spot in either of the other two blocks; and at the same time
another vessel lying at the east block opposite may have its cargo
housed in the west block. Thus it often happens that two streams
of grain are flowing in opposite directions, and that one or both of
these is carried right round the warehouses. The bands in the
east and west blocks are divided into two lengths, and the bands
Connecting these two blocks and passing through the north block
are in one length. Each band is fitted with a separate tightening-
up apparatus, seen in Fig. 2 I3 at M ; and is driven by a separate
hydraulic engine N, of about 3 horse-power, having two cylinders,
and fitted with reversing and regulating gear, which can be con-
trolled from any point along the entire length of the band. At
each point where the flow of grain has to be diverted from a main
band to a cross band, a fixed throwing-off carriage is stationed.
Two movable throwing-off carriages are provided on each main
band, for casting the grain off the band into the wooden descending
spouts, 8% inches square, which convey it from the top of the
warehouse to any floor in the building. There are fifty-six of these
spouts U U, Fig. 2 I5, passing from the upper machinery floor down
to the lower 12-inch bands in the arched subway V V below the quay
level; they are provided with sliding doors at the different floor
levels, to admit of the grain being shovelled into waggons on the
railway which traverses the centre of the block, or on to the lower
I2-inch bands for conveying to the elevators. A number of othèr
shoots at suitable intervals are built in the walls of the warehouses
342 MODERN STEAM PRACTICE.
fronting the dock at the levels of the several floors, and each is
provided at the first floor with a delivery outlet, to which a movable
spout is hooked on, for delivering grain from the warehouse into
vessels. The arrangement of the lowering band machinery is a
counterpart of the upper, but upon a smaller scale, and without the
movable throwing-off carriages provided on the upper bands, which
are not required for the lower. These lower bands are employed
for the purpose of conveying grain from any of the descending
spouts to any of the five elevators W, which are fixed in the crane
towers. The grain conveyed along these I2-inch main bands is
thrown upon the 18-inch cross bands, which deliver it into the
hopper X, supplying the elevator W.; one 18-inch cross band will
carry the full quantity of grain conveyed by the two 12-inch bands,
and the cross bands are arranged to receive their motion from
either line of the main bands. Much of the grain discharged from
the vessels in the dock is sorted upon the quay, and is then thrown
by hand into the hopper X of the elevators.
The elevator for raising the grain from the bottom to the top of
the warehouses is shown on a larger scale in Fig. 217. The wrought-
iron bucket W, capable of containing about 2 I cwts, is slung from
the lifting chain by an arrangement of bars and levers, and provided
with guiding rollers running between the upright timbers, so
arranged that on reaching the top the bucket tips over, and dis-
charges the grain into the hopper Y. This hopper delivers the
grain upon the same inclined cross bands Q that convey it from
the outer crane hopper P. The bottom hopper is made in two
parts, the upper of which X, protected by a grating, receives the
bulk of the grain, while the lower compartment Z contains only one
charge at a time for the elevator bucket W, and is separated from
the upper portion by a sliding valve. The descending speed of the
bucket having been checked, as it approaches the bottom it strikes
the arm of the tappet lever A, which closes the valve between the
two compartments X and Z of the hopper; and continuing its
descent still more slowly, the bucket strikes another tappet arm B,
which disengages the iron flap C that covers the front of the lower
compartment Z; this flap, falling forwards by the weight of the
grain behind it, shoots the contents of the lower hopper Z into the
bucket W. As soon as the bucket has received its charge, the
motion is reversed for lifting. Beginning to ascend at a moderate
speed, the bucket closes the flap C of the lower hopper, which
STATIONARY ENGINES.
343
is held up against it, as shown dotted, by means of spring,
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C, Flap. D D, Spring catches. O, Chain.
z, Filling compartment.
Fig. 217.—Elevator for Lifting Grain into Warehouse.
Y, Receiving hopper.
B, Tappet arm.
and the bucket then strikes the tappet lever A of the
x, Filling hopper.
y
A, Tappet lever.
catches D D






344 MODERN STEAM PRACTICE.
hopper valve, and re-opens the communication between the two
compartments X and Z. The speed is then accelerated until the
bucket arrives near the receiving hopper Y, when it is again retarded
before the grain is shot out. The motion of the bucket is regulated
by self-acting gear. These bucket elevators are intended to raise the
grain at the rate of 50 tons per hour, but they are capable of being
worked at a higher speed. The chain O of the crane is employed
for lifting the bucket of the elevator; but it has been found expedient,
on account of the demands of the traffic, to make the elevators also
independent of the cranes, and therefore separate hydraulic cylinders
with their adjuncts have been supplied for working the former.
Trials have been made for lifting grain by means of dredging
machines, and it has been found that with a dredger 30 feet long
50 per cent. of the applied power proved effective. Experiments
have also been made for raising corn by air pressure or suction,
and the results obtained are sufficient to prove that this system
possesses certain advantages over the plan in use; but it is sur-
rounded with difficulties and obstructions which must be removed
before it can be employed with advantage upon a large scale.
Casks, bags, and other merchandise are raised or lowered either
by hydraulic cradle hoists or by jiggers. There are twelve hydraulic
hoists of the ordinary construction, each capable of lifting a load
of 1 ton to the uppermost floor of the warehouses. They are found
also serviceable in breaking out the cargoes from the fore and aft
hatchways of a vessel lying with its centre hatch in line with the
crane or elevator. For this purpose the lifting chain is disconnected
from the cradle of the hoist, and led through a snatch block fastened
to some part of the vessel. The twenty single-acting outside
jiggers, originally constructed only for lowering loads by friction,
have been supplied with auxiliary hydraulic power for lifting loads
from 6 to 7 cwts. Twelve double-acting jiggers, for loads up to
10 cwts, have been added in the centre of the warehouses, for lifting
or lowering goods to railway waggons; they are so constructed that
they can be used singly or together, and for lifting or lowering.
Both machines may be alternately lowering goods into waggons
below from any of the floors of the warehouses, or by means of the
water pressure they may both be raising goods from the waggons
to any of the floors; or one side of the machine may be lowering
whilst the other is hoisting goods from the hatchways of vessels to
which the lifting chain has been led.

HYDRAULIC $
§
{
MACHINE TOOLS
r
!
|
!
f
E F Parallel Motion, with Eccentric G, and Handles for
L Hand Wheel for moving the Trolly
K. Plates of Ship.
*tº * -
\g >D->
F O
G
E
49
K SOº K
G-H.-E.
} © • * * (C) B
—e A
}.
Fig. 5.-ANGLE-IRoN or BEAM STRAIGHTENER OR BENDER,
from 5 to Ioo tons power.
a A Right- and Left-handed Screws, carrying the Abutting Blocks B B, on
which rests the Angle Iron to be bent c, by the Block D, controlled by
Tappet Gear which regulates the supply of water.
E Tappet Gear working Valve F, admitting pressure to the Cylinder G,
in which works the Ram H., carrying the Block D.
k k Elevating Screws to vary height of work being bent.
ſº
à
sip
A Trolly,
zººs • * *
a ſº º
%2%Ns
& Z NSS
§ SYS..º.º. ººzzº
NS& º:
Ż s > ...~~~~
2222222222222232
vertical adjustment.
º º ŽKN
&Z>} | sº & a 4 ºr e º mº tº
Fig. 1.-PoRTABLE RIVETTER.
F Tension Rods which draw
the Levers together and
adjust the space G be-
tween them.
E Gap, closing small Rivets; H H The Hydraulic Ramcarry-
A Cylinder.
B Fulcrum.
cc Rivetting Dies.
D Gap, closing large Rivets.
in this case Abutments
B are transposed with
Dies co.
ing the Moving Lever M.
K Valve for admitting and
exhausting the water.
B B Post supporting Turntable.
H. H. Flush-topped Cylinder.
M. Handle and Screw for adjusting the Rivet.
B B Walking Pipes.
Fig. 4.—MACHINE FOR RIVETTING
D Carriage
I Keel of Ship.
N Balance Weight.
c Pair of Levers.
A Stop Valve on Mains.
c Swivel Joint.
D Connecting Pipe to Swivel E.
F Carriage.
G Hydraulic Lift.
H. Pipe conveying pressure from the
Lift to the Rivetter.
11 Pipe conveying water to the Swivelç.
I'1' Walking Pipes conveying water to
the Hydraulic Lift.
k Rivetter, 4' 6" opening.
1. Arm of Frame.
M Balance Weight.
2:l_wº º
ºs::::::=
~ sº-sº ºr
C
==S-S-5S->
º “s º
wº Sº § Fº
§ -> #3 3. §
º
A B Top and Bottom Castings.
c Moving Table or Follower.
D Matrix.
E Block.
F Lower or holding-up Cylinder,
G Vice-Table,
H Plunger for Vice-Table.
I Main Cylinder.
K Valves.
L Main Ram carry-
ing the moving
Table c.
Fig. 2.-TRAVELLLING CRANE FOR RIVETTER.
ºb Y:
D
Fig. 3.-HYDRAULIC PRESS FOR FLANGING PLATES.
HYDRAULIC MACHINES FOR RIVETTING AND FLANGING PLATES, RIVETTING KEELS, AND
DESIGNED BY MR, R. H. TWEDDELL, LONDON.
ANGLE-IRON OR BEAM STRAIGHTENER OR BEN DER.






























STATIONARY ENGINES. -: 345
HYDRAULIC MACHINE TOOLS.
(SEE PLATE.)
The application of hydraulic pressure to single machine tools
may be said to date from about the year 1847, when Mr. Fox used
the Bramah press for the purpose of forging. Since then a variety
of hydraulic tools have been introduced, amongst which may be
mentioned those for forging and welding, rivetting boilers and ships'
frames, fixing boiler tubes, for bridge and girder work, bending
angle irons, flanging plates, shears for cutting chain cables, beam
straighteners or benders, &c. 4.
Fig. I in the Plate shows a portable rivetter, having the cylinder
A between the fulcrum B and the rivetting dies CC.
In designing portable rivetters for ship and bridge rivetting some
form of flexible pipe is necessary, to convey the water to the
working parts; and copper pipes or india-rubber hose are used for
this purpose. The cranes carrying the rivetters are either attached
to fixed posts, or, as shown by fig. 2, the posts are movable on a
trolly, and by means of the walking pipes B B, connected to the stop
valve A and a swivel joint C, the whole apparatus may be moved at
pleasure. By means of connections at D and E at the foot of the
crane post, the pressure is conveyed by the pipe II to swivel Q,
where the walking pipes I'I' convey the water to the hydraulic lift
G on the carriage F, and a copper pipe H conveys the pressure to
the rivetter. Such a machine will put in over 2000 rivets per day.
Fig. 4 shows an arrangement designed for the rivetting of ships'
keels, where the small depth of the rivet heads and their great size
requires special arrangement. A post BB carrying a turntable revolves
on the trolly A, a pair of levers C, attached to a carriage D, carry the
rivetter E, which can be raised at pleasure to suit the work, and is
kept vertical by means of a parallel motion F; the whole is counter-
balanced by the weight N. The keels of the City of Rome and
Servia were rivetted by such a machine, and the advantage of so
powerful a method of closing up the rivets is evident when it is
considered that the keels of such large vessels are made up of a
number of plates and bars of great thickness. As a matter of
experiment, as many as 24 plates, each 3% inch thick, have been
closed up or rivetted apparently into a solid piece, showing what
346 MODERN STEAM PRACTICE.
work can be done by a suitable combination of pressure and per-
cussive action.
Fig. 3 shows a machine for flanging plates. On the bottom
casting B a matrix D is fitted, upon which the plate to be flanged is
placed, and by means of the block E descending the plate is turned
over upon its edges; to prevent buckling a cylinder F is fitted with
a plunger H carrying a table G on its ram, by means of which the
plates can be gripped between the table G and the block E.
Fig. 5 shows a machine for bending or straightening angle irons
and beams. The piece to be bent rests upon the abutting blocks
B B, which are adjustable by right- and left-handed screws AA, and by
means of a tappet gear the supply of water and also the travel are
regulated according to the work required, thus insuring exact repe-
tition and accuracy in work.
A very extensive adoption of hydraulic power to machine work
has been made at the French arsenal at Toulon, where amongst
others two punching and shearing machines, and also angle-iron
benders similar to fig. 5 are used, capable of exerting IOO tons of
pressure. There is also a stationary rivetting machine exerting
40 tons pressure, and a number of portable rivetting machines for
rivetting the cellular bottoms and decks of ships, at a distance
of I3OO feet from the accumulator. The pressure used is 1500 lbs.
per square inch. It appears that less steam power is required by
this hydraulic arrangement than would otherwise be the case, and
the author of the paper to which we are at present indebted says, “A
moment's consideration will show that when gearing is used the
prime mover must be equal to the maximum demand which can
be made on it at any moment. The accumulator, however, affords
a smaller engine the opportunity, when not otherwise fully engaged,
of storing up by easy stages an amount of power equal to the greatest
instantaneous demand likely to be made, and as long as the work
required is not equal to the power of the pumps, this process of
putting by power, as it were, is going on, consequently a much
smaller prime mover will suffice, which means less boiler power and
a more economic use of steam.”
* See a valuable paper and drawings in Trans. Just. Engineers and Shipbuilders in Scot-
iand, vol. xxiv., by Mr. R. H. Tweddell of London, who has been of late years highly
successful in applying hydraulic pressure to tools on a complete scale.
MARINE ENGINES.
THE OSCILLATING ENGINE.
The vibrating or oscillating engine introduced by Maudslay in 1827,
with its varied modern improvements, is very suitable for paddle-
wheel steamers, the comparatively small space it requires fitting it
admirably for this class of vessel. It is the most direct-acting kind
of engine which we have; the piston rod is connected to the crank
pin directly, thus saving height in the engines where that is a
desideratum, and the weight is most satisfactorily placed, being
neither too high nor too low in the ship. The many examples—
from the small river boats on the Thames of 30 horse-power collec-
tively, to large ocean steam ships such as the Great Eastern, the
largest ship as yet constructed, with oscillating engines for the
paddle wheels of IOOO nominal horse-power collectively—all bear
testimony to the success of the oscillating type of engine. It may
be regarded as the only example left of the many classes of engines
that have been successfully applied to paddle-wheel ships; and
from our being able to couple the crosshead of the piston rod
directly on the crank pin, and keep the weight of the machinery
below the deck, the oscillating engine is likely to remain long in use
for shallow river boats propelled by paddle wheels, for undoubtedly
this method of propulsion possesses many advantages over the
screw propeller for vessels of light draught, especially when they
are built to attain great speed.
The peculiar motion of these engines—the cylinders vibrating on
central hollow trunnions—requires the parts to be nicely balanced;
and as the piston rod takes the side strain and the strains imparted
by the action of the steam on the piston, it requires to be made of
greater diameter than for ordinary engines, where it is only sub-
jected to tension and compressive stress.
The trunnions should be so placed that the preponderance of the
weight of the cylinder is towards the bottom, by which means the
348 MODERN STEAM PRACTICE.
strain on the piston rod is not so much felt, and when the crossheads
are uncoupled from the crank pins the cylinders are not so liable
to tilt. This will be found a great convenience when undergoing
repairs at sea. The larboard and starboard trunnions are for the
steam, which passes through a belt cast along with the cylinder
into the valve casing. The faces for the valves are generally of the
three-ported type, two ports are for the steam and a central one for
the exhaust. The two central trunnions are for the exhaust steam,
which passes into the belt around the cylinder, and then into the
F
§§
#º
SSSSSSSSSS
&
3.
Sissºrs
NNNNNNSSNNSYNºNSN
% N
ºº: TISSS
Bºğ
Z Šº
%
%
% G
§
s
Fig. 220.-Cylinder. Fig. 221.—Trunnion Pipe and Stuffing Box.
A, Cylinder. B B, Trunnions. C, Cylinder cover. A, Trunnion pipe. B, Gland for stuffing box, c, Cy-
D, Bottom cover. E. E., Valve faces. FF, Steam linder. D, Throttle-valve pipe. E, Bracket for
passages. G, Exhaust passage. - supporting do. F, Pillow block. G, Frame.
condenser through the hollow trunnions; thus one half of the belt
allows the steam from the boiler to pass into the valve casing, and
the other half acts as a passage to the condenser, the division being
formed by feathers or bars cast in the cylinder.
The trunnion pipes for the steam and exhaust are fitted with glands
and packing spaces formed in each trunnion; the former are bolted
to the branch pipes, which are supported by brackets bolted to the
bottom frames, and the latter are bolted to the condenser casting,

MARINE ENGINES. - 349
and packed with hemp or other packing, similar to the piston-rod
packing. The branch pipes are bent upwards, and on the top flanges
are placed the throttle and expansion valves; thus an immovable
pipe, in communication with the valve casing which vibrates along
with the cylinder, is made perfectly steam-tight.
The steam valves are generally formed in duplicate, one being
placed on each side of the cylinder; while, for long-stroked engines
of this class, four valves have been introduced. In the former case
the horizontal line of location, or centre line of the exhaust port, is
on the centre line of the trunnions; in the latter, the valves are
placed above and below the trunnion centre line, with the object
of reducing the length of the steam ports, and thereby saving steam
at each stroke of the engine, and consequently fuel. The object of
placing the valves on each side of the cylinder is to balance it,
each valve is also greatly reduced in size; but notwithstanding that
the valve gearing is more complicated, double valves are generally
adopted, as they secure a neater and more equally balanced cylin-
der. One valve may be used for very small power, and a weighted
lever placed on the opposite side of the cylinder to balance it.
The stuffing bow and gland for the piston
rod of the oscillating engine is made very
deep, giving a large bearing surface to take
the side strain caused by the vibration of the
cylinder; and in cases where the proportions
allow of great space between the end of the
crosshead and the top of the gland bolts,
the part cast along with the cylinder cover
can be made of any convenient length, with
a brass bush inserted at the bottom, and the §
§ NS
necessary bushes and glands at the top of Fig. 222. — Cylinder- cover
the long neck piece, as in ordinary arrange- "stuffing Box.
ments. Care must be taken to have a A, Stuffing box. . B. Gland.
small amount of clearance all round the c. Bottom bush.
piston rod below the stuffing box, or to insert a very deep bush.
The condenser in the ordinary injection system is placed between
the cylinders, and in the surface system it is placed on the centre
line of the ship, behind or before the cylinders as the case may be.
The latter is not so compact an arrangement as the former, but it
is necessary, as the space taken up by the surface system will not
allow the condenser to be placed as with plain injection.
- IT-




350 MODERN STEAM PRACTICE.
The air pumps for the injection system are either single or in
duplicate, lying at an angle; when one pump is used it is
Sr*s
N
§
N
N
N
§
N
§
N
Šg32źSSSSSSSSSSSSSSSSS
Fig. 223.—Single Air Pump and Condenser.
A, Condenser. B, Airpump. C, Air-pump cover. D, Exhaust passage. E, Hole for injection valves.
generally placed forward in connection with the cylinders; when
two are adopted, one is forward and the other aft of the centre line
of the engine. They are worked directly from the intermediate
Fig. 224.—Double Air Pump and Condenser.
A, Condenser. B B, Air pumps. cc, Air-pump covers. D, Exhaust passage. E E, Hot wells.
crank shaft, with one rod for the single pump and two rods on the
same crank for the double arrangement. The rods have suitable
crossheads for taking the crank pin, and their bottom ends are
fitted with pins and joints, secured with large brass nuts through
the air-pump buckets, with trunks fitted to them, which serve as
guides, instead of crossheads and guide bars. The bottom part of




MARINE ENGINES. 35 I
the connecting rod has a hole bored up through it, and is fitted
with an internal steel rod which can adjust the bottom brasses with
a screwed key and jib. ..
In some examples the air | `-- :: *--. §
pumps have been placed i.....------' -- F •
vertically, one on each side
of the centre line of the
engines, having a single
connecting rod from the
crank pin, taking a vibrat-
ing beam placed above the
pumps, to which the buck-
ets are connected at the ſº
ends by rods and guiding H- - wº Aſºº
trunks, the p Oint of COIl- Fig. 225.--Double Air Pump and Condenser, arranged
nection for the main rod vertically.
being placed within the , ..."...hº...,
centre line of the forward
pump, whereby less throw is required for the crank on the inter-
mediate shaft. This plan, however, is not so good as working the
pump directly from the shaft, the
connecting rod taking a crosshead
on the air-pump rod, and which is
guided with cast-iron guide frames
bolted to the top of the air-pump
COVer. -
The air-pump bucket head and foot
valves (Fig.227) are fitted with round
discs of india rubber, working on
suitable gratings cast on the bucket
and valve seats, with the necessary * *-sº º Condenser,
guards to prevent or limit the lift of a, condenser e, Air pump. c. Airpump cover.
the discs. These valves are intro- ***.*.*.***
duced to obviate the disagreeable
knocking action felt in all pumps with metallic valves when working
at great speed. Instead of one large disc of india rubber, several
smaller ones have been fitted to the air-pump bucket head and foot
valve, but for slow-speed engines one disc is quite sufficient. In all
pump arrangements doors should be provided to inspect the valves,
without requiring to draw the air-pump bucket; in this respect it is
%
N
;
§
* = --~~~~~~~~~
t
|
j
t
g
|



352 MODERN STEAM PRACTICE.
more convenient to use smaller discs for the foot and head valves,
the latter being placed above the bucket, at the bottom of the hot
well, which is also fitted with a door to admit of occasional inspection.
&
22
º
%
Š%
* *
s
§
Fig. 227.—Bucket and Head Valve.
B, Disc of india rubber. C, Guard. D, Bucket. E, Disc of india rubber.
A, Head-valve seat.
F, Guard. G, Joint and pin for rod.
Cranked shaft.—As the intermediate cranked shaft in some engines,
more especially those of large power, has caused great trouble, plain
shafts have been substituted, and the air pumps worked by means of
eccentrics. A single eccentric may be adopted for a small diameter
of pump; but when the pump is large it is preferable to have two,
with rods connected to a crosshead, with a single central rod for












MARINE ENGINES. 353
taking the joint at the bottom of the trunk. In this way ample
bearing surface is obtained, and the shaft is not so liable to be
fractured as when the strain is re-
ceived on the middle. The eccen-
trics should also be placed as near
the main bearings in the head-
stock or top frame for taking the
shafting as can be conveniently
done, as the strain on the inter-
mediate shaft is thereby better Fig. 228–Cranked Shaft for Air Pump.
e e A, Cranked shaft. B, Main bearing. C, Bearing
distributed. - for eccentric. D, Crank pin for air-pump rod.
The feed and bi /ge f umpS 21 e E, Part for the piston-rod crank.
sometimes worked off a double -
lever arm, fitted to the end of the trunnions; this plan necessitates
a large diameter of pump, having a very short stroke, owing to the
length of the vibrating arm. This arrangement does not make so
Fig. 229.-Feed and Bilge Pumps.
A, Feed pump. B, Bilge pump. C, Rocking arm and rods. D, Plunger and stuffing box.
E, Suction valve. F, Discharge valve. G, Relief valve and spring.
effective a pump as when the stroke is increased, giving less dia-
meter of plunger, which can be readily attained by placing the
pumps on each side of the air pump, and connecting them to the
crosshead fitted to the top of the trunk, when they have the same


23
354 - MODERN STEAM PRACTICE.
length of stroke as the air pump. In this case the one acts as the
feed pump, and the other, technically termed the “bilge pump,"
pumps out the water that accumu-
lates in the hold of the ship. The
feed-pump valves are formed either
of metal or discs of india rubber;
but as the bilge pump takes in many
foreign substances, metallic valves of
the flap type are preferable for it.
Such valves answer very well for
moderate speed, but should never be
- º
[ED
* *
& 4
* *
S$S
2. Ele - gº
e.” 2 |
& 3.
&” º
:* ę
§§§
SN
S
N ss=E=SE; }# sº §
N 22, 2 Šſ
N S ŚW &
3S §s &s § | §
º §§ § *S$
NSN3–Nº. NěººV
N
N N
N
sks
A. v ſ
NSN \
Fig. 230.-Feed Pump.
àº, Ž
2
& º
ŠN
A, Feed pump. B, Ram for do. C, Pin for taking the air-pump crosshead at one end, and bilge pump
at the other end. D, Suction valve. E, Discharge valve. F, Relief valve and spring. G, Air vessel.
adopted for quick-going engines, as they would soon be knocked
to pieces, and the noise they make at each stroke is far from
agreeable.
The bottom bed plate for taking the trunnion blocks is a light
casting of a T section; the pillow blocks for the larboard and star-
board trunnions are sometimes cast on, and are fitted with brasses
at the top and bottom, like any ordinary pillow block. Holes are left
in the block piece for the main columns supporting the headstock
to pass through, which are fastened by cotters secured through the
casting. This arrangement makes a very stiff and strong bed plate.
The trunnion blocks are sometimes separate, bolted down on
flanges on the bed plate; and the main columns are secured to









MARINE ENGINES. 355
P
A
N
º
N
RN
%
%
|
%s
O O
Fig. 231-Trunnion Pillow Block cast on the Bed Plate. . .
A, Pillow block cast on frame. B, Cap for do. C C, Bolts for do. D D, Columns for supporting
the headstock.
Tſ
4
Fig. 232,-Trunnion Pillow Block separate.
A, Pillow block. B, Cap for do. cc, Bolts for do. D, Frame. E. E., Columns for supporting
- the headstock.
















356 MODERN STEAM PRACTICE.
strongly feathered bosses, and the necessary flanges are provided
for bolting the bed plate to the condenser casting. The frame
should be no larger than what is required for the oscillation of the
cylinder; and the whole is bolted down on the top of wrought-iron
bearers, securely riv-
etted to the vessel.
The headstock for
the crank shaft is of
cast iron, but in some
instances, where light-
ness is a desideratum,
wrought iron has been
used. For small en-
gines the headstock
casting is generally
of an I section, but
for large ones a box
section is preferable.
It is usually cast in
two halves, bolted at
the centre on the
centre line of paddle-
wheel ships, each half
being fitted with two
pillow blocks cast on,
fitted with brasses at
the top and bottom,
and secured with caps
of cast iron, having
bolts passing down
through the frame.
* Bosses for taking the
main columns are cast
along with the head-
stock. These columns are made of wrought iron, and are of suffi-
cient strength to receive the thrust and weight that they are sub-
jected to; and to give greater rigidity between the bed plate and
the headstock, cross stays of cast-iron are introduced on the lar-
board and starboard columns. The headstock is placed between the
engine beams which are made of plate iron of a box section; these
©º
Fig. 233.-Headstock.
A A, Headstock pillow blocks. B, Cap for do. C C, Holes for columns.

MARINE ENGINES. 357
beams run from one side of the ship to the other, underneath the
deck, and the lateral strain imparted from the headstock is taken on
them, wedge pieces being introduced between them and the cast-
ing. As the strain is fore and aft, these engine beams should be
made broad in the direction of the length of the vessel. The hatch-
way for the headstock cuts the deck in two at the middle of the
vessel where strength is most required, and breaks the continuity
of the deck stringers running fore and aft on the top of the deck
beams to stiffen the vessel; it -
is therefore desirable to pass
bolts of large diameter through
the engine beams and head-
stock, by which the frame is
firmly secured to the engine
beams, and as the stringers are
rivetted to these beams the
longitudinal strength is main-
tained.
The main cranks arearranged
in the usual manner, the crank
pins being firmly secured in
the inner ones; while the lar- | * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
board and starboard cranks are
fitted with brass bushes for the Fig. 234.—Main Cranks.
reception of the ends of the **** * º pin. C, Bush.
pins, in which they work quite
loosely, thus preventing any undue stress on the main shaft in a
heavy sea. .
Piston ring and block-We now come to notice the piston of the
oscillating engine, which is fitted with a ring on the top, termed the
junk ring. This is introduced to keep the packing ring in its place,
and is bolted down with screw bolts, the brass nuts for which are let
into recesses left in the body of the piston; the heads of the bolts are
flush with the top of the junk ring, and are screwed down with a box
key. The packing ring is generally in one piece; after it is turned on
the rubbing face it is cut at one part and sprung into its place, the
cut part being made steam-tight by a block piece of brass, with
a wrought-iron guard secured to the Spring ring at one end, and
moving in a slot at the other end on a guide pin; the brass block
is also secured to the ring at one end, and left loose at the other.

358 - MODERN STEAM PRACTICE.
The use of this guard piece is to allow a wedge to be driven between
it and the brass block, which contracts the spring ring; the piston
- is then placed in the cylinder, and when the
wedge is removed the ring expands and fits
the cylinder exactly. Curved steel springs are
then inserted between the piston and the pack-
ing ring all round; thus with its own elasticity,
and with the aid of these springs, the surfaces
between the piston and cylinder are made quite
steam-tight. All the parts should be cărefully
turned, and the surfaces between the junk ring
fluº and the piston Scraped; no grinding material
%fift § should be used to make this joint tight; in fact
% N § S.
* § à is º o º -
** * the use of emery for making steam joints, or
ài º for getting up journals, has long been discarded,
*º "#."
as the small particles of grit are sometimes
Fig. *... Ring and imbedded in the metal, and soon play havoc
OCK PleCe. º e
- . . . with rubbing surfaces. -
A, Piston. B, Packing ring. …'s * º
c, Junk ring. D, Bolt and The pistore rod is secured by a nut, sometimes
recessed nut. E, Block and &
uard. . placed at the top, in other cases at the bottom
g y y
- square threads for which are cut on the
rod. The nut is sometimes flush with the top of the piston, and is
screwed into the recess by a spanner, fitted with a pin which takes
Y
§
Fig. 236.--Top Nut for Piston Rod. Fig. 237.-Bottom Nut for Piston Rod.
A, Piston. B, Cone on piston rod. C, Nut. A, Piston. B, Cone. C, Nut. D, Pin.
the holes drilled in the top surface of the nut; a better plan, how-
ever, is to recess the nut partly, leaving sufficient projection so that
it can be tightened up with an ordinary key. Of course the end of





















MARINE ENGINES. 359
the piston rod must be turned with a taper, to secure a perfect fit
between the piston and rod. When the nut is placed at the bottom
of the piston it is screwed up against the face ring, and is further
secured by a cotter passing through the rod; this plan is gen-
erally adopted when the crosshead for the crank pin forms part of
the rod. Some makers leave a collar for bearing on the top of
the piston; and with a solid piston rod and crosshead the glands
require to be cut. The collar, however, may be dispensed with,
as a plain cone is quite sufficient. Recesses must be left in the
cover and the bottom of the cylinders for the securing nut to pass
into. -
The crossheads for the piston rod are of various forms. Some are
forged along with the rod, and slotted out for the reception of
C
-it
i
* sº
:
G
&
|
A.
t—r
—
L -
- SNS
Fig. 238.-Piston Rod and Crosshead forged on. Fig. 239.-Piston Rod and Socket for Crosshead.
A, Crosshead. B, Cap. cc, Bolts. D, Piston rod. A, Crosshead of brass. B, Cap. cc, Bolts.
E, Brasses. D, Socket piece. E, Cotter.
brasses, which are secured by means of caps, held down with bolts
passing through the crosshead; others are forged all in one piece,
and are bored out for the reception of the rod, which is held in
position by a cotter; others again have a T piece left on the rod,
or a T bottom piece cottered to the rod, having the brasses cast to
form the middle part of the crosshead, on the top of which is placed

360 MODERN STEAM PRACTICE.
the cap with bolts for screwing up the brasses. An oil chamber
should be forged on the cap and then bored out, or a separate oil cup
fitted with a siphon wick, for lubricating
the crank pin. SNS
The air-pump rod crosshead is simi- […]
larly constructed, with a T piece formed
on the rod, having brasses and cap with L..…~~ º
bolts passing through. The bottom part Tº -----
of the air-pump rod is generally left
§
§ N
§lsº
Nºë
Fig. 240.—Air-pump Rod Crosshead. Fig. 241–Air-pump Rod, bottom end.
A, Crosshead of brass. B, Cap. C C, Bolts and A, Rod. B, Inside rod. C, Jib and cotter.
nuts. D, Rod. - D, Bush.
hollow, and is fitted with a steel bar inside, so as to be able to
adjust the wear of the brasses; this plan is of course only adopted
when the bottom of the rod is attached to the pin on the crosshead
placed in a hollow trunk.
The injection valve generally adopted is the simple cone plug (Fig.
242), cast hollow and fitted with a stuffing box at the top, with a
spindle carried up and supported by a round pillar, on the top of which
is fitted an index; a handle is fitted to the spindle for actuating the
plug, which has passages in connection with pipes from the sea for
admitting water into the condenser. Sometimes flat sluices and
gridiron valves are adopted, worked by levers connected to the
valve spindles; others prefer disc valves having spindles through






MARINE ENGINES. 361
the centre bosses left in the valve seatings, and lifted by separate
screwed spindles with turn wheels and handles; and some small
- valves of this type are lifted by
levers, the short end of the lever
working in a slot crosshead
screwed on the vertical spindle. The pipe placed
inside of the condenser, in connection with the
injection valve, should be perforated with a num-
ber of round holes or slits, so placed that the
water is distributed or showered over a large sur-
E. -
Ø
ğŽ
%t
\
º
Ø
%
$JA £ºs tº «» sº *
Ef º, face. Some engineers have adopted distributing
āşE}sº
plates, perforated with round holes, so that the
water falls into the condenser as in an ordinary
shower bath. We prefer, however, the perforated
copper pipe, which should taper to a smaller dia-
meter at the end furthest from the valve. By this
means the water is more equally distributed; for
Fig. †º were the pipe to be made of equal area throughout
A, rº º, chest the pressure would decrease, owing to the water
& Gland and stuffing bºx escaping through the perforations, but when the
D, Standard. E, Handle. & tº e
pipe is contracted from the valve to the end which
is filled up then the pressure is maintained more equally all
along its length.
The Kingston valve (Fig. 243) is fitted to the side of the ship, with
a cast-iron piece between the iron plates and the brass, to prevent
corrosion from the oxidation caused by placing brass in contact with
wrought iron. These valves are fitted to the vessel before it is
launched; they consist of cone valves lifted by means of spindles,
and are held in position by cotters passing through the spindles
and bearing upon columns fixed to the covers; the spindles pass
through these covers, and are made tight by stuffing boxes and
glands. A gridiron is fitted at the bottom of the case or pipe
containing the valve, to prevent extraneous matter entering the
condenser. The use of the Kingston valve is to shut off the sea
water in the event of any of the pipes which supply the engines
getting damaged, in which case, if some contrivance were not
adopted, the sea water would rush in and fill the engine or boiler
room. A plug valve is also fitted to the Kingston valve, so as
to shut off the sea water effectually. -
The blow-through valve (Fig. 244) is fitted to the steam pipe, or
§
E
t
E
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Z
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4
S
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§
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ſ
SSSSSSSSSSS!
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362
MODERN STEAM PRACTICE.
in communication with it and the condenser, so that steam from
the boiler may be blown through the condenser and also into the
Fig. 243.--Kingston Valve.
*A, Valve chest.
(C)
B, Valve, c, Spindle.
D, Cotter. E, Branch piece on ship's bottom.
%
º
% sº
2
E - - ſº
ãº
& º §
Žf
%
t
Fig. 244.—Blow-through Valve.
A, Valve. B, Chest. C, Lifting spindle,
D, Handle., E, Stud.
cylinder, warming these parts and expelling the air; thus by turning
on the injection a vacuum is formed in the condenser, before the steam
Fig. 245.-Snifting
Valve.
A, Valve. B, Chest.
c, Set screw.
from the valve casing is admitted into the cylinder.
This valve is a spindle one, opened with a lever
handle, and is held down by the steam pressure on
the top side.
The snifting valve is fitted to the lowest part of
the condenser; by it all the air in the condenser
escapes in the process of blowing through. It is
a plain spindle valve, fitted in a valve chest; the
chest and valve are generally of brass, or a cast-
iron chest may be substituted, with a brass valve
seating let into it. The steam in blowing through
opens the valve, and all the air is driven out; but
when the injection is turned on and the vacuum









MARINE ENGINES. 363
formed it instantly closes, and is secured by a thumb screw, passing
through the baffle plate which
is sometimes fitted for throw-
ing downwards the water ex-
pelled from the condenser.
The relief valves, placed at
the top and bottom of the tº
cylinder, are for the ejection ; :
... • *
sº
as m a.º. as * * * * * - - - - -s º ºs.
fºr:::::---...:*T.
*s sº-
º eae ºr
of the water collected through i tº:
priming and from the conden- ºsº
sation of the steam. They are
spindle valves, with seats of
the usual form. The valve for ! .
the cylinder cover has a cap on ºf Biºs §
the top, on which are placed ãºf Eſº
the Spring and top cap, and a Fig 2,6–Relief valve on cover.
set screw which passes through A. Valve. B, Cylinder cover, c, Spring. D, Set screw.
the cover required to prevent E, Baffle cover.
the hot water from scattering. The valve for the cylinder bottom is
provided with a long spindle, on the top
of which are placed the cap and spring, and
which is screwed down by a screw pass-
ing through a bow secured to the valve
casing, the baffle plate being fitted under
the bottom cap. In some examples the
valve is cast with a long spindle on the
top of the disc, which passes through a
hollow screw, fitted to a stud placed on
the cylinder; between this stud and the
valve there is a spiral spring with a cap at
the top; by screwing up the hollow screw
against this cap the spring is compressed
to any desired extent; the downward pres-
sure should be slightly in excess of the
steam pressure on the valve, so that when
water collects in the cylinder the piston
impinges on it and forces it through the -
valve into the bilges. A baffle plate must * w—ºr for Bottom of
be fitted to throw the hot water down- a valve and spindle. , Chest.
o c, Spring. D, Bow. E, Set screw.
wards; and these valves should be placed F, Baffle plate.
%
2.
%
2
%
2.
%










364 MODERN STEAM PRACTICE.
at the back of the cylinder or the part furthest removed from the
starting platform, to prevent the engineer from getting scalded by
the steam and hot water. A supplementary plug valve is also fitted
at each end of the cylinder, for allowing the water to escape; these
valves should have a handle common to both, with a pipe connec-
tion for passing the water down to the bilges; in this way the water
can be blown out of the cylinder independently of the loaded spring
relief valves, which are only brought into action in cases of heavy
priming or other serious causes.
The expansion valve, when one is fitted, is placed on the top of
the trunnion pipes at the side of the vessel. This valve is usually
of the double-beat Cornish type, and is a very convenient form,
requiring but little power to lift it. It is raised by a variable cam
placed on the paddle-wheel shaft, having a balanced lever with rod
passing down to the valve; on one end of this lever there is a small
roller, fitted on a spindle between the jaws of the lever, having a
screwed spindle so arranged that it can be turned by hand, moving
the roller to suit the grade of the expansion required. Sometimes,
when a certain grade of expansion is fixed upon, the valve can be
lifted and shut by a rod from a crank pin placed on a wheel driven
off another wheel on the paddle shaft; by moving the pin in a slot
any amount of opening by valve can be obtained, the rod which
connects the valve to the pin being fitted
n with a right and left hand screw for adjust-
ing the length. -
The throttle valve is placed between the
boiler and expansion valve, where an expan-
sion valve is used; but where it is not, the
throttle valve is placed on the top of the el-
bow trunnion pipe (Fig. 22 I). The valve is of
the butterfly kind, hung equally by a central
spindle passing through it, fitted with levers
and rods passing along to the starting plat-
form. The seat for the valve consists of a
short flanged pipe, with gland and stuffing
Fig. 248–Lublicator for the box for making the spindle steam tight, the
Cylinder. other end of the spindle having a reduced
pin let into a hole bored in the casting.
This kind of valve is rather troublesome to get up, so as to properly
fill the cylinder in which it works; two pins, one on each side, should
©
A, Oil cup. B, Plug tap. C, Handle.

MARINE ENGINEs. 365
be left in the pattern, placed at the angle the valve is designed for,
and the valve can thus be turned to fit the seating exactly.
The lubricating cups should be plain, having pipes passing down
to the bearings, fitted with siphon wicks; and they should have
covers to prevent dirt lodging in them. Some engineers cast the
cups on the various parts, while others prefer light cups cast in
brass. Fig. 248 shows the lubricator cup with hollow plug fitted to
the cylinder cover for lubricating the piston.
SLIDE-VALVE GEAR.
The slide-valve gear for the oscillating engine differs so much
from other arrangements that it requires to be treated somewhat in
detail. The mode of setting out this valve motion has been already
2. f
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Fig. 249.-Slide Valve.1
A, Slide valve. B, Ring for taking off the back pressure. c, Valve spindle. D, Valve casing.
E, Valve-casing cover. F, Cylinder.
described, and although the various plans adopted may differ in
detail, the motion produced is the same in all. Take, for example,
* In this section the various figures are diminished as in working drawings for the
workshop.


366 MODERN STEAM PRACTICE.
the case of a marine engine having a cylinder 4 feet 3 inches in
diameter, and length of stroke 4 feet. The short D slide valve is
usually adopted, with a packing ring on the back of the most
improved description. The ports in the cylinder are not nearly so
short as for direct-acting engines having the multiple-ported arrange-
ment. There is a port at the top and bottom for the steam, in
connection with one half of the passage or the belt cast on or about
the centre length of the cylinder; the trunnion or pipe on which
the cylinder oscillates is cast on the centre line of the belt. The
outside one, or the one nearest the ship's side, in paddle-wheel
engines, is for the steam, and the one nearest the centre line of the
vessel is for the exhaust into the condenser, being in communication
with the central ports on the cylinder. The slide valve is contained
in a suitable casing bolted on the cylinder, and provided with a
movable cover at the back. The inside face is planed and scraped
perfectly true, so that the slide rings are steam-tight; there is a
small hole bored in the back of the valve to take away any steam
that may pass, which of course finds its way into the condenser.
There are generally two valves, one on each side of the cylinder;
such an arrangement not only reduces the size of the ports, but
also balances the cylinder better. When one valve is used, a coun-
terpoise weight, fixed on a lever, is attached to the cylinder, and
oscillates with it; but such a plan, when adopted for large power, is
neither so neat nor so compact as the double slide valves, although
these require more working parts. At the same time, when two
valves are used, the details can be made much lighter, as the area
of each valve is much less. The usual mode of Securing the valve'
spindle to the valve is by a T nut let into the valve, having a cor-
responding thread on the valve spindle, with a jam nut to secure it
in its position; and in other arrangements a Snug is cast on the
valve, with a hole for the reception of the valve spindle, having
nuts at the top and bottom. The centre of the exhaust port and
trunnion may be taken as the starting point for setting out the
valve faces, their place being the centre line of oscillation of the
cylinder. The opening of the port by the valve is found by the
same rule as that used in other arrangements. Thus, suppose for
the cylinder 4 feet 3 inches in diameter, with stroke of 4 feet, the
number of revolutions is 28 = 224 feet of piston speed per minute:
we have therefore— .
2O42 × 224
1oooo T 7 45°7 Square inches,
MARINE ENGINEs. 367
... which, divided by 2, equals 22.8 square inches of opening of port
by valve for each. The length of the ports is found by dividing
the diameter of the cylinder by 34, thus: 51--34–15 inches long;
and 228 -- 15 = I’52 inch, the opening of port by valve. The
combined area of the steam ports equals #th, and that of the
exhaust 15th of the area of the cylinder: thus—
** = 81-6+2 = 40-8 square inches in steam port;
2O42
# = 157 -- 2 = 79 square inches in exhaust port.
A little more or less may be allowed to secure even dimensions.
Throw of eccentric, slide gear, &c.—The oscillating engine differs
from all others in having reciprocating pistons, and no connecting
rod, the piston rod and crosshead being attached directly to the
crank pin. We may, however, term the
distance from the centre of oscillation to
the crank centre the length of the con-
necting rod, as from A to B, and with this
length as a radius, from the point B sweep
the crank path, this radius is the length
of the supposed connecting rod when the
piston is at half stroke. It will be seen
that this length varies, being greatest
when the rod is vertical, the piston com-
mencing the IN stroke, and rapidly short-
ening as the piston, descends, until the
crank pin reaches the bottom of the crank
path, when the length will be simply the
vertical height from B to OUT, or the com-
mencement of the up stroke. It will thus
be evident that the radius for finding the
correct angle of the crank for cutting off
at any part of the piston stroke varies.
To explain this more fully: Divide the
vertical diameter of the crank path from
IN to OUT into eight equal parts, fix the
point of the compasses at the point of
oscillation as at B, the vertical distance to
any point that may be determined on for cutting off the steam, say
at five-eighths of the stroke of the piston, as from IN to OUT, is the
Fig. 250.-Path of Crank.

368 MODERN STEAM PRACTICE.
radius that determines the point C or centre of crank pin, when the
steam is cut off at five-eighths of the piston stroke. Thus the versed
sine of the chord of the arc of supply to the cylinder can be found,
namely, D E, which measures nearly IO inches. The diameter of
the circle described by the centre of the eccentric can also be now
found, as already described for direct motion; but as the lever for
taking the valve spindle may be shorter than the one for the slot
link, it is evident that the eccentric circle must have a greater
diameter. Supposing this is the arrangement adopted, and the
length of the lever for the valve to be 12 inches, and that for the
slot link 15% inches (those lengths can be only determined by
laying down in plan the valve and gear). When it is known that
the versed sine of the chord of the eccentric circle for the arc of
supply is the full opening of the port by valve minus one-half of
the lead, we have the following, supposing the lead to be 96th part of
an inch: The full opening of the port by valve as already found is
I-5 inch minus ºº inch=1:468 inch as the versed sine of the chord
of the arc described by the eccentric circle for direct motion. The
diameter of the crank circle is equal to 48 inches, and the versed
sine of the chord of arc of supply is IO inches. We have therefore
Io : 48 :: I'468=7'O4 inches diameter of eccentric circle for direct
motion, or for levers of equal length; but as the levers for working
the valve are of unequal length, we have 7"O4: I2 :: I5'5 = 9'OI
inches diameter of the eccentric path or full travel of the valve.
Eccentric and hoop.–The eccentric is cast in two halves and bolted
together, for the convenience of taking it to pieces or placing it on
the shaft. Were the eccentric placed on a plain shaft at the end,
with nothing to interfere, it would be cast all in one piece; but as
it is generally placed between collars turned on the shaft, at the
side of the main cranks, the ring requires to be in two halves. The
eccentric sheave revolves freely on the shaft, and has a catch cast
on it, with a corresponding catch fixed to the shaft, so as to suit the
forward and backward movements. The eccentric sheave is also
fitted with a back balance, so that when the engine is reversed by
hand, the eccentric rod being out of gear and the sheave being
loose on the shaft, the latter is perfectly balanced, and prevented
from revolving when the catch is not driving it. This is most
required for engines of great power, where the sheaves being
large would turn rapidly round, and being met by the catch would
impart a smart blow, tending to disarrange the gear. For small
MARINE ENGINES. - 369
power the eccentric is fitted with a brass hoop, bolted together, for
taking the eccentric rod, and large engines have the hoop forged
C
- I.
2 ::::A;
: :::: : *
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Fig. 251.—Eccentric and Hoop.
A, Eccentric. B., Hoop for do. C, Catch. D, Balance.
on the eccentric rod, and lined with brass pieces at intervals. The
siphon cup for lubricating the sheave is either cast on the brass
hoop, or is separate, as when the hoop ſq
and rod are forged all in one piece.
Catch on shaft. — To determine the
position of the catch on the shaft to suit sº-T->
the forward and backward movements;
the position of the eccentric centre for
the forward movement being directly
opposite to that for the backward move-
ment. Draw A B, the line of crank, and
describe the circle in dotted lines equal
to the throw of the eccentric; then find
the versed sine of the chord of arc of
supply, and the point E can be fixed,
that being the centre of the eccentric
for the forward movement; from the point E draw a line perpendi-
cular to A B, and produce it until it cut the eccentric path on the
opposite side, that is the point or centre of the eccentric for the
- 24
Fig. 252–Catch for Eccentric on Shaft.


37O MODERN STEAM PRACTICE.
backward movement. Draw the line A E, which is the centre line
of the catch on the eccentric sheave, which is set off equally on
each side as represented in section, F is the forward end of catch,
and G the end of catch for the backward movement. The driving
catch on the shaft, represented in black, is secured by bolts. It will
be seen that the line of crank is so much in advance of the point
on the end of the catch on the eccentric at G, for the forward move-
ment; and that it must be so much in advance of the point F for
the backward movement. Thus, supposing the catch on the eccen-
tric were stationary, and the crank free to go backward to the line
represented at AI, it would travel through an arc the distance from
H to G, when it would be down, and the catch on the shaft would
be moving the eccentric the contrary way from the direction shown
by the arrow, and the crank turning the paddle wheel astern. It
- will be seen that the catch
F- on the eccentric sheave is
placed so that the driving
: catch embraces one-half of
$2. the circumference of the
; #2% shaft, although at times it
§ ... S. C. D.
* Y- * may be less, owing to the
43%; _B length of the catch on the
; : eccentric; but when conve-
J nient this position of the
driving catch on the shaft is.
to be preferred. Thus, when
the line of crank A B is in
słº, the position delineated, it
.#2%; will move in the direction of
• * * the arrow when the end of
* © º the catch at F is the driver;
but when the end of the
catch at H becomes the
driver, it must move in the
D contrary direction. The
- - catch on the eccentric is re-
Fig. 253. —Eccentric Rod and Socket. presented by dotted lines:
A, Eccentric rod. B, Socket and pin. © tº tº º
the line of crank is equidis–
tant from the points G and K. When the engine is required to
move either forward or backward, the slide valve is worked by

MARINE ENGINES. 37 I
hand, and the eccentric accommodates itself to the catch fixed on
and revolving with the main crank shaft.
Eccentric rod and valve gear.—The eccentric rod in this example
(Fig. 253) is a plain round bar, with a T end for taking the eccentric
strap; the end for taking the slot link passes through a long guiding
piece, oscillating on the link through a hole having a brass bush.
Some—indeed we may say the most—are arranged with a plain gab
end, that is thrown out of gear when the engine or rather the valve is
worked by hand; but
in this arrangement
the rod always slides
in the socket, and is
thrown into gear with
a plain round pin pass-
ing through the socket
in which the rod slides.
The plain gab end,
however, is usually
considered preferable
for large engines. The
valve rod is attached
to the lug cast on the
valve by a screw cut
on the end, with nuts
on the top and bottom,
which are screwed up
against the lug on the
valve. The top end
has a slot fitted with
a sliding block; a pin
passes through the
block, and is secured
through the eye on the
rocking lever. The
valve rod is guided at
the top by means of
a bracket fitted to the
cylinder. There are
i
1
‘ts
Fig. 254.—Valve Rod and Guide. Rocking Levers and Stud.
A, Valve rod. B, Block for do. c, Guide for do. D, Lever for
valve. E, Lever for eccentric rod. F, Stud for levers.
two rocking levers for each valve: one has a slide block working in
the slot link, with a radius suited for the valve gear when placed at

372 MODERN STEAM PRACTICE.
half stroke; the other lever, as before stated, takes the slide valve
rod. When the slide is at half stroke, the valve covering all the ports,
the distance or vertical height from the centre of oscillation to the
slide rod pin is the position in which the rocking levers are level.
The sliding blocks on the slot link are placed slightly apart, and
from the centre of the trunnions on which the cylinder oscillates to
the centre of the sliding block pins is the radius of the link. The
rocking levers for taking the slot link and valve spindle oscillate
- on a fixed centre or pin fitted to the
cylinder, the rocking centres on levers
being bushed with brass. This bearing
is usually in the form of a pillow block,
bolted to a bracket cast on the cylinder;
the journal and covers are forged all in
one piece, the bearing being in the middle
with the levers on each side. The radius
of the slot link, as before stated, is the
vertical height from the centre of the
trunnions to the centre of the pins on the
levers, when the valve is placed at half
stroke, the levers lying level. The ends
of the slot link are fitted with brass guid-
ing pieces, one of the guides having a
rack or teeth cast on, working into a
pinion fitted to the starting-wheel shaft.
These guides are hollowed out to slide on
- S. (O) LP and between the wrought-iron columns
Fig. ass–Sector and Brasses for supporting the crank-shaft framing.
A, Sector *...* for socket. The slot link is likewise guided at the
x *-** * *****, * ~~~~~~ top, a small bracket being bolted to the
headstock, through which the round part of its shank slides. The
length of the slot link must be determined from the angle of oscilla-
tion at half stroke, and the necessary clearance for the sliding blocks
on the levers must also be allowed for. The centre of oscillation of
the socket for taking the eccentric rod has a brass bush fitted to the
slot link, but when a gab end is used a plain pin is simply fastened
to the link.
Starting gear.—For working the slide valve by hand, in engines
of small power, a long lever handle is attached to the wrought-iron
columns; this lever is fitted with a link, connected to the slot link
;


MARINE ENGINES. 373
by means of a pin; the handle vibrates with the upward and down-
ward motion of the sector, and the eccentric rod, fitted with a gab,
is thrown out of gear by a small lever and rod, so placed that it
tends to keep in the gab when in gear, and prevents it falling into
gear when thrown out. In some examples springs and catches are
used for the same object. Sometimes the lever handle is adopted
for heavy engines, in which case it is advisable to have a socket, so
as to detach the handle when the engine is working; but the better
y”
2,
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Fig. 256.—Starting Gear.
A, Starting wheel. B, Bracket. C, Pinion-rod shaft. D, Column. E, Throw-out handle.
plan is to have this part of the gearing arranged so as to be able
to handle the valves at the shortest notice. A very general arrange-
ment is by means of a pinion, working in a rack placed on one of
the guides that is bolted to the sector or slot link; on the other
end of the shaft for carrying the pinion is placed the starting wheel.
In the example before us, the starting wheel has four arms, with a
central boss, which is keyed on the shaft. The pinion is thrown
in and out of gear by a lever, the same motion disengaging and
putting in gear the eccentric rod. A spring detent is fitted through


374 MODERN STEAM PRACTICE.
a slot on the throw-out handle, a rod being attached to it and the
pin which passes through the socket on which the eccentric rod
slides. This arrangement of starting gear is certainly very compact,
although for heavy engines we prefer the plain gab on the eccentric
rod. The bracket for carrying the starting wheel, &c., for small
power, is generally bolted to the columns for carrying the head-
stock.
THE LINK MOTION.
The application of double eccentrics and link motion to the
oscillating engine affects but little the general arrangement of the
valve gear. The pin on the sector for taking the gab end of the
eccentric rod, as for the single-eccentric arrangement, is used for
the block on which the link slides; in fact, this pin and block
may be compared to the pin and block on the slide-valve rod,
in the direct applications of the link motion to the locomotive, or in
horizontal direct-acting marine engines. Indeed, the oscillating
engine may be considered a direct-acting engine, whether set verti-
cally, horizontally, or lying at an angle; but as levers are interposed
between the sector and valve spindle, the motion becomes indirect.
As the sector always moves in a direct line similar to the slide-
valve spindle in horizontal arrangements, and as the pin for taking
the block on which the link slides is fitted directly to the sector, it
only remains to consider the application of the double eccentrics
and link motion from this point to the centre of the main crank
shaft. Thus when the levers are placed horizontally or at right
angles to the valve spindle, the slide valve being at half stroke,
then from the centre of the pin on the sector to the centre of the
main crank shaft is the radius for describing the link, to which the
double eccentrics and rods are fitted in the usual manner. So it
will be understood that the double eccentrics, keyed fast on the
crank shaft, having rods and link working directly in a line with
the slot link or sector for taking the levers for actuating the slide-
valve spindle, simply take the place of the single-eccentric rod and
gab end, having means of throwing out and also of actuating the
valve by hand, to suit the direction required for the forward or
backward movements. The link, however, being attached to eccen-
trics for both the forward and backward motions, the combin-
ation of both can never err (with proper mechanism for moving it
on the block which oscillates on the pin attached to the sector) in
MARINE ENGINES. * 375
actuating the valves as required. The valve mechanism of oscillating
engines, in combination with the link motion, is beautifully simple
in its multiplicity of parts, and in the science of engine-building it
may be truthfully regarded as the perfection of valve gearing. It
must be borne in mind that, although the positions of the centres
of eccentrics are the same in relation to the centre line of crank as
for direct motion, yet as the lever for taking the sector must move
upwards, to depress the one for taking the valve, the positions of
the eccentrics on the eccentric path are different, that for the oscil-
lating engine being on the circumference of the path nearest the
crank pin, while for direct action the centres are on the opposite
circumference of the eccentric path. The mechanism for actuating
the links acts simultaneously, and a very general arrangement is to
have a thread cut on the shaft for taking the starting handle, fitted
with a crosshead working in suitable guides, the centre of the cross-
head being bored out and screwed to suit the thread on the shaft.
At each end of the crosshead there is a part turned for the reception
of side rods, connecting the crosshead with the main links. Thus
by turning the starting wheel in either direction, the crosshead, side
rods, and links are moved in the direction required. The bracket
for carrying the starting-wheel shaft and for guiding the crosshead
is cast all in one piece, and is fitted to the condenser on the centre
line of the ship, as for paddle-wheel arrangements. This motion
for actuating the link has the advantage of holding it in any position
when at work, without the aid of set screws or any other appliance,
which is a great desideratum when the link is used for working
expansively. In some arrangements the starting wheel and shaft
actuate a crosshead, generally cast in brass, on which lugs are
formed for the reception of a single central rod, which takes a lever
on a cross shaft, vibrating on two pillow blocks. On each end of
this shaft a lever is fitted, having a pin and rod in connection with
each link; thus motion is imparted, and the link put in forward or
backward gear as required. In other arrangements the crosshead
and guides are dispensed with, and a worm wheel substituted, which
is placed on the end of the starting-wheel shaft, and works into a
pinion placed central with the cross shaft, having levers and rods
in connection with the link, as already described. Sometimes the
bracket for carrying the starting-wheel shaft in this arrangement
is simply a pipe bushed at each end, cast along with the hot well,
to which the cross shaft has pillow blocks also. In fact, the main
376 - MODERN STEAM PRACTICE.
thing to be studied in the mechanism for actuating the link motion
is the side rods for taking the link: let them be of sufficient length,
so that the versed sine of the chord of the arc of oscillation may
not affect the link in relation to its block; because, when they are
made too short, a sliding action takes place, which in some instances
seriously affects the proper working of the valve. When this point
is duly attended to, power has only to be applied to the lifting or
reversing rods, and the mechanism for applying this power should
in all cases be as simple as possible. For small engines, a cross
shaft with pillow blocks cast on the condenser, and having levers
and rods at each end, actuated by a plain lever handle, and with
quadrant and catch similar to the locomotive engine, is as good an
arrangement as can be adopted.
The link generally used is of the solid type, slotted to receive
the block on the sector, all of which are made to the proper radius,
The lugs for taking the eccentric rods are forged on, but in some
instances lugs are wanting, and the rods are simply attached to the
ends of the link. The former is the better arrangement, as the pin
on the eccentric rod is nearly in a line with the pin for taking the
link block, thus direct motion is obtained; while in the latter
arrangement, the eccentric rod pin is all to the one side, and in
addition a larger eccentric sheave is required, which is not desirable.
The pin on the link for taking the lifting or reversing rods is placed
midway between the eccentric-rod ends, on the radius line of the
link, and it is forged on a cross bar secured to the link by rivets.
In some cases the eccentric-rod straps are forged along with the rods,
having a lining of brass, and are secured on the eccentric sheaves
with bolts and nuts; in others they are cast in brass, and the rod
attached by means of a T piece forged on the end, with suitable
bolts and nuts, lock nuts, and securing split pins. The eccentric
sheaves are cast in two pieces, accurately fitted together, and bolted
similarly to the sheaves for single-eccentric arrangements; this is
done for the convenience of getting them on or off the shaft, but
where circumstances will allow of it, the sheaves are better cast in
one piece, which simplifies the manufacture.
| MARINE ENGINES, - 377
SPECIFIC NOTICES OF MARINE ENGINES.
The oscillating engines of the Great Eastern are the largest yet
made, there being four paddle cylinders of 74 inches diameter and
I4 feet stroke; the diameter of the paddle wheels is 58 feet.
The oscillating engines of the Clyde river steamer Columba are
probably the largest yet used in any river steamer, each of the
two cylinders being 53 inches in diameter, and the stroke 5 ft. 6 in.
The Lord of the Isles, another large Clyde river steamer, has two
diagonal oscillating cylinders, working on the same crank pin. The
diameter of these cylinders is 46 inches, with a 5 feet 6 inches
stroke. These steamers are fitted with surface condensers.
In the Post Boy, a vessel of 65 tons and 20 horse-power, built on
the Clyde in 1820, the late Mr. David Napier appears to have tried
a surface condenser, consisting of a series of small copper tubes
through which the steam passed, and was condensed by a circulation
of cold water on the outside of the tubes.
The Fairy Queen, the first iron steamer plying on the Clyde,
launched in 1831, had an oscillating engine.
The steeple engine, first introduced on the Clyde about 1836 by
Mr. David Napier, is a convenient form of engine for river boats.
It consists essentially in an overhung triangular frame from the
crosshead, on which hangs the connecting rod. This frame and
rod are connected with the piston by either one or more piston
rods. In the earlier forms one rod was commonly fixed to the
lower part of the triangular frame, in other forms two and often
four piston rods are used.
The side-lever engine was extensively used in paddle-wheel
steamers, the arrangement being very much that of an inverted
beam engine.
The first paddle steamer to cross the Atlantic from Britain was
the Sirius, built at Leith in 1837, and engined by Messrs. Wingate
& Co. of Glasgow. The Great Western, built at Bristol, also made
the passage, the two arriving in New York about the same time.
The Sirius measured 178 feet long by 25 feet 8 in. beam, depth
18 feet 3 in., and was 450 tons register. She was fitted with two
side-lever engines of 270 horse-power; diameter of cylinder 60 in.,
stroke 6 feet; paddle-wheels 24 feet diameter with twenty-two
floats, and appears to have had Hall's surface condensers.
The Cunard steamer Scotia, the last great ocean-going paddle-
378 MODERN STEAM PRACTICE.
wheel vessel built, was fitted with a pair of side-lever engines, the
diameter of cylinders being 100 inches, with a stroke of 12 feet.
The diameter of paddle wheels was 40 feet. -
A specimen of the early side-lever engine may still be seen placed
on a pedestal at Dumbarton pier on the Clyde. It is the first marine
engine made in 1824 by Mr. Robert Napier, the well-known Clyde
engineer, for the steamer Leven.
Trunk engines were introduced by Penn, and have been much
used in H.M. navy. The piston rod is made hollow, and the connect-
ing rod being centered well down in it a saving of room is effected.
A form of engine now common on Clyde river steamers is the
diagonal direct-acting. In these engines the piston rod is attached
to a crosshead working in slides, and from this crosshead the con-
necting rod stretches to the crank pin. It may be of interest here
to state that the first efficiently steam-propelled vessel, the Char-
/otte Dundas, was fitted with a horizontal direct-acting engine; this
vessel was tried successfully on the Forth and Clyde Canal in 1802.
In many of the earlier steam vessels, from the Comet downwards,
spur-wheel gearing was used to connect the engine with the paddle
shaft. A few details of the size of the Comet may be interesting.
She was about 25 tons burden, and was built for Henry Bell in 1812
by Mr. John Wood of Port-Glasgow. She measured 42 feet long,
40 feet keel, and I I feet broad, with 5 feet 6 in. draft of water.
The engine, made by John Robertson of Glasgow, was a condensing
one of 3 horse-power, the diameter of cylinder being II inches, and
the stroke I6 -inches, the crank working below the cylinder; the
engine-shaft, connected with a fly-wheel, is said to have been of
cast-iron, and 3% in. Square. The engine was fitted on board before
launching and steam raised. At first the Comet was fitted with
two pairs of paddles, 7 feet diameter, with spur-wheels of 3% feet
diameter; but soon afterwards she was lengthened to 60 feet, and
a new engine with a single pair of paddles substituted, the speed
being now greatly improved, and reaching from five to six miles an
hour. The diameter of the cylinder is stated as 12% inches and
the horse-power 4.
THE PADDLE WHEEL.
The paddle wheels now in use are generally of the feathering type,
the floats entering and leaving the water almost vertically; having thus
a better hold of the water than the fixed floats, which enter obliquely,
MARINE ENGINES. - 379
and whose full propelling area is only attained when the arms to
which they are bolted are vertical. Thus when fixed the floats
depress the water on entering, and tend to lift it when leaving, and
i
:
*
f
§
|
A.
*af
dº
j
:
to obviate this difficulty each float was formerly stepped, or made
in two or more separate pieces, placed one before another. This
plan, however, is now become almost obsolete; the feathering floats,
although somewhat complicated, being generally adopted for all

38O MODERN STEAM PRACTICE.
fast river steamers, and the screw superseding the paddle wheel
almost universally for ocean-going steamers.
To understand the action of the feathering paddle wheel we have
to consider each float free to oscillate on pins passing through
brackets forged on the paddle arms; on one of these journals an
arm is fixed, and a rod for each float is attached to a pin on the
Z3 end of each arm, the arms being all con-
nected to a strap (Fig. 259), which is free
to revolve on a sheave (Fig. 26O) placed
eccentrically with the main shaft. One
sº
º
º º
ſºn
92%
SSSSSSS
T O & S - - - - - - 2. O
Hi-H- |(-|o] o O O
Fig. 259.—Eccentric Strap. Fig. 26o.—Eccentric Sheave for Paddle Wheel.
A, Strap with brass lining pieces. B, Seat for A, Eccentric. B, Flange for bolting it to the ship's
driving rod. C C, Holes for radial rods. side.
of these connecting rods is the driver, and is firmly secured to
the eccentric strap in a way similar to an eccentric rod for the
valve motion. When the paddle wheel is overhung, with one
pillow block at the side of the
vessel, this bearing being support-
ed with a wrought-iron bracket
rivetted to the side of the ship, the
eccentric sheave is secured at the
end of the pillow block; and when
the paddle wheel is supported with
an outside bearing bolted to the
C sponsons, the eccentric sheave is
Fig. 26r.—Boss for Paddle-wheel A bolted to the side of the ship direct.
1g. 201. OSS TOr tº a e-Winee TITIS. *
A, Boss. B B, Seats for arms. C, Wrought-iron ring. In setting out the mechanism,
we consider the position of the
driving float, as we may term it; at its deepest immersion it is
quite vertical, and as the rod from the arm that is fixed on the float
is secured to the eccentric strap, as the paddle wheel revolves the










MARINE ENGINES. 381
eccentric ring is dragged round, and the driving float always assumes
that vertical position at the deepest immersion, as indeed do all the
other floats, the only difference being that they are secured to pins
on the eccentric strap, instead of being firmly bolted to it; thus
when the centre line of the eccentric is placed on a level line, all
the floats assume different angles, but at the same time each float
enters the water in a slightly oblique direction, and leaves it verti-
cally. It is obvious that the floats must not be placed too closely
O
|o o o o o oſ |o
Fig. 262.-Arm and Brackets for Floats.
A, Arm and bracket. B, Pin and brass bush. C, Brass bush. D., Bracket. E, Pin and brass
bush. F, Bracket.
together, three immersed at one time is considered sufficient; if
closer packed they only disturb the water and clog the action of
the wheels. Some builders prefer simply an eccentric or a circular
sheave (Figs. 264 and 265), revolving on a pin firmly secured to the
sponsons, and fixed aft of the centre of the paddle shaft in a hori-
zontal line; the sheave is formed of two flanges, with a projecting
piece for the driving arm, and pins for all the other rods: in action
this form is similar to the foregoing. All the moving joints must
be bushed with brass, both on the pins and eyes, to preserve and
keep fair the various joints; unless this is properly attended to
corrosion would set in, and soon destroy the feathering paddle
wheel. -
The pillow block for the overhung paddle wheel is a plain casting
fitted with a cap, the bolts for securing which pass down through


382 MODERN STEAM PRACTICE.
i–11—1–)
Fig. 264.—Eccentric and Pin for Paddle Wheel.
A, Eccentric. B, Part for driving rod. C, Pin for
radial rod. D, Bracket bolted to the sponson.
ſ ſ O E, Pin for eccentric.
**)' . . . º->
tº gº tº ºi º ſº O O
|-
Fig. 263.−Eccentric rod, &c., for Floats.
* A, Driving or eccentric rod. B, Radial rod.
Fig. 265.—Overhung Feathering Paddle Wheel.—A, Boss. B B, Arms, c, Rim. D, Float. E, Arm for
float, F, Driving rod. G G, Stays. H, Eccentric and pin bolted to the sponson. I I, Brackets.



MARINE ENGINES. 383
the bracket fitted to the side of the ship; the sole of the block is
also bolted to the bracket, as shown in Fig. 266.
In some ocean steamers the paddle-wheel shaft was arranged so
that it could be disconnected from the engine when the ship was
under sail alone. The simplest plan for effecting this is by fitting
a disc on the end of the shaft, instead of the usual crank, the disc
having a hoop with a projecting - -
lug piece for taking the crank Q It C
pin; the hoop is forged all in one 7. P N
piece, and is held in position with / 2 N.
a fast-and-loose collar on the #4.
round disc; the grip is attained by
friction blocks, or wedges, firmly
screwed between the disc and the
hoop on the circumferential line,
the disc being keyed to the shaft SS
with one or more keys. There-
fore when the friction blocks
are released, the shaft and disc
revolve independently of the O O O O
engine, the motion of the vessel -
through the water, driven by the
sails, causing the paddle wheels to g e
s Fig. 266.—Pillow Block for Paddle Wheel.
revolve. In this way the progress A, Pillow Block. e. Cap for do. cc, Holding down
of the vessel is not impeded so bolts.
much as it would be were the floats stationary, and offering a great
resistance for the wind to overcome.
The paddle wheel of a ship may be compared to an ordinary
carriage wheel, any point in the circumference describing a cycloid
curve. The circumferential distance a carriage wheel travels over
is an exact measure of the distance the carriage has gone; but as
the paddle wheel acts in a yielding fluid, the distance travelled
over by it is not an exact measure of the vessel's progress through
the water. The difference is termed the slip of the paddle, and
ranges from one-fourth to one-fifth of the circumferential distance
the paddle wheel has gone over, which of course must be measured
on the mean centre of propulsion of the floats, and not on the
extreme diameter. -
The reciprocating parts of marine engines are generally balanced
with suitable weights, and notwithstanding that the cylinders of
|
-
-
|j:

384 MODERN STEAM PRACTICE.
the oscillating engine are properly balanced, yet the pistons and
cranks must be also balanced by a metal float fitted on each paddle
wheel, although that is partly done by the air-pump bucket and
its adjuncts, the crank of which divides the path of the main
cranks into three parts—that is to say, the cylinder cranks being
at right angles, the line of the air-pump crank divides the longest
circumferential line between the main crank pin centres into equal
parts. * -
The feathering paddle wheel was tried at various times, but not
with much success till about the year 1850. Fixed floats were
mostly used in ocean-going steamers, being considered less liable to
derangement. g
Two pairs of paddle wheels have been proposed to be used.
The Comcz had at first, as we have said (p. 378), two pairs, but
these were removed, and a single pair substituted. Single wheels
at the stern and amidship, as in twin-boat arrangements, have also
been tried, as also endless chains with floats attached, passing round
a couple of drums driven by the engine. Iron floats have some-
times been used instead of wood floats in paddle wheels.
Besides the screw propeller, to be afterwards treated of, the
propulsion of vessels by a jet of water has been tried. This con-
trivance is known as “Ruthven's Hydraulic Propeller,” and consists
of a turbine-like wheel driven by a steam engine. The water is
first of all drawn in by the turbine, and then driven out at openings
along the ship's side in such a manner as to keep up a constant
stream. A vessel named the AWautilus, furnished with Ruthven's
propeller, had a trial trip on the Thames in 1868. She ran at
the rate of 135 and 7.2 miles per hour with and against the tide
respectively, or at an average speed of IO-35 miles per hour; and
when going at full speed, with both wind and tide in her favour, she
was made, by reversing the valves, to stop dead in less than ten
seconds and in about a quarter of her length. The plan has also
been tried in H.M. iron-clad gun-boat Waterzwiſch, of about 780 tons,
with some success. It has also been tried in the United States of
America, but without commending itself as against either the
paddle or the screw. p
It should be noted in all questions of propulsion that the principle
involved is the putting in motion of a quantity of water in a back-
ward direction, the reaction from which action is the propulsive
effect. Professor Rankine gives the following rule for the thrust
MARINE ENGINES. - 385
of a propeller, whether paddle, screw, or jet, in lºs.:-"Multiply
together the transverse sectional area in square feet of the stream
driven astern by the propeller; the speed of that stream relatively
to the ship, in knots; the real slip, or part of that speed, which is
impressed on that stream by the propeller, also in knots; and the
constant 5'66 for sea water and 5.5 for fresh water.”
HORIZONTAL DIRECT - ACTING AND RETURN
CONNECTING-ROD ENGINES.
In these engines the cylinders are placed side by side, as in the
locomotive engine, and the steam valves are worked directly off
the cranked shaft by double eccentrics and link motion. The
condensers are placed on the opposite side of the shaft for return
connecting-rod engines; they are fitted with guides for the cross-
heads; the piston rods are secured to arms forged on the crosshead,
and are so arranged for the rods crossing the cranked shaft, one above
and the other under the shaft. The connecting rod by this arrange-
ment is not in a direct line with the piston rods, but goes backwards,
while the piston rods are connecting to the piston in a forward line
crossing the main shaft of the engine.
The distance between the centres of the cylinders in these engines
is regulated by the arrangement of the air pumps and valves. When
the air pumps are close together on each side of the centre frame,
the distance between the centres is greater than when the air pumps
and adjuncts are placed further apart, close to the outer frames;
however, it is not a good plan to contract the water passages in
connection with the air pumps and condenser to gain a few inches
between the centres of the cylinders. Steam jackets are generally
used, cast along with the cylinder; the fronts and cylinder covers
are also made double, so that the steam from the boiler freely
circulates all round the cylinder, and the full pressure is better
maintained on the piston, a higher indicated measure being given out
than by an unjacketed cylinder. To prevent condensation in the
steam casing the outside of the cylinder should be covered with
felt, and then overlaid with lagging or narrow strips of wood, which
are secured to wooden hoops, bolted to the strengthening ribs left
in the casting. The passages for the steam and exhaust are arranged
25°
386 \ MODERN STEAM PRACTICE.
for double-ported valves, that is to say, there are two steam
passages at each end, and one central passage, in communication
with the condenser. The joints should be placed metal to metal,
all planed or surfaced in the boring lathe, and the rubbing surfaces
Figs. 267–268.—Cylinder.”
for the slide valve should also be carefully
planed as Smooth as possible, and then
scraped to a face plate, before the slide
valve is fitted, which should also be care- F
fully faced on the plate, and thus both
surfaces will only require a finishing touch.
All the other joints are made steam-tight
by interposing a thin coating of red lead.
The joints being thus metallic, the work-
ing of the engine has but little tendency
to loosen them, which might otherwise
happen were an elastic joint adopted. On
the front end of the cylinder a central manhole must be left, for the
boring bar to pass through; with single piston rods there is a small
cover with stuffing box and gland, but with double or more piston
rods a plain cover is fitted; holes are also left in the front end of the
cylinder for the air-pump rod, with suitable glands and bushes, and a
hole at the bottom for the relief valve; narrow fitting strips should
be left at those parts where the main framing abuts against the
other fittings. The cylinders are bolted together, with flanges placed
between them, having narrow fitting strips all round, which are care-
fully planed; all the holes should be drilled, and rimed out to make
º
º
ſº Ç 2
zzzzzzzzzzzzzzzzzº
Cºlº 2.
º
222222222222-2222*22222222 -
:
ę
2.
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º
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tf
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wº&
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4A, Cylinder. B, Annular steam space. C C, Steam ports. D, Exhaust port. E, Exhaust branch.
FF, Piston-rod glands. G, Cover for hole for boring bar.



















MARINE ENGINES, 387
them quite fair; by this means the turned bolts fit the holes
exactly, and good firm work is obtained. The flanges at the top
and bottom are planed, and the latter are cast along with the
flanges for bolting down the cylinder on the keelsons. Raised parts
should be left on the casting at all the places where the bolts are
arranged; in this way an even face is easily made for screwing the
nuts up against, which helps to secure first-rate work.
The cylinder cover should be a deep and strongly-ribbed casting,
fitted with a central manhole door, through which the bolts of the
piston and piston rods may be inspected without requiring to break
the joint of the cover, which is a somewhat difficult task at sea,
s&#2&s= w
== tºssŞsº
N % §
%|N
- sºlº C § N
§sºz § §§
zºğ
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rººmŻzá * Ž
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l 2. 2. ZºZZ *- 2% #
:*:: ***…*** ZZ322
Fig. 269.—Cylinder Covers.
A A, Covers. B B, Manhole covers. c c, Recesses for piston-rod nuts. D, Recess for air-pump rod nut.
E, Hole for relief. F, Recess for single piston-rod nut,
more especially with large and heavy covers. The number of bolts
should be carefully calculated, so as not to have a great prepon-
derance of strength in that part, for in the event of the cover
receiving a violent blow from the piston striking against water in
the cylinder due to violent priming, when the flanges in the cylinder









283 t MODERN STEAM PRACTICE.
and cover are properly proportioned the bolts should rather give
than a breakage occur. A hole is left at the bottom of the cover
for the relief valve, similar to that in the front of the cylinder.
The stuffing bores for the piston rods are fitted with a lantern or
hollow distance piece, with an extra light gland placed on the main
one, the stuffing box of which is packed in the usual manner. The
lantern brass is placed in the outside
stuffing box, and then a gasket of hemp or
other packing is placed on the back of it,
and screwed up with the light gland. The
use of this lantern brass is to leave a space
all round the piston rod for containing the
lubricating oil; the piston rod has thus a
ring of oil all round, which is kept in the
space by the hemp packing, and pre-
vented from dropping down and running
to waste. The main glands are gener-
Fig. 270.--Piston-rod Gland with
Iantern Brass.
ally Screwed down with plain bolts and A, Packing space. B,Gland. c.Oil space.
wº & te º D, Gland. E, Bush. F, Cylinder cover.
nuts; but in fast-going engines a risk y
attends this method, as the gland is liable to be pressed against the
side of the rod, and thereby to throw an undue strain on the piston
these C
% Nºra 2
tº 23: &
ºf Eºs
A
; :
§§§
Ż
ZZZ
ZZ
JºšSNSS Nº.
É22. % H
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F
it - - - -
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Fig. 271.—Piston-rod Gland with Adjusting Gear.
A, Packing space. B, Gland. cc, Worm wheels and pinions. D, Spindle.
rods. In order to effect a parallel strain on the packing, as well as
to be able to tighten up the gland when the engines are in motion,
two large bolts are used, with worm wheels and pinions on each,
and a spindle connecting them; thus by one movement the gland
can be tightened up in a parallel manner. In some engines of the


MARINE ENGINES. * 389
direct-acting type the packing gland for the piston rod is recessed
into the end of the cylinder, the end being curved, as well as the
piston and cover: by this means a slight gain is obtained in the
length of the main connecting rod, but otherwise it affords no
advantage, and the patterns are more difficult to make.
The exhaust pipe in communication with the condenser is cast
along with the cylinder, and can be made of any required shape,
provided the area is sufficient. The circular shape, however, is the
strongest and best for that part of the exhaust pipe which joins the
thin copper pipe leading to the condenser, as the latter pipe forms
really part of the condenser, and unless it were made circular it
would collapse with the atmospheric pressure. The ends and covers
of the cylinder must be strongly ribbed in the casting with feathers
radiating from the centre; from this not being properly attended
to, the pulsation of the cast iron in some covers is quite visible at
each stroke of the piston. This bending and unbending of the
metal of course deteriorates its molecular particles, and when any
undue strain comes upon the cover from excessive priming, there is
danger of its becoming fractured, or indeed of being blown out
altogether, as has happened to many covers and ends. A small
branch pipe should be cast on the exhaust pipe, for the blow-
through valve, which is connected to the valve casing or the steam
pipe, according to the locality of other details. Small bosses should
also be cast on the bottom of the cylinder at each end, to which
small plug valves are fixed for allowing the water to escape out of
the cylinder before starting; these valves are connected together
with levers and rods, one handle Serving to open them both. All
small fittings that are intended to be fixed on the cylinder should
have facing strips cast on, which tends to lessen the labour in the
workshop. To effect this important object more completely, some
makers have cast the cylinders together, but the risk in this method
is considerable. We have seen castings of this kind that looked
sound, and one of the cylinders on being bored out presented a
good surface, but the other was quite porous and full of blown
holes; both of the cylinders of course requiring to be broken up as
useless. This fact may deter many from trying such a plan, at
least for large cylinders, yet for small ones the advantages are
great, and the risk proportionately less. Care should be taken,
however, that the metal be neither too soft nor too hard, more
especially the latter, as extremely hard castings should be avoided,
390 MODERN STEAM PRACTICE.
particularly for great steam pressure. Many cylinders cast too
hard have cracked in all directions after being but a very short
time in use, owing, it is considered, to the unequal expansion of
the metal. The core of the casting has been removed in the
moulding pit to cool the inside of the cylinder, which makes
this portion harder than the outside portions, and strains the metal
forming the whole casting, rendering it brittle, and very liable to
give way under steam pressure in those parts where the expansion
of the metal is the greatest. Good metal only should be employed,
and the casting allowed to cool slowly.
The slide valve is a very important detail, and is generally of the
double-ported type, although treble ports are sometimes introduced.
Considering the great size that is required for direct-acting engines,
this valve should be well proportioned, and all its gear of a strong
and substantial make. Some engineers still prefer valve facings of
hard brass, secured to the cylinder face by screwed pins rivetted
over; and even steel facings have been successfully used for high-
pressure marine engines. There can be no doubt that when
3.2
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Fig. 272.—Slide Valve, with rod passing through it.
A, Slide valve. B, Valve rod. cc, Steam ports. D, Exhaust port. E, Guide for valve rod.
the slide valve is placed on its edge, cast-iron surfaces are found
to answer, when properly provided with means for running off
the water that collects in the valve casing when the engines
are standing, still, as the moisture must impair the cast-iron
surfaces, and the slightest unevenness of the facings will pass
steam, it is perhaps advisable in some cases to use brass sur-
faces. Perfection in detail is doubtless the main thing to be
studied, even although it may entail at first considerable cost in
construction. Various methods are adopted for securing the valve
rod to the valve. In some engines the rod passes through a tube
cast along with the valve, and is secured by a collar at one end of
the rod and two nuts at the other end; in others again the valve
















MARINE ENGINES. 39 I
rod is screwed (Fig. 272), having a raised screwed part at both ends
and double nuts; by this means the valve can be very accurately
set at any time. The hole through the valve should be slightly
mº
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oblong, to allow for the wear and close contact between the faces of
the valve and cylinder. The valve rod, in some examples, is guided
at the end through a hollow brass pipe, or a stuffing box and gland,
similar to the front end. In other arrangements the end of the
valve spindle is screwed into a nut recessed in the valve casing; the
thrust is taken on the end of the nut, and the pull on projections

392 MODERN STEAM PRACTICE.
formed on the nut of a T shape; a thin jam nut is fitted, so, as
thoroughly to bind the rod and nut together: both of these nuts
should be made of steel, and case-hardened. Another method of
Securing the valve rod is by a cotter passing through a boss cast
on the valve, the cotter being fitted with a split pin to prevent it
shaking loose, With the view of relieving the rod and adjuncts
from the severe strain caused by the steam acting on the back of the
valve, packing rings are fitted to the valve, or rings of metal pressed
up against it; in the former case the ring is recessed in the valve,
and pressed up with Springs against a planed piece on the valve-
casing cover; in the latter, the ring is recessed in the valve-casing
cover, and pressed up with set Screws against the valve. The
object of both of these plans is to obtain a large area on the back
of the valve from which the steam in the casing is excluded, by
means of the metallic rings, which of course do not leave such
large surfaces for the steam pressure to act upon. This hollow
space is sometimes fitted with a small pipe in communication with
the condenser; thus the valve is partly drawn from the face as it
were by the vacuum.
The valve casing is a separate open frame,
cast with flanges for securing it to the cylinder.
It is very rarely cast along with the cylinder,
at least for heavy engines; although for engines
of small power this plan may be advantage-
ously adopted. The casing cover is generally
cast with a recessed ring, and bosses for
springs, which are accurately turned out for
the reception of the packing rings and springs; Fig. 274–spring and Packing
it is of a curved shape, quite plain on the . * * *
outside, and well ribbed on the inside, which tºº."
prevents the dust from lodging, and the plain "...º.º...” *
exterior surface is easily wiped down, an im-
portant consideration in all the parts of a marine engine, as that
operation can only be properly attended to when the vessel is in port.
A snug should be cast along with the cover, having a hole bored in
it for a wrought-iron shackle and pin, to which blocks and tackle
can be secured when taking off and putting on the heavy covers.
The branch for the steam pipe is generally placed at the back
of the valve casing, and is cast along with it, the flanges looking
towards each other from cylinder to cylinder. At one end there

MARINE ENGINES. * 393
is a stuffing box and gland, and at the other end the copper pipe
is bolted to a plain flange; while the part in the gland is quite
loose, expanding and contracting with the varying pressure.
Becentric and link motion.—Various descriptions of valve gear
are in use, but the one generally adopted is the double eccentrics and
link motion. This is only introduced as a sure means of handling
the engines, and is but rarely used for working expansively, as in the
locomotive, for the obvious reason that were the slide valve travel-
–
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H
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8. Dſº |
Fig. 275.—Eccentric Sheaves. Fig. 276.—Eccentric Strap and Rod.
A, Eccentric. B B, Keys. C, Bolt for A, Eccentric strap. B, Rod. C, Lubricator cup. D, Jaw
eccentric. and pin for link.
ling only a small portion of its stroke, and kept running for weeks
in this reduced grade, a groove would be formed on the cylinder
face, which would pass steam into the condenser when the valve or
link was put in full gear, and so impair the vacuum ; and it thus
becomes imperative to have a separate expansion valve. In the
example in Fig. 275 the eccentrics are cast in two halves and
secured with bolts and nuts, in other examples they are cast solid;
in both cases they are firmly secured to the shaft by keys, as shown.

394 sº
MODERN STEAM PRACTICE.
The eccentric strap (Fig. 276) is of brass, having a wrought-iron rod
with T-piece forged on one end, secured to the strap by bolts and
nuts, the heads of the bolts being re-
cessed in the strap; on the other end a
jaw is formed for taking the link. The
latter has eyes forged on and fitted
with brasses and set screws for adjust-
ing the wear on the eccentric-rod
pins; the suspending pin for the link
is formed with a palm, which is se-
curely rivetted to the link.
The various arrangements of valve
mechanism have been treated more
fully in a former part of this Work (see
page I IO).
When gridiron expansion valves are
used, the seating on the valve face is
H
Fig. 277.-Link.
A, Link. B, Suspending pin. CC, Eyes for
eccentric rods. D, Block on slide-valve rod.
cast along with the casing, making a very compact arrangement.
The valve in Fig. 278 is cast in brass, and is worked by a single
eccentric and varying link. In some examples the valve is circular;
º 2
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Fig. 278.—Gridiron Expansion Valves.
A, Expansion valve. B, Facing for do. C, Steam pipe. D, Main slide valve. E, Cylinder.
by adopting this shape the steam pressure is taken off the back,
and the valve is consequently more easily handled.




















MARINE ENGINES. 395
The throttle valve is generally of the butterfly type, and is located
between the expansion valve and the boiler, having hand gear for
each valve passing along to the starting platform. Some engineers
use only one handle for both valves, but this arrangement is not
advisable, as one engine or cylinder may require more or less
throttling than the other, although the cylinders are lying quite
close together. A
small plug or other
valve is fitted be-
tween the gridiron
expansion casing
and the main valve
casing, by which
steam can be admitted from the one to the other, in the event of
the engines stopping at a part of the stroke where the expansion
valve covers the ports, and it would be difficult to start again
without this auxiliary valve.
The blow-through valve is a common spindle one, guided at the
bottom through a hole in the centre boss cast along with the seating,
with a single feather; or the valve may
be of the three-feather type, turned to
the inside diameter of the seating. The
A, Throttle valve. B, Spindle ſor do. c, Chest.
* % former has a long spindle at the top,
&\ſº º º which passes through a stuffing box on
§§§ {NS * s
gº Rºzasa the cover of the valve box. This spindle
is fitted with a slot crosshead for the
lifting arm to pass through, with a lever
and rod passing along to the starting
platform. Some makers have used a
small slide valve, with steam and ex-
Fig. 280–Blow-through Valve haust ports placed on the top of the
•º sºn, º cylinder, with steam passages and
* valve chest cast in brass. This valve
is worked by hand off the platform, and can be used for blowing
through, or even turning the engines gently, in which respect
it serves as a means of starting the machinery independently
of the main slide valve—a great desideratum in large-powered
engines. Plain plug valves may be conveniently used for the blow
through, but it is not advisable to adopt them for heavy engines.
The plug should be packed with hemp at the top, having a suitable
ãº
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306 MoDERN STEAM PRACTICE.
packing gland, and the bottom or small end of the plug is merely
fitted, and ground into the seating, which is cast solid at the end;
by this means no leakage can occur except at the top, which is
made steam-tight by the packing gland.
The escape or relief valve, fitted to the bottom of the cylinder
cover and to the front end of the cylinder, is intended to allow the
escape of the water which finds its way into the cylinder from
priming and condensation of the steam. It consists of a disc valve
with a spring fitted to the top, screwed down sufficiently tight to
resist the steam pressure acting on the internal area of the valve.
The valve can only be opened, and the water which is not com-
pressible ejected, by the piston striking against the water, and
forcibly lifting the valve, compressing the spring, which again
reacts when the cylinder is free of water. The valve should be
inclosed in a light dome, with a hole at the bottom side for allowing
the hot water to escape downwards
into the bilges. In other examples a
dash or splash plate is cast along with
the valves, when placed horizontally
and vertically; the plate being of a
curved shape, the water escaping all
round the valve is returned or thrown
back again, and so prevented from being
Scattered about the engine room, and Fig. 28.—Relief valve with movable
scalding the engineers or those in at- A. Valve and * Valve seat.
tendance. The spring is usually Screwed c, Spring, d, Crosshead. E e, Columns.
down with a crosshead, through which F, Baffle piece.
the valve spindle passes loosely through a hole bored in the centre.
At each end of the crosshead is a column, secured to the valve seat at
one end, and the other end screwed, passing through a hole in the
crosshead, and fitted with nuts above and below. The spring is placed
around the spindle, between the valve and the crosshead, which by
means of the nuts is screwed up carefully, compressing the valve to
a little above the working pressure of the steam in the cylinders,
which can be easily adjusted when the engines are started, and then
the nuts below the crosshead can be screwed hard up; in this way the
valve is guided at the top through the crosshead, and at the bottom
the spindle passes through the hole in the central boss cast along
with the valve seating. Some engineers dispense with the movable
crosshead, using merely a bow or fixed crosshead of wrought iron

MARINE ENGINES. º 397
secured to the seating with nuts, and a central boss at the top, for
the reception of a screwed stud for tightening up or compressing
the spring; one cap being cast along with the valve for the spring to
rest on, and another cap at the top of the spring on which the screw
~ F
Słżh—t—rø.
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s E.
Fig. 282.—Relief Valve with fixed Crosshead.
A, Valve. B, Valve seat. c, Spring. D, Cross-
head. E, Set screw. FF, Columns. G, Baffle
piece.
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Sºx'Nº S alº
4&y
B % 22222222 \ º º
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Fig. 283.—Relief Valve with Stud on Cylinder Cover. Fig. 284.—Relief Valve with Dome.
A, Valve. B, Valve seat, c, Spring. D, Cap. A, Valve and spindle. B, Valve seat.
E, Set screw. F, Stud. G, Baffle piece. H, Cylinder cover. c, Spring. D, Baffle dome.
for compressing the spring bears: in this arrangement the valve
is guided by the spindle passing through the seating. A very
simple form of this description dispenses with the wrought-iron
bow, a stud being screwed into the cylinder cover and end, through
which the screw for tightening up the spring passes; while in other
forms the dome fitted over the spring for protecting it from being
injured, as well as for preventing the water flying about the engine
room, is fitted with a boss at the top, through which the tightening-
up screw passes, the dome being bolted to the covers and end with
stud bolts. Many prefer a fixed pressure on the relief valve, but,
















398 MODERN STEAM PRACTICE.
on the whole, we think it should be fitted with set screws, to adjust
the pressure against the valve at any time to suit the reduction in
steam pressure that may be considered advisable after the boiler
has worked for a lengthened period. Some makers have fitted an
additional valve opening downwards, seated on the main relief
valve, and opened by hand, while another valve of india rubber is
placed on the top of the main relief one, so that when the additional
valve is opened, in the event of violent priming at the return stroke
of the piston, the disc of india rubber, or metal valve if so fitted,
closes, and does not impair the vacuum. This is a complicated
arrangement, not in general use; and the same object is attained
by fitting a plug valve at the bottom of each end of the cylin-
der, worked simultaneously from the starting platform, and which
can be opened when violent priming occurs, or in the act of
blowing through before starting the engine,—in the same way as
the plug valves in the locomotive engine cylinder, which are left
open for a considerable time to blow out thoroughly all the water
from the cylinders. Some first-class engineers consider that greater
safety would be insured by dispensing with the springs for holding
down the relief valves, and this seems a step in the right direction;
for when valves are so arranged that they are held down simply
by the steam, and have the means of blowing all the water back
again into the steam pipes, and collecting it in a suitable separator,
we secure two advantages, namely, that the valves are not so liable
to stick or get damaged, and that the hot water does not fly about,
but is received into the separator, which can be run off occasionally.
For this purpose, double-beat valves, giving a large circumferential
area for the water to escape, or common spindle valves, are fitted to
the top of the cylinder, in valve chests, which communicate by
pipes with the cylinder on the bottom of the valve and the steam
pipe on the top of the valve; the steam pressure above the valve
being greater than that in the cylinder, the valves are of course
held down by the difference of pressure, and the water is ejected
as in ordinary arrangements, with this difference that it is collected
in a vessel for the purpose, instead of finding its way into the
bilges.
Lubricators.-Grease cups are fitted to the steam ports at the
front and back of the cylinder, for lubricating the valve and piston,
the lubricant being drawn in with the vacuum. These cups should
be fitted in connection with a plug valve having a screwed part at
MARINE ENGINES. 399
the top, to suit the screw of the indicator, with a pipe connected
between the plug valves, so that an indicated card may be taken
from the front end and back of the cylinder without shifting the
instrument. The pipe between the plug valves should be fitted
with an additional valve, for cutting off the communication when it
is desirable to take a card from the front end, and vice versa. The
liquid tallow is poured into the cup, and flows through a hole into
the hollow plug; the valve is then turned by hand, bringing the
hole into communication with a small hole on the opposite side
leading into the port, and the oil is drawn into the cylinder by the
vacuum. Sometimes a plug tap is fitted into the tallow cup, and
opened and shut by hand; but this operation requires some care, as
it is evident that it must not be opened until the vacuum is formed,
or the tallow would be blown out of the cup. The attendant must
therefore watch the motion of the engine, and shut off the com-
munication with the cylinder before the steam is again admitted,
so as to allow the tallow to be drawn into the cylinder with the
vacuum—an operation requiring some dexterity, with the piston
doing sixty strokes or so per minute. It is therefore preferable to
use the hollow plug valve, as described above.
We now come to consider the piston for the various forms of
horizontal marine engines. In the construction of this part the
main point to be studied is to provide ample surface for wear.
The thrust is imparted more directly on the piston in the single-
trunk type than where there is a trunk at each end of the cylinder.
In the latter arrangement the trunks form a hollow support for the
piston, while the thrust of the connecting rod is taken on the bushes
and packing glands in the ends of the cylinder, and the rubbing
surface of the piston can be made much less than for any other
class of horizontal engine. While other pistons must have a broad
surface for wear, the packing rings for the double-trunk system
have in some instances merely slight steel or brass hoops for making
them steam-tight. Pistons for two or more piston rods on the
return connecting-rod principle require less area for the rubbing
surface than those for direct-action single piston-rod engines, the
former being partly balanced by the long rods and heavy cross-
heads, the stuffing boxes serving as a fulcrum by which the weight
of the piston is partly taken off the cylinder surface, and this tends
to prevent them wearing so rapidly as in the direct-acting type,
although the diameter of the piston rod in the latter is increased to
400 MODERN STEAM PRACTICE.
gain more surface in the glands, and by the increased weight of
the rod and its adjuncts to relieve the piston rubbing surface. The
total rubbing surface or depth * *
of the piston, for double trunks,
may be taken at one-eleventh
of the diameter of the cylinder;
for double piston-rod engines
on the return connecting prin-
flºº
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ciple, one-sixth ; for single rººm
piston-rod and single-trunk Bºž º
arrangements, one-fifth: this à Nº
depth being the breadth over
the surface in contact with the - Fig ass–Piston Rings.
cylinder. Most pistons have AA, Pistons. B B, Packing rings. cc, Junk rings.
- º g D D, Bolts with recessed nuts. E, Bolt with hole tapped
projecting rings CaSt along in the body of the piston.
with the junk ring, and some - -
have also projecting rings cast along with the main body of the
piston—both having in view the equalization of the junk ring and
end surface in connec-
tion with the main
packing ring; this is
necessary, as the rub-
bing surfaces on the
junk and back ring have
the weight of the piston,
and in some instances
the thrust of the con-
necting rod, to sustain,
while the packing ring
has not so much duty
to perform. In order
to make the junk ring
and other surfaces to
bear more equally, and
to keep the piston cen- - Fig. 286. —Diston.
tral with the cylinder, A, Piston. B, Packing ring. C C C, Springs. D D, Cast-iron pieces.
- : .. E E, Bosses for piston rods. F, Boss for air-pump rod. G G, Ribs
tWO pieces of cast iron to strengthen the body of the piston. H, Tongue at division.
are placed on the under -
side, between the packing ring and the main body of the piston,
pitched about one-fifth of the diameter of the piston apart; in this























| MARINE ENGINES. 4OI
way the weight of the piston is transmitted through rigid blocks to
the packing ring, which bears on the internal surface of the cylinder.
Short springs of a bow shape are placed all round the packing ring,
to keep it well up to the cylinder surface. In some cases these
springs are of a U shape, let into recesses in the body of the piston.
The main body of the piston is strengthened with ribs radiating
from the centre, and has the necessary bosses, which are bored out
for the reception of the piston and air-pump rods; the holes are
sometimes tapered to receive the ends of the rods, and in other
examples they are quite parallel; in the former case, the piston, rod
is screwed tightly against the cone, and in the latter against a
shoulder left on the rod itself. Holes are cast in the body of the
piston for the purpose of extracting the cores; these are accurately
bored out with a slight cone, and
A plugged up with cast-iron plugs,
having a thin coating of red lead
to make the joint perfectly steam-
N tight. They are further secured
§ by boring holes on the circum-
* ferential line of the joint, which
ºº are tapped for the reception of
º brass or wrought-iron screws,
Fig. 287-Block Piece for Piston Ring. firmly screwed in, one-half of the
A, Piston. B, Junk ring, c, Packing ring. Screw being in the body of the
D, Tongue. E, Bridle. piston and the other half in the
plug; these screws are cut off flush with the surface of the casting.
The junk ring is held down by bolts screwed into the cast-iron
piston, or brass or wrought-iron nuts are fitted, recessed into it,
having a thickness of metal all round; the bolts are kept from
turning by a screwed stud recessed in the head, and tapped into
the junk ring. The ring is accurately turned, as also the surfaces
bearing on the piston and the spring ring, which are then scraped
to a true surface, and made perfectly steam-tight. After the pack-
ing ring is turned, an oblong hole is cut out at the centre at that
part where the ring is cut through, and a brass piece with a flange
all round is fitted into the hole, filling it up, while the flanges make
the spring joint steam-tight; the end of the brass filling-in piece
is secured to the packing ring at one end with screwed studs, and
a wrought-iron bridle is placed over the tongue, and secured like-
wise at one end to the packing ring. The object of this arrangement
gº tº
* Q
§§ §jº, […]
§ºº
º
º
§
|




















4O2 MODERN STEAM PRACTICE.
is to compress the packing ring, by the insertion of a wedge between
the tongue piece at the fast end and the bridle at the loose end, so
that when the wedge is driven in between the two the packing ring
is drawn together, and can be readily placed in the piston when in
the cylinder; the cotter is then drawn out, and the packing ring
expands to its original size, and fills the cylinder somewhat tightly.
The projections left on the junk rings and the body of the piston
must have recessed parts in the cover and end of the cylinder, with
sufficient clearance at the end and round the projections; and it is
advisable to leave recessed parts at both ends of the cylinder,
making the part bored out somewhat shorter than the actual stroke
of the piston, so that the rubbing surface travels over it at each end,
and prevents a groove forming in the cylinder that would eventu-
ally prove destructive to the engine, in the event of the connecting
rods requiring lining up in the brasses, by causing the piston to
strike hard against the projections. Sometimes the piston for
direct-acting single piston-rod engines is dished out or formed of a
curved shape, with the view of getting more room for the crosshead,
the gland for the rod being recessed into the end of the cylinder.
This is the only advantage to be derived from this plan, and it is
but rarely adopted. The fittings of such pistons are identical with
those for the plain-ended arrangement. When annular cylinders
are adopted for high and low pressure combined engines, the Small
piston for the high-pressure cylinder is similar to an ordinary one,
but the piston for the annular cylinder must have two packing
rings, the outside ring bearing on the cylinder surface, as in ordinary
arrangements, but the internal packing ring bears on the inside
diameter of the ring, the ring being pressed up against the barrel
of the high-pressure cylinder with strong steel springs. These
pistons are generally connected to the crosshead by a central piston
rod for the high-pressure cylinder, and two side ones for the low-
pressure cylinder, with one crosshead common to both. There
must be block pieces fitted between each packing ring and the
body of the pistons, to keep them all fair with one another. The
packing rings of all pistons are generally made thicker at the bottom
where these blocks are fitted, and thinner at the top where the
ring is cut; this is necessary, as in all horizontal arrangements the
severest strains and wear are undoubtedly at the bottom of the
piston.
As bearing on this subject the following extracts are from a
MARINE ENGINES. 4O3
paper on “Pistons,” read by Mr. James Howden before the Institu-
tion of Engineers and Shipbuilders in Scotland, session 1880–
81:-" Absolute steam-tightness in a piston at work very seldom
occurs. It is much more difficult to secure than is generally Sup-
posed. Probably steam-tightness has never existed in any piston
with a single packing ring after it has worked a short time, even
though the piston has been perfectly steam-tight at first starting.
On removing the junk ring of any such piston after it has worked
for some time, evidences of steam having passed between the faces
of the packing ring and junk ring or piston flange into the interior
space are quite apparent. The scraped or ground faces are in
places dull and steam worn, and if oil or grease has been used to
lubricate the cylinder, grease and dirt will be ſound in the space
inside of the packing ring. -
“In pistons with double packing rings leakage over their end
faces is sought to be overcome by a pressure endwise from a spring
which presses the packing rings at same time outwards towards the
walls of the cylinder. This causes undue friction and wear of the
cylinder and packing rings; and where there is much wear there
will soon necessarily be leakage through the packing rings and
interior of the piston. The dirt and grease often so plentifully
found inside the packing rings, show that steam has been passing
about as freely to the inside of the piston as into the cylinder itself.
“The element of friction is an important one, and a piston at
once steam-tight and practically frictionless possesses a value which
it would be difficult to overestimate. There cannot, of course, be
an entire absence of friction, but it may be reduced to the least
possible extent. The piston of a well-made indicator is an example
of a piston steam-tight under any usual pressure, and practically
frictionless. It works without any pressure outwards against the
walls of the cylinder. In pistons with packing rings and compen-
sating springs, one of their greatest defects is the universal excess
of pressure outwards against the cylinder. It is generally supposed
that when a cylinder is found smooth and polished, that the piston
is working with very little friction. This is often a delusive infer-
ence, for in a well-lubricated cylinder the packing rings, if bearing
fairly all round, will make a smooth skin on the cylinder, even
under a strong pressure against it.”
The author, in describing a new form of piston, the invention of
Mr. Wm. Rowan of Belfast, states:–“This piston is, however,
2,O4. - MODERN STEAM PRACTICE.
distinguished from all other pistons of this class by effecting the
endwise and outward pressures by separate springs, each exactly
suited for the work they have to perform. As I have shown, the
pressure of the packing rings endwise should be strong, and their
pressure outward against the cylinder light, or exactly the reverse
of what occurs in all other double packing ring pistons.
“The springs are extremely simple in their character and con-
struction. They are made from light hoop spring steel, varying in
breadth and thickness to suit the diameter of the piston. Breadths
from 3% inch to 2 inches, and thicknesses from ſº inch to ſº, inch,
will serve for pistons from I to 6 feet in diameter. To one
seeing them for the first time these springs look quite inadequate to
accomplish the ends proposed. It is surprising to see a spring of
Figs. 287A, 287B.—A, Junk ring. B B, Packing rings. C, Spring. D, Flange on piston.
E, Part where the packing rings are cut.
a few pounds weight in a large piston accomplishing an effect
to obtain which in other pistons continuous springs weighing several
hundredweights are used. . w •
“The spring for pressing the packing rings against the junk ring
and piston flange is bent round on its flat to the required diameter,
and may have projections on either side alternately at definite
distances apart, or the projections may be similarly placed on the
contiguous faces of the packing rings, between which these Springs
are placed. The preferable mode, however, and that usually
adopted, is to have the projections on the spring itself in the form
of waves, as shown in Figs. 287A and 287B, and where they are
shown in position between the two packing rings. It is found that
springs made in this manner to definite proportions of height and
length of waves, now fully ascertained for all dimensions, can be
made to give an almost unlimited pressure when screwed to re-
quired position, and the elasticity remains good for years. -

MARINE ENGINES. - 405
º
%
W
º
%
<!
& -
“The springs for pressing the packing rings outwards, against the
cylinder, are made simply of the steel hoop bent round to somewhat
more than the circle of the inside of the packing rings. The ends
meet inside the thin flat sleeve piece shown in Figs. 287C—287E.”
A screwed part at the end of the pistore zod, of less diameter



















4O6 MODERN STEAM PRACTICE.
than the main part of the rod, receives a large nut, by which the
piston rod is secured to the piston. The part of the rod passing
through the piston is of increased diameter and cone-shaped, this
cone is drawn through a corresponding hole bored in the piston,
and held firmly by the large nut at the end, which is kept from
turning backwards by a split pin bearing on it, and passing through
a hole bored in the end of the rod. This cone in some examples
is no larger than the rod at the one end, and is reduced at the end
nearest the nut, in which case no raised part is required to be forged
on the rod; a collar, however, is sometimes left to screw the piston
against. Some makers prefer having that part of the rod which
§
§
§
C
N
H
s
§ º
Fig. 288.-Tapered Rod and Nut for Piston. Fig. 289.—Parallel Rod and Nut for Piston.
A, Piston. B, Taper on rod. C, Nut. A, Piston. B, Parallel part on the piston rod. C, Nut.
D, Split pin. D, Split pin.
passes through the piston quite parallel, or nearly so, with a shoulder
formed by the reduction of diameter, against which the piston is
screwed. The screw is generally of a V form, rounded at the top
and bottom of the thread; others are cut square, but the V thread
is preferable. The nut in most examples projects from the body
of the piston, and bears on a turned raised part formed on the
casting; in others it is recessed into the piston, and in others again
it is flush with it, or a small projection of the nut is left, so that it
can be turned round with an ordinary spanner. When the rod
passes through a crosshead, its end is turned down quite parallel
and secured to the crosshead with a nut, in the same way as for the
piston. Some engineers place a jam nut on the back of the main
one, with split pins passing through both nuts, thus making a very
secure fastening. These lock nuts should be placed on all the
parts which are liable to shake loose, more especially for direct-
action engines, as the speed at which these are driven is liable to





MARINE ENGINES. - 4O7 .
loosen the parts if not properly secured. For direct-acting single
piston-rod arrangements a T-shaped piece is formed on the end, for
taking the crosshead, or brasses, which are secured to the rod by
two bolts passing through the T piece, brasses, and cap; the nuts
being secured at the ends of the bolts with split pins. The nut
can be fitted with a washer with pin let into the cap, and a small
set screw placed at the top of the one and the bottom side of the
other, passing through the washer and bearing in a hollow turned
in the reduced part of the nut. With the T form there must not
be any raised part on the piston rod at the piston end, so as
to allow the glands and
bushes to pass freely
along ; these must of
course be placed on the
rod before it is secured to
the piston, for it is not
advisable, under any cir-
cumstances, to cut the
glands in two, as some
prefer doing in oscillat-
ing arrangements.
The guides and cross-
head for double piston-
rod engines, on the return
connecting-rod principle,
are best arranged with
two guides or motion
bars, one on each side of
the connecting rod. By
this arrangement the
Crosshead is well sup-
ported at the ends, and
the strain on the guide bars is in a direct line with the centre line of
the cylinder. The crosshead is a circular forging, with arms forged
on for taking the piston rods. In some cases it is turned quite
parallel between the arms, these being forged on at right angles to
the main part of the crosshead; in others a collar is formed on each
side between the connecting-rod brasses and the guide blocks.
When the arms are forged on at an angle with the crosshead, it is
advisable to make the connecting-rod bearing of a larger diameter,
Š
à Z
9%222 le.
Fig. 290.-Crosshead Gudgeon and Motion Bars.
A, Gudgeon. B B, Slide blocks. CC, Motion bars.
: C
N
}_º






408 MODERN STEAM PRACTICE.
finishing up the arms quite square, and fitting the sliding blocks of
brass to them. When this part of the crosshead is turned, the
sliding blocks are bored out, and are held in position with a side
flange; the blocks are planed at the top and bottom. In some
instances cast-iron blocks have been used, lined on the rubbing
surfaces with white metal. The motion bars are of cast iron, the
bottom one is cast along with the condenser, and the top one, of an
I section, is bolted down at each end with one large bolt, passing
down through the vertical distance pieces cast along with the bar;
or two smaller bolts passing through flanges at the bottom may be
conveniently adopted, in which case the bottom motion bar is
generally raised up from the condenser casting, having strength-
ening ribs cast along with it. One or more oil cups, provided
with covers and wick siphon pipes, should be cast on the top of
the guide bar, to lubricate the sliding surfaces. The crosshead in
other arrangements is let into the pillow-block pieces (fitted with
caps and bolts), which are cast along with a T piece at the bottom,
placed centrally, and which is fitted with a separate brass casting,
having clips at the end to take the sliding strain. This guide block
has a large flat surface at the bottom, but the surface at the top is
not of so large an area, owing to the thrust of the connecting rod
being neutralized by the weight of the crosshead and adjuncts.
Some engineers, indeed, have left a small space between the top
surfaces, thus showing clearly that the top thrust is but little felt.
The guide bar is of a trough section, and is bolted down to the
condenser casting, having means of adjusting it to suit the wear of
the brass sliding piece. The lubrication of the parts is effected by
means of an open oil well at each end, which is kept constantly full;
the bottom sliding piece travels a somewhat greater length than
the surface provided on the trough guide plate, consequently its
bottom skims the oil in the receivers at each end, thus keeping the
guide plate thoroughly lubricated. All these arrangements of
Crossheads are Suited for plain connecting rods; some builders,
however, adopt forked connecting rods, having the crosshead, or
rather the pin for the connecting rod, fixed firmly on the rod,
working in a single pillow block and guide piece, provided with
caps and brasses, as in the previous example. The crosshead for
taking the piston rods can by this means be forged and finished
quite flat, and it is bolted to the guide block with the two large bolts
taking the cap and securing the brasses for the connecting-rod pin.
MARINE ENGINES. 4O9
This arrangement of crosshead is certainly preferable to those having
the arms forged on at an angle from the connecting rod bearing, as
it assumes a more direct form of
beam, loaded at the end with the
steam pressure communicated from
the piston through the piston rods,
taken centrally with the connecting
rod, which in its turn acts on the arms
of the cranked shaft, the bearing of
which is subjected to torsional stress.
We have now to consider the con-
nection between the piston rod and
the connecting rod for direct-action
single piston-rod arrangements. The
brasses for taking the forked end of -
the connecting rod are cast in two Fig. 291–Crosshead for Piston Rods.
halves, on each of which is cast a º º: º ºsº
bottom guide piece; they are grooved E. E. Eyes for the piston rods. F, Brass
out for the reception of a wedge plate, sliding piece.
the bottom of which is parallel with the centre line of the rod, but of
a wedge shape on its upper surface, which bears on the brass pieces,
and which is secured at one end, but having the means of adjusting
D]; ; * * * - - º FF+
º ë sº º
exo-oe II.
F
Fig. 292.-Crosshead for Single Piston Rod.
O
* * * * * *
§§ §§ - - - - - - -
A, Brass crosshead. B, Cap. C, T piece forged on the piston rod. D D, Bolts and nuts.
E, Adjustable plate. F, Guide for crosshead.
the sliding brass against the bottom guide plate, as in the examples
already described. The piston rod has a T piece for attachment
to these brasses, and at the connecting-rod end a cap is fitted; these
are all held together by two large bolts passing through the T piece,






















4 IO MODERN STEAM PRACTICE.
brasses, and cap. This is a neat form of connection; whether the
brasses have a plain exterior or are cut out in the pattern, the
bottom part is generally cored out to save weight and metal. For
trunk engines of the single class the brasses are placed in a pillow
block, cast along with the piston, and two bolts pass through the
piston for securing the cap. This arrangement is adopted for forked
connecting rods; but for single connecting rod ends, both in single-
trunk and double-trunk arrangements, the pillow block and brasses
are dispensed with, and a crosshead of wrought iron is substituted,
with bosses forged on the end, through which it is securely bolted
to the trunk. In single-trunk engines raised bosses are cast on the
piston, and accurately faced for fitting against, the bolts passing
through the piston, and having their heads covered with a plate
let into the piston, which prevents the steam escaping through the
trunk into the atmosphere; while in the double-trunk engine the
crosshead is Secured by bolts which pass through snugs cast along
with the trunk, and do not require to be made steam-tight, as in
the preceding case. The snugs should be strengthened with a deep
feather, so as to take the thrust and pull which is transmitted on
all connecting-rod attachments.
The most approved form of connecting rod between the cross-
Fig. 293. –Connecting-rod End for Cranked Shaft.
A, End forged on the piston rod. B, Cap. C C, Bolts and nuts. D, Brasses.
head and cranked shaft is that with solid ends forged on, slotted
out for the reception of the brasses, with caps of wrought iron
secured by two large bolts. The part for taking the brasses can
be bored out, the bedding forming a true circle; the ends and cap
are forged, turned, and finished entire, with holes bored for the
reception of the bolts, which are so spaced that part of the brasses
require to be Scooped out, which prevents them turning round in


MARINE ENGINES. 41 I
their seats. After the end is finished it is slotted across the middle,
the part slotted off forming the cap; the brasses have the usual
flanges all round, and are entirely finished in the turning lathe.
The bolts have solid heads, with part of the nuts recessed into the
cap, and a set screw passes through the side of the head, pressing
against the nut to prevent it becoming loose; the bolts are secured
in like manner: these precautions being necessary with high-speed
s
Fig. 294.—Connecting-rod End for Cranked Shaft.
A, End forged on the piston rod. B, Cap. cc, Bolts and nuts. D, Brasses.
engines. Some engineers prefer to have a flat part left for the
sides of the brasses, made deep enough to take a part of the top.
brass, with a cap of sufficient depth to suit the requirements; the
heads and nuts of the bolts are not generally recessed into the
block and cap, but the nuts are turned down, leaving a hollow part,
and a washer fitted with a pin in the cap, with a set screw bearing
in the groove cut out in the nut to prevent it shaking loose. In
some examples both of the ends are forged on in one block; and
others have forked ends to suit the crosshead adopted, having a
pin securely fastened through holes bored out in the forked ends,
with a collar at one end and a pin at the other end securely rivetted
in. Other forms of connecting rods have T pieces forged on the ends,
with brass distance blocks between the T piece and the cap, bolted
together with two bolts. These blocks are lined with white metal,
and are bored out to suit the pin on the cranked shaft; the end for the
crosshead does not require white metal let in. In some cases the
blocks are made quite plain and flat on the sides, in others the
pattern is cut out to save metal. The bolts for securing the brasses
are fitted with nuts and washers, having set screws for preventing
the nuts working loose. Sometimes a round boss is left on the
bottom brass, having a corresponding hole in the T piece; this

4 I2 MODERN STEAM PRACTICE.
helps to take the side strain off the bolts, but the generality of
makers leave these surfaces quite plain. When the bottom end of
- the connecting rod is con-
nected to a journal inside of a
O trunk, it is necessary that the
brasses can be tightened up
from the outside, and for this
purpose the eye of the rod is
forged on solid, and bored and
slotted out for the brasses;
the rod is then bored out for
nearly its entire length, for the
reception of an inside steel bar,
which is fitted at the top with
a cotter for tightening up the
rod against a steel plate let
Fig. 295.-Connecting-rod End for Cranked Shaſt. into the top brass, the bottom
a A, Brass ends, B, Cap. cc, Bolts and nuts. brass having al projection Cast
D, T piece forged on the piston rod. E, Oil cup. e º -
on, which fits into the central
hole in the connecting rod. This is a neat arrangement, and can-
not be dispensed with when the brasses work in a crosshead held
L-IT-I quite rigid. *
[. º The old form of connecting
U-T- rod, with straps, jibs, and keys,
IE may in some instances be bene-
ficially adopted, more especially
for the crosshead for double
piston-rod return connecting-rod
engines; in this arrangement,
having the keys passing through
a slotted-out part left in the
broad rubbing surface, with a
groove formed in the condenser
casting for the end of the key
to travel backward and forward
Fig. 296.-Connecting-rod End ſor Cranked Siaº, in, the distance from the Centre
A. Rod B, But, cc, Strap. D, Brasses of the journal of the crosshead
E, Jibs and cotters. ->
- to the plate on which the block
slides can be greatly reduced, which is a somewhat important con-
sideration. A very simple form of connecting rod has half brasses


MARINE ENGINES. 413
at the top and bottom, with a small rod on each side, on which are
left collars for the bottom part or inside brasses to bear against,
while the two outside brasses are bolted hard up against the inside
ones, with a screwed part on the ends of the rods having nuts and
washers: these rods therefore act as the main connecting rod and
tightening-up bolts. This plan, however, has not been much
adopted. -
The next detail to consider is the cranked shaft—a term adopted
to distinguish between cranks forged in one piece with the shaft,
and plain ones having cranks shrunk on. The crank arms are
forged on solid at right angles
to each other, they are then bored C
across and slotted out for the
part between the jaws, leaving a A A
part for the crank pin, which is R |)
turned out in the turning lathes \ \ A
or cutting-out machines used for - -
that purpose. There are three
main bearings, one on each side
of the cranks at the outside
and one central bearing between A. A.
them. When the distance be-
tween the cylinders is great, the
cranked shaft is separated at
the centre between the cranks,
having solid discs forged on, secured with bolts and nuts, and a
cross key for taking the sheering strain off the bolts: in this
arrangement two central bearings are provided, instead of one,
as when both cranks are forged on entire. The end parts of
the crank arms are often finished in the turning lathe, but some
examples have the circular form; the former, however, is the better
plan when counter weights are strapped on for balancing the weight
of the crank arms. These straps are quite flat, except where they
pass through the cast-iron balancing piece, where they are rounded.
The balancing piece is secured with nuts, let into the block at the
extreme end, and joggled into the arms at the crank end; the end
of the strap should have a round pin rivetted in, with a correspond-
ing hole bored on the crank end, which tends to prevent the strap
moving sideways. Some makers leave a joggle on each side of
the strap by planing out the sides of the crank arm, which makes
#
&
Fig. 297.-Cranked Shaft.
A A, Cranked shaft. B, Main bearing. C, Crank pin.

4I4 MODERN STEAM PRACTICE.
a first-class piece of work, effectually preventing these balance
weights moving sideways. The crank arms in some cases taper
from the shaft to the crank-
pin bearing, in others they are
left parallel; and when other
modes of balancing the cranks
and connecting rods are adop-
ted, the corners of the cranks
can be finished to a bold radius,
by which part of the weight re-
- quiring balancing is removed.
Fig. 298.—Balance and Cranked Shaft. - The journals for the cranked
A A, Cranked *. 5. º c c, Balances. shaft, and indeed all journals,
should be finished with the
tool in the lathe; the use of emery to get up a smooth face is a
practice long ago exploded, and rightly so, as many journals and
bearings have been torn and rutted up by the fine particles of
- emery indented in the iron. All
} the collars should be turned
j with a bold radius, for when
they are left square it is gen-
erally here that the shaft gives
way after long use. As the
strain imparted from the thrust
and pull, passing from the
piston through the rods, is
both rapid and severe, this
accident may occur with the
best arrangements; it is there-
fore always advisable to have
a spare cranked shaft stowed
on board the ship.
What are called built shafts
are those in which the crank
Fig. 299.-Main Framing of T. Section. and crank pins are shrunk on.
lºº.º.º.º.º.º.º. A fire, generally of wood, is
F, Flange for boiling to condenser. G, Oil cup. * lighted round the Cranks, and
when sufficient expansion has
taken place the parts are slipped into position. The crank on
cooling down grips the shaft and pin tightly.


MARINE ENGINES. 415
Fig. 298A shows the crank shaft of the screw steamer Arizona. It
is built up of five pieces. Of these
of steel and made by Sir J. Whit-
worth's process, the steel being
known as fluid compressed, this me-
thod being adopted to insure uni-
formity in structure. The process
consists in first of all casting the steel
in a mould having a core; thereafter,
and while still fluid,thecasting is sub-
jected to an intense hydraulic pres-
sure, which forces the air and gaseous
matters out of the fluid mass. After
solidifying the metal is reheated and
forged down to a length suitable for
the purpose for which it is to be ap-
plied. A stronger shaft for the same
weight of metal is thus obtained.
The main framing (Fig. 299) on
which the pillow blocks are cast for
sustaining the cranked shaft may be
regarded as the backbone of horizon-
tal marine engines. It is subjected to
; ; ; - tensional, compressive, and twisting
| He strain, and must therefore be made
of great strength. Some makers adopt the T section, others the +,
yº
H
==
•
# , four are made of hammered and
: rö º
§§ rolled scrap iron, the fifth, or crank
3: pin, being made of steel. The dia-
gi meter is 22% inches.
b) • - -
.# * The immense power of engines in
ç • *
# 5 some of the recently launched ocean
#3 steamships for the Atlantic service
ź E º e
i # = necessitates correspondingly heavy
† : T2- . ; ; and strong machinery; thus the
; : * * S- * := º e
; : | - § # crank shaft of the Servia, City of
; : & º- º/2 O -
łº +--!> ‘ā9 Rome, and Alaska areabout 25 inches
:: | ©- .x: 0 . tº e
is: | ās in diameter; those of the Servia and
, ; ; TH-Z ºf 5 e e
#4-H...--- . . ; Alaska are solid, whilst that of the
; : | : " : City of Rome is hollow. This shaft is
; : cº
º .#
º:
©
O
3
3
Tº
c
O
§
º
tº
§
|
wº-i.:*--* \tº**--
a.-|*jº
••, º|se.|º ºes$
-e---
§
:
|


416 MODERN STEAM PRACTICE.
while some consider the box form preferable; and all these forms are
successfully carried out in practice. Strength is the main thing to be
looked to; but the open form of framing has the advantage of giving
more convenient access to the various glands. The frame is firmly
bolted to the cylinder at the top and bottom, and also to a flange
carried along from the cylinder to the condenser. This flange is
| –
Fig. 3oo.—Main Framing of + Section.
A, Frame. B, Brasses. C, Cap. D D, Bolts and nuts. E. E., Flanges for bolting to cylinder.
F, Flange for bolting to condenser.
secured to the keelson or engine bearers by long bolts passing
down to the under side of the bearers, with cross bars of cast iron
at the under side; in this way the whole depth of the engine bearer
is secured. All the bolt holes should have proper bosses cast on
the framing, to suit the bottom and other flanges connected to the
cylinder and condenser, so that a fair bed for the nuts can easily
be faced up. The b1a;ses for the pillow blocks are fitted just as in
any other arrangement lying on its side, and are secured by caps
of cast or wrought iron; each cap has two large bolts passing
through it into holes cast and bored out in the casting, and fastened
with cotters. The cap is fitted with clips at the top and bottom, nicely
fitted to the pillow block, to prevent its sides springing; and the
nuts for the bolts are fitted with washers and set pins, to prevent
them becoming loose. All the work connected with the pillow

MARINE ENGINES. 417
blocks must be well executed, for the main stress is directly taken
on these bearings. When the distance between the cylinders is
great, leaving a long centre part on the cranked shaft between the
cranks, the centre bearing should be increased in length, so that no
undue strain is taken on the cranked shaft; in fact, the shaft should
be always supported as close to the cranks as is practicable. All
the brass bearings are recessed for the reception of white metal,
which is poured in while in a fluid state, a cast-iron core piece,
somewhat less than the diameter of the shaft, being first inserted
P
Fig. 30r.—Main Framing of Box Section.
A, Frame. B, Brasses, c, Cap. D D, Bolts and nuts. E, Wrought-iron stay. F, Slipper guide.
G, Oil cup.
in the bearing, so as to keep the white metal in its place; the half
brasses are held together prior to this operation, and are bored out
in the lathe and then separated. In this way fair work is secured;
but some makers prefer boring out the brasses in situ, and no
doubt when properly executed this plan has its advantages. In
most machinery there are numerous fittings which can be con-
veniently cast on the main framing, or bolted on fitting strips left
for that purpose; and proper attention to these points shows the
skilfulness of the designer, and saves much work afterwards.
The box form of framing differs materially from th;F and +

418 MODERN STEAM PRACTICE.
sections, although the brasses are also fitted in lying on their side,
in order to adjust them in a direct line with the strain given off from
the piston. The part of the bottom frame which forms the con-
nection between the cylinder and the condenser is retained, but the
top part is dispensed with, and a wrought-iron stay introduced,
keyed through a boss bored out for its reception in the head or
pillow block; on the other end of this stay a flange is formed for
securing it by bolts and end keys to the cylinder at the side of the
steam jacket. Between the bottom part of the framing and the
cylinder a bed plate is introduced, on which raised parts are cast
to receive what is termed the slipper guide plate for the crosshead
of direct-acting single piston-rod arrangements. This part of the
framing extends across the engine, embracing all the pillow blocks
for carrying the cranked shaft, which blocks are also cast entire
along with the bottom frame plate; but at the condenser end parts
are cut out in the bottom having merely projections opposite the
bearings for bolting to the condenser. This form of framing
has a strong yet light appear-
ance, and cannot be excelled
for the peculiar type of engine
for which it is designed, as all
the parts are easily reached—
a great desideratum in the
marine engine; while the whole
framework is firmly united to
the keelsons by one broad base
plate.
In another form of framing,
Fig. 3O2, we have the means of
tightening up the main brasses
by wedge pieces let into the
pillow blocks. This frame
extends from the cylinder to
the condenser, with ribs and Fig. 302.-Main Framing with. Adjusting Wedges.
feathers cast along with, and ***". º: *: º IlutS.
in a direct line with the sides -
of the pillow block or bearing piece, the cap for holding down
the brasses being placed on the top, instead of on the side as in
the previous examples. Between the brasses at the cylinder end
two wedge pieces of wrought iron are introduced, extending across

MARINE ENGINES. 419
between the flanges, having a spindle forged on, and passing
through the cap; they have a screw cut on the end with nut and
lock nut fitted, by which means the brasses can be tightened up or
adjusted at any time. In other arrangements a single wedge piece
is introduced, having one central spindle fitted with two nuts for
tightening up against the cap. Some makers introduce the brasses
in four parts, one at each side and one at the top and bottom; by
this means they can be adjusted vertically and longitudinally.
The condenser.—We now come to consider the arrangements for
effecting the condensation of the steam with ordinary injection
condensers. All condensing vessels should be constructed as simply
as possible; and the arrangement of the water pipes leading into
and from them, as well as valve seats, discharge chambers or hot
wells, and all their vari-
ous fittings, requires
careful consideration.
Where large flat sur-
4. faces are required, they
should be well strength-
ened with ribbed bars
in the casting; some
- makers use wrought-
Fig. 303.-Exhaust Pipe. iron stays, which tend
A, Pipe. B, Stuffing box and gland. c, Baffle plate. greatly to Stren gthen
D, Condenser. E, Hole for running off condensed steam.
the condensing vessel
against collapsing. The other parts of the general casting must be
well bound with the various divisions required for the air pump and
valve fittings. The capacity of the condenser is greatly affected
by the size of the exhaust pipe from the cylinder; this pipe should
have a large area, so as to freely pass the steam to that part of the
condenser where the water from the sea is showered in; thus the
large pipe receives the steam, which is at once condensed, and the
capacity of the condensing vessel need not be so large as when the
exhaust steam finds its way into a condenser placed alongside of
a cylinder having no pipe connection.
. The exhaust pipe should be fitted with an expansion joint, which
is generally placed on the condenser casting, the end of the pipe
passing through a loose hoop placed at the bottom of the stuffing
box; by this means the pipe can be angled into its place without
disturbing the cylinder or condenser. The loose hoop and gland

42O MODERN STEAM PRACTICE.
being placed on the pipe in the first instance, the hoop is then
slipped into its place, and the gland pressed down on the hemp
packing in the usual manner; the other end of the pipe is secured
by a flange bolted to the cylinder. There are also other forms of
expansion joints. Some have hollow discs formed on the body of
the pipe, with end flanges for securing the pipe to the cylinder and
condenser, thus forming a rigid stay between the two, but having
the power of expanding by compressing the flat discs, and con-
tracting when the strain is off by opening the disc plates. We
prefer, however, the usual mode with stuffing box and gland. The
position of the condensing chambers varies, and depends greatly on
the location of the air pumps. When these are placed together, one
on each side of the middle frame for carrying the cranked shaft,
the condensers are then generally in a line with the outer frames, or
fore and aft of the outer lines of the cylinders. In return connect-
ing-rod engines, with the discharge chambers placed, between the
centre lines of the cylinders, and in similar arrangements of air
pumps, the condensing chamber and discharge chambers are both
placed between the centre lines of cylinders; this plan necessitates
the cylinders to be placed further apart from centre to centre—that
is to say, when the air pumps are located at the side of the motion
or guide bars for the crosshead. Sometimes the air pumps are
arranged underneath the motion bars, having the discharge chamber
at the middle between them, and the condensing chambers on each
side; while, in other examples, with one air pump on the outside
of each outer frame, fore and aft, the condensing chamber and
discharge chamber are cast together immediately over the air pump.
In direct-acting single piston-rod and double-trunk engines, the
air pumps are always placed one on each side of the centre frame,
having the condensing and discharge chambers located immediately
above them; while in plunger air pumps with single-acting arrange-
ments for foot and head valves, suited for single trunk and return
connecting-rod engines, the condensing and discharge chambers
are placed immediately over the pumps.
The general arrangement of all these forms of condensers,
exhaust, discharge, and injection pipes, air pumps, with foot and
head valves, &c., cast in one or more castings, is as follows. When
the air pumps are arranged one on each side of the middle frame,
there are generally two separate castings, all the fittings for which
are kept quite independent. The air pump in all the exâmples
MARINE ENGINES. 42 I
under notice, whether fitted with an internal plunger or a simple
piston, is of the double-acting type, and is worked directly off the
steam piston by means of a rod connected to it, having packing
glands on cylinder end and
air-pump cover. When the
pumps are placed as above
described, the foot valves are
underneath and the head
valves above them; there are
separate chambers for the
foot valves at each end, but
the head valves are fitted in
one chamber common to both
Fig. 304.—Air Pump with Condenser outside and ends. Doors for the foot
Discharge Chambers at centre. valves are fitted at each end,
, fl..." ...”., one of which forms the cover,
and the other is an ordinary
door; on each of these doors a circular pipe piece is cast, for filling'
up the space above the foot valves, so as not to leave so much dead
water in the foot-valve chambers. The doors on the discharge
chamber containing the head valves
are of the ordinary description;
these as well as the other doors are
generally bolted by stud bolts and
nuts. Two deep feathers are cast
along with the hot well, which forms
an air chamber tending to relieve
the shock caused by the rapid dis-
charge of the water. The discharge
pipe is fitted to one end of the
- hot well, at the top, and is placed
Fig. sº * in communication with one pipe
A, Condenser. B, Hot well. º, Foot-valve seat. Overboard Common to both air
...”.”... pumps. The condensing chamber
is on the opposite side of the centre
line of the cylinder in regard to the air pump, the exhaust comes
in at the top, and the injection pipe immediately under it. The
condensing chamber is ribbed and cast with circular parts, which are
bored out for the reception of the air-pump barrels; these are cast
in brass, and fitted with Solid-ended pistons of the same material.
• * * * * *
% à \\
ºzā N
SºğSSS
*
****** ** *
ºr ~ * * * ~ *






422 MODERN STEAM PRACTICE.
The snifting valve for all condensers is fitted as low down as
possible.
For similar arrangements of air pumps situated on each side of
the middle frame, the foot valves are placed low down on the other
side of the centre line of the cylinder in regard to the air pump,
with the head valves in one chamber common to both, arranged
between the air pumps; the doors for getting at the valves are
placed on the top of the valve chambers, which is found a very con-
venient and handy arrangement. One discharge pipe, placed
centrally with the hot well, serves for both of the pumps. The
exhaust steam comes in at the top end of the chamber, and the
water falls down underneath the air pumps, the condenser being
partly above and partly below --
the pumps, and having a divi-
sion cast in for separating and
strengthening it. The injection
valve can be placed above the
exhaust pipes, and thus shower
the injection water down on the
steam, instead of meeting it as
in the previous example.
When the air pumps are situ- Fig. 306.-Air Pump with Condenser outside fitted with
& * ted Foot Valves and Discharge Chamber at
ated underneath the motion bars, . g
CeIl tre.
3. good plan is to invert the foot A, Condenser. B, Hot well. c, Foot-valve seat.
valves, placing them in the * Head-valve seat. E E, Guide bars for piston-rod
crosshead. F, Air pump. G, Discharge pipe.
bottom of the condensers, which -
are seated in a line with the outside frame; thus the condensing
water and the condensed water from the steam fall into each
suction chamber by their own gravity. In this arrangement the
head valves are placed in a central chamber between the pumps;
and this chamber has one discharge pipe common to both sets
of air pumps. The exhaust steam enters at the top, the injec-
tion pipe is placed under and showers the water upwards to
meet the steam, care being taken that the water cannot pass
into the exhaust pipe. The injection pipe, when placed below the
exhaust pipe, should always be pierced with holes, to shower the
Condensing water meeting the steam, instead of pouring it down
vertically; by this means the water and steam are brought into
better contact, and form a more rapid vacuum. -
When the air pumps and condensers are arranged in a line with

MARINE ENGINES. 423
the outside frames, the foot valves are inverted, the head valves
being over the pump, with a discharge chamber and pipe, having
the condenser immediately over it, separated by means of division
plates in the casting; the exhaust pipe is placed at one side, and
the injection pipe on the opposite side arranged for showering the
water downwards. A bed plate for carrying the guides for the
crossheads, &c., lies between the two pumps, and forms a very
convenient starting platform, nearly on a level with the engine floor
plate. Some engineers, however, make use of this space for arrang-
ing the condensing chambers between the guide bars, with the air
pumps placed as before inside of the outer frames. The foot valves
are placed at the bottom and
side of the air pump, and the
head valves immediately over
them, with side doors to each,
and a discharge pipe for the
pump. The exhaust pipes
enter at the top of the cen-
tral condensing chambers,
and the injection pipes are
placed lower down. It is ad-
- .. visable with this form of con-
"...º.º denser, at least for engines of
all in one casting. great power, that the pumps
A, Condenser. B, Hot well, c, Foot valve seat. should be separate Castings;
D, Head-valve seat. E E, Guide bars for piston-rod cross- ę &
head. F, Air pump. G, Exhaust pipe. provision should also be made
on the patterns for attach-
ing and fitting to the general casting the feed and bilge-water
pumps, which are generally worked off arms keyed on the piston
rods, or with studs fitted to the crossheads, or even with direct rods
from the steam piston. We have here given examples of condensers
with their adjuncts which are in general use; but it will be under-
stood that a variety of forms can be arranged for return connecting-
rod engines. - -
We now turn to arrangements that have been adopted for direct-
acting, single piston-rod, and double trunk engines. There is a
great similarity in the various parts of these, chiefly owing to the
air pumps being located one on each side of the middle frame for
carrying the cranked shaft. The condenser is situated centrally
above the pumps, having the foot valves inverted, so that the water

424. MODERN STEAM PRACTICE.
falls into the pump chamber by gravitation; the head valves are
foot valves, with a hot well
placed at the side and above the line of
for each pump fitted with separate
discharge pipes overboard. With this
arrangement of foot and head valves
air is not so liable to collect between
the piston and valves; it is therefore
preferable to have an air valve—
should it be desirable to place the
discharge valves below the line of
head valves—arranged at the highest
point in the foot-valve chamber, by
which the air is forced into the dis- Fig. 308.—Air Pumps with Condenser at centre
charge pipe overboard. The exhaust
fitted with inverted Foot Valves and Dis-
charge Chambers at side, all in one casting.
pipe is of a large diameter, suited for A, Condenser. B, Hot well. C, Foot-valve
both engines, placed in the centre of
the condenser, and the injection pipe
seat. D, Head-valve seat. E, Air pump.
F, Feed pump. G, Exhaust pipe.
is placed at the top on the same centre line, thus the water is
showered down on each side of the
condensing chamber: this
arrangement is very effective. In other arrangements the valves
are placed vice versä, the condensing
chambers being at the side, and the dis-
charge chamber placed centrally above
the pumps, with one discharge pipe
overboard; while there are two exhaust
pipes, each passing into a separate Con-
denser, with the injection pipes under-
neath. This arrangement has the ad-
vantage of the condensers for the cylin-
ders being separate from each other,
and this enables us to regulate the in-
jection water required by each, which
we cannot do when one injection pipe
serves for both condensers. These con-
densers, when required for engines of
ordinary power, are generally cast in
º
*
º
&W.
\\
[-];
º
Vº
w
\
|
#
t
§
N
º
aº.
Fig. 309.-Air Pump with Condenser at
side fitted with inverted Foot Valves and
Discharge Chamber at centre.
A, Condenser. B, Hot well. c, Foot-valve
seat. D., Head-valve seat. E, Air pump.
F, Feed pump. G, Exhaust pipe.
one piece, but for heavy
engines they should be two separate castings, with air pump and
adjuncts arranged as in the previous examples.
THE SURFACE SYSTEM OF CONDENSATION.—Before describing
the construction of the condenser for the surface system of con-








MARINE ENGINES. 425
densation, we shall notice the disadvantages attending the injection
system for the condensing of steam in marine engines. The chief
objection doubtless arises from the necessity for using a continuous
supply of salt water in the boilers, the salt accumulating to such
an extent that a high degree of heat is required to raise the steam.
This accumulation of salt proceeds so rapidly, that it is necessary
to blow off the water in the boiler every two hours or so, the feed
from the hot well at the same time is turned on, thus the hot brine
being blown off, and replaced with a colder fluid, the temperature
of the water in the boiler is greatly reduced, and requires much
valuable fuel to keep it up to the proper working point. The rapid
incrustation that takes place is likewise a serious objection, as the
scale formed all round the parts immediately exposed to the action
of the flame is a very bad conductor of heat, and not only impedes
the free transmission of the heat to the water, but in many parts
of the boiler it forms to such an extent that rupture of the plates
takes place, more especially on the back parts of the furnaces where
the flame returns through the tubes—necessitating frequent inspec-
tion, for the purpose of cleaning the boilers, and removing the
incrustations, so as to prevent the plates wearing out too rapidly.
In fact, for the high-pressure compound engine system, the injection
condenser has been discarded, because distilled water is preferable
to impure salt water; and with proper precautions we can safely
adopt high-pressure steam with fresh water, and thereby save much
valuable fuel. -
The action of surface condensation may be familiarly illustrated
by the well known deposition of moisture on the windows of a
crowded room, due to the cooling surface of the glass. So with
the steam from the cylinder: surface must be provided, and cold
must be applied to that surface, so that with cold on the one side,
and the steam impinging against the cold surface on the other, the
caloric is extracted, and water flows down, similar to that on the
window. Thus when the boilers are provided in the first instance
with pure water, it is used over and over again, with just sufficient
water injected from the sea to meet the waste, and keep the density
of the water in the boiler at about the same as the water in the
ocean, this being considered in practice very safe. And as water
requires a large surface in the boiler for the heat to act upon it in
raising steam, so in condensing the steam rapidly we must have a
large amount of cold surface for it likewise. The surface condenser
426 MODERN STEAM PRACTICE.
is simply an arrangement of tubing placed in a convenient vessel
surrounded with water; in some cases the tubes are filled with
water, in others the water in the vessel flows all round their exter-
nal surface. This water must be kept constantly flowing through
the vessel, so as to maintain the refrigerating surface at a proper
working temperature. For this purpose a circulating pump is
fitted, which draws the water through the tubes or around them,
as the case may be; in other arrangements the water is forced
through or amongst the tubes. The water from the condenser is
carried off by an air pump similar in construction to that used for
ordinary injection condensers, and is delivered into a separate
vessel, from which it is pumped into the boilers, in some instances
directly by the air pump, but usually feed pumps are fitted for the
purpose. In some convenient part of the condenser a valve and
inside pipe are fitted, perforated with slits or holes for showering
into the condenser the sea water necessary to keep up the requisite
amount of feed for the boiler.
We now come to consider the manufacture and arrangement of
surface condensers. The tubes vary from 9% inch to 7% inch internal
diameter, thickness about I's inch; generally 34 inch outside dia:
meter; they are made of composition metal, and are known by the
name of cold-drawn composition tubes. The tubes for government
contracts are tinned outside and inside to prevent chemical action.
They are 9 feet long.
The tube plates are of copper, and vary in thickness from
+ºr inch to ## inch; they are fitted to plane surfaces on the casting
forming the vessel containing the tubes, and are secured with com-
position metal bolts and nuts. A variety of plans are adopted for
making the ends of the tubes air and water tight. The original plan
(Fig. 3 IO), still much used, consists in forming screwed stuffing boxes
in the tube plate, the packing being a tape of cotton or linen sewn
together, which is slipped over the ends of the tubes, and pressed
into the stuffing box with a screwed gland. These glands are
manufactured from solid rolled tubes of composition or Muntz
metal, and can be obtained of suitable lengths; the inside diameter
must slip easily over the tubes in the condenser, while the thickness
is regulated by the size of the gland, so that a proper thread is cut
in a similar way to bolts in the common screwing machine; they
are cut off into proper lengths by a circular saw, and notched in a
machine with two notches, for screwing them into the stuffing box
MARINE ENGINES. 427
with a screw driver.
sºº
42
i
*
*
N
Š
§
N
§
T
º
º
N
&
º
º
N
N
N
§
º
N
*
N
º
N
X
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i
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ºf
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Another mode of making the tube joints is
with a sheet of india rubber having holes suited to the pitch of the
; :
º
Fig. 3ro.—Tape Packing for Tubes.
A, Tube. B, Packing gland.
tube. The holes are left smaller than
the outside diameter, and when the tubes
are all in position, being merely passed
through plain holes drilled in the tube
plates, the india-rubber sheet is laid over
them, and an outside plate is bolted up
against it, which plate is recessed for the
reception of the tubes, and leaves a
narrow edge round each tube; thus with
the pressure, and the holes in the india
rubber being much smaller than the
diameter of the tube, a raised flange of
india rubber is formed around each tube,
and the tubes are gripped by an elastic
medium, while the pressure transmitted
through the plate by the bolts to the
flat surface of the india rubber keeps it
in perfect contact with the plate, and a
good joint is obtained. Some engineers, however, think that each
tube should be made air and water tight separately, so that if a
joint gets out of order it can be repaired without disturbing the
4.
Fig. 311.-Sheet mode of making the Tubes tight.
N
-—- whole series; besides with such
| thin tubes it is an object to have
the joint elastic, so that the tubes
%
can expand and contract easily.
With these objects in view the
author has arranged a packing ring
of a peculiar construction. The
holes in the tube plate are bored
parallel, and then tapped; a gland
or Screwed nut having a recess for
a ring of india rubber or any other
º
:
AA, Tubes. B, India-rubber sheet. C, Plate. elastic medium 1S fitted to each
hole. The india rubber ring is a
good fit in the recess, and is put in place by merely squeezing
it together; its inside diameter is made smaller than that of the
tube, according to the amount of grip required; and to facili-
tate the operation of tubing, a loose cone plug is inserted in


428 MODERN STEAM PRACTICE.
the ring, and the nut being placed over the tube when in posi-
tion, it is screwed up, then the cone is forced through the india
rubber and expands it for the reception of the tube; in this way
the ring is spread out, tightly filling the recess, and binding the
tube firmly; the nut is screwed hard up on the tube plate, against
a washer, or simply metal to metal, having a little red lead inter-
posed. By this plan the tubes can be readily and quickly made
tight, and the elasticity of the ring allows of free movement
for expansion and contraction. When
india rubber is used the tube ends should
be tinned to prevent the deterioration
which takes place when brass and india
rubber are in contact. In some ar-
rangements when the water is forced
through the tubes, their ends are made
tight with a simple flat ring washer of
india rubber, placed over the tube
tightly, the flat end surface bearing on
the tube plate, which is recessed for its
reception, and in others wooden plugs
are used, driven over the tubes, and
firmly held in the tube plate, the expan-
sion of the wood when wetted making
a very good joint. -
The arrangement of the refrigerat-
ing surface now falls to be noticed. Fig. 312-Packing Ring for Tubes.
When the water passes through the Ҽ. "..."
tubes and the steam all around them,
we obtain a larger amount of surface than when the steam is
condensed inside of the tubes; but in the former case any incrus-
tation that takes place tends to choke up the spaces between
the tubes, and so far renders them useless, as there is no pos-
sibility of getting them cleaned; whereas, when the steam is con-
densed inside of the tube, the surface can be cleansed occasionally.
Again, should any of the tubes require repacking at Sea, with the
water circulating around them, the large covers which form part of
the condenser require to be taken off, and should any leakage
occur through the joint being imperfectly re-made, air finds its way
into the chamber and impairs the vacuum; whereas, when the
water passes through the tubes, with any leakage occurring, the

MARINE ENGINES. 429
water simply finds its way into 'the ship, and the working of the
engines is not sensibly affected. Looking, however, at all sides of
the question, we may conclude that the advantages are in favour of
inside condensation,-provided that the circulation of the water is
properly attended to and uniformly distributed all round the
exterior surfaces. When the surface system of condensation was
first introduced into side lever engines for the Royal Navy, 28OO
square inches of tube surface was adopted for the condensation of
6O,OOO cubic inches of steam per minute, the quantity of cold water
injected being IO gallons. To compare these quantities with pre-
sent practice, let us take an example of an engine of 400 nominal
horse-power, having 3170 square inches of area in each cylinder,
with a piston speed of 300 feet or 36OO inches per minute:
3170 × 2 × 3600 38o × 28oo
6oooo - R44 7389.
We thus have 7389 square feet of tube surface, equal to 18.4 square
feet per nominal horse-power. It will be observed that this result
is about the same as that given for total heating surface of boiler
per nominal horse-power, although it is in excess of present prac-
tice, I 5 to 16 square feet of condensing tubes being now considered
sufficient. To find the quantity of water required for condensation:
a cylindrical foot of water equals 5 gallons, IO gallons will be con-
tained in 3456 circular inches, and as 380 times 6O,OOO cubic inches
of steam passes the engine per minute, we have
*…* = 364 + 2 = 182
circular inches of area for each pump, when two pumps of the
double-action type are fitted—or a diameter of Say I4 inches will be
enough for each of the two circulating pumps. (See pages 508–51O.)
The air pumps are generally made of the same capacity as for
plain injection condensers, and when one circulating pump is fitted,
it is of the same capacity as the air pump; one set of patterns thus
serves for both, and in the event of using the condenser with plain
injection, valves are so arranged that the circulating pump can be
used for an air pump. The circulating pump should be fitted with
a valve for turning on the bilge water, in case of great leakage in
the ship; a valve must also be placed on the pipe for shutting off
the sea-water. Should both of the pumps be used as air pumps
(in cases of failure), a bilge injection valve should be fitted. When
43O MODERN STEAM PRACTICE.
a separate centrifugal pump is used, driven by a small engine, for
circulating the water, and two air pumps are fitted, the centrifugal
pump should be arranged to pump the bilge water overboard, and
one of the air pumps turned into a circulating pump, the requisite
valves being placed so as to be opened at the shortest notice. To
provide against any accident to the surface system, a plain injection
valve is placed on the condenser, and a valve is also fitted at some
convenient part to drain all the water out of the condenser when .
necessary. -
Various arrangements of the tubes for surface condensers are
adopted. For direct-acting horizontal engines of the return con-
necting-rod type, they are ar-
ranged vertically, placed between
the crosshead guides in one, or E.
else there is a separate condenser
for each cylinder. The steam 4.
from the cylinders enters above 2 * * à) 21 'N
the top plate, and being con- f g
densed falls directly through the k
tubes into the air pump, which ºf .
is situated on the inside of the -
outer frame, and worked directly P-
from the steam piston, while the Fig. 313.—vertical Arrangement of Tubes for Return
e * ge Connecting-rod Engines.
circulating pump occupies the e tº º º
tº . tº A, Tube chamber. B, Air pump. C, Circulating
same position as regards the pump.
other cylinder; the water is
drawn through the vessel containing the tubes, coming in at the
top, circulating around the tubes, and being drawn away, instead
of forced, by the circulating pump. The bottom part of the con-
denser is generally cast in two, containing the guide bars for the
piston-rod crosshead, the chamber for the gun-metal air pump or
circulating pump, barrel, valve seats, air vessels, &c. The flange
for holding the bottom tube plate extends the length and breadth
of the casting between the guide bars, and is planed all over; the
bottom tube plate is fitted on it, the vessel containing the tubes is
placed over it, and the top tube plate secured on the top. Above
this is placed the top part of the condenser, where the steam enters;
it is fitted with covers on the top for getting at the tubes, the
bottom joints are reached through a door on the bottom chamber
of sufficient height for a man to enter. Some arrangements of the

MARINE ENGINES. 43 I
vertical type have a circulating pump worked directly off the piston,
with an arm keyed on the bottom piston rod for taking the air-
pump rod; two circulating and two air pumps are fitted, in other
words the separate condensers have each a
circulating and air pump. As the water,
either from the sea or from the condensa-
tion of the steam, gravitates directly into
the pumps, this arrangement is very effec-
‘tive, although the circulation of the water
is not so good as could be desired—a fault
inherent in all cases where the conden-
sation takes place inside of the tubes;
* ar, vertical Arrangement nevertheless, when the water passages are
suited for each Cylinderindependently properly arranged, inside condensation is
A, tº: ë. ºw to be preferred, as there is then some pos-
sibility of cleaning the tubes from lubri-
cating matter carried over by the steam. As an improvement on
the vertical arrangement, some engineers have made the condenser
cylindrical, with a space in the centre for the steam pipe from the
cylinder, around which the tubes are arranged in rings. The ex-
haust steam pipe is perforated with holes for distributing the steam
equally; the condensing surface is on the outside of the tubes, the
water circulating through them. In some cases the condenser is
fitted with circulating and air pumps worked directly off the piston,
in others the air pumps work direct, with a centrifugal circulating
pump driven by an auxiliary engine. -
The horizontal arrangement of tubes next claims attention. For
direct-acting horizontal engines the tubes are placed fore and aft
the ship, arranged in three divisional parcels, with the view of
giving time for the transit of the circulating water which is being
forced; and this passes in the first instance through the bottom
row, returning through the middle row, and then passing through
the third or top row before escaping overboard, in this way securing
a more equal distribution. The condenser vessel may be cast in one
or more pieces, with all the necessary passages, valve seats, &c., for
the pumps; the joint faces for the tube plates are all planed, and the
tube plate accurately fitted. As the doors for getting at the tubes
are placed at the ends of the condenser, both of the tube plates
are easily managed, whether as regards fitting in the tubes in the
workshop, or repairing leaky joints at Sea. To ease the passage of

4.32 MODERN STEAM PRACTICE.
the water through the tubes, flat air vessels are cast along with the
end doors, by which the flow of water is rendered smoother and
• more equal. The steam enters
at the top through an exhaust
pipe at each corner, the water
from condensation falls down
amongst the tubes and is car-
ried away by the air pumps;
one pump only is fitted to
engines of small power, but
heavier engines have two air
- tº sº and two circulating pumps.
Fig. 315.-Horizontal Arrangement of Tubes for Return
Connecting-rod Engines. A, Tube chamber. B, Air From the great number of
pump. C, Circulating pump. such tubes required to give the
necessary cooling surface, or about 2 square feet per indicated horse-
power, the length reaches in large vessels to many miles of tubing;
thus in the surface condensers for the new Inman steamer City of
Rome, the total length of tubes is about 17 miles.
It appears to be of little consequence whether the water flows in-
side or outside of the tubes, so long as a good circulation is kept up.
Sometimes the tubes are arranged independently for each
cylinder, the water from the circulating pump only passing through
the tubes twice, instead of three times. The pumps are located on
each side of the middle frame, and are worked directly off the ,
piston of each cylinder. They are of large diameter, one end being
fitted for the circulating pump, and the other end for the air pump;
thus for each function this arrangement may be termed a single-
action double-acting pump. There is one central chamber and
pipe for the suction to the circulating pumps, which first discharges
the water right and left into a chamber common to both, and then
through the tubes; the water returns through the top row, and is
discharged into one central chamber, with one pipe overboard for
both pumps. The arrangement of the valve seats is simple: they
are sometimes placed at the side of the pump, sometimes at the top
and bottom. It may be questioned whether single-acting circulating
pumps are preferable to smaller sized double-action pumps. Many
engineers are in favour of the double-action type, but consider, so
long as a sufficient quantity of condensing water passes through or
amongst the tubes, that a single-acting pump, discharging into a
capacious air vessel, makes the flow quite uniform enough for all

MARINE ENGINES. 433
practical purposes. The doors in the arrangement of condenser
under notice only admit of inspecting one end of the tubes; for
packing their central ends a manhole is arranged in the bottom
and top chambers, through which the water enters the tubes at the
bottom, and from which it is discharged overboard at the top. A.
plate abutting on both tube plates forms the division between the
two. This arrangement is very good for engines of large power, as
the tubes are of a suitable length, neither too long nor too short.
To facilitate the water from the condensed steam flowing away
from the tubes, when condensation takes place on their internal
circumference, the tubes have been arranged lying at an angle.
They may be so disposed right and left, or all in a cluster; when
arranged right and left, the central chamber, as in the foregoing
example, becomes the exhaust steam chamber, instead of the water
chambers. The air pumps are arranged on each side of the outer
frames of the engine, and the circulating pumps on each side of the
central frame; the suction valves for both pumps are inverted and
placed above the pumps, while the discharge valves are arranged
alongside, the circulating water flowing amongst the tubes at the
bottom end near the central frame, and ejected from the vessel
containing the tubes at the opposite corner at the top: thus the
water is well distributed amongst the tubes—a very necessary thing
to attend to in all arrangements.
The valves for the pumps are of the round disc type, made of
india rubber, having grated seatings and guards of brass. Some of
these valves fold up all round against a saucer-shaped guard per-
forated with holes, and are secured to each hole in the condenser
by a cross bar of iron and a single bolt. This bolt passes through
the centre of the bar, seating, and guard, and is secured with one
nut at the top, pressing the guard and seating downwards, and
drawing the cross bar upwards against the under side of the metal
surrounding the hole in the condenser casting; but the general way
is to secure the guard and valve by a screwed stud with a nut at
the top to a large plate containing all the gratings for valves, the
plate being secured over one large hole in the condenser casting by
gun-metal stud bolts and nuts. Sometimes the guards are made
quite flat, the valve moving upwards and downwards on the boss
of the guard, the central hole in the india-rubber disc being made
slightly larger, so that it moves easily; this arrangement can be
secured with a cross bar, or with stud bolts, on a plate common to
-*
434 MODERN STEAM PRACTICE.
all the valves, as before described. The gratings for these valves
are formed of ribs radiating from the centre, having one or more
concentric rings, keeping the area of each hole in the grating equal
to about I square inch. The ribs on the guard radiate from the
central boss, and the ends of the elongated apertures are rounded
or left square as taste may dictate. Other forms of valves are
oblong shaped, folding up against a flat guard, the india rubber
being secured at the middle with stud bolts; the holes in the
gratings being made hexagonal, formed around a circle I inch in
diameter. This grating resembles a honeycomb, and may be said
to combine the greatest area with the least material, thus obtaining
more free way for the passage of the water—a very desirable point
to attain in designing pump valves. For this object a valve seat
has been designed by the author in which five discs can be placed
in about the same space as is usually occupied by one; the seating
is in the form of a square box open at the bottom, with a flange
all round for securing it to the condenser, one valve being placed
on the top and one on each of the four sides. This plan can be
modified by making the valve seating cylindrical, the side valve
being simply a band of india rubber, secured at one end to the
cylindrical seating, and a round disc valve placed on the top. The
action of the band valve is one of expansion and contraction as it
opens and shuts with the reciprocating motion of the pump piston,
or plunger if so fitted. It is scarcely necessary to state that india-
rubber valves will work in any position, whether lying flat, or at an
angle, or even inverted; the latter position is fast finding favour,
where the passages of the pump are so arranged that the water
gravitates into the pump chamber instead of being Sucked or
} drawn in.
The pistons for the circulating pumps of direct-acting horizontal
engines are packed with a metallic ring; in Some instances wood
packing has been adopted, lignum-vitae being preferred. In other
cases plungers instead of pistons are used. The plunger consists
of a cylinder of brass working in a central Stuffing box, hemp
packing being used in the form of a gasket. The cylinder forms
as it were the pump barrel and piston, as in the double-action
pump; it is worked directly off the steam piston, with a small rod
secured to the cylinder with a single nut. It may be argued that
the plunger is heavier than a plain piston, but it must be remem-
bered that as it is surrounded with water, it partially floats as it were
MARINE ENGINES. & 435
in the fluid, consequently the wear is much reduced; however, for
surface condensers it is not so compact as a plain piston. Some-
times the water chambers at the ends of the pumps are partially
filled up with a cylindrical casting, formed on the end covers; the
piston rod works through this at one end, and it is left plain at the
other end of the pump, that is to say, no stuffing box is required,
but the cylindrical filling-up piece is simply cast along with the
end cover.
Air Pump.—The air-pump barrel is cast in brass, with fitting
rings at each end and at the
middle, which are turned to fit
the parts bored out in the con-
denser casting; the barrel is se-
cured by lugs cast on the end,
with brass bolts for firmly bolt-
ing it to the condenser. When
internal plungers are used, the
barrel of the pump forms as it
were the central gland, which
is packed with hemp in the usual
manner. All the bolts and nuts
used in the internal fittings
should be of brass or Muntz
metal; this is absolutely neces-
sary, for with wrought-iron nuts
oxidation rapidly takes place,
and the violent motion of the
water passing through the pumps
would wash away the rust as it
formed, and soon render the bolts
Fig. 316.-Air-pump Barrel and Piston. useless.
A, Barrel. B, Piston. C, Rod. D, Junk ring. The pistons are of the usual
E, Packing *. #. part on rod. kind, cast in brass; some are
merely recessed for the recep-
...tion of a plaited gasket, while others have metallic spring rings,
the piston being fitted with a junk ring held down with bolts;
a gasket is sometimes placed in the space between the brass
packing ring and the body of the piston, thus dispensing with
springs for keeping the packing ring up to the face of the barrel.
Hydraulic pressure is conveniently employed in some pumps
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436, MODERN STEAM PRACTICE.
for this purpose. A small hole is bored at each end, in com-
munication with the open space between the ring and the piston, .
and the mere forcing of the water causes a pressure inside, which
presses the packing ring outwards against the barrel of the pump.
When one ring is used, a small india-rubber ball valve opening
inwards, placed at both ends, will tend to make the action more
perfect; as the piston is going forward the front valve would open
and the back one would shut, and vice versd; thus there would be
no escape through the piston, but probably this is not required, as
a very small hole suffices, and the escape is but little felt; and if
two rings were fitted in recesses, one hole suffices at each end.
Thin spring rings of brass have been used with advantage; in this
case the piston is made quite solid at the ends, with three recesses
turned out on the rubbing surface for the reception of the rings,
which are truly turned a
very little larger than the
interior diameter of the
pump; they are then sawn
through at one part, ex-
panded over the piston,
and sprung into the re-
cesses; in this way there ,2/ZZ
is a slight spring in the
rings, which keeps them
well up to the surface of 0–3–2, zº
the barrel. Wood packing º
with lignum-vitae has been
often successfully used ;
the piston is cast as before,
and the space for the
packing is filled up entirely with curved blocks, which are made
to overlap one another at the joinings, and then the ring is turned
to the exact diameter of the barrel, the body of the piston being a
trifle less in diameter. This arrangement is what may be termed a
solid piston, and is one which can only be adopted with a material
that expands in water; lignum-vitae is well fitted for the purpose.
Solid brass pistons without any packing have been tried, but did
not succeed, as they soon failed to afford a perfect vacuum. Hollow
plunger pistons have, however, been arranged, both internally and
externally. In the former plan the plunger has a central packing
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Fig. 317.-Air-pump Plunger and Gland.
A, Plunger. B, Stuffing box and gland. C, Rod.





MARINE ENGINES. 437
gland for forming the joint between the two ends of the pump; it
is solid at the ends, and has a boss at the centre, bored out for the
reception of the Muntz metal rod, which is secured by a screwed
part at the end with a brass nut, drawing up the plunger against
a collar formed on the rod. In
the latter plan the plunger is
moved by a connecting rod
working directly from the
i cranked shaft, having a bear-
sic ing inside of the plunger. I’or
this arrangement the bushes
and glands should be made
very deep; while in others,
Fig. 318.—Air-pump Plunger and Gland. when the main connecting rod
A, Plunger. B, * C, End cover. for the en gin e works a plung er,
which in its turn moves the
steam piston by rods attached to it, it is advisable to form the
bottom bush of the gland the entire length of the stroke, thus
supporting and taking the thrust of the connecting rod on a large
surface. In this arrangement of air pump it is necessary to reduce
the area of the plunger, by having a hollow guiding trunk at the
other end, working through a suitable packing space and gland.
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* Fig. 319.—Air-pump Plunger acting as a guide for the Crosshead and Piston Rods.
A, Plunger. B, Stuffing box and gland. C, Hollow guide. D, Bearing. E, Rod for adjusting brasses.
All air-pump rods should be made of Muntz metal, secured to
the rod from the main piston by a cotter passing through a boss
formed on the wrought-iron rod which is bored out for its reception.
' The foot and head valves are formed of discs of india rubber,
working on brass seatings. They are introduced in all fast-going
engines, to lessen the disagreeable sound caused by the metallic
valves, and they have materially assisted in bringing the direct-
action engine to that high state of perfection which it has now











4.38 MODERN STEAM PRACTICE.
attained. Still further to diminish the noise, the liſt of the india-
rubber discs is limited by
means of a curved guard, hav-
ing a boss at the centre; this
boss rests on the seating, and
is bored out for receiving one
end of the holding-down bolt,
the other end passing through
a cross piece of wrought iron,
which bears on the under side
of the round hole over which
the grating for the disc of india
rubber is placed. The hole
in the india-rubber disc should - O C
fit loosely round the boss -
formed on the guard, and in
no case should the india rubber P Š4
be pressed down on the seat- -
ing. These gratings consist - : %
of annular rings and ribs ra- A :
diating to the centre of the
boss, thus forming a number of Fig. 320.—Single Valve for Air Pump.
oblong holes through which A, Valve seat B, India-rubber valve, c, Guard.
the water passes. The guard Hoursewºº cºw.
also requires to be pierced with o!
holes, as the discs of india à
rubber have a tendency to 3:
work or close slowly, were £d
not the water acting on the 3.
º * &Q
top surface and pressing it #...Nº.;;...Nº. 3...Nº
G
downwards on the return : - #
stroke. Some of these valve : ſº i
seatings are secured by brass - L. Ll.[Nº ºn 1 -
stud bolts and nuts, with s—sº- -
lugs cast on the seating for ZT3%; Zºr-g
bolting them down over the
holes left in the condenser -
casting, the joint being made Fig. 321.—Arrangement of Valves adopted for Air
with a ring of india rubber Pump.
e sº A, Grating. B, India-rubber valve. C C, Guards. -
recessed into the Seating; DD, Studs for guards. -
3.
. Cl
º










MARINE ENGINES. . 439
while the guard is secured to the seating by a plain bolt and nut.
The plan now universally adopted is to cast a number of these
circular gratings in one large brass seating, which is bolted down
over the oblong holes left in the casting ; this brass plate is
strengthened with bars on the under side, and has a flange all
round for the holding-down bolts, which are screwed in the casting
as studs with nuts on the top; the guards are fastened down to the
valve gratings by a stud bolt passing through each guard, having
a nut bearing on the top of the guard; in other cases the stud is
formed with a collar to screw up
against in the grating, which
collar is somewhat deeper than
the thickness of the india rubber,
and the guard is bolted down on
the top of it. All the nuts on
these studs should have split pins
passing through the points of the
bolts, to prevent the guards shak-
--º-º-º- ing loose. In some arrangements .
- the valve seats are all bolted
down to one brass seating, having
a number of large holes left in
it and bored out for their recep-
ſ tion; and when the large plate
ū is properly planed on the surface,
| and all the Small gratings turned,
the joints may be simply me-
tallic, with a little thin red lead
25 tº placed between the surfaces
O *-** O before they are bolted down. In
Fig. 322.-Box Valve seat with sloping sides, S9° instances it is advisable to
arranged for five Valves for the Air Pumps. place a number of valves in a
A, Box * ...”.... ." * small space; with this object in
- view, as well as to decrease the
circumferential opening of the valves, and yet give a large area
for the passage of the water, the valve seating may be made in
the form of a square box, open at the bottom, with side flanges
all round for bolting it to the condenser casting. With this
form one valve can be placed on the top and one on each side,
making five valves in all; thus with this arrangement, and the same
;


440 MODERN STEAM PRACTICE.
lift of valve as in the former examples, five times the area is
obtained; or with excessively
fast-going engines, the lift of
valve can be reduced, a great
desideratum even with india-
rubber valves, for undoubt-
edly the wear and tear cannot
be so great, while the area
for the passage of the water
is always greater than in a
single valve. In another ar-
rangement four valves are
placed on the top of a square
box, and two on each side,
making twelve valves in all.
These sets, and indeed all
india-rubber valve arrange-
ments, can be placed upside
down, or at any angle that
C
**
-º
D
º
Fig. 323. --Box Valve Seat with square sides, arranged
for twelve Valves for Air Pumps.
, A, Box with twelve-valves. B, India-rubber valve.
c, Guards. D, Stud for guard.
may be considered best for the free entrance and exit of the
water from the air pumps. In-
stead of round valves, some
makers cut the india rubber
into oblong flaps, hinged at
the centre and folding up
against the guard on each
side; by this means the holes
for the bolts do not weaken
the india rubber so much as
when they are placed along
the edge. The holes for the
passages of the water are
hexagonal, formed around
circles I inch in diameter,
with webs similar to a honey-
comb. The area through the
valves should be as large as
possible, and the grated space
equal to the length and
breadth of the hole in the
O - O
Fig. 324.—Double Oblong Valve with Hexagonal
Grating for Air Pumps.
A, Grating. B, India-rubber valve. C, Guard.
D D, Studs.
#




MARINE ENGINES. 44?
condenser, even although half-grated holes are cut in the pattern;
they are bolted down with stud bolts and nuts, and collar bolts at
the hinge for taking the flat guard, these bolts being screwed into
holes bored and tapped in cross webs cast in the condenser for
supporting the grated plate, because with the peculiar form of
hexagonal holes it is not convenient to introduce strengthening
ribs in the grating.
Discharge Valve.—We will now consider the arrangements
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Fig. 325.—Brass Discharge Valve and Box for Dis- Fig. 326.-Brass Discharge Valve and Seat, with
charge Pipe from Hot Well, fitted with Expan: cast-iron Valve Chest for Discharge Pipes from
sion Joint. — A, Valve. B, Chest. C, Stuffing Hot Well. —A, Valve. B, Chest. c, Lifling eye
box and gland. D, Lifting spindle. E, Cover. and spindle. D, Cover. E, Hole for cotter.
F, Cotter. G, Hole for donkey feed-valve box. F, Hole for donkey feed-valve box. G, Branch
H, Branch at side of ship. at side of ship.
required outside of the condenser. The discharge pipe from the
hot well should be fitted with an expansion joint, placed on the
valve chest at the ship's side; this valve is introduced so that the
sea water can be shut off when the fittings inside of the condenser
and air pump require inspection. The valve in most cases is a
spindle one, with a long rod Secured to the top, passing through a
stuffing box on the valve-chest cover, and having a ring handle
fitted at the top, for attaching a block and tackle for lifting it; and
as the valve box is generally placed inside of the coal boxes, means










442 MODERN STEAM PRACTICE.
for lifting it from the orlop deck should be provided. In other
examples the valve is coned, fitting into a seat turned out for its
reception, the rod at the top being secured by a nut on the under side,
and having a ring handle as before; when the valve is lifted up a
flat key is driven through a slotted hole in the rod, the key rests on
the top of the gland, and by this means the valve is held up. Hemp
packing may be placed in a recess turned in the valve to insure its
being perfectly water tight. A variety of forms of gridiron sluice
valves have been introduced, each *
having a screwed spindle stepped
at the bottom of the valve chest,
and working in a nut on the back
of the valve, passing through a
stuffing box in the cover, and its
end fitted with a handle. Outside
of the stuffing box a collar is left
on the rod, which is held down by
this collar placed under a cross
bar fitted to the cover with studs;
thus when the handle is turned
round, the nut and valves move
up or down, opening the apertures
or shutting off the sea water when
the handle is turned the reverse
way. For convenience in turning
the handle, the valve chest should
be placed outside of the coal boxes, º
and a strong pipe fitted between Fig. 327 –Comical Brass Valve and Seat, with
gº • ? & cast-iron Valve Box for Discharge Pipes
it and the ship's side. The valve from Hot Well.
chest may be of cast iron, but a, Valve. B, Chest. c, Lifting eye and spindle.
D, Cover. E, Hole for cotter. F, Hole for don-
- the valve and Seat should be of key feed-valve box. G, Branch at side of ship.
brass, and the top spindle of Muntz -
metal. Sometimes large flap valves are used on the side of the
ship; these are generally hung with a spindle at the top passing
through the side of the box, and may be kept shut with a weighted
lever on the end of the spindle: this plan has the advantage of the
valve opening outwards, and should the engine be started with the
valve shut, the pressure of the water in the discharge pipe would
open it. Of course spindle and conical valves are likewise placed
so that the discharged water forces them up; but sluice valves must
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MARINE ENGINES. 443
be moved by hand before starting the engines, and in that respect
they are not so safe as the spindle valves and other arrangements.
The injection valve is simply a sluice, placed in a suitable valve
a - chest, which is bolted to the
side of the condenser; the
}V
% % valve is of brass, sliding
% — against a surface of the same
% &
º O © material, let into the cast-
, E º O O iron valve box. The valve
ſ--H- is provided, with a Muntz-
O I o metal spindle, keyed through
- t | a boss cast on the back of
O O the valve; at the top end of
the spindle a slotted cross-
head is fitted for the lifting
lever to pass through, and
Fig. 328–Sluice Injection Valve. which is generally arranged
A, Sluice valve. B, Chest, c, Cover. D, Spindle. On the top of the condenser.
E. Condenser. © & *
y Gridiron valves are some-
times used, which are moved by a spindle attached to the valve
with an eye and pin passing through a snug cast on the back of
the valve; with this arrangement it is advisable to cast the valve
chest in brass, having a
screwed packing nut at
the top for the valve
spindle, with a corres-
§
i
à
JE º Ž ponding screw tapped or
§ cut in the valve-chest
cover. For engines of
small power plug taps
may be used, so arranged
that the water comes in
through a branch on the
bottom side of the conical
Fig. 329.—Gridiron Injection Valve. valve seat, and passes
A, Gridiron *.º*. c. *: D, Joint for through a hollow plug, the
bottom part of the cone
being tapped for the reception of a screwed brass piece which
is brazed on the tapered copper injection pipe. The top part
of the plug is fitted with a packed gland, or a gland without
|
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º
sº
|
º






























444 MODERN STEAM PRACTICE.
packing may be used; this is introduced to keep the plug in its
seat. A handle is keyed on the plug for moving by hand, or levers
are arranged with rods passing along to the starting platform.
The inside injection pipe is made of a conical form, tapering from
the valve to the end; the apertures are placed so as to shower the
water over a large surface in a way regulated by the form of the
condenser. These apertures are bored out, or else cut across with
a saw; the former plan may be named the jet system, the latter the
sheet system, as the water then falls into the condenser in small
sheets. The injection pipe is sometimes fitted with a longitudinal
plate passing up the centre for one half of its length, by which the
water after passing through the injection valve is divided into a top
and bottom stream, with holes pierced in the pipe for each; but
this is an unnecessary refinement, for the injection valve may be
placed on the condenser, so that the - -
internal pipe can have a branch on
the middle of its length, and thus
distribute the water right and left.
This form of internal pipe should
likewise taper from the middle to
each end, so that the jets at the
end may rush into the condenser Fig. 330.—Inside Injection Pipes.
g * A, Injection pipe tapering toward ends.
with about as much force as those B, Tapering injection pipe.
nearest the valve; for undoubt-
edly were the pipe made quite parallel, and pierced with the
same number of apertures along its entire length, the pressure
of the water would decrease at the extreme ends, owing to its
escaping into the condenser, but the tapering of the pipe contracts
the water along its entire length, and the pressure from the head of
water outside of the ship is better maintained, consequently the
water is showered over the condensing area more equally. It is
necessary to support these inside injection pipes, as the weight of
water is considerable; this can be done with a wrought-iron support,
fastened to any of the ribs inside of the condenser.
The bilge injection valve (Fig. 331) is fitted as low down in the con-
denser as may be deemed necessary, and consists of a spindle valve
of brass fitting into a seat cast along with the valve chest, also of
brass. The valve has a spindle on the top passing through a stuffing
box in the cover; the top end of the spindle is screwed, and works
through a brass bush secured in a cross bar, which is supported

MARINE ENGINES. 445
with suitable studs let into the cover. On the end of the spindle a
plain handle or small hand wheel is fitted, by which the valve is
screwed up from and down on its seat. These
valves are only used in the event of great leak-
age in the ship, the bilge water being then taken
into the condenser, and pumped overboard as in
the ordinary injection system. In order to keep
foreign matter from entering the condenser, it
is necessary to protect the pipe passing from the
bilge injection valve down to the bottom of the
ship with a box piece at the end, perforated with
a number of small holes.
The snifting valve, for blowing all the air and
water out of the condenser previous to starting
the engine, is placed at the lowest part of the
condenser, on which a branch is cast for holding
it. It is a spindle valve opening upwards, and is
*º-ºº: fitted with a baffle plate placed on the valve box,
alve. — A, Spindle and & -
valve, e,chest, c,Cover through which a thumb screw works in a screwed
...”.” brass bush; by this means the valve is held
down after the process of blowing through is
completed, and indeed, when the vacuum is formed in the con-
denser, the atmospheric pressure comes instantly into operation,
firmly closing the valve, which can then be
secured by the thumb screw at leisure.
The feed pump is generally of the single-act-
ing plunger type; the body of the pump is of
cast iron, with a brass gland and bush at the
..., bottom of the stuffing box; when bolted to the
side of the condenser casting, the brass plunger
| is worked from an arm keyed on the piston
rod, and has an inside rod of iron, by which
the plunger can be disconnected while the
4 engine is in motion. The disconnecting gear
Fig. 33°-shifting Valve consists of a thumb screw pressing against a
A, Valve. º * brass block let into the end of the pump ram,
the inside rod being of sufficient length to
work loosely in the hollow ram when the plunger is at the bottom
of the stroke. When connecting the pump, the thumb screw should
press lightly on the brass block until the plunger is pressed up


446 MODERN STEAM PRACTICE.
against a collar left on the rod (this must take place in the act of
forcing the water), the ram is drawn outwards, and in the return
stroke it slips or slides on the bush piece, until it is stopped with
a collar on the rod, then the thumb screw
can be tightened up. This simple contrivance
is far superior to any other for disconnecting the
plungers when the engine is in motion. Some
makers prefer placing these pumps at the back
of the condenser, fitting them to the platform
on which the gearing is located for handling
the engine, either above or below the centre line
of motion of the piston and adjuncts; with the
former arrangement the plunger is connected
to a stud placed on the top of the crosshead
arm for taking the piston rods, and in some
cases is worked directly from a prolongation of
the air-pump rod, which passes through a stuff-
ing box at the back of the air-pump cover.
Piston pumps are sometimes used with ad-
vantage, the brass cylinder in which the solid
or packed piston works being let into a part
of the condenser casting, and generally worked
directly off the steam piston, in the same
manner as the air-pump piston; with this ar-
rangement the pump is double acting, one end
being used for the feed and the other for the
bilge pump. The latter, in other arrangements,
is exactly similar to the feed-pump barrel, and
is placed on the condenser on the opposite
side of the centre line of crosshead from that
of the feed pump, and can be worked off an
arm keyed on the piston rod; or when it is
fitted to the starting platform at the back of
the condensers, it is connected to the bottom
arm of the crosshead in a similar way to that
of the feed pump. Many prefer the pump ar-
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Fig. 333.—Feed and Bilge Pump.
A, Pump. B, Ram, c, Inside
rod. D, Thumb screw.
E, Stuffing box and gland.
rangements fitted to the condenser, as the labour of fitting up
is thereby greatly reduced, and the engine as a whole rendered
more compact.
The valve box for the feed pump is of brass, and is generally




















MARINE ENGINES. 447
placed at the end of the pump; the feed or delivery and the relief
valves are placed on the same level, while the suction valve is
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Fig. 334.—Valve Box for Feed Pump.
A, Valve box. B, Suction valve.
c, Delivery valve. D, Relief valve.
E, Spring. F, Bow. G, Set screw.
immediately under the relief valve, which
is fitted with a spiral spring compressed
by a set screw working in the top of a brass
bow placed over the spring; the pressure
on the valve should be a little in excess of
the steam pressure in the boiler. The sole
use of this valve is to allow the water in.
the pump to escape into the hot well when
the feed regulating valve on the boiler is
shut; a branch is cast on the relief-valve
box, with a pipe leading into the chamber
above the head valves, by which the water
when not required in the boiler is returned
and finds its way overboard. A plug valve
for shutting off the suction is also fitted to
the valve box; this is used for shutting off
the water in the event of any of the pump valves requiring inspec-
tion, and may be used for stopping the supply to the pumps, in
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Fig. 335.-Valve Box for Feed Pump.
A, Valve box, B, Suction valve. C, Delivery valve. D, Relief valve. E, Spring.
F, Bow. G, Set screw.
which case the plungers may be kept working, although no water
can be forced into the
boiler or through the relief valve. India-













448 MODERN STEAM PRACTICE.
rubber valves are sometimes used for the feed pump, having
conical brass seats grated in the casting, and let into a cast-iron
valve box containing the suction, discharge, and relief valves,
the latter being a brass valve fitted with a spring in the usual
manner. All the valves may be placed on the same level; the
suction at one end of the valve box, the discharge in the middle,
and the escape at the other end, with a passage leading underneath
the discharge and escape valves from the top of the suction valve,
and a lower return passage from above the escape in connection
with the suction pipe or hot well. In some instances suction and
discharge valves only are fitted, with a separate relief valve placed
on some other part of the feed pipe. A similar arrangement of
valves is required for the bilge pump, but of course a relief valve is
not needed, as the bilge water is pumped directly
overboard, and a non-return valve placed on the
ship's side. The india-rubber valves are used
to prevent the disagreeable noise caused by
brass valves beating sixty or more times in
the minute. To obviate this evil wooden rings
have been recessed into the valve with advan-
tage. Perhaps the best plan of doing this would
be the Cornish one of recessing the wood into
the valve seating, in the same way as for large
double-beat valves for the pumps in deep mines.
The valves in this case would be discs turned Fig. 336–Valve Box for Dilge
on the face, with central holes for working on ~~~~ -
spindles; thus the valves are guided by this c, Delivery valve. D, Guard
means, necessitating a central boss with wood- :*:*
bearing surface. Of course the valves can be -
of the spindle type, working through and guided by holes bored .
in the bosses cast along with the valve seats. An air vessel
should be placed on the feed-pump valve box, or on some
part of the feed pipe between the boiler and the top of the dis-
charge valve, by which any sudden strain caused by the passage
of the water through the pipes is greatly neutralized, and the
discharge into the boiler is rendered more equal. *
The hand pump (Fig. 337) is an additional one, which can be worked
either by hand, or if required connected to the engine. Its duty is
somewhat complicated, as it must be fitted to draw water from the
boiler, from the bilge, and from the sea; while the discharge pipes
%
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MARINE ENGINES. 449
must be arranged to pump water into the boilers, on deck, and over-
board. The most convenient form for this pump is the plunger type.
It is generally placed vertically at the end of the cranked shaft, the
body of the pump being bolted down to the engine keelson; some-
times it is placed horizontally, and is fitted to the condenser, fitting
strips and joggles being cast on the parts for its reception. The
trunk plunger is actuated by a pin and rod; the pin is fitted to the
- end of the cranked shaft, and has a
rod with a plain brass bush, working in
a hollow plunger rod attached to a pin
passing through a joint at the bottom
of the plunger; this hollow rod has a
thumb screw and brass block at the top
for throwing into gear or disengaging
the pump. When working free, the
inside rod merely moves up and down
in the hollow brass piece, which vibrates
along with the rod as the crank pin
revolves; when the pump is required,
with the engine in motion, a cotter is
driven through a slot in the brass rod,
and forms the stop for the inside rod
butting against, which it does gently
by means of the thumb screw and fric-
tion block, as with the feed pumps; the
thumb screw is then tightened up and
the connection is complete. For work-
ing the pump by hand, a bracket is
cast along with the body of the pump,
• A, Pump. B, Plunger. C, Stuffing box and on which a lever is fitted, and flat side
gland. D, Hand lever with side connect- rods are connected to the pin at the
†† *..."... bottom of the plunger, while the lever
necting rod. k, Crank pin on the end has a part forged along with it for the
of shaft º
reception of a long handle. When the
inside rod is disengaged, and when the engine is not going, or even
were it in motion, the pump can be thus worked by hand, the hollow
brass rod merely sliding on the wrought-iron one inside. Of course
when the pump is worked by the engine, the hand lever and con-
nection vibrate with the motion, it is therefore imperative that the
handle should be disengaged from the pump lever, a socket being
Fig. 337,-Hand Pump.

29
450 MODERN STEAM PRACTICE.
forged on it for that purpose. The pin on the end of the cranked
shaft is forged on a flat ring, which is accurately turned, and bolted
to the end of the main shaft, a projection being left on the shaft for
its reception. Some makers connect the pump by means of a plain
rod, having a sliding block fitted with a pin, working in a guide
formed on the disc that is bolted to the end of the cranked shaft;
this block and pin is moved by a screw and thumb handle, by
which means the stroke can be varied to any extent within the full
throw, and even brought to the centre of the shaft, thus imparting
no motion whatever to the pump ram. This is certainly a very
simple means for disconnecting the pump, but at the same time no
provision is made for working it by hand, -
which is the chief thing to be studied in these ſº
pump arrangements.
The valves are generally metallic, or india-
rubber discs may be used, and at the bottom
of the pump an escape valve is fitted loaded
with a lead weight. This latter valve is re-
quired, as there are many valves on the delivery
pipe which may be shut when the engine is
started, or even close when it is in motion, due
notice of which will be given by the water being
ejected through the escape valve. The end of
§
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the Suction pipe passing down to the bilges fºr Hirº
must have a box perforated with small holes to us §
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prevent foreign matter entering the pump.
A 2ngston valves.—Kingston valves must be . . . *
º tº º A, Spindle and valve. B, Chest.
fitted to the pipes for injection, feed, and blow- c, stuffing box. pp, columns.
off for the boiler, steam pump, &c., and indeed . i. º
to all pipes passing through the bottom of the
ship. The arrangement here is similar to that for the oscillating
engine already described; strong cast-iron branches being placed at
the ship's side for preventing the rapid deterioration of the wrought-
iron plates by the galvanic action of the two metals—brass and
wrought iron—in juxtaposition, assisted greatly by the adjoining
copper pipes. In preference to the Kingston, Some use spindle
valves, fitted with a screw on the spindle working into a nut in the
cross piece, having a jam thumb screw fitted on the top of the
crosshead.
The various arrangements of hand wheels for starting, reversing,
Fig. 338.-Kingston Valve.














MARINE ENGINES. 45 I
and stopping the engines are given in another part of this Work (See
page IIO).
The usual ſtand gear for the blow-through, injection, throttle
valve, blow-off valve from cylinder, and all the other necessary
handles, should be arranged on the same platform. We prefer this
platform to be on the same level as the engine-room floor plates,
but some engineers place it on the top of the condenser; and cer-
tainly in this position the engineer commands a better view of the
machinery, but his duties when the ship is under steam lying
between the engine and the boiler rooms, the hand gear should be
placed in such a position that it can be reached at a moment's
notice, and as near the main starting wheel governing the link
motion for actuating the steam valves as convenient. The blow-
through, injection, and throttle valve handles should be placed in a
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Fig. 339.-Hand Gear.
A, Injection handle and lever. B, Blow-through handle and lever. C, Throttle handle and lever.
D, Sectors. E E, Thumb screws.
row. Some arrangements have a central rod for the injection valve,
a hollow tube with levers for the blow-through placed over it, and
another over this for the throttle. When thus arranged the rods
cannot be connected directly to the various valves, but the line of
motion can be conveniently changed by Small sector wheels cast in
brass, and bevelled to suit the requirements; in other cases short
levers are keyed on the ends of the inside rod and to the outside
tubes, and fitted with pins and rods for changing the direction of
the motion. .
Having considered the main details necessary in the manufacture
of the direct-action horizontal marine engine, we will now notice
the means to be adopted for effecting a thorough Zubrication of all
the moving parts in the machinery. The main bearings are those







452 MODERN STEAM PRACTICE.
most important, and their friction can always be reduced to the
minimum by giving them ample rubbing surface,—this, combined
with good material and first-class workmanship, being essential in
all engines, more especially in those of great power, encountering
permanent loads, and working at a high velocity. Lubricators
should not be too elaborate in design; in their construction plain-
ness and efficiency should rather be aimed at. The oil cups placed
on the main bearings are cast in brass, with covers and oil pipes for
siphon wicks; they should be divided into two compartments, one
for the oil and another having a plain hole bored down through the
brasses, for water lubrication in the event of the bearings becoming
hot. To effect this properly a pipe is carried across the engine
directly over the main bearings, and supported with standards of
wrought iron secured to the main framing. This pipe is provided
with plug taps and water distributors for each main bearing and
crank pin; it also carries oil cups with long siphon pipes for
lubricating the crank pins, the wick hanging down a very little
past the end of the pipe. The water enters from the sea directly,
a branch pipe being cast on one of the Kingston valves, and an
ample flow is obtained for showering over the bearings in the case
of violent heating. Sometimes the standards for carrying the water
pipe placed over the main bearings are hollow pipes jointed on the
top of the framing, and provided with a valve at the bottom, one
pipe standard being placed on each frame; thus each bearing can
be supplied with water independently. The pipe at the top has
coupling joints with nuts, or simple flange joints may be adopted;
on the standard pipe nearest the Kingston valve a branch is cast,
for connecting the supply pipe to the Kingston, and a plug tap is
generally fitted to one of the standards, with means of attaching a
ſlexible pipe to it, for showering water over any other part of the
engine. The connecting rods have cups fitted on, with covers
having raised pipes and tongue pieces, for licking off the oil from
the siphon wicks suspended from the oil cup fitted overhead; by
this means the crank pin is thoroughly supplicq at each revolution
of the cranked shaft. All the other lubricators for the engine con-
sist of cups cast in brass, fitted with inside pipes and siphon wicks,
and fastened to the various parts in such a way that they can be
removed when they require to be cleaned. Many journal bearings
have cups cast on, and plain holes bored through ; this plan is
preferable to that of merely boring a countersunk hole in the journal
MARINE ENGINES. 453
brackets, into which the oil cannot be poured steadily, and generally
runs over on the machinery, whereas in the former plan the oil is
poured into the small oil cup and is beneficially used. The tallow
cups for lubricating the slide valve, cylinder, and pistons are similar
to those in general use, which have been already explained in
treating of the oscillating engine.
Turning gear.—When the vessel is in port, with the steam down,
it is necessary to turn the engines daily by hand, so as to change
- the relative position of the work-
ing parts, and prevent the fur-
rowing induced by the galvanic
action resulting from the contact
of the wrought-iron piston rods
**----, and brass glands, as well as to
facilitate the adjustment of the.
** slide valves or any other part of
~...~~~ the machinery. The arrange-
T ment for doing so consists of a
worm working into a wheel fitted
ft. C. l. liſh to the end of the cranked shaſt,
iii O O which has a cast-iron coupling
for bolting it to the boss or coup-
- à ling cast on the wheel; the worm
D| j E wheel being thrown in and ou
–4 -25. with suitable mechanism. Some
à O 9 makers simply key up the worm-
-T shaft bearings, which work in
à blocks fitted to a cast-iron guide
; : plate, arranged across the line of
# O O the lying shafting; others place
tº—a-i-l. =l the worm wheel vertically at the
Fig. 34o.—Turning Gear. side of the turning wheel, and
A, Worm wheel, B, Worm pinion. cc, Eccentrics. draw out the bottom bush on
º * * * which the worm shaft is stepped,
by means of a small hand screw
and wheel working through a brass bush cast on the plate the
bush rests on, the top part of the shaft being supported by a
bracket bolted to some part of the engine-room bulkhead. Some
engineers adopt an eccentric motion similar to the back motion of
a turning lathe, as a means of putting the worm wheel in and out
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454 MODERN STEAM PRACTICE.
of gear. A Square part is formed on the end of the worm-wheel
shaft, to receive a ratchet brace lever, fitted with a double paul to
work either way, and a part is left on the lever to receive the
socket formed on the long hand lever, on the end of which is forged
an eye for Securing a rope, which can be taken to any part, so that
a number of hands can be employed in turning the engine—a
needful provision as the back of the engine space is generally
Confined.
BOILER FITTINGS.
Safety valve.—Amongst the boiler fittings the most important
is the safety valve. In river steamers there are generally two valves
fitted to each boiler, placed .
in one valve chest, with the |
waste-Steam pipe between
them. The valves and 3–
seatings are of brass; a
spindle of wrought iron is
fitted to the top of the
valve, passing through a
Cover on the valve chest,
and is fitted with an eye
on the outside. This eye
is arranged so as to turn
round the valve with a H= - §
hand bar, to prevent it [
becoming fast on its seat. Sir
The valve is loaded with Fig. 341.—Safety Valve.
a certain weight placed in A, Valve and spindle. B, Chest. c, Weights. P. Turning
the valve chest above the handle. E, wastesteam pipe. F, Hole for running of the
condensed steam, G, Boiler.
valve; and on the outside
of the casing flat discs of cast iron are placed on the spindle, or
taken off, as the steam is raised above the usual working pressure,
or is blown off by the waste pipe. The waste-steam pipe is of
copper, fitted with a gland and stuffing box, cast on the valve chest;
and there is a small branch at the bottom of the chest for running
off the water accumulating from the condensation of the waste
steam. This water is generally collected in a tank fitted to the
side of the vessel, and is used for cooking purposes, being an all-
important fresh-water supply for ocean steam ships.

MARINE ENGINES. 45.5
The safety valves for such ships differ materially from those of
river steamers, inasmuch as the weights are placed entirely in the
valve chest above the valves, or else inside of the boiler; the latter
method requiring a long spindle and socket connected to the valve
spindle. In the former method the valve-chest covers are under
lock and key, and in the latter the weights cannot be got at; the
valves cannot therefore be tampered with, or the boilers subjected
to undue pressure. Two safety valves are fitted to each boiler,
placed in one valve chest, with a branch cast on for the horizontal
copper pipes passing along to the branch pipe for the vertical
waste-steam funnel; this
branch is fitted with a stuff-
ing box and gland, to allow
for the expansion of the
copper pipes. The main
waste-steam pipe is fitted to
a flange on the top of the
central branch box, which is
made of cast iron, having a
w small branch at the bottom
it.....: 1 * Sº for running off the water de-
º rived from the condensation
of the waste steam in the
act of blowing off from
undue pressure or otherwise.
The valves are lifted by a
lever arrangement, having a
spindle within the valve
chest; this lever is carried
Fig. 342. –Saſety Valve. along to any convenient
A, Walve. B, Chest. c, Weights. D, Slot rod for * , sº
lifting arm. E, Liſting arm. F, Guide. position, and supported by
a bracket at the end, which
is bolted to the top of the boiler; a long lever handle or other
arrangement is fitted at the end of the shaft, with a quadrant fitted
to the boiler, and drilled with a number of holes; a small pin is
provided, connected to a fine chain to prevent it being lost. By
this means the valves can be raised their full lift, or only a very
small part, as may be desired, and held in position by passing the
pin through the quadrant and lever handle. When the weights
are inside of the boiler, the spindle for supporting them has a pin
ŞŞ
2%



456 MODERN STEAM PRACTICE,
joint connected to a collar brass connecting piece, which is cottered
to the valve spindle, the forked lifting arms of wrought iron work
loosely on the collar, and the shaft is bracketed at the one end from
the crown of the boiler, and at the other end it passes through a
stuffing box with gland, fitted to the front plate of the boiler; the
shaft being fitted with a lever handle and quadrant, or any other
suitable appliance, such as a worm wheel and toothed quadrant on
the shaft, with a turning handle and bracket fitted to the worm
spindle. -
In all arrangements for lifting the valves it is imperative that
their free action should not be interfered with; at any position of
the lifting levers, the valves when acted on by the steam pressure
must liſt solely by that pressure, as the lever handles are only
arranged to lift the valves in the act of blowing out the boilers or
easing them when the engine is not at work. It is also essential
that all the rubbing parts should be bushed with brass to prevent
corrosion: this is a most important point, for where the free action
of the levers and shaft is not perfect, accidents may occur, which
due attention to their fittings will alone prevent. In order that
the surfaces of the valves may be changed occasionally, the covers
are fitted with hollow guides for the ends of the spindles, that is,
when the weights are contained in the valve chests; the chests are
removed, when the spindle can be gripped and the weights and
valves turned slightly round. When the weights are placed inside
of the boiler, the valve-casing covers can be removed, and the
valves turned with a key or spanner, by means of a projecting
square piece cast on the top of each valve. Many arrangements
do not allow of this being done,—for instance, when the lifting arms
work in slotted connections, as is sometimes the case when the
weights are inside of the boiler; but all lifting arms should be
forked, lifting the valves and weight by working on a collar formed
on the weight spindle. For inside-weighted valves the spindle must
be guided at the bottom through brass bushes on the spindle and
guiding piece fitted to the boiler. (See page 462.)
The steam stop valve is simply a spindle one, generally lying on
its side, fitted with a brass seating, placed in a cast-iron valve chest,
laving a branch cast on above the valve for the pipe connections.
Where two valves are used, one of these branches has a plain flange,
and the branch on the other valve chest is fitted with an expansion
joint. On the top of the valve is cast a part for taking the head of
MARINE ENGINES. 4.57
the lifting spindle, in which it can freely revolve; the spindle passes
through a stuffing box on the casing cover, with a gland for pressing
down the packing; between the valve and the bottom part of the
stuffing box a screwed part is turned on the spindle, working in a
brass nut let into the bottom part of the stuffing box. A handle
is fitted to the spindle, and when it can be conveniently reached is
quite close to the gland; but when the valve box is placed beyond
reach of the attendant, the spindle is prolonged by a wrought-iron
connecting piece, fitted with a socket for taking the brass valve
spindle, and a wrought-iron bracket is fitted to the casing cover.
The valve chest in those instances is placed vertically and inverted,
so as to be worked from the
boiler-room floor plates, which
is decidedly the most convenient
position for turning round the
handle for opening and shutting
the valve. A small branch is
generally cast on one of the stop-
valve chests between the boiler
and the valve, for fitting the small
stop valve in connection with the
auxiliary Steam pump, by this
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ū āsā ā & * , -
§=Fº the boiler plates. Of course the
N N * . . .
s § s position of the steam pump must
N g g
§ N be fixed in the engine room, and
the branch cast on the stop valve
Fig. 343.—Stop Valve. nearest to it, thus effecting a
**.*.*.*.* saving in piping, which would
not be the case if, for instance,
the steam pump was arranged on the starboard, while the small
stop valve was fitted to the larboard main stop valve, as the case
may be. The stop valve for the auxiliary steam pump should in
no instance be fitted to the steam pipes, but connected directly to
the steam space in the boiler, so that it can be wrought inde-
pendently even although the main stop valve is closed.
The brancſ, steam pipe between the stop valves and the engine
must be arranged to suit the number of boilers; where two boilers
are used, the main pipe branch should be larger than the branches
from the boilers. These branch pieces are fitted with expansion































458 MODERN STEAM PRACTICE.
stuffing boxes and glands, to suit the direction of the expansion
and contraction of the copper pipes. In all bends care must be
taken to fit a collar on the end of the pipe, the gland and bottom
tº
Ž º
sº Errrrrrrºzz” K22 I
º º X º
C |-
Fig. 344.—Branch Steam Pipe.
A, Branch pipe. B, Stuffing box and gland. C, Iloose bush.
bush being first placed on the pipe; this precaution is necessary,
as bends under pressure have a tendency to assume a straight line,
and fatal accidents have occurred from the steam by its reactive
force blowing out the bend and filling the engine room direct
from the boiler.
Clothing the steam pipes.—In order to prevent condensation
taking place in the passage of the steam to the cylinder, all the
steam pipes should be carefully clothed with felt, secured with fine
wire wound round the pipe, and covered over all with canvas sewn
tightly on, which should receive two or three coats of paint. In
Some instances the pipes are lagged with wood, and secured with
neat brass hoops.
Separator.—Some makers fit a moisture separator to the steam
pipes. This appliance acts by abruptly changing the flow of
the steam, and is similar to those used for land engines, which
have been explained in a former part of this Work. By this means
much of the moisture is got rid of, trickling down the baffle plate
to the bottom of the separator, and then run off by a valve into the
bilges, or used for washing and cooking purposes.
Covering the boilers.--To prevent radiation, and consequently
waste of fuel, the boilers are lagged in all available parts. This
form of lagging consists in fastening square pieces of wood at the
corners and at intermediate distances on the boiler, the wood being
fastened by small stud bolts and nuts; felt is then laid in between

MARINE ENGINES. 459
the wooden battens, flush with the top of the wood, and the lagging
or strips of wood, which are grooved and feathered, is then laid on,
and securely fastened to the battens with screw nails. The wood
is then painted all over, and on the top of the boiler and round the
top corners thin sheet lead is laid, which thoroughly protects the
top of the boiler plates from the moisture that lodges on the
lagging, and would run between the joints were the lead not form-
ing an effectual waterproof covering. This covering also keeps the
boiler room comparatively cool. In many examples, however, with
dry uptakes, as fitted to high-pressure boilers, lagging cannot be
used, because it would ignite and smoulder away; in these cases
the boiler room is kept cool by air spaces formed with thin plates
placed in front of the uptakes, by which a current of air is continu-
ally flowing up between the uptakes and the plates, and prevents
in a great measure the radiation of heat affecting the attendants.
Check valve.—The valves fitted to the boiler at the end of the
feed pipes, termed the check valves, are spindle valves, contained in
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SS
S.
Fig. 345.-Check Valve. Fig. 346.—Check Valve and Plug Valve, &c.
A, Valve. B, Chest. C, Cover. D, Set A, Plug valve. B, Chest. C, Screwed cover. D, Check
SCreW. valve. E, Handle.
brass valve boxes; the seating is turned in the box, and the valve
ground in, having a separate Screwed hand spindle passing through
a stuffing box on the cover. By this means, when no water is re-
quired in the boiler, the spindle is screwed down hard on the top
of the valve, the water passing through the pumps, escaping by
thé relief valve into the hot well. This valve on the boiler also













4CO MODERN STEAM PRACTICE.
acts as a non-return valve, easing as it were the pipes at each return
stroke of the pump, and in the event of any of the feed pipes giving
way the valve of course instantly shuts with the steam pressure,
and thus prevents an escape of hot water and steam into the boiler
room: in this respect it may be termed the non-return safety valve.
In some examples a plug valve has been fitted in connection with
the non-return valve box. This is a refinement, however, which
has not come into general use; ground plug valves are at the best
very imperfect, and give a great deal of trouble to keep them in
thorough working order. It will be seen in Fig. 346 that there is a
handle Secured to the plug at the bottom, which is hollow; and the
non-return valve is fitted to the top of the plug, and guided by a
Spindle passing upwards through a hollow tube bored in the cover.
The gauge glass for indicating the height of water in the boiler is
fitted to brass connecting pieces having a screwed packing gland, with
plug tap at the top, and two taps in the bottom connection, screwed
into a separate pipe, on which bosses are cast for that purpose;
there are also three separate test taps fitted to the side of the pipe;
these are required, as the gauge, although protected with a shield,
sometimes breaks, in which case its plug taps are shut, and the
attendant ascertains by opening the side taps if there is a sufficient
quantity of water in the boiler. These taps have funnels and small
pipes for blowing the water down into the bilge. The taps on the
glass gauge should be so arranged on the branch screwed into the
large pipe, that when they are shut a nut on the top of the con-
nection can be unscrewed, and a new glass fitted without disturbing
the joints. Plugs have sometimes been fitted in the connection in
a line with the glass gauge, but such an arrangement is not quite
convenient when a tube requires refitting; for, in the former plan
the nut at the top being unscrewed the glass tube is put in vertically,
whereas in the latter the nut requires to be edged in, and conse-
quently does not fit so nicely; and the only saving effected is the .
small test tap placed at the bottom, although some makers fit two
taps at the bottom, one over the other—an arrangement not at all
required. It is preferable to cast the pipe which carries the gauge
glass and test taps in brass, or a copper pipe may be used, with
bosses brazed on for screwing the connection to. As the small
taps are liable to get choked with deposit, they should be always
so arranged with a nut on the connection which can be unscrewed,
and a small rod pushed through to clear away the deposit.
MARINE ENGINES, 461
Scum taps are fitted in connection with an internal pipe, for
collecting the froth or scum at about the level of the water in the
boiler, and a copper pipe is connected to the tap for blowing the
dirty water overboard. The usual blow-off cock is fitted to the
bottom of the boiler, with pipe connection and expansion joints on
the blow-off Kingston valves, which is fitted to a strong cast-iron
pipe at the bottom of the vessel.
Vacuum valve.—In the event of the steam in the boiler falling
below the atmospheric pressure—or a partial vacuum being formed—
a reverse valve is fitted to the
boiler. It is of the spindle kind,
nicely ground into its seat formed -
in the brass valve box. The
steam acts on the top of the valve,
while the bottom is open to the
: a-sº
fºLº-
Sº
SS ŞS
N
ŽS
Ş
N
%
§
N
3.
º
%"
º
Fig. 347.-Vacuum Valve. Fig. 348.-Whistle
A, Valve. B, Chest. c, Screw cover. A, Bell. I, Bottom piece. C C, Annular space.
D, Boiler. D, Plug tap. E, Handle.
atmosphere; thus when a partial vacuum is formed in the boiler
the atmospheric pressure lifts the valve, and the vacuum is at once
destroyed, consequently the flat sides of the boiler have no tendency
to collapse.
Steam whistles should be fitted to all vessels, for use in foggy
weather. They are generally placed on the bridge, with a pipe
connection to the boiler; and are formed exactly like the steam
whistle for the locomotive engine. The depth of the bell varies to
suit the note desired; but a deep bell, producing a full note similar
to the guard's alarm on the railway engine, is desirable for Ocean
steam ships.




















462 MODERN STEAM PRACTICE.
The following is an extract from a Report on Safety Valves,
drawn up by a committee of the Institution of Engineers and Ship-
builders in Scotland," which presents the various features of the
question of area and method of loading in a succinct form:—
“SAFETY VALVE OPENINGS.—Since an orifice, with a square-
edged entrance, reduces the flow from 12 to 14 per cent, this allow-
ance will require to be made in computing the requisite area, and
opening of a safety valve, which cannot be considered as presenting
a much better entrance to the steam than a square-edged orifice.
In making this I4 per cent, allowance the weight in pounds of Steam
. discharged per minute per square inch of opening, with square-
edged entrance, corresponds very nearly with three-fourths of the
absolute pressure in the boiler as long as that pressure is not less
than 25:37 lbs. Examples of this are shown in the following table:—

Weight Discharged per tº º
Absolute Pressure *- $º Weight Discharged per Three-fourths
in lbs. per Square oniº d Minute with of Absolute Pres-
Inch. Entrance, per Minute. Square-edged Orifice. SUlré,
Ax. Z07. 70s, % A.
25°37 22-8 I 19:6 I9
3O 26-84 23 22°5
4O 35'48 3O'5 3O
45 39.78 - 34'2 33.8
5O 44'O6 37'9 37'5
6O 52'59 45'2 45
7o 61 of 52'5 52'5
75 65.30 56. I 56.2
90 77'94 67 67.5
IOO 86°34 74’3 75
The area of opening, requisite to the discharge of any given con-
stant weight of steam, it will be observed, is very nearly in the
inverse ratio of the pressure. Thus, while 3 Square inches of open-
ing, with square-edged entrance, will discharge 3 × 23=69 lbs.
weight of 30 lbs, pressure steam per minute, one Square inch of
opening will discharge 67 lbs. per minute of 90 lbs. pressure steam.
The quantity of heat, however, requisite to generate (from water
at IOO”) 67 lbs. weight of steam, at 90 lbs. pressure, is only I per
cent, less than is required to evaporate 69 lbs. at 30 lbs. pressure.
The boiler which will generate 69 lbs. of steam per minute at
30 lbs. cannot, therefore, possibly generate more than 67.7 lbs. at a
pressure of 90 lbs. ; but many experiments on record seem to indicate
that the deficiency at the higher pressure is more than ten per cent.
* See Trans. of that Institution, vol. xviii.
1MARINE ENGINES. 463
In ordinary marine practice there is not often more than 20 lbs.
of coal consumed per hour per square foot of fire grate, and the
water evaporated Seldom exceeds 9 lbs. per lb. of coal, which corre-
sponds to 180 lbs. per hour, or an evaporation of 3 lbs. per minute
per square foot of fire grate. Under those conditions the area of
Opening requisite to discharge all the steam a boiler can generate
corresponds to four times the square feet of fire grate, divided by
the absolute pressure; or, let a denote the area of orifice in square
inches, and £1 the absolute pressure—
2–4 × square feet of fire grate.
Al
The Board of Trade allowance is half of one square inch area of
safety valve for each square foot of fire grate. Hence, the lift of
valve is proportional to the diameter, and inversely as the pressure.
For a discharge of 3 lbs. per minute per square foot of fire grate the
requisite lift in inches is twice the diameter of a (flat-faced) valve,
divided by the absolute pressure; this, however, does not apply to
pressures less than 25 lbs.
Take, for example, a valve 5 inches in diameter, 19.6 square
inches in area, which corresponds to 2 × 19.6=392 square feet of
fire grate, which would evaporate 39.2 × 3–1 17:6 lbs. of water per
minute. Then since the area a in square inches, requisite to dis-
charge any weight, w in lbs. of Steam per minute at the pressure
Al is—
a=4°,
3A
we would have, by taking the pressure p = 60, and the weight
w = II 7-6, the area
(Z E 4× ºf 6–2.61 Square inches,
3 x 60
which corresponds to the opening of a flat-faced valve, 5 inches
diameter, when lifting *: = 1667 inches.
• The circumference of a 5-inch valve being 15.7 inches and
I5.7 × 1667 = 2-61 square inches of opening, as stated.
When the angle of seat of valve is 45°, the lift required in inches
is—
2-8 x diameter of valve.
Al
When a boiler is regularly fired, and all the steam generated
discharged through an ordinary Safety valve, under a succession of
464 MODERN STEAM PRACTICE.
different pressures, the liſt of valve, multiplied by those absolute
pressures, should be a constant quantity, provided the same quantity
of heat is constantly entering the boiler, and provided also that the
absolute pressure in the boiler or pipe below the valve is not less
than 1726 times the absolute pressure of the steam in the chamber
above the valve.
In actual experiment a deficiency is generally manifested at the
higher pressures. IHence the suspicion of some considerable loss of
heat at the higher temperatures. -
It has been suggested that this might be accounted for by the
low-pressure steam carrying water along with it—retarding its
motion—and thereby requiring a larger opening; but this would
only aggravate the case, since the same opening will permit of a
much larger quantity of heat being discharged from the boiler with
wet than with dry steam. This phenomenon may be suggested as
one worthy of further investigation.
According to the Prussian law, as taken from Engineering of
December 6th, 1872, and allowing 30 square feet of heating surface
per square foot of fire grate, the area of safety valve is—
36 x square feet of fire grate.
A valve of this size, when full open, is capable of carrying away
nine times the quantity of steam generated at the pressure p, and
therefore will, at the designed pressure pl; be able to discharge all
the steam by lifting I-36th part of its diameter.
At absolute pressures of 72 lbs., the British and Prussian laws
prescribe precisely the same area of valve. -
Take, for example, 20:36 square feet of fire grate, which requires
by British rule a valve IO I 8 square inches in area, equal to 3-6
inches diameter, and which if flat-faced would, at a pressure of
7.2 lbs., require to lift *::: equal to I-IOth of an inch.
Then, by the Prussian rule the area of valve is, for 20'36 feet of
36 x 20'36
72
36 inches diameter; and the requisite liſt is (diameter 36) as before
grate and 72 lbs. pressure: a = = IO 18 square inches =
- ; = I-Ioth of an inch. The circumference of this valve being
I I-31 inches, would (if flat-faced) by lifting I-IOth inch give a clear
opening of I’I31 square inch, which opening would, at 72 lbs. pres-
sure, discharge 34 × 72 × I*I 3 I =6I'O7 lbs. of steam per minute, and
which corresponds to 3 lbs. per foot of fire grate—as, 20'36 x 3=61-03.
MARINE ENGINES. 465
At absolute pressures of 36 lbs. the Prussian law prescribes double,
and at 144 lbs. only half the area of the British.
At all pressures above 1726 atmosphere, the area of valve when
full open, by Prussian rule, is nine times that requisite to discharge
all the steam generated, while by British rule it is 4% times at 36 lbs.
pressure, and 18 times more than is required at 144 lbs. absolute
pressure; and this is after allowing for an evaporation of 3 lbs. of
water per minute per square foot of fire grate, which is considerably
more than is usually realized in marine practice.
Before the ordinary valves rise and give sufficient opening, the
pressure of steam frequently greatly exceeds the load under which
the valve begins to rise. Hence the requirement of large areas.
With a properly constructed valve, however, such as many now in
use, which rise one-fourth of their diameter by an increment of I to
3 lbs. above the load, there is no necessity for the area being much
(if any) more than 1-9th of that prescribed by the Prussian rule.
4 × square ff. of grate
A1
valves here referred to are so very small that the stems, or wings,
Occupy a considerable proportion of the area, and must in the above
equation be allowed for. Those small valves give much more
prompt relief to the boiler, and never permit the pressure to rise
much beyond the load.
“RESULT OF A SERIES OF EXPERIMENTS, made to ascertain
the increase of pressure in a boiler when all the steam raised was
allowed to pass away by the safety valves unassisted.—Two valves
were used, the united area of which was half an inch per foot of
grate surface. The boiler used was tubular, with 2 furnaces; the
grate surface was 25 square feet; the heating surface 746 square
feet. The valves were each 276 inches diameter, the fuel used was
ordinary good Glasgow dross, the firing good, and as nearly uniform
during all the experiments as possible. The valves were loaded by
direct weights. On next page we give table of results.
With flat-faced valves having, according to Board of Trade rule,
e PL
half of one square inch area per foot of fire grate, W = *::: e
Say, area a-
plus the area of wings of valve. The
But the valve seats being to an angle of 45 degrees,
W =;=weight of steam discharged per minute per square foot of fire grate,
P= Absolute pressure in lbs. per square inch.
D=Diameter of valve in inches.
L= Lift of valve in inches.
466 MODERN STEAM PRACTICE.

*
Load on Valve, | Press. rose to Incr. per cent. | Liſt of Valve. W. Lbs.
5 lbs. I3 lbs. I6o" "325 3'39
IO , , 19 , , 90° ‘255 3'223
I5 , , 25 , , 66" "I 8 2’68
2O >> 3O 2', 50° "I6 2-676
25 , , 36 , 44." “I425 27
3O , , 4O 5, 33" “I262 2:58
35 , , 44 25'7 “I I25 2:466
4O , , 48%, 2 I " “IO3 2'437
45 , , 52 , , I5'5 ‘og/ 2'4I
The guides of valve would reduce the clear opening by full one-
ninth, for which no allowance has in the above been made.
Table showing the respective area of valve for the boiler in
question, if made according to the committee's recommendation, as
compared with present practice in this country, and at the several
undernoted absolute pressures:–

Absolute Ar f V - - -
Pressure ... Asey of British
of Steam. Committee. alves.
20 lbs. 45' Square in. I2.5 square in.
25 3 3 36' 5 3 I2 ‘5 3 3
3O , , 3O' 3 3 I2 5 2 3
35 5 3. 25 7 33 I2'5 2 3
4O 3 3 22°5. 3 5 I2 '5 9 3
45 , , 2O" 9 3 I2'5 } %
5O 5 2. I8- y 5 I2 '5 33
55 3 3 16:36 2 3 I2'5 9 3
6O , I5' 2 3 I2'5 99
65 3 y I3-84 33 I2'5 92
7O , , I3° 22 I2'5 33
75 , , I2 * 9 y I2°5 5 y
Safety valves of ordinary construction, if loaded by direct weight,
do not allow all the steam to escape which can be raised in the
boiler until the pressure has increased above that at which the
valve opens, and an additional increase of pressure will take place
when the valves are loaded by springs. That such has been the
case in the past by dead-weight loading and imperfectly propor-
tioned valves is fully illustrated by reference to the foregoing
experiments.
The object in appointing this committee was to investigate the
cause of this increase of pressure, especially with boilers propor-
tioned in strength to work at low pressures, and it is hoped that the
result of these investigations will clearly show that the great cause
MARINE ENGINES. 467
lay in using valves of too small dimensions; and that with valves
proportioned as proposed, properly constructed and loaded by
springs, anything approaching a dangerous increase of pressure is
entirely avoided.
“ON LOADING SAFETY VALVES BY DIRECT SPRINGS. — It
has been shown that valves having half an inch of area per
sº & g ly
square foot of grate surface require to lift axiºms; of valve
order perfectly to relieve the boiler; and if proportioned as is
recommended in this report, then the lift would be in all cases
diameter of valve.
36
Having determined the requisite lift, it remains to fix any reason-
able or desired per centage of the load, which is not to be exceeded
by the additional load due to the compression or extension of the
spring, caused by the lift of the valve. Let this, for example, be
restricted to 2% per cent of the original load.
Then the spring loading the valve should be so proportioned that
the compression or extension, to produce the initial load, shall be
40 times the lift of the valve.
So that with valves having half an inch area per foot of grate
surface, the initial compression or extension of spring would be =
80 x diameter of valve
P
pression or extension would be I’II × diameter of valve. The
following formula refers to spiral springs, made of steel in the usual
way:—
With valves as recommended, the initial Com-
E = Compression or extension of one coil in inches.
d = Diameter from centre to centre of steel composing spring in
inches.
zy = Weight applied in pounds.
D = Diameter or side of square of steel of which the spring is
made in 16ths of an inch. -
C = A constant which, from experiments made, may be taken
as 22 for round steel and 30 for Square steel.
dº x zo
E =#.
The total compression or extension of such a spring is equal to
that of one coil into the number of effective coils, which may
be taken as two less than the apparent number, the end coils
468 - MODERN STEAM PRACTICE.
being usually flattened to serve as bases for the spring to rest
upon. • -
The relation between the safe load, size of steel, and the diameter
of the coil has been deduced from the works of the late Professor
Rankine, and may be taken for practical purposes as follows:–
3 y—
D = wº for round steel.
J
*/ro, XZ
D = + for square steel.
4'29
The application of the above formulae may be illustrated by the
following calculations of three different proportions of springs, all
designed to give the same result. Diameter of valve, 4" - I 2.5 area
in square inches. Boiler pressure 60 lbs. per square inch. Omitting
weight of valve, spindle, and spring; load required= I2.5 × 60=750
lbs. Then, assuming that this valve is in the proportion of half a
square inch area per foot of grate surface, the lift of valve would
2
be- #=105, say "I".
X
Initial compression of spring, sº = 4":26, say 4 inches.
3 y—
Ist. Supposed diameter of spring, or d, equal 4 in. D = Vſº4.
- e º - - _ 64 × 750 . A/
= Io, diameter of spring steel = 10-16ths. E = ... ... = 218".
Effective number of coils = #s = 18.3, say 18. Pitch of spiral,
allowing between each coil a distance equal to twice the intended
compression = I"'O61, say I inch; effective length of spring
= 1.8 × 1 = 18", and allowing for two end coils as bases, say 19%", =
the length of spring before compression.
3
2d. Supposed diameter of spring, 6 in. D = A/ tº = I I'447,
say I 2-16ths. E = ;#. = 35.5". Effective number of coils
4.
* 355
of spring, I'46 x II = 16:06", and allowing for two end abutment
coils, say 17%" = the length of spring before compression.
required = 1 12, say II. Pitch of spiral, I'46"; effective length
3 /------
3d. Supposed diameter of spring 12 in. D = Viº # = 14:42,
say 14-16ths. E = 1728 × 750 I'533". Effective number of coils
384163. 22
**; = 2.61. Pitch of spiral, 39"; effective length of spring,
required, I’53 T
MARINE ENGINES. 469
3.9 x 2.61 = IO'17", say IO", and allowing for two end abutment coils,
say I 134" = the length of spring before compression.
In cases where it is desirable or perhaps necessary to employ
springs acting at the ends of levers, the same formulae can be em-
ployed for determining the proportion of springs, bearing in mind
that the lift of the end of the lever where the spring is attached, is
to be taken instead of the simple lift of valve.
The above illustrative calculations have all reference to Springs
made of round steel, and used in compression. In many cases two
or more springs, one within the other, may be used with advantage.
After consideration of the whole of the experimental information
obtained, and the necessities required in practice, the committee
have come to the following conclusions:– s
Ist. The present practice in this country of constructing safety
valves of uniform size for all pressures is incorrect.
2d. The valves should be flat-faced, and the breadth of face need
not exceed one-twelfth of an inch.
3d. The present system of loading valves on marine boilers by
direct weight is faulty, and ill adapted for sea-going vessels, a con-
siderable quantity of steam being lost during heavy weather, in
consequence of the reduced effect of direct load—the result of the
angle or list of the vessel, and also of the inertia of the weight
itself, the latter not being self-accommodating at once to the down-
ward movements of the vessel, and, moreover, the impossibility of
keeping the valves when so loaded in good working order.
4th. That two safety valves be fitted to each marine boiler, one
of which should be an easing valve.
5th. The dimensions of each of these valves, if of the ordinary
construction, should be calculated by the following rule:–
O-6 × H S
P
A = Area of valve in square inches.
G = Grate surface in square feet.
HS = Heating surface in square feet.
P = Absolute pressure in lbs. per square inch.
A = *#9 or A =
6th. The committee suggest that only one of the valves may be
of the ordinary kind, and proportioned as above, and that it should
be the easing valve. The other may be so constructed as to lift
one quarter of its diameter without increase of pressure. Valves
of this kind are now in use, and one such valve, if calculated by
47O
MODERN STEAM PRACTICE.
the following rule, would be of itself sufficient to relieve the
boilers:—
_ 4 × G.
A = P
or A = ºlis
+ area of guides of valve,
+ area of guides of valves.
This valve should be loaded, say I lb. per square inch, less than
ſº-ſº #
iſſiſſilii
vºiſ Hillſº º
| --
º - t
º İşı §:
sº
tººſ,
| i. #
ãº
fºL |
E-
%
Rººs §
fºllº
2&18S zºzº
Fº
S
ſº
Figs. 248A, 348B.—A, Safety valve. B, Spring cc, Studs
with screwed ends. D, Cap. EE, Chest leading to waste
pipe and nozzle at the side of ship. F, Hand lever for lift-
ing valve.
3.
foot of grate
valve is to be
surface. -
of steam, and
R
\
Fig. 3 (8c—Section of Silent Blow-
of Nozzle on Ship's side. A,
l’ipe from safety valve. B.,
Nozzle. C, Nozzle chest. D,
Ship's side. o
loading safety
direct-acting where practicable.
When levers are used, the friction.
|º º-
the easing valve.
7th. As experience in
the use of valves of this
description is acquired,
both may be of this kind,
and one of them made to
blow into the sea without
any increase of pressure,
as is illustrated by the dia-
grams (Figs. 348A—348C)
from actual practice; the
other to be the easing
valve, and loaded I lb. per
square inch in excess of
the working valve.
8th. If the heating sur-
face exceeds 30 feet per
surface, the size of safety
determined by the heating
ſc 9th. As boilers decay from age it is
necessary gradually to reduce the pressure
the committee recommend
that valves should be made of a size to suit
the pressure to which the boiler may ulti-
mately be worked when it becomes old.
IOth. Springs should be adopted for
valves, and they should be
of the joints will cause an
extra resistance, and consequent increase of pressure, when the
valve is rising, and a loss of steam through diminution of pressure
before it will close.”
























MARINE ENGINES, - 47 I
THE SCREW PROPELLER,
This mode of propulsion is now universally adopted in Ocean-
going vessels. For war vessels the screw propeller recommends
itself because it and its machinery can be placed below the water
line, and thus be protected in a great measure from the effect of
shot; while for merchant vessels the advantages over the paddle-
wheel arrangement consist in a saving in bulk and weight of
the engines and boilers, by which the ship is enabled to carry
more cargo, and greater coal stowage is allowed in cases of long
voyages.
SHAFTING FOR THE SCREW PROPELLER.
The arrangements in the passage from the engine to the after
part of the ship, technically
termed the “screw alley,” first
calls for notice. The line of
shafting which connects the en-
gine or cranked shaft with the
propeller shaft is similar to any
other line of shafting for general
purposes. The most approved Fig. 349.-Coupling for Shafts.
form of coupling is the solid disc * *...*.*: *
forged along with each separate
shaft, with a projection left on the one, which fits into a recessed
hole turned out in the other. By this means the whole line of
shafting is kept central the one with the other, and the discs are
bolted together with bolts accurately turned and driven tightly into
the holes, the holes being bored and rimelled out, and the discs
faced for the heads and nuts to bear against. A key is fitted into
the two discs, secured by screws into the one, but only fitting
somewhat tightly into the other; by this means the shearing strain
is taken off the bolts. Some engineers dispense with the key and
projecting piece, having the ends turned quite fair, and depend
on a greater sectional area of bolts for holding the discs together
and taking the twisting strain. The part of each shaft which rests
on the pillow block should be raised a little above the main part,
and must be turned quite truly; at the same time in some cases it

472 MODERN STEAM PRACTICE.
is advisable to turn the shaft from end to end with a rough cut, to
insure a fair and true line, which tends to make the machinery run
Fig. 35o.—Repairing Coupling.
A, Coupling, B, Bolt holes. C C, Keys. D, Shaft.
E, Recess for taking coupling on shaft.
more smoothly; but when the
shafting is truly forged this is
not required. -
Repairing couplings.-The
lying shafting is generally
fitted rough from the steam
hammer. In the event of one
of these shafts breaking, a
ready means for temporarily
repairing it is of the highest
importance. In the example (Fig. 350), the coupling is made in
four pieces, bolted together lengthways with flanges, and trans-
versely with bolts passing through discs cast on the coupling, the
torsional strain being taken on four keys.
P.
I)
Figs. 352, 353.-Repairing Couplings in Cast Iron.
A, Screw shaft. B. Coupling. C C, Bolts.
D, Set screws. E, Recessed nut. F, Keys.
G G, Set screws. H, Raised strips.
We have arranged a simpler form of coupling, which possesses
the following advantages. It is evident that a shaft breaking at
sea must be repaired as speedily as possible, and that the contact
between the rough shaft and the coupling must only be partial,


MARINE ENGINES. 473
otherwise it would be impossible for the best mechanic to adjust
the one to the other in a limited time. The points of contact are
taken on raised strips, cast or forged on as the case may be, forming
a V section, with flat parts cut across the shaft, and the fracture is
drawn together by means of the longitudinal flanges and bolts.
There are four series of strips in the length of the coupling, making
sixteen points of contact in all. These couplings can be fitted with
keys for taking the shearing strain; but it is evident that cutting
and filing up key beds on the shaft in a heavy seaway would be a
work of difficulty, and therefore in emergencies the necessary amount
of grip can be obtained with a series of cupped set Screws and nuts
recessed in the coupling, considering that the coupling of the V sec-
tion takes the greater part of the torsional strain. To lighten these
Couplings so that they can be easily adjusted, we propose making
them of cast steel. Wrought iron or even cast iron can be used,
but the latter will be of considerable weight; and perhaps the more
expensive material may not be considered too much, when we
remember that the light coupling is more easily handled on board
ship. - -
The pillow blocks are of cast iron, lined with white metal; they
are quite plain, and are fitted with a cover, parting at the centre
line. Oil cups are cast on the top of the covers, fitted with pipes,
syphon wicks, and light cover. The base of the block is quite
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Fig. 354.—Pillow Block for Shafting.
A, Pillow Block. B, Cover for do. C C, Bolts and nuts. D, Oil cup.
flat, and is generally bolted down to wooden beams placed on the
top of wrought-iron standards, which are carried up from and
strongly rivetted to the floor plates. The pillow block for receiving
the thrust or forward motion of the line of shafting imparted by the
action of the screw propeller—this push being always in the direc-
tion of the path of the vessel, whether moving ahead or astern—











474 MODERN STEAM PRACTICE.
must be fitted with a series of collars in the bushes for taking a
corresponding series turned on one of the lying shafts, generally
located near the engine end, although they are sometimes fitted at
both ends of the shafting. These bushes are fitted into the pillow
blocks in the usual manner, and are secured with a cover and bolts,
à.
3
:=:
O
U’
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: 3
O # #
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º, #
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—
with oil cup cast on, and pieces left to form the pipes for the syphon
wicks, having holes bored through the top brasses for each collar
on the shaft. The block is cast with a long bottom piece, which is
bolted down to a separate plate planed for its reception, and fitted
with joggles for firmly wedging the block and plate together, the
latter being securely joggled and bolted to the wrought-iron stan-


MARINE ENGINES. 475
dard frames rivetted to the top of the floor plates. In connection
with the pillow blocks, a water pipe is carried along the entire
length of the screw alley, supplied from the same source as for the
main bearings of the engine, and fitted with a plug tap for each
bearing, with flexible pipe and water distributor for
showering the water by hand all over the bearing in
the event of heating.
The stern tube is made
of cast iron, and of suffi-
cient length to suit the
fineness of the run of the )*—|................g...........................
vessel. A flange is cast on " ===
for bolting it to the plate
laid across the ship from
frame to fram C, by which Fig. 356.—Stern Tube, forward end.
A, Stern tube. B, Flange. C, Stuffing box and gland.
D, Shaft.
ØSº
º sº A.
3. -
------> ** * * * ********** *** - - - - - - - - - - - - - - - - - - - - -
- - -º-º-º-º-
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> #3 =#52
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º º §§
Z 2N
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ºr-
3.
Fig. 357.-Stern Tube, aft end.
A, Stern tube. B, Snugs. c, Stern post. D, Tube with lignum vitae. E, Brass bush on shaft.
the tube is firmly pressed into the tapered part of the stern post, a
corresponding taper being accurately turned on its own end. A
packing space is left, fitted with a gland cast in brass or of cast iron
lined with brass, for packing the shaft and rendering it perfectly
water tight; care must be taken that ample room is left between
the gland and the skin of the ship. The tube has rings cast on
and turned; these rings are placed to suit the frames of the ship,
which have plates accurately bored out, and in this way the tube is
supported along its entire length. At the extreme end of the tube
a brass bearing is let in, having strips of lignum vitae for the bearing
surface. This was found an immense improvement over the ordin-


























476
MODERN STEAM PRACTICE.
ary brass bushes, and has been a chief cause of the great success
Without this wooden bearing
surface solely lubricated by the sea water, it would be impossible
of the screw mode of propulsion.
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for ships to remain long on any station without incurring constant
expense in docking them to repair the bushes, as was required in
the old method, where the action of the screw soon played sad havoc
with the brass bushes, wearing them by repeated blows out of truth,
and consequently shaking the after part of the ship.








MARINE ENGINES. 477
Figs, 357 and 358 show methods of securing the stern tube to the
stern post. In some examples where the stern tube is turned tapered
at the end, fitting into a corresponding hole bored out in the stern
post, as will be seen by Fig. 359, the tube is held in position by three
large bolts, with distance pieces of cast iron placed between the
floor plates of the ship, which are strengthened with extra plates at
the front end and at the middle of the tube, and bored out for the
reception of the raised parts on the tube, also truly turned. The tube
is fitted with the usual brass bush, lined with lignum vitae, and is
bolted by a flange and stud bolts to the stern post. The fore end has
a cast-iron gland bushed with brass, with a brass bush at the bottom
of the stuffing box, which prevents the water entering the ship.
The screw shaft should be made of larger diameter than the lying
shafting, and is fitted with a disc for connecting it to the latter, and
also with a thrust block, by which the longitudinal pressure from the
action of the screw is partly taken, relieving in a measure the for-
ward, one. Raised parts are left on the shaft at both ends, for
shrinking on brass tubes for the end bearing, which should be of
great length. At the end of the shaft a tapered part is turned, with
a collar near the front extremity, and screwed with a bold square
thread at the extreme end, which is fitted with a nut and washer for
pressing the screw propeller up against the collar. Sometimes the
end of the tube is fitted with a packing ring, to prevent the water
acting on the end where it is let into the stern tube.
In the navy and also in some mercantile vessels hollow propeller
steel shafts are used. The outside diameter is usually about double
of the inside diameter, and the steel is that known as Whitworth's
fluid compressed steel, i.e. the casting is made with a core, and
compressed by hydraulic pressure of from 5 to 6 tons per sq. inch.
and thereafter drawn out by hammering to the required length.
CONSTRUCTION AND FORMS OF THE PROPELLER.
Before discussing the action of the screw propeller, we will con-
sider its form and construction. The boss or centre piece, as in an
ordinary screwed bolt, may be said to form the bottom of the
thread, and the blade forms the thread itself. The thread of a
screw can be illustrated by rolling a piece of paper cut in the form
of a right-angled triangle round a cylindrical piece of wood: the
base is the circumference, the perpendicular is the pitch, and the
478 MODERN STEAM PRACTICE.
hypothenuse is the line that will delineate the thread when wound
round the wood. Thus a point on the thread, when working in a
nut with a corresponding thread, will move forward the extent of
the pitch in a single revolution. In this way the screw propeller
may be termed an endless screw, working into an endless nut—the
ocean. Thus supposing the pitch of the screw is 20 feet, and the
distance the vessel has to go forward 40OO feet, the screw propeller
would require to make 200 revolutions to move the vessel that
distance. The action of a cork-screw is similar to the action of
the screw propeller: with each revolution of the screw a certain
progressive movement is made through the cork, due of course to
the pitch or spiral of the screw; but as the screw propeller moves
in a yielding fluid, sometimes the action ceases by the thread of
the watery nut becoming as it were broken for a time, and the
propeller revolves without imparting any forward motion to the
vessel. This is termed the “slip” of the screw, and varies from
about IO to 20 per cent. Again we have what is termed “negative
slip,” the screw moving through less space (even although working
as in a solid nut) than the speed of the vessel, the vessel as it were
outstripping the screw and dragging it through the water. This
negative slip occurs only in vessels having full after lines; in those
having a clean run aft it is never felt. The question of the best
pitch for the screw propeller depends on the lines to be given to
the ship, and shows the necessity for the builder and the engineer
working hand in hand. When a maker of marine engines contracts
for the machinery of a vessel built by another firm, he should
always be provided with the full lines of the ship, so as to meet the
requirements of the particular case. Some screw propellers are
made to feather, by which means the best pitch for propelling the
vessel cheaply is arrived at; but it is not advisable to carry this
practice too far, for then the blade of the screw presents neither
more nor less than the action of an oblique board. And although
we may be able to get a little more speed out of the vessel by this
deviation from a truly scientifically constructed propeller to suit
the known run of the vessel as found, surely it is preferable to
arrive in the first instance at the pitch to be adopted, which can
only be successfully found by studying the lines of the ship, and
comparing them with former practice. And when we do get a
good result from the best form of vessel yet constructed, it can be
used as the basis for further improvements, increasing the speed of
MARINE ENGINES. 479
the ship if desired, bearing in mind that the power required varies
as the cube of the speed. The question of relation between power
and speed has received recently much attention through progressive
speed trials carried out by Mr. William Denny of Dumbarton, who,
as to the usual formulae or rules, says:—“The common fault is the
supposition that the power required to produce certain speeds varies
as the cubes of these speeds. This is a very fallacious theory, and
one which experience does not bear out.” See page 513 for an in-
vestigation of this question.
In the moulding shop a nearly uniform plan of constructing the
moulds is adopted for all the forms of screw propeller. In the
early screws the boss was round, tapering from the front to the back
to suit the taper turned on the screw shaft, the thickness of the
boss being greater at the front, with a reduced thickness at the end
of the shaft. The blades are formed or struck up by means of a
board, revolving round a central spindle, placed vertically in the
centre of the mould for the boss. An inclined plane is formed of
wrought-iron plating to suit the pitch required, and this plate is
bent round to the true circumference of the outer diameter of the
blades; in this way the mould is formed of loam by moving round
the board on the edge of the wrought-iron plating, care being taken
that the board always moves upwards on the spindle in a level
manner; the bottom edge of the board then scrapes the loam, which
is built up on a large cast-iron plate, and the true flat form of the
screw's disc is described. It is then necessary to divide the outer
circumference of the blades, which is generally one-sixth of the
total circumference, or the radius of the blade from the centre to
the point, the sides or edges of the blade radiating from those
points on the circumference to the centre. The thickness of the
blades at the point and root is then laid on, the corners of the blade
at the circumferential line are rounded off, and the mould finally
finished for casting. With this form of screw propeller, a great
portion of the central part of the blades strikes the water nearly
flat, merely disturbing the water, and throwing it off at right angles
to the path of the vessel, causing much vibration without producing
any useful effect. It was also found that the greatest effect was
produced by cutting down the blades at the circumferential line, and
forming the edges curved, having the greatest breadth nearer the
centre, instead of on the extreme circumferential line of configuration.
This effect of vibration in the earlier screws was got rid of in a
48O - MODERN STEAM PRACTICE.
measure by making the boss spherical, and filling up a great por-
tion of the central part of the blades with the ball, from which the
water glides off, while the blades cut their passage through the
water in a more direct line, instead of striking
azzº, it at right angles to the vessel's path. This
,' Aft \ is the greatest improvement that has as yet
à § been introduced in the formation of the screw
* # § propeller, and it is now universally adopted,
#: in some cases with slight but non-essential
& - variations.
izzºz.sº Great difference of opinion exists as re-
: ...li. # gards the number and configuration of the
& “f** A blades for the screw propeller. When the
44 * vessel is pitching or rather plunging in a
... . . . heavy sea, a two-bladed screw cannot have
Fig. 32-form of Bade very so much hold of the water as one with three
generally adopted. or more blades; but the two-bladed screw
A, Boss. B, Blade. C, Blade e wº
shºwing hij of metal possesses a great advantage in being more
easily lifted for repair or inspection; and in
addition the “well,” as it is termed, that is cut down from the deck
does not require to be so large. For war vessels so fitted, two-
bladed screws are adopted; but for the mercantile marine three
and even six blades are beneficially used.
The common propeller is arranged for two, three, or four blades;
;
º
o
i
|
º
Fig. 361.—Common Screw Propeller.
A, Boss. B, Blade. C, Blade showing thickness of metal.
they are generally cast along with the boss, of an elongated or
spherical shape. The side view of the blade is quite parallel and
more or less rounded at the point, and the thickness gradually
tapers from the centre to the point. Some of the common forms,


MARINE ENGINES. 481
are made to feather, and are arranged for four blades, having a
flange on each blade, which is turned, fitting into recesses cast and
turned out in the boss, the end of the blade having a projection
cast on, and turned to fit holes in the boss bored out exactly. The
blades are bolted to the boss with a number of bolts all round the
flange, fitted with elongated holes
in the blades. The hole for re-
ceiving the propeller shaft is
turned of a tapered form, and
the propeller is screwed hard into
its place with a large nut at the
end, having a recessed key on
the shaft to prevent the propeller
turning round. Some engineers
have fitted keys through the boss
for this purpose, but these are
not required, as practice has
proved that with a proper taper
on the shaft the nut is powerful
enough to hold the screw firmly
in position, the grip being quite
sufficient to resist the torsional
stress imparted from the blades
turning round in the water.
In some arrangements for
twin-screw propulsion, two pro-
pellers have been fitted to each
shaft, one before and another be- !
hind the hanging outside bear- Fig. 362.-Feathering Propeller with four Blades.
* * A, Boss. B, Blade.
ings, by which plan more pro-
pelling surface is obtained for vessels of light draught. The forward
screw having a finer pitch than the after one, the water given off or
pushed back by the one is taken up by the other. This plan is correct
in theory, whether applied to the screw or paddle wheel. It is more
evident in the latter case, where the tail water given off by the forward
paddle wheel acquires a certain velocity; and when two wheels have
been fitted to each side, the after one must have a larger diameter,
or be driven at greater velocity, so as to pick up the tail water
beneficially. To carry out this principle more fully in the screw
propeller, two blades have been cast on the same boss, one in


31
482 MODERN STEAM PRACTICE.
advance of the other, or, in other words, a two-bladed screw is
formed in duplicate. It is advisable to cut away the sides from the
Fig. 363.−Two Propellers cast on one Boss.
A, Boss. B, Double blades.
middle of the blades to the centre (as seen in Fig. 363), by which
means the water is not churned so much, while the after blade gets
Fig. 364—Six-bladed Feathering Propeller.
A, Boss. B, Blade, c, Blade showing thickness of metal.
a better grip. In other forms six blades have been successfully
adopted. The blades are narrow and almost parallel in the front


MARINE ENGINES. e 483
view; in the end view they are bent backwards. This form pre-
sents a number of blades of small area, and it gives equal satisfac-
tion in other arrangements with two or more blades of greater
surface in each; but it is obvious that it is not nearly so strong as
the ordinary mode of construction, and therefore more liable to get
damaged.
We now notice a form of pro-
peller which has been exten-
sively used both in the royal
navy and the mercantile marine.
The boss is of a ball shape,
and may be considered damage
proof; the blades have a curved
shape on the sides, and their
greatest breadth is at the centre
%
13
s&Tàs
4.
º
*
Fig. 365.-Boss for a Six-bladed Feathering Fig. 366.-Four-bladed Propeller cast on
- Propeller. the Boss.
A, Boss, B, Blade, c, Key. D, Wedge A, Boss. B, Blade. C, Taper on shaft.
pieces. E E, Plates. D, Nut with split pin.
or nearly so; the points and that portion cast on the boss are
made narrow; they are bent forward at the points, by which
a better grip of the water is obtained. This form of propeller
has generally either three or four blades, all cast along with the
boss. The success which has attended it has produced various



















484 MODERN STEAM PRACTICE.
modifications in the form of the blade, by which its general appear-
ance has been altered, but its usefulness in no way improved. With
the view of arriving at the best pitch for propelling the vessel, the
designer of this form generally prefers the blades cast separate
from the boss, and all keyed to it by a key passing through a shank
accurately turned to fit a corresponding hole in the boss; the flange
has also elongated holes all round through which bolts pass; by
this means a greater or less pitch is given to the blades, the number
of which is generally two, although three can also be conveniently
Aft
§
N
§ 2 N N
Ns º
Fig. 367.—Feathering Propellers. Fig. 368.-Boss for Feathering Propeller.
A, Boss. B, Blades. - A, Boss. B, Taper on shaft, c, Nut and split pin.
D, Key. E, Wedge pieces. F, Plate. G, Plate
fitted to hole for putting in the key. . A
adopted. All these screws are either fitted with a large nut for
firmly screwing or forcing them in the tapered part left on the
propeller shaft; or are held in position by flat side keys, a part
being cut in the shaft for their reception. The keys are driven:
tightly in, bearing laterally and longitudinally against the boss and
the shaft, and are held in position by a nut and lock nut bearing











MARINE ENGINES. 485
on a suitable washer, the whole being inclosed within the hollow
boss properly strengthened in the casting. -
The mode of attaching the blades to the boss is by a cotter
passing through the shank and boss, and held in position by nuts
and lock nuts at each end, bearing on washers, the hole being cut
of a wedge form, tapering to the centre of the cotter. By this
means the blade can be turned in either direction for feathering, or
for adjusting the pitch; and when the pitch is once fairly adjusted,
Fig. 369.-Bolt Fastenings. Fig. 370.—Bolt Fastenings.
A, Boss. B, Blade. C, Bolt. D, Plate. A, Boss. B, Blade. C, Plate. D D, Bolts.
- E, Guard plate. E, Guard plate.
the blade can then be firmly held in the proper position by driving
in wedge pieces between the boss and the cotter, the washers and
nuts preventing them shaking loose. -
The bolts for the flanges of the
blade when so fitted are generally
tapped into the boss, the head bear-
ing on a plate fitted to two of them.
Various plans are adopted for pre-
venting these bolts from turning
round: by notching the head for a Fig. 371.-Bolt Fastenings.
split pin, or by notched washer * * * *...* D, Washer.
plates fitting to the heads and Se-
cured with set screws, or with stud and split pin tapped into the
bottom plate, or by small square pieces butting against the nut,
held with a single set screw, the bottom washer or plate being


486 MODERN STEAM PRACTICE.
bored with a number of holes, so that the plate can be shifted to
accommodate the head. Others use T bolts, which are let into the
boss, the nut being cross cut at the top for a split pin to pass
through, which prevents it from turning round; a plan likewise
adopted when the bolts are tapped into the boss.
Propeller blades are made of cast iron or steel, and recently
T
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o
~
wº
º
|-
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H
l
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j
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bronze has been used for this purpose. The advantage in
using bronze for propellers lies in the greater durability and the
smoothness of the skin. Manganese bronze has now been in use










MARINE ENGINES. 487
by the Admiralty and mercantile firms with good results. The
blades can be made thinner and smoother than with steel, the latter
suffering from corrosion. The cost of the former is greater than
steel, but the endurance being in excess economy appears to be
attained by its use.
Plan for Lowering the Propeller below the Keel of the Ship.–
In long ships the pitching in a heavy Sea, and the vertical motion
of the waves, injuriously affect the action of the propeller when
fitted in the usual way, causing the engines to “race” dangerously,
as well as diminishing the speed of the vessel. In Fig. 372, the
propeller is shown in its normal position, the shaft being in a
straight line with the rest of the shafting. On the ship arriving in
shallow water the screw is raised so that the point of the blades
rotate above the level of the keel; and the shaft can be still further
raised, exposing the boss, when the ship is in light trim. In this
way a broken blade can also be replaced without dry dock accom-
modation.
To effect this movement of the screw the two last lengths of
the shafting are coupled with a universal joint, the inboard shaft
having a fixed pillow block, while the screw shaft is fitted with a
sliding bush, lined with strips of lignum vitae in the usual manner.
The bush is guided by the two cheeks of the stern post, and it is
raised by means of a rack which passes upwards and is connected
by gearing to a steam engine placed on the upper deck. The
shaft works through a slot in the after bulkhead, the water being
excluded by a radial gland working on two centres; while the
universal joint works in a chamber in the after end of the screw
alley, and is at all times accessible to the engineers. The lifting
rod and gearing are inclosed in iron casings, which extend to the
upper deck, and exclude any water that may rise. To prevent
warps from fouling the screw when raised in shallow water, a sliding
keel is run out by a mechanism placed on the upper deck. The
want of the usual keel piece joining the inner and outer stern post
is fully compensated by the increased width and extra thickness at
the head of the screw aperture, the centre of effort of the rudder
being raised above the ordinary height. A false foot is fitted to
the bottom of the rudder post, which can be readily removed,
allowing the screw boss to be changed in a dry dock without dis-
turbing the shaft. &
488 MODERN STEAM PRACTICE.
RAISING THE SCREW PROPELLER AND SHAFT.
The first point to be considered in our plan for raising the shaft
and Screw at an angle from a point forward from the stern post, is
the swivelling action fitted to a water-tight bulkhead, with all the
usual appliances now in use for securing an efficient bearing for the
shaft. On consideration we think that the hemp-packed ball-and-
socket joint is best adapted for this purpose. A perfectly water-
tight joint with great swivelling action can be attained by clasping
the short swivelling tube with an elastic ring expanded over the
tube, at the same time compressing the ring into a recessed gland,
in a way similar to what we adopted Some years ago for packing
Fig. 373.-Liſting Gear for Screw Propeller.
A, Propeller. B, Shaft. c, Ball and socket. D, Coupling. E, Pillow block. F, Curved stern post.
G, Bearing. H., Rack. I, Well. K, Manhole. L, Steam purchase.
the tubes of the surface condenser; but as part of the weight of the
propeller is taken at this swivelling centre, the plan is not rigid
enough, and a hemp-packed metallic ball and Socket is to be pre-
ferred. This should be fitted with a lignum-vitae bearing, and
stuffing box for the shaft; the socket having a projecting ring cast
on, which is accurately turned, and fits into a strong ring rivetted
to the bulkhead, the ring projecting through a hole cut in the
bulkhead, which is made very stiff at that part; this ring is bored
out in the ship in the usual manner. The seating has likewise a
flange cast on for bolting it firmly to the ring. The gland for the
stuffing box of the ball is made very strong, for taking the inward

MARINE ENGINES. 489
pressure due to the head of water, as well as for clasping the ball
firmly, preventing it from turning; while the hemp packing has
but little to do, as there is no movement of the ball when the shaft
is revolving. When the surfaces of the ball and socket are properly
machined in the workshop, the same means being used for turning
the ball-and-socket connections as for the locomotive engine, the
two surfaces will be mathematically exact and perfectly water-
tight.
The stuffing box for the shaft is of the usual description, fitted
with a lantern brass for keeping the shaft properly lubricated with
oil. On the under side of this stuffing box a broad flat sector is
fitted, the principal use of which is for holding the ball at any angle,
and which may be made stiff enough to prevent any movement of
the ball.
The coupling may be of the disc description, having a concave
surface on the one side and convex on the other, or as it were part
of a ball and socket; this form we consider necessary to raise the
shaft easily at an angle. Part of the surfaces remain in contact
when the shaft and propeller are raised for inspection or to replace
a broken blade, or when the vessel is under wind power alone.
But as we consider the propeller shaft should be placed in from
the stern of the vessel, so as to be able to replace a shaft at sea or
when lying in harbour, we propose using a box coupling for the
connection between the propeller shaft and the main line of shafting.
The outside bearing brass for the shaft is cast in two halves, the
division being in a vertical line, and is fitted with lignum vitae in
the usual way. Flanges are cast on the brass at the under side,
and secured with bolts and nuts. The top is secured by a cap of
brass or wrought iron; if the latter is used it should be dipped in a
zinc bath to prevent oxidation. The flanges cast on the brasses
for taking the cap are quite flat across the bearing; all the bolts
should be of Muntz metal, with brass nuts. There is a bottom
bush of metal, which is accurately turned, and fits into the half eye
formed on the stern post; this bush is bored out conically, for
taking a corresponding turned part on the brass bush. The stern
post is bored out in the ship along with the ring fitted to the water-
tight bulkhead. The cap has two lugs forged or cast on, for taking
an eye formed on the lifting rack; the eye should be bushed, and
the pin forming the joint made of Muntz metal. The cap has a
part cut out at the sides which work in the sector guides, placed on
490 MODERN STEAM PRACTICE.
each side of the well formed in the stern of the vessel, the curve of
the guiding plates being struck from the swivelling centre.
The hoisting gear for small propellers is placed on the deck, and
consists of a screw and worm wheel, with a pinion on the worm-
‘wheel shaft, working into teeth cut in the rack, which is directly
connected by the pin joint on the bearing cap; the rack slides on
a roller placed at the top, opposite the pinion on the worm-wheel
shaft. This gear is sufficient for small propellers, and has the
advantage of sustaining the weight in any position without the use
of pauls, as in ordinary crane purchases. Of course, steam power
may be used, as shown in Fig. 373; and the arrangement can be
modified for propellers of the largest size.
The inside stern post is carried up just a little above the centre
line of the shafting; the curved guide plates may either be rivetted
or forged on. These guide plates are also rivetted to the side of the
well, which is carried forward to the bulkhead, and strongly rivetted
to the angle-iron ring, as shown. The stern post and the keel are
stiffened with a plate, rabbetted to the keel and to the stern post,
and firmly rivetted to it, and to the under side of the well and the
bulkhead, by means of angle iron. Every alternate floor plate is
also carried up and rivetted to the plating forming the well, which
is carried up to the under side of the deck, forming a very strong
attachment between the keel and the top of the ship. A manhole
is fitted to the top of the well inside of the ship, through which a
sling can be attached to the under side of the shaſt, when lifting it
out or putting it in; another sling passes over the boss of the
propeller at the top end. Before lifting the shaft out, a guiding
shackle is hung from and secured to the manhole.
We will now describe the manner in which by this arrangement
the shaft and screw are lifted and again replaced, when the vessel
is at sea or lying in some foreign port. In the first place the box
coupling on the end of the shaft and inside of the ship must be
drawn back; the gland bolts on the socket holding the ball
slackened a very little, and the nuts on the sector underneath eased:
then we are ready to lift the propeller and shaft. Before doing so
the manhole cover should be removed on the top of the well, and
all the necessary tackle be got in readiness. The propeller and shaft
are then raised a little with the hoisting gear, and the blades of the
screw taken off the boss; the shaft is then lifted a little farther, to
the angle of inclination for withdrawing it out of the ball and
MARINE ENGINES. 491
socket; prior to which a blind flange with a short pipe accurately
bored and turned is slipped over the end of the shaft, with a
ring of india rubber placed over the short tube. The slings are
then put on the shaft, and when the top one can be attached to a
crane, it is easily drawn out of the ball, the blind flange and short
pipe follows it up, and takes the place of the shaft, keeping the
packing in its proper position; the flange is then screwed up with
the same nuts as for the gland, and in this way a double protection
is afforded by the ring joint against water getting into the ship.
The guiding shackle is then-fastened to the manhole, and as it is
only a foot or so below the water, it acts as a guide in placing the
shaft in again. When the shaft is clear of the ball it can be easily
lifted out; and it is replaced in the same way; the ball being held
at the inclination by the nuts on the sector placed underneath the
Socket. When the shaft is put in again, it is passed through the
top bearing brass, then through the guiding shackle, and is lowered
into the wooden bearing in the ball, and then into the short pipe
on the blind flange. A small testing tap is fitted on the flange, for
allowing the compressed water to escape, as also to prove if the
packing around the shaft is perfectly tight before withdrawing or
taking off the flange or pipe piece.
THE COMPOUND ENGINE.
The Cornish engineers have for a long period taken the lead in
the important matter of the economy of the steam engine, some of
their large pumping engines doing duty with barely 3 lbs. of coal
per actual horse power per hour. This result is due to the high .
steam pressure used, cutting off the steam Soon, and working with
a large measure of expansion, for which the long stroke of the
piston in these engines is admirably suited; these facts, combined
with the careful clothing of the parts where radiation takes place,
account for the small amount of fuel consumed over that of ordinary
engines. The principle of compounding was tried many years ago
by Hornblower, Woolfe, and M“Naught, but was not introduced
successfully into marine practice till 1854, when Messrs. Randolph,
Elder, & Co. fitted up the steamer Brandon. The first vessel of
492 MODERN STEAM PRACTICE.
H.M. navy to be fitted with compound engines was the Constance,
built by the same firm in 1863. In marine engines the Cornish
principle has to a certain extent been carried out. Large cylinders
have been adopted, but we consider that there is still great room for
improvement. Longer strokes should be aimed at, although there
must be a limit in this direction, owing to the confined space of the
midship section of steam vessels; but with horizontal engines on the
return connecting-rod principle there is nothing to hinder the intro-
duction of strokes of 4 feet 6 inches and upwards for engines placed
in exceedingly fine sections. This for medium power would be a
great advantage over those engines having a stroke of 3 feet or so.
A full measure of expansion with a single cylinder has often been
obtained, and with good results; but there are certain difficulties
to contend with, the chief one lying in the details, as all the parts
require to be made of extra strength, and when 60-lb. steam per
Square inch is used, with a large area of piston, the engine becomes
very heavy. This is not at all to be desired, as the permanent load
should be kept as low as possible, more especially for high-speed
horizontal engines, there being no doubt that the wear and tear of
large heavy pistons and their adjuncts forms a serious item of ex-
pense on board ship. Trunk engines have been recommended, so
as to carry up as it were the weight of the piston; and there is little
doubt that the large surface of the trunks tends to lessen the wear,
but it does so at the expense of lubricants, more especially with the
high pressure and dry steam now adopted.
To obviate the defects inherent in the single-cylinder arrange-
ment, using high steam with a large measure of expansion acting
on these great pistons, the Compound Engine has been adopted to
a considerable extent; although the same type of engine is by no
means a novelty, as, for manufacturing purposes requiring great
regularity of motion, beam engines fitted with high and low pressure
cylinders have long been used. The motion is very easy and
uniform, more especially at the beginning and ending of the stroke
of the piston, which is due to the steam expanding from the bottom
of the Small piston to the top of the large one, and vice versa; thus
the steam from the boiler acting on the small piston is met by
a counteracting pressure, which tends to lessen the shock more
or less felt with ordinary engines. The large or low-pressure cylin-
der is placed at the end of the beam, and the small or high-pressure
cylinder is usually one-half of the diameter of the low-pressure one;
g
MARINE ENGINES. 493
the contents of the smaller cylinder is about one-fifth of that of
the large one, owing to the stroke of the high-pressure piston being
shorter, consequently when the steam is admitted the entire length
of the stroke it afterwards expands into the large cylinder, the
measure of expansion, theoretically speaking, being as five to one.
Practice and theory are fully carried out in this arangement;
the steam, after doing duty in the high-pressure cylinder, is imme-
diately taken up and expanded in the low-pressure one, and then
exhausted into the condenser. Some of those engines have a fixed
measure of expansion, the valves having no lap, thus admitting the
steam from the boiler into the cylinder the entire length of the
stroke of the piston; in others the expansion of the steam is more
fully carried out by cutting it off in the high-pressure cylinder.
In marine engines this principle is carried to the utmost limit by
cutting off quickly in the high-pressure cylinder; thus in the first
instance there is a large measure of expansion taking place in the
small cylinder before the steam is admitted into the large one,
where it is still further expanded.
The late Professor Rankine, in treating of this subject, defines a
compound steam engine as “one in which the mechanical action of
the steam commences in a small cylinder and is completed in a
larger cylinder;” these engines, again, are divided into two classes:
“first, those in which the steam passes directly, or almost directly,
from the high-pressure to the low-pressure cylinder,” the forward
stroke of the latter cylinder taking place either exactly or nearly at
the same time with the return stroke of the former cylinder; and
secondly, those in which the steam, on its way from the high-pres-
sure to the low-pressure cylinder, is stored in a reservoir, so that
any convenient fraction of a revolution may intervene between the
ends of the strokes of the cylinders. As regards the theoretical
efficiency of the steam the compound engine possesses no advantage
over an engine with a single cylinder of the dimensions of the low-
pressure cylinder, working with the same pressure of steam and the
same rate of expansion.” In pointing out the advantages which the
compound engine possesses the following are referred to:—First,
in point of strength the action of the steam when at its highest
pressure takes place in the compound engine upon a comparatively
small piston, thus diminishing the amount of the greatest straining
force exerted on the mechanism and framing; secondly, it is shown
that for economy of heat a single-cylindered engine requires to be
494. MODERN STEAM PRACTICE.
wholly jacketted so that the temperature may be kept up to that
of the steam on admission; but in the compound engine the
smaller or high-pressure cylinder only requires to be kept to this
high temperature; and thirdly, economy of work is obtained
through the equalizing of the strains by the piston-rods on the
bearings. …”
The machinery employed in our large ocean steamers is now
of a very massive description, the high and low-pressure cylin-
ders being of large diameter and the steam pressure very high. The
Alaska recently launched on the Clyde (1881) is supplied with engines
working up to IO,OOO horse-power, the pressure of steam being
IOO lbs., the high-pressure cylinder being 68 inches and the low-
pressure cylinders IOO inches in diameter, the stroke being 6 feet.
The arrangements for direct-acting horizontal engines are various.
In some examples the small cylinder is placed on the same centre
line as the large one, bracketed or fitted to the cover of the latter,
with one piston rod common to both pistons. In other arrange-
ments an annular cylinder is placed around the small high-pressure
one; this plan requires a long crosshead for taking the central or
high-pressure piston rod, while there are two piston rods for the
annular piston, one on each side of the high-pressure one, the
connecting rod joining the crosshead directly to the cranked shaft,
while in the former plan the connecting rod can be either direct
or on the return principle. Some makers have introduced a sort
of large hollow cast-iron piston rod, having a piston at each end;
this great rod is kept steam-tight by an internal stuffing box,
placed at the centre length of the cylinder. This arrangement,
therefore, is simply two cylinders placed back to back formed in
one casting, the two central cylinders being the high-pressure ones,
while the low-pressure cylinders are at each end; or, more correctly
writing, the high and low pressure principle is carried out in one
cylinder common to both. A single-acting engine on this mode of
construction would be simply a single trunk engine, the trunk end
being for the high pressure and the other end for the low pressure.
The power, however, is better equalized by adopting the trunk
engine in duplicate, as described above; and this arrangement can
be worked direct, or return connecting rods may be adopted for
marine purposes. As the cylinder is double the length of the
ordinary arrangements, the latter plan is adopted to Suit fine mid-
ship sections.
MARINE ENGINES. 495
In some examples of combined engines the high-pressure cylinder
is placed on the top of the large cylinder, and connected by means
of a rocking beam. Although the valves are greatly simplified in
this plan, yet it cannot be considered a good one. When the pistons
work in opposite directions, the steam expands from the one to
the other, and the OUT stroke expansion of the small cylinder is
taken up by the IN stroke of the large cylinder, and vice versa;
but when the small piston is attached directly to the large one,
the OUT stroke expansion of the small cylinder is taken up by
the OUT stroke of the large one, thus entailing long steam passages
between them, not to be desired. To obviate the objections to
the short rocking beam, spur-wheel gearing has been introduced,
having separate cranked shafts for each cylinder. This plan, how-
ever, involves complication, and is not needed, for when the
high-pressure cylinder is placed alongside of the low-pressure one,
as in the ordinary horizontal engine, such an arrangement meets
all the requirements, and as simplicity on board ship is the main
thing to study, the reduction of the wear and tear becomes of the
first importance.
In reference to this point attention may be drawn to the vertical
class of engine, more especially adapted for the mercantile marine,
so successfully constructed by various engineering firms. The
platform space occupied by these engines is not so great as that
required for the horizontal type, and the wear and tear is greatly
diminished, vertical pistons, valves, &c., keeping longer in good
working order than those lying on their side,-a fact now beyond
dispute. In the ordinary arrangement of this class of engine, the
cylinders are supported overhead on a cast-iron framing securely
bolted to the bed plate, on which is cast the pillow blocks for the
cranked shaft. The cylinders are arranged the same as for inside-
cylinder locomotive engines with the valves placed between the
cylinders, thus placing the valve gear centrally and greatly simpli-
fying the mechanism for working the valve. This engine, strictly
speaking, is not of the direct-acting type, as the air pumps in
most cases are worked by a rocking beam for each; when so fitted
the descent of the pistons and adjuncts is in a measure balanced
by the column of water lifted by the pump. This is a great
advantage, and is decidedly to be preferred to the direct mode of
working the air pumps from the piston by a rod passing through
the bottom of the cylinder and attaching to it the air-pump bucket.
496 & MODERN STEAM PRACTICE.
For engines of small power eccentrics have been successfully adopted
for working air pumps lying in a horizontal position, but the plan
is not nearly so effective as a means of balancing the machinery as
working the pumps by the rocking lever already described, with
links in connection with the crosshead of the piston rod at one end
and the crosshead of the air pump at the other end.
The arrangements for compound engines of the vertical class are
similar to those for single engines of the same class. The cylinders
are supported from the top of the surface condenser on the one
side, and there are cast-iron frames on the other; in some cases
wrought-iron columns are introduced. The high-pressure cylinder
is fitted to the side of the low-pressure one, and connected by
means of a rocking beam for each; thus the pistons travel in
opposite directions, and the valve gear is simplified as in horizontal
arrangements. Some engineers place the high-pressure cylinder
on the top of the cover of the low-pressure one, with one piston
rod common to both pistons.
Theoretically and practically, direct action is correct, as the
steam from the one cylinder is immediately taken up by the other;
but the complication of the parts is an evil to be avoided, and
engines are now introduced having the minimum of working parts.
These engines consist of one high-pressure cylinder and a low-
pressure one. The cranks in some examples are at right angles
or 90°, in others the crank centres are 135° apart (and even, going
to extremes, in a line with each other), with which the crank
for the low-pressure cylinder leads, thus the piston being met by
the expanding steam from the high-pressure cylinder, it is cushioned
at each end of the stroke—a point necessary in all engines having
a high rate of piston speed. When the cranks are placed at right
angles, the exhaust steam is admitted into a compartment, generally
taking the form of a casing around the cylinder, before it is
expanded into the large cylinder. This plan is necessary to reduce
the back pressure on the small piston; besides, the large piston is
not in a proper position at the ending and returning of the high-
pressure piston fully to utilize the steam. The large piston, too,
must travel a little more before the expanding steam can be
admitted into the cylinder.
In the large vessels recently built three cylinders are commonly
adopted, two large and one smaller, the cranks being placed at 120°.
See Plate of the engines of the S.S. Parisian. .;
ENGINES OF STEAM–SHIP “PARISIAN.”
Two Low-pressure Cylinders (each 85%
diam.), with one High-pressure Cylin-
der (60" diam.) between them. Stroke
of each Piston 5 ft. Steam Pressure
70 lbs. Condensing Surface 96.24 sq. ft.
Indicated Horse-power Gorg.
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THREE-CYLINDER COMPOUND INVERTED ENGINES OF STEAM-SHIP “PARISIAN,”
5359 TONS GROSS.
CONSTRUCTED BY MESSRS, ROBERT NAPIER AND SONS, GLASGOW, FOR THE
ALLAN LINE OF ROYAL MAIL ATLANTIC STEAMERS.












































MARINE ENGINES. 497
The engines are three-cylinder compound inverted-cylinder type,
working cranks set equal distances apart, that is 120°; the high-
pressure cylinder is placed between the two low-pressure cylinders,
into which its exhaust steam is
led by means of two brass pipes
attached to the valve casings.
The admission of steam to
each cylinder is regulated by
means of a piston valve, worked
by a rocking shaft and levers, Fig. 373A.—High Pressure.
which are in turn driven by
means of double eccentrics and
link from the crank shaft. N->~T)
The crank shaft is a “built- -
up” one of steel, and in three 'º' - - - `s
distinct pieces coupled together -
with flanges and bolts. - Fig. 373 B.—Aft Low Pressure.
The surface condenser con-
tains 96.24 square feet of Con-
densing surface. Two air pumps -
are bolted on the back of the -
condenser, and worked, along
with the feed and bilge pumps,
by means of levers and links Fig. 373c.—Forward Low Pressure.
from the low-pressure cylinder
crossheads. The circulating INDICATED DIAGRAMs FROM ENGINES OF
e º Screw STEAMER “PARISIAN.”
pumps consist of two centri-
fugal pumps, each worked by Steam 70 lbs., Vacuum 29, Revolutions 837.
separate engines.
The high-pressure cylinder is 60 inches diameter × 5 feet
stroke. Each low-pressure cylinder is 85 inches diameter × 5 feet
stroke.
The engines of the Servia and City of Rome, the largest ships
afloat excepting the Great Eastern, are also of the compound
inverted type, those of the Servia working up to about IOOOO
indicated horse-power. The Alaska's engines are also capable of
working up to this high figure. -
It may seem strange to pass high-pressure steam through the
small cylinder, and reduce the pressure before it enters the large
cylinder; but we must take into consideration that when the

32
... 498 MODERN STEAM PRACTICE.
cranks are placed at right angles to each other, the engines are
found to be more easily handled, while it is necessary, as before
described, to reduce the back pressure on the small piston: this
deviation from what theory points out as correct is successfully
adopted in practice. To meet theory on the one hand, and over-
come the difficulty of starting the engine on the other, the cranks
have been placed farther apart; thus the expanding steam from
the high-pressure cylinder is sooner picked up by the low-pressure
* * * * * *-* - " - ºn sºme s =s* dº sº.
Fig. 374.—Compound Marine Engines, by Fawcett, Preston, & Co., Liverpool, fitted on
board the Screw-ship “Itata.” Sectional End Elevation.
piston, while the large piston is properly cushioned, which would
not be the case were the crank centres directly opposite each other
—a position in which it is very difficult to start the engines, although

MARINE ENGINES. . 499
... " when once set in motion they work pretty well, but on the whole
not so steadily as in the intermediate position. The air pump and
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Fig. 375.-Compound Marine Engines, by Fawcett, Preston, & Co., Liverpool, fitted on
board the Screw-ship “Itata.” Sectional Side Elevation.
circulating pump are worked by rocking levers for large power;
while for small power, eccentrics are used to give motion to the
pistons of the pumps.


5OO MODERN STEAM PRACTICE.
SCREW STEAMSHIP “SERVIA.” Gross Tonnage 74oo, nett 3900 tons.
(SEE PLATE.)
The Engines are of the three-cylinder compound direct-acting
arrangement; one high-pressure cylinder of 72 inches diameter
and two low-pressure cylinders of IOO inches diameter each, and
78-inch stroke of piston; the valves for high pressure are piston
valves, and those for low pressure slide valves, with four ports, as
shown on plans. The surface condensers (two) are placed fore and
aſt, forming part of support for the cylinders; they can be worked
together or separately; the circulation of water is effected by two
of J. & H. Gwynne's 20-inch Invincible pumps; the air and feed
pumps are worked off lever on low-pressure engines. The crank
shaft is in three pieces, of Vicker's steel, and is 25 inches diameter.
The propeller is 24 ſeet diameter, and the boss and blades are of
Vicker's steel. The starting gear is Brown's patent steam and
hydraulic gear. *
Steam is supplied to the engines by seven Boilers, six of these
double-ended, with six furnaces in each, and one single-ended with
three furnaces, in all thirty-nine furnaces, of 4 feet 2 inches dia-
meter and 6 feet 9 inches long; the total effective grate surface being
IO50 square feet, and the total heating surface 27,OOO square feet.
The boilers are of oval form, 14 feet IO inches wide, 18 feet high,
and 18 feet 3 inches long.
The engines on trial developed Io,500 I. H. P., and the speed at
sea 17% knots per hour. The dimensions of the ship are: Length
over all, 530 ft.; breadth, 52 ft.; depth from top of keel to top of
upper deck beams, 42 ft. The Servia crosses the Atlantic in little
over seven days, consuming 1300 tons of coal on the passage.
SCREW STEAMSIIIP “ITATA.” Tonnage 2391 B.M.
See Figs. 374 and 375, pages 498, 499.
The Engines, of 340 nominal horse-power, have one high-pressure
cylinder 3 ft. IO in. diameter, and one low-pressure cylinder 7 ft. 2 in.
diameter; length of stroke 3 ft. 6 in. Number of tubes in surface
condenser I 164, diameter I inch. Diameter of circulating pump
I ft. 8 in., stroke I ft. 9 in. Diameter of air pump 2 ft. 8 in., stroke
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ExPLANATION of LiterAL REFERENCEs.
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l - Jaśket.
Al Steain Ports.
.
* TTTTTTTTTTTTTTTTl|| A* Exhaust Passage to the Low-pressure
ſ | | | | || |||||||||| Cylinders. * -
} ||| B B Lowtpressure Cylinders with Steam
º . . . Jackets.
B' Stearh Ports.
l B2 Exhaust Port into the Surface Con-
C} i - denser.
cc Cylinder Covers.
D D Stuffing Boxes and Glands for Piston
Rods.
di Di Stuffing Boxes and Glands for pro-
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E E Escape Valves.
F F Pistón Valves for the High-pressure
Cylinder.
i Fl Piston for carrying up the weight of
the Valves.
G Slide Valve for the Low-pressure
Cylinders.
\
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Pl
the Valve.
1 Spring on the back of the Valve.
K High-pressure Valve Spindles. Link
and Lever in connection with the
Double Eccentrics and Link Motion
for the High-pressure Cylinder.
k! High-pressure Piston Valve Rocking
Shaft.
L Double Eccentrics and Link Motion
for the High-pressure Valves.
M. M. Valve Spindles for the Low-pressure
Cylinders. *
N N Double Eccentrics and Link Motion
fortie Low-pressure CylinderValves.
O Steam and Hydraulic Starting Gear,
with Shaft, Lever, and Rods, in
cominection with the Link Motion.
P Auxiliary Starting Valve.
Pl Steam Pipe.
Q Main Framing for supporting the
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Q Q1 Pillow Blocks for the Crank Shaft.
R Piston for the High-pressure Cylinder:
R! Piston Rod.
R* Prolēngation of the Piston Rod.
R* Nut for securing the Piston.
s Crosshead and Gudgeon.
- T Piston for the Low-pressure Cylinder.
Ti Piston Rod.
Tº Prolongation of the Piston Rod.
Tº Nut for securing the Piston.
U Crosshead and Gudgeon.
vv Connecting Rods.
w Crank Pin and Shaft.
x Surface Condenser.
Y Air Pump.
Yl Cover.
yº Bucket.
N
7
H Piston for carrying up the weight of {
Cylinders. __ --~~
vº Head Valves.
vº Hot Well.
vº Air Pump Discharge Pipe.
|
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zł Prolongation of the Air Pump Rod.
2° Guide for the top of the Air Pump
Rod.
zº Links connecting the Air Pump Cross-
head with the Rocking Levers.
zº Rocking Levers.
zº Links connecting the Rocking Levers
with the Piston Rod Crosshead.
z" Throttle Valve and Steam Pipes from
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6
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the Boiler.
Płand Gear.
Starting Cylinder Valve.
Low-p. Auxiliary Starting Slide Valve.
High-p. 23 33 22
Low-p. 33 33 3 y
Conical Valve to admit Steam to Reser-
voir.
Double-beat Valve to admit Steam to
High-pressure Valve Casing.
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High-pressure Cylinder Drain Plug
Taps and Handles.
Low-pressure Cylinders Drain
Taps and Handles.
Cºmmon Injection Valve.
Plug
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High-pressure Cylinder
72" diam., and two Low-
pressure Cylinders each
Ioo" diam. Stroke of Pis-
ton 78". Two Surface
Condensers, placed fore
and aft. Seven Boilers of
oval form, 14' 10" wide,
18' high, and 18’ 3” long;
having thirty-nine Fur-
naces 4' 2" diam. and 6' 9"
long. Effective Grate Sur-
face Ioso sq. ft. ; total
Heating Surface 27,ooo sq.
ft. Diameter of Propeller
24 ft. Indicated Horse-
power Io,5oo.
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CONSTRUCTED BY MESSRS. JAMES AND GEORGE THOMSON, GLASGow, FóR
ſ
i
THREE-CYLINDER COMPOUND DIRECT-ACTING ENGINES OF STEAM SHIPs “UMBRIA AND “ETRURIA.”
- THE CUNARD LINE OF ROYAL MAIL ATLANTIC STEAMERS.













MARINE ENGINES. 5OI
1 ſt. 9 in. Diametcr of feed and bilge pumps (two of each) 6 in,
stroke I ft. 9 in.
There are four Boilers, each 9 ft. 7 in. in length, and 11 ft. 6 in.
diameter. Each boiler has three furnaces, of 3 ft. diameter. The
total heating surface is 5140 sq. feet. Pressure 70 lbs.
The diameter of the screw propeller is 16 ft. 6 in., the varying
pitch 24 ft. to 27 ft. . -
The feed steam pumps, of which there are two, have each a
cylinder of 8 inches diameter and 9 inches stroke, driving a double-
acting pump 4 inches in diameter. They are arranged to draw
water from either the sea or the bilges, and to discharge into the
boilers, on deck, or into the sea, as may be desired. There is also
a ballast steam pump, with a cylinder 7 inches in diameter and a
stroke of 9 inches, driving a double-acting pump of 9 inches in
diameter, which draws the water from the fore and aft ballast
Compartments. A double-acting hand pump is also provided,
having a diameter of 7 inches and a stroke of 15 inches, which can
also be worked from the main engines.
The Itata has a length over all of 305 ft., breadth of beam 40 ft.,
and depth under main deck of 19 ft 6 in. The average Consump-
tion of fuel during a voyage of this ship from Liverpool to
Valparaiso was only I’OO7 ton per hour of steaming, and taking the
indicated horse-power as 3% times the nominal horse-power, we
have a coal consumption of under 2 lbs. per indicated horse-power.
SCREW STEAMSHIP “SIR BEVIS.” Tonnage 919 B.M.
See Figs. 376, 377, 378, pages 502-564.
The Engines, of II 5 nominal horse-power, have one high-pressure
cylinder 2 ft. 2 in. diameter, and one low-pressure cylinder 4 ft. 4 in.
diameter; length of stroke 3 ft. The surface condenser has 944
tubes, 6 ft. long and 34 in. diameter; condensing surface of tubes
II 12 sq. feet.
The Boilers are cylindrical, with a total heating surface of 1982
sq. feet; area of fire grate 65 sq. feet. Steam pressure in boiler
60 lbs. per sq. inch.
The diameter of the screw propeller (four-bladed) is 13 ft. 4 in.,
the varying pitch 16 ft. to 18 ft. The Sir Bevis has a length over
all of 2 IO ft., breadth of beam 30 ft., depth 17 ft.
5O2 MODERN STEAM PRACTICE.
The vessel has a carrying capacity of 1020 tons of dead weight,
Fig. 376. End Elevation.
-Hº
T
i
O
of which 120 tons of coal is carried in the bunkers. Thus loaded
she has steamed at an average rate of 9 knots per hour, with an








MARINE ENGINEs. - 503
average consumption of 7 tons 12 cwts. o qr, 12 lbs. of Newcastle
Fig. 377.
Transverse Sectional Elevation.
• e
.*.*.*.*.*.*.*.*.*.*.*.
e e -
Sectional Plan.
coal per twenty-four hours; and as the average indicated horse-
power is 360, this gives I’9 lb. per hour as the consumption of fuel.

SO4. MODERN STEAM PRACTICE.
-*—º
G
Lºſli -- . I’ſ |
Side Elevation.
|| ||
Sectional Plan of Condenser
and Main Frame.



MARINE ENGINES. - 5O5
The S.S. Arizona, built in 1879 for the Guion line by Messrs.
Elder & Co. of Glasgow, is a good type of the fast ocean steamers
of the present day. She measures 465 ft. in length by 45 ft. 6 in.
breadth, and 37 ft. 6 in. deep, the tonnage being 5146. The engines
developed on trial 6357 indicated horse-power with 56 revolutions
per minute; the speed being 17.3 knots per hour.
The engines are compound with three inverted cylinders. The
high-pressure one is 62 inches diameter, and the two low-pressure
ones 90 inches diameter each; the stroke is 5 feet 6 inches; the
slide valves are of the piston equilibrium form; the surface con-
denser has a cooling area of 12,540 sq. ft., the water being circulated
by two large centrifugal pumps; the crank shaft is “built,” and
is 22% inches diameter (see p. 415); the propeller is 23 feet dia-
meter with steel blades.
There are one single-ended and six double-ended boilers, of a
diameter of 13 feet 6 inches, and length of 18 feet for the double-
ended and Io feet for the single-ended. These are fitted with 39
furnaces 3 feet 3 inches diameter, having a grate area of 780 sq. feet
and a total heating surface of 19,500 sq. feet. The shell plates are
13/16" thick, the working steam pressure is 90 lbs.
GOVERNORS.—As the piston speed varies greatly in marine
engines when the vessel pitches in rough weather, causing a severe
strain both to the engines and hull, governors have been introduced
to regulate the supply of steam to the cylinders, and so prevent
what is technically termed “racing ” of the engines, due to the screw
being only partly submerged when the vessel is pitching. Governors
should be exceedingly sensitive, and quick in acting upon the valve
for throttling as it were the steam in its passage to the cylinders,
when the pistons have a tendency to sudden acceleration of speed.
Various forms have been tried, as the four-ball, the fly-wheel, fly-
wheel fitted with vanes, &c., and others. The first-mentioned
form acts as an ordinary ball governor, the four balls being intro-
duced to remedy an evil felt with the ordinary two-ball arrange-
ment, which did not act in a satisfactory manner owing to the
motion of the vessel. The arrangement consists of a spindle taking
two arms which cross each other, and are jointed with one pin
passing through a jaw on the spindle; on each end of the arm a
ball is fitted, by this means balancing the pendulum arm of the
governor. The spindle is fitted with a sliding collar, and is con-
nected to the pendulum arms with two links, and there is a spiral
506 * . MODERN STEAM PRACTICE.
spring bearing on the collar, to regulate its return action, while at
the other end of the collar is fitted a lever and rod communicating
with the throttle valve. This
governor is carried in a suit-
able frame, and is driven by a
band passing round a pulley
fitted to the revolving spindle,
the whole arrangement lying
horizontally.
Fig. 378A shows Dunlop's
Pneumatic Marine Governor,
which has been found very
serviceable for compound
' marine engines. In this gover-
nor the controlling power
lies in the level of the water
outside the ship, as this varies
from time to time with the
pitching of the vessel. -
A is an air vessel, which is
placed in communication with
the sea by the valve C. The
air becoming compressed the
action is communicated to
the governor G, which con-
sists of a casing containing
- an air-tight space in connec-
tion with the pipe P and fitted with an india-rubber diaphragm D.
This diaphragm, as it rises and falls due to the pressure of the air
as acted upon by the varying level of the waves, acts upon the
spring S, which motion is communicated to the throttle valve by
means of the link K.
Fig. 378B shows an arrangement of Compound Engine which
appears to have been applied successfully for paddle-wheel steamers.
It is illustrated and described in a paper read by Mr. F. C.
Marshall, at a meeting of the Institute of Mechanical Engineers,
held in Newcastle in 1881, in which he shows that such engines
may be grouped in three typical forms, viz.:-
1st. The two-cylinder intermediate receiver compound engine
having cranks at right angles. 2d. The Woolf engine in the
º
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*śs
ºr sºrº
§s
º fºº
&\s &#32 -
&Silſº :*
ºsº.º.º.º.º.º. º.º.º.º.º.º.º.
º Ş Sº, º
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* * * * * *
à
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º
§
º
3.
Eig. 378A.—Dunlop's Pheumatic Marine Governor.






















MARINE ENGINES. 507
tandem form, having generally the high-pressure and low-pressure
cylinders in line, but occasionally alongside, and always communi-
cating their power to one crank, 3d. The three-cylinder intermed-
F, Crosshead for connecting rod.
G, Connecting rod.
H. H., Frame and guides for crosshead.
I, Crank.
K K, Main frame.
LL, Columns supporting main frame.
M, Condenser.
N, Lever for working air-pump.
o, Air-pump.
P, Feed pumps, &c.
Q, Kingston valve.
A, High-pressure cylinder.
B B, Low-pressure cylin-
ders.
cc, Piston rods.
D, Crosshead for piston
rods.
EE, Side rods connecting
bottom and top cross-
heads.
Fig. 378 B. —Three-cylinder Compound Steeple Engine for the Paddle.
iate receiver compound engine with one high- and two low-pressure
cylinders, the steam passing from the high-pressure cylinder into the
receiver, and thence into the two low-pressure cylinders respectively.
The arrangement shown by Fig. 378B is of the three-cylinder
class. The steeple form of engine is adopted; the three cylinders
of each engine being bolted to each other and to the keelsons.












508
MODERN STEAM PRACTICE.
AVERAGE CONSUMPTION OF COAL, PER INDICATED HoRSE-Power PER Hour,
(See Mr. F. C. MARSHALL's Paper “On the Progress and Development of the Marine

ENGINES. BOI LERS.
Cylinders. •: ****
w; Piston Diame- Yºg 2 § Shell. Furnaces.
No. 3 Diam 45 Speed aś ºr of above | }. #
*t .* per § Screw Atmo- | E 9
‘’’ |2 A > * 3 || Min. Surface. Propeller. sphere. 5% l *
*ś º § 5 • 2. Diameter. Length. Tº nº.
- ºn- C-
In. In. Im. | Ft. Sq. Ft. | Ft. In. Lbs. Ft. In. | Ft. In. Ft. In.
r A 34 61 || 45 || 45o 2466 | 15 3 || 7o 2 12 9 15 9 8 || 3 6
2 A 42 8o || 48 || 552 is us * 72°5 2 13 6 I8 6 tº e * *
3 | A 35 | 7o 48 || 4oo 24oo 17 o 90 2 II 6 I8 6 8 || 3 6
4 A 46 | 87 57 || 484 5000 19 o 8o 3 12 3 18 6 I 2 3 9
5 A 22 || 44 3o 360 705 II o IOO I wº º 11 6 3 : 3 O
6 | A 5o 86 54 54o 4865 17 6 72 4. { H iá : } Io o? | 12 || 3 6
7 | A 35 | 7o || 48 424 2OOO 17 o 90 2 9 6 18 6 8 3 6.
8 || A 54 94 | 6o 530 || 7420 | 18 3} | 75 6 12 9 || Io 6 | 18 || 3 2
9 A 54 94 || 6o 486 7422 18 o 82°5 6 12 9 1o 6 18 3 2
Io | A || 3o 58 || 39 || 4oo 1518 || 14 2 8o 2 I 2 O Io 6 4 3 2
I I A 29 56 || 33 35o I25o IS 3 7o 2 I O Io 6 4 || 3 O
12 | A 34 | 66 || 42 | 406 17oo | 15 6 8o 2 I3 4 1o 6 6 || 3 3
13 | A 36 | 68 || 42 434 1821 16 3 77 2 14 4% Io 3 6 || 3 4
14 | A 54 97 || 6o 48o 7427 | 18 Io; 7o 6 15 Iok | Io 6 18 || 3 2
A 88 || 60 § {} I2
IS 5.I 590 || 5ooo | 17 6 || 75 4 |\ H13 6 IO 9 4 2
I6 A 28 53 38 || 38o 1560 || 14 o 75 2 I2 I 9 5 4 : 3 3
17 | A 5o | 86 54 54o 55oo | 17 6 7o 4 ſ W13 8 } IO. O. 12 || 3 6
8 || A 38 8 6 6oo 7 8 R H17 3
I 3 7o 4 4 I ~, 2 17 9 O * e tº gº º tº gº tº &
I9 A 35 | 7o 48 || 408 2005 || 17 o 90 2 II 6 r8 6 8 || 3 5
2O | A 35 | 7o || 48 44o 2000 20 9 90 2 IO II I8 6 8 || 3 3
21 | A 34}| 64 || 42 5oo 1647 | 15 4 8o 2 W 9 6 I3 O 8 || 2 8
22 || A 48 | 84 || 6o 55o 4468 || 19 o 7o 3 #. ; } I6 6 18 3 2
23 | A 5o | 86 54 || 510 4842 17 9 7o 6 11 3} 9 Io 18 3 o
24 A 54 94 6o 441 || 7420 17 9 || 7 6 12 9 Io 6 18 || 3 2
25 | A 56 | 97 || 54 || 504 5ooo 18 6 7o 6 I3 O IO 3 18 || 3 3
26 A 3o 6o 36 || 372 16oo 13 o 90 2 II 3 9 7 6 || 3 2%
27 | A 36 || 7o 45 56o 29OO || 13 O 75 2 I3 O I4 O I2 || 3 I
28 A 36 || 64 || 36 || 45o 2O59 || 13 O 7o 2 13 O 9 4. 6 || 3 2
29 || A 36 | 68 || 42 53o 25oo | I3 O 7o 2 I4 O II O 6 || 3 6
3o A 36 || 67 || 42 53o 24oo I5 O 7o 2 I4 O II O 6 || 3 6
Mean 467 — 77.4
31 || C 48 || 83 || 6o 523 90oo 23 6 7o 8 §: *} 19 ro 32 3 3
32 | B | 26 58 || 45 444 17oo 15 o 8o 2 I3 4 9 6 || 3 o
WI2 o
33 || B | 27 | 56 || 52 || 395 || 1730 | 15 9 || 8o * | \ H14 2 } 24 6 || 3 4
34 || B | 27 | 56 52 || 412 | 165o 15 9 75 T & © g & 6 || 3 4
35 | C 28 || 6o | 54 || 504 4Too 20 o 90 3 II 6 17 6 18 2 Io
36 || C 28 6o 54 || 522 4 roo 20 O 8o 3 II 6 17 6 18 2 Io
% 8 16 || 34 || 30 || 360 768 12 6 68 I II 6 9 Io à 3 2
3 26 2 2 || 336 24OO || 17 3 7o 2 Io 9 17 o I
52 42 3 4. 7 W = Width 3
Mean 437 76.6 H = Height
90 - six 18 oil. *
39 D 62 :} 66 605 21 O || 9o 7 13 6 {: ol, 39 || 3 3
Class A–Compound Engines with one High and one Low-pressure vertical
B
3 3
9 3
55
C
D
One , , One
two , , tWO
On 6 two
9 3
5 y
33
* Always working with early cut-off; engines never pressed; Welsh coal.
MARINE ENGINES. 509
BY STEAM SHIPS WITH COMPOUND ENGINES IN LONG SEA Voy AGES.
Engine,” read at meeting of Inst. Mechanical Engineers, held at Newcastle, 1881.)

BOILERS, PERFORMANCE.
Tubes. †otal Heating Surface. Hºst. I. Coal Consumption. .g
I re- Cate
ol. 5: *::: ; *::::
Total Jut- sº Furna- I.H.P. & In Per J. H. P. OUlſ.
- Nº. Length. B. Tubes. é. Total. #. per Hour.
Hall Il.
Ft. In. In. Sq. Ft. Sq. Ft. Sq. Ft. Sq. Ft. Sq. Ft. I.H.P. Tons. Lºs sq. ft.
8oo || 6 o 3 I4o 3688 528 4216 || 4-68 90o I4'5 *1 5o 3'12
g & gº * * gº & gº tº * * 6ooo 3' 19 1881 32'25 I "60 I '993
64o || 6 Io 3} | 16o 3814 * 626 4440 || 3: 7 I2O.O. 2 I I '63 2°265
1164 || 6 7 34 || 25o 642O 1383 78o3 || 3’545 2200 4O I '66 2° 136
172 || 7 3 || 3} || 49'5 || Iobo 342 14O2 3'34 42O 75 1:67 2 "O
1024 7 o 3} 273 653o 1192 || 7722 || 2:88 2677 || 48 1-67 I 725
608 || 6 Ioš 3} | 1.5o 3822 952 4774 3’97 I2OO 21'5 I'69 2°35
1308 || 7 6 3% 313 8983 1856 || 10839 || 4-9 22O7 4o 3 I '7 2°88
1266 7 6 3} | 324 8735 26o5 I [340 6'3 18or 32-8 17 37OS
344 || 7 3 34 69'64 || 212o 488 2608 || 4 65o I2 I 72 2 34
316 || 7 o' | 3 | 66°o 1891 488 || 2379 4'74 5oo 9'5 176. 2’69
352 || 7 3 || 3} | Io'ſ 25 2708 766 || 3474 || 3'975 | 875 | 16.5 179 2'27
460 || 7 o 3} | I lo 295o 764 3714 || 4 34 854 1675 I '763 2°46
1314 || 7 6 3} | 329 9198 1847 | 11o 45 5'52 2OOO 38-6 I '8o 3'o65
1224 || 7 o 3} | 332'5 7850 1398 9248 || 3:365 2745 54 183 I '839
328 7 o 3# 78 2O5o 383 2433 || 4 34 56o II I '84 2 36
roL6 || 7 o 3} | 273 6393 II.32 7525 3"Ios 2422 48 I-85 I 647
* e tº ºr tº º 65 & ſº * * 4864 || 4°18 116o 23 I '85 2'26
616 || 6 Ioš 3} | 156 3872 954 4826 4’39 Io99 22 I '87 2'35
544 || 6 9 3} | 136 3384 IOI 2 4396 || 3 875 | 1135 23 I '89 2’os
368 || 6 9 |, 3} | 106 2332 618 2950 3'35 88o 18 I '90 I '762
114o 6 9 || 3} | 34o 7:53 roaz 8200 || 3:56 l 2300 47 I '90 1873
1188 || 7 o 3% 31o 7603 || 2236 9839 4'44 2213 || 43’5 I '90 2'34
1326 || 7 6 3} | 312 9I49 26or II 75o 4'9 24OO 48'9 I '90 2'58
ro52 7 3 3% 292 6913 I3O2 8215 3282 || 25oo 5I 9 I '93 1°7o
360 6 8 3: I I5 223o 523 2753 4'59 6oo I2'5 I '945 2°36
912 || 5 4 3 I66 3884 738 4622 2-88 16oo 32 fº o I 44
38o || 6 4 3} | Ioë 2272 582 2854 2'795 || Iozo 22 #2 125 I 315
408 || 7 o 3} | 130 2876 586 3462 2'77 125o 29 f2'25 I 23
e e 7 o 3} | 129 2866 585 3451 || 2 8 1230 28 t2'25 I 243
3.917 1-828 2-1.78
2432 || 7 2 || 3} |624 15783 || 3321 | 19104 || 3:9. 4900 || 93 I '77 2'2
472 || 6 6 3} 99 2566 594 316o 3'85 82d 16'75 I '90 2 oz.6
284 || 9 o || 4 || Io2 2675 569 || 3244 4'45 73o I5'I I '92 || 2 32
296 || 9 o IO2 2750 82d 35.70 || 4'63 771 I6 I '93 2^4
I I I6 6 6 3} |3oo 61.65 I235 74oo 3’89 Igoo 4O I '96 I '986
II 16 || 6 6 3# 302 6171 I 243 74I3 4'o 1850 4O 2 OI I '95
150 || 6 6 4. 47'25 | IOO4 346 I35O || 5 "O 27o 7 2'25 2 22
544 || 6 I 3} | 132 3O33 617 3650 || 4'o6 9CO 24 2'47 I-641
4-22 2-026 2°096
2522 || 7 o 3} |78o 162oo 33OO | IQ5OO 3'O9 63oo | 137 2"oss I’52
Cylinder, working two cranks at right angles.
2 3 one crank. Cylinders in line (tandem).
3, 5 two cranks at right angles. Cylinders in line (tandem).
99 three cranks at 120°.
† These four ships are very limited in boiler power,
5 IO MODERN STEAM PRACTICE.
The preceding table of results from recent practice with the
marine engine is a valuable and interesting one, and not the least
important part of its information is that showing the relations
existing between some of the more particular parts when compared
with each other, and with the power developed by the engines. Thus
it is shown that the heating surface is about 4 sq. ft., and the con-
densing surface about 2 sq. ft. per indicated horse-power. Again, the
consumption of coal is about I’8 lb. per indicated horse-power per
hour, and the heating surface is about 30 times the grate surface. The
indicated horse-power appears to be about 8 times the grate surface,
and the heating surface per lb. of coal per hour is about 2% sq. ft.
RULES FOR THE HORIZONTAL DIRECT-ACTION
MARINE ENGINE, &c.
Nominal horse-power. — For calculating marine engines a com-
mercial unit is used, termed “nominal horse-power.” A certain
number of square inches of cylinder area, and a velocity of piston
in feet per minute, are given; 7 lbs. per square inch being the
recognized pressure, and 33,OOO lbs. the duty of one horse-power
per minute. Hence the formula—
Area of cylinder in square inches x 7 lbs. x feet per minute
33OOO
= N.H.P.
The indicated horse-power of an engine has nothing whatever to
do with the nominal horse-power, and can only be found by means
of an indicator diagram taken off the engine, from which the mean
pressure on the piston is found, as explained in another part of this
Work. The engine maker is often asked to give four, six, or even
more times the nominal measure; and this can readily be calcu-
lated by giving a large steam pressure over that used for finding
the nominal power, determining the point of cut off, besides taking
into consideration the vacuum in the condenser, which may be put
down in round numbers at I2 lbs. per square inch. Hence the
formula—
Area of cylinder in . (Mº. steam pressure , Vacuum i.) Velocity of piston attained
square inches per square inch square inch in feet per minute
33OOO
gives the indicated horse-power, which is simply the actual power
given off on the piston.
MARINE ENGINES. , 5 II
The power varies approximately as the cube of the speed of vessel
(see p. 513).-A vessel of a certain form and tonnage, and of 200
horse-power, has a speed of 12 knots per hour, and we wish another
vessel of the same lines and tonnage to attain a speed of 15 knots
per hour: the cube of 12 is 1728, and of 15 is 3375; thus— -
sº = 390 horse-power.
Thus very nearly double the power. is required to give an additional
speed of 3 knots per hour to the vessel, and this is a serious matter
when we remember that the amount of coal consumed is in the
same ratio. For example: supposing the vessel had to steam over
3OOO knots, going at a speed of 12 knots per hour it would take
250 hours to run the distance, and going at I 5 knots per hour it
would take 200 hours; therefore taking the horse-power as indi-
cated, and the coal consumed per horse-power per hour at 2% lbs.,
we have—
200 x 2.5 × 250 = 125,000 lbs. of coal
390 × 2.5 x 200 = 195,000 lbs. of coal.
or, 1n round numbers, 31 tons more coal is required to perform the
same distance at the quicker rate of speed. In the construction of
all steam vessels, respect must of course be had to the facilities for
coaling at the stations on which they are intended to run, and their
carrying capacity for coal adapted accordingly. Theoretically and
practically it has been proved, under all circumstances, that a low
rate of speed is the most advantageous in an economical point of
view. Thus when ships of war are cruising at sea it is advisable to
work the engines at half-power, or such a fractional part of the
power as may be thought best under the circumstances; but on no
account should the steam power be decreased in cases where the
full power may be demanded at a moment's notice,—economy in
coal being but a secondary consideration when the safety of the
vessel is in question.
Proportion of power to tonnage.—In the merchant service the
proportion of power to tonnage for vessels of about 2000 tons of
tonnage ranges from I to 5'6 to I to 38; in a number of vessels,
with a horse-power ranging from 80 to 700, the average proportion
was I horse-power to 4-6 tons of tonnage. This is only the nominal
or commercial horse-power allowed; but the actual or indicated
horse-power depends on the lines and draught of water of the
vessel, taking into consideration the speed that may be required.
5 I2 MODERN S TEAM PRACTICE.
To determine this point correctly the shipbuilder and engineer
should work hand in hand; and by studying the lines and configu-
ration of a particular class of vessel, with a knowledge of the power
actually required to propel her at a certain speed, they may be
able to adapt the power to the requirements of future vessels.
Rule for tonnage.— Multiply the length of vessel between per-
pendiculars, minus three-fifths of the breadth, by the square of the
breadth divided by 2, and divide the result by 94 as a constant:
the quotient gives the tonnage in old builders' measurement.
Aerformance of screw vessels.--To find the coefficient for screw
ships, multiply the cube of the speed in knots per hour by the
midship section of the vessel in square feet, dividing the result by
the indicated horse-power: the quotient will be the coefficient of
performance—the higher the number the better the result.
To find the speed with the coefficient, multiply the indicated
horse-power the engine is intended to work to by the coefficient
for the class of vessel, dividing the result by the area of midship
section in square feet: the cube root of the quotient is an approxi-
mate of the speed the vessel will attain. *
Another method for finding the coefficient of performance is to
multiply the cube of the speed in knots by the cube root of the
displacement in tons squared, and divide the result by the indicated
horse-power. Hence the following formulas—
(First method) Speed" x midship section in square feet
Indicated horse-power
= coefficient.
(Second method) Speed" x displacement &
Indicated horse-power = coefficient.
For 14 knots per hour, the coefficient for ironclads by the
former method—the length of the vessel being seven times its
breadth–may be taken at 600 as a constant, and 500 when the
vessel's length is five times its breadth. For the merchant service
the coefficient varies according to the length of the vessel—the
greater the length the better the coefficient becomes. For instance,
the steamship Cadiz, with a proportion of length of eight beams,
has a coefficient of 800; while in others, with a length of seven
and three-quarter beams, it is about 662. It will thus be seen that
long vessels are the most economical in carrying power, the speed
attained being better than in a shorter vessel for the same indicated
horse-power, while of course more stowage is afforded for Cargo;
and many screw steamships, after running for years, have been
MARINE ENGINES. 5 I 3
lengthened, with a view to gain these important advantages, whilst
retaining their original engines and boilers.
The following extracts from a recent paper on this subject will
show the conditions involved in this question."
“It is an immediate consequence of the fundamental definitions
of mechanics that if the gross indicated horse-power required to
propel a vessel at the rate of V nautical miles per hour be denoted
by E, then the gross resistances to the motion of that vessel is
#,
cient dependent upon the construction elements and development
of power in the engines, or, in an equivalent, but directly opposite
point of view, the construction elements of the hull and circum-
stances affecting the expenditure of the developed power.
Now, a first approximate statement of the problem of steamship
propulsion, according to mechanical principles as stated by Smeaton
and other mechanicians, is furnished by the well-known formula,
expressed by a quantity of the form C:, in which C is a coeffi-
- 8
C = My', sometimes termed the “Admiralty Formula,' in which M
is the immerged midship area, E the gross indicated horse-power
corresponding to the trial speed, V nautical miles, and C, a numeri-
cal coefficient, which, in the cases where M, E, and V are known, is
easily calculated, and which, subject to the following reservations,
has been generally adopted as an approximate measure of the
efficiency. It is found, however, in trying experiments on the same
vessel at different speeds, where there would seem to be no good
reason for supposing great variations in efficiency, the coefficients
thus found vary in an extraordinary degree; also, in passing from
one vessel to another, the variations have been found irregular, con-
tradictory, and perplexing to a degree which, without the aid of
other considerations, principally derived from experience of the
values which have been obtained in vessels of similar dimensions
and speed, would render these coefficients of doubtful value as a
measure of efficiency; and, although a coefficient of efficiency is
undoubtedly involved in this quantity, all experience points to the
conclusion that it involves variable elements, and the hypothesis that
it is a constant of one term, is not in accordance with the physical
conditions of the problem, and that this formula requires correction
for ignored and misrepresented elements.
*See paper “on Steamship Efficiency,” by Mr. Robert Mansel, 7% ans. Inst. Engineers
and Shipbuilders in Scotland, vol. xxii.
33
5 I4. MODERN STEAM PRACTICE,
Obviously, the formula may be written–
c; – M v. (1)
in which it is asserted, the true form of C in the , first member is
unknown, and the quantities represented by the factors M, and V*
of the second, are, at best, but rudely approximate.
It has been stated by me that a better approximate form for the
factor expressed by M in the Admiralty formula is the quantity
LVM, that is to say, the product of the length of the vessel into the
square root of the immerged midship section; only, to meet a
correction necessitated by the known fact that when uninfluenced
by restricted depth of water, small vessels experience greater pro-
portional resistance than larger ones, and also corroborated by
D'Arcy's exhaustive experiments on the flow of water, in which it
was shown that the diameter of the pipe entered inversely as an
element of the resistance. It was therefore proposed, as a practical
but empirical correction, to take the 76th power of this quantity
instead of its full value, and hence, on this hypothesis, the quantity
b comes to be represented by the approximate value—
_(LVM)%.
C &
In which C is a constant involving a number of factors, and corre-
sponds to, but is not the same as the C of the Admiralty formula,
and thus we finally arrive at the following equation— *
E (LVM)%
V C
The factor log. Tº a V of the second number being the notation by
which is expressed, the number whose common logarithm is the pro-
duct of a small quantity, a, into the speed, V knots.
The crucial practical test of the accuracy of the speed, factor of
the second member, is to apply the formula to the progressive speed
trials of actual steam vessels. For, taking the common logarithms
of both members, and with the speeds taken along an axis as
b
log. - a V. (3)
E sº
y, as ordin-
ates; these values will range in a straight line, inclined to the axis
at an angle dependent upon the value of a, and having the ordinate
at the origin equal to the value of the factor log. º, or, simply,
abscissas, if we set up the values of the first number log.
log. 6; whence, by measurement and calculation, or calculation
alone, it is easy to obtain the value of C, which will be found a .
MARINE ENGINES. 5 I 5
constant quantity in all the experiments, so long as the conditions of
the trial are unchanged. We thus completely remove the objection-
able variations of coefficient of the Admiralty formula, which, in the
same vessel and circumstances, usually gives a new value of C for
every value of V. & -
To illustrate the constancy of the derived coefficient, in passing
from vessel to vessel, let us make use of experimental data which,
treated by the Admiralty formula, offer great variations; for ex-
ample, to a few cases of paddle vessels with feathering floats, of
which (except the Paris), having only one experiment, and con-
sequently being unable to determine a, it is assumed that the
value of this is O796. (Tabular results of experiments are given by
the author.) The problem therefore is, having given the length and
area, power and Corresponding speed, of certain paddle vessels, to
calculate from the formula,
c;= (LVM)% log- ogów,
the value of C the efficiency coefficient, and to contrast the same
with the values yielded by the formula,
E
C -.' – M V*.
V
RESULTS OF CALCULATION OF EFFICIENCY OF THE FOLLOWING PADDLE VESSELS.
e Trial Correspond- Efficiency Admiralty
Name. Length. Mid. Area. Log.(LvMI); Power. ing Speed. | Co-efficient. Co-efficient.
Shannon, ..] 329 6 Io 3'4212 2928 I 3 '90 I6o'o 559°5
Paramatta, 329 606 || 3:41.99 294O I 3 '95 16O'9 560°o
Admiral, ..] 2 II 2I4. 3'O557 744 I I '87 I 59'8 4S5'7
Aaris, ...... 2 IQ 177 3'O248 IO3O I3°4 I I6 I to 4OO'4.
Wol/, ....... 239 22O 3 IO59 I5OO I4 I9 I 59°2 39 I ‘I

It will be seen that the formula virtually embracing the whole is,
- E -ºh V log. - 'oZ96 V.
The efficiency coefficient 1604 giving as close a result as would be
obtained by the use of three values of the Admiralty formula coeffi-
cient, say 560, 486, and 40O. Having thus exhibited the range and
accuracy of the proposed system of comparison with the ordinary
run of merchant vessels, let us now apply them to the valuable data
furnished by Mr. White, so as to compare results.”
The author then proceeds to a comparison of various experi-
mental results, and finds that the efficiency coefficient for vessels of
H.M. navy and mercantile marine vary from about 80 to nearly
600, and points out that the conflicting elements which enter into
515. - MODERN STEAM PRACTICE.
this question, especially when dealing with screw steamers, still de-
mand carefully made experiments for their solution. - -
Diameter of cylinder.—To find the diameter of the cylinder, the
velocity of the piston in feet per minute must be determined, and
it ranges from 300 feet for short strokes, to 6OO feet and upwards
for strokes of 4 feet 6 inches. The maker is generally allowed to
fix the speed he considers best under the circumstances. To find
the number of square inches per horse-power, divide the constant
33,OOO by the product of the speed multiplied by 7, the result gives
the square inches per horse-power; then multiply this by one-half
of the nominal power required, and the result is the area of each
cylinder in square inches. When great exactitude is required, add
one-half of the area of the piston rod, or trunk, if adopted for single
trunks, or, the whole area for double trunks; this is necessary, as the
trunks take up a large area in comparison, to the piston rod. These.
combined areas in either case will give the true area of the cylinder
in square inches, and by a table of areas, which the engineer should
always have by him, the diameter of the cylinder is easily ascer-
tained. t
Stroke of piston.—For short strokes giving a large area of piston
per horse-power, a good result will be obtained by dividing the
diameter of the cylinder by 176. It is evident, however, that when
high steam pressure is used, much longer strokes can be beneficially
adopted; and by this means we can reduce the weight of the parts
below what is required when the steam is admitted into the cylinder
at a high rate of pressure, as in the combined high and low pressure
cylinder arrangements, now extensively adopted. i
Depth of piston and ſcng//, of cylinder inside. —The depth of
piston is usually one-fifth to one-sixth of the diameter of the cylin-
der, to which add the length of the stroke, making an allowance for
clearance at the ends of 34 inch for small, to 34 inch for large pis-
tons, and the product is the length of the cylinder inside, or space
occupied by the steam from the inside of the front end to the inside
of the cover. -
Sfcame and er/laust fort in cylinder. —To obtain a free steam
and exhaust, the ports in the cylinder are greatly in excess of the
valve opening—one-nineteenth of the area of the cylinder for the
steam port, and one-eighth for the exhaust port. The latter is
ruled by the distance of the face of the valve from the centre of the
cylinder; and as the exhaust into the condenser is greatly contracted
MARINE ENGINES. - 5 17
in the passage at the side of the port, the exhaust port is made
broad in the direction of the travel of the valve.
Length of ports for double-ported valves.—The steam ports in
the cylinder are divided by a centre rib about 1% inch broad, while
the exhaust port is left free. The combined length of the steam
ports is found by dividing the diameter of the cylinder by 17, to
which add the breadth of the centre rib. -
Steam way or opening by valve, lap, &c.—The full opening of
the steam way by valve is found by multiplying the area of the
cylinder in Square inches by the speed of the piston in feet per
minute, dividing the product by the constant IO,OOO; the result
divided by 2 gives the openings for double-ported valves, or four
openings formed with the central ribs. The width of the opening
is of course determined by the length of the ports, and it is an all-
important consideration, as it regulates the supply of the steam into
the cylinder, and consequently the number of strokes or revolutions
of the cranked shaft; and from it the correct lap of the valve is
obtained for cutting off the steam at that part of the stroke which is
arranged for giving the greatest indicated measure of power in con-
junction with the steam pressure that is determined on. The lap of
the valve depends on what part of the stroke of the piston the cut-off
commences, and is explained at p. 122; the length depends on which
class of valve is adopted. The length of doubled-ported valves is
considerable, but the benefit of having a short stroke is obvious, as
the eccentrics are not nearly so large, and all the minor details are
correspondingly reduced. The length of the valve is simply the
sum of the ports and bridges or bars on the cylinder face, to which
must be added the two outside laps.
Steam pipe on valve casing and er/laust pipe.—The steam-pipe
branch on the valve casing is about one-twentieth of the area of
the cylinder; the main steam pipe is two-thirds of the two com-
bined. The exhaust pipe into the condenser is one-twelfth of the
area of the cylinder.
Relief valve for cylinder.—The diameter of the relief valve is
found by dividing the diameter of the cylinder by 12. Smaller
cocks are sometimes fitted on the same valve chest, and worked by
levers, rods, and handles from the starting platform.
Thickncss of cylinder—For ordinary steam pressure ranging up
to 30 lbs. per square inch in the boiler, the thickness of a cylinder
25 inches in diameter is 76 inch, and for every 5 inches of additional
518 - MODERN STEAM PRACTICE.
diameter add ºr inch to the thickness. The flanges for the covers
should be one-fourth more than the body; the ends and covers one-
tenth more than the body. The ends and covers should be strongly
ribbed with deep bars cast on, radiating from the centre; the depth
of the covers, including ribs, should be about one-eighth of the
diameter of the cylinder. For additional strength the body of the
cylinder is cast with two or more deep rings, to which are secured
the rings of wood fastened to the lagging with ordinary screw nails.
A manhole is cast in the covers of large cylinders, fitted with a lid;
and the hole for the boring bar on the end of the cylinder is of
sufficient size to inspect the inside of the cylinder, and is also fitted
with a cover which can be easily removed. The thickness of the
sides of the steam chest varies from 34 inch for small to I }4 inch
for large diameters, and is strongly bracketed where required. The
steam ports are divided by a central rib, but the exhaust port is
left free, so that the passage for the waste steam to the condenser
is not interfered with. The exhaust is generally carried round the
cylinder through a broad belt, but this depends entirely on the
arrangement of the pipes leading into the condenser.
Double-ported valve.—The thickness of this valve for small sizes
is 5% inch, ranging to I }4 inch for larger sizes; and it is cast with
a centre rib to strengthen it. The diameter of the annular space
for receiving the metallic rings, for taking the pressure of the steam
off the back of the valve, should be as large as convenient; the
depth of the recess in the cover is found by multiplying the breadth
of the rings by 2; the breadth of the rings ranges from I }% to 134
inch, their thickness being about 5% inch for large sizes, to 34 inch
or more for extra sizes. The set screws are generally 34 inch in
diameter, fitted with jam nuts and washers. The valve casing is
an open casting varying from 34 to 134 inch in thickness; the
flanges for bolting it to the cylinder, and for the cover, may be
% inch more than the thickness of the sides. The steam pipe is at
one end, and the steam passage tapering to the extreme end.
Piston rod and stuffing bor—To find the diameter of the piston
rod multiply the area of the piston by the full pressure in the boiler,
to which add the vacuum or I2 lbs. per Square inch, and divide the
product by 2240; the quotient gives the area of the rod in square
inches for compressive strain. For tensional strain where cotters
are used, or where the piston is attached to the rod by a nut, divide
by 40OO, which gives the Sectional area at the bottom of the thread.
MARINE ENGINES. 519
No part of the piston rod, such as the sectional area at the part
where cotters are used, should be made smaller, so that the rod may
safely take the greatest tensional strain imparted by the full steam
pressure plus the vacuum. When two piston rods are used for
return connecting-rod engines, add one-fourth more area; this is
necessary as the vibration of long rods is rather severe at the high
rate of piston speed now adopted. The depth of the stuffing box,
from inside of the cylinder end to the face of the flange, equals the
diameter of the piston rod multiplied by 2; the breadth of the packing
space equals the diameter of the rod divided by 4; and the thickness
of the stuffing-box flange equals the rod divided by 3. When four
or more bolts are used for tightening up the gland, their combined
area is found by dividing the piston rod area by 6.
Slide-valve rod.—To find the sectional area of the slide-valve
rod, multiply the full area of the valve by the full pressure, as for the
piston rod (i.e. steam and vacuum), to which add the weight of the
valve in lbs., and divide the result by 2240; one-sixth of the quo-
tient equals the area of the valve rod in square inches at the weakest
part. Sometimes two rods are adopted, passing over the shaft on
the return principle; in such cases each rod is but little reduced
from the single-rod arrangement. To prevent the rods bending or
springing, guides are fitted at about the middle of their length.
Eccentric strap, rod, and link.-The dimensions of the bolts for
the eccentric strap are found by multiplying the total area of the
slide valve by the steam pressure, adding the weight of the valve
in lbs. as for the slide-valve rod, and dividing the result by 4000;
one-sixth of the quotient divided by 2 will give the area of each
bolt at the bottom of the thread. Find from a table of areas the
corresponding diameter, to which add the depth of the two threads,
which will give the full diameter; this may be made a trifle more
to enable the thread or screwed part of the bolt to pass easily
through the hole in the strap. The sectional area of the gun metal
strap where it is bolted together at the lugs should be three times the
area of the bolt at the bottom of the thread, increasing in thickness
all the way round; its breadth equals about twice the diameter of
the bolt. The thickness of the snugs should be one-fourth more than
the thickness of the strap at the lugs. The thickness of the eccen-
tric ring equals one-eighth of the diameter of the shaft, and the metal
round the boss for securing the eccentric to the shaft equals one-
seventh of the diameter. The eccentrics are generally cast open,
52O MODERN STEAM PRACTICE.
with a strengthening rib between the boss and the outside ring.
The pins for the eccentric rods are the same diameter as the slide-
valve rod. The rods are forked at the link end, with a T end for
bolting to the gun-metal eccentric strap; they are made quite flat,
the area at the Smallest end equals the area of the slide-valve rod,
and for every foot in length add about 9% inch to the breadth of
the rod. The bolts for the T ends are the same diameter as those
for the strap. The slotted link is generally adopted; the distance
between the centres of the eccentric rods on the link equals three
times the throw of the eccentric. The holes for receiving the pins
are fitted with gun-metal bushes cast hard, and adjusted with set
screws, screwed into the lugs on the link. The sectional area of the
slide-block pin is found by multiplying the slide-valve rod area by
I'3. The pin is conical, and fitted with a tapered ferrule of steel,
which is split, having set screws and nuts on pin for adjusting the
wear. The slide block is of brass, with a loose side flange secured
with screws; the length of the block equals twice the diameter of
the pin. The width of the link should be about one-sixth more
than the diameter of the slide rod; the sectional area equals that
of the slide-block pin. The sliding block or crosshead to which the
pin is secured is generally a flat bar, moving in brass guides, the
crosshead having a lug forged on for taking the slide-valve rod.
The point of suspension on the link is midway between the eccentric
rod pins, on the radius line of the link, a cross bar and pin being
rivetted to the link at that point. The suspension rods are found
by dividing the valve-rod area by I-6, which gives the area of the
pin in square inches; their diameter at ends equals the diameter
of the pin. The suspension rods have brass bushes fitted in the
eyes.
Power required to move the slide valve.—The power required
to move the slide valve depends on the size of the valve and amount
of pressure on the back of it, to which is added the weight of the
valve in lbs. One-sixth of the total may be considered the force
in lbs. that is required to move the valve when under full pressure
(i.e. steam and vacuum). In practice, for an area of 800 square
inches of valve surface on the back of valve, and when provision is
made with rings on the back to relieve the valve from the steam
pressure, a power of 7 to I is allowed; with a steam pressure from
2O to 30 lbs. per Square inch, Supposing the valve's area was 4000
square inches, more of course would be needed, the area being five
MARINE ENGINES. 52I
times as much, or a proportion of 35 to I would be required; that
is to say, the starting wheel would require to make 35 revolutions
for one of the shaft on which the lifting arm for raising and lower-
ing the link is fitted. Of course for small power a valve should be
arranged to take the steam pressure off the back, when the slide
valve is moved by hand, thus lessening the labour in reversing the
gear.
Connecting rod.—The thrust and pull on the connecting rod
receive the full force exerted on the piston, and the same rule holds
good as for the piston rod, namely, 2240 lbs. for compressive stress
and 40OO for tensional strain. This gives the number of Square
inches of area for the ends of the rod, an allowance of one-fourth of
an inch in diameter for every foot in length gives the diameter at
the middle. The thickness of caps, when so fitted, is one-half of the
diameter of the rod. The combined sectional area of the bolts at
the bottom of the thread is found by dividing the total pressure on
piston (i.e. steam and vacuum) by 40OO. When straps are used,
the combined area at the brasses and key-ways must equal the area.
of the rod at end. The breadth of jibs and cotters equals the
diameter of the rod, and the thickness of the key is found by mul-
tiplying the diameter of rod by 31; the thickness of brasses at
ends is found by dividing the diameter of the crank pin by 8, and
for the side one-half will suffice. The brasses are planed out and
lined with white metal, the proportion being for large sizes I 34 inch
of brass surface all round with a mid strip left.
Main cranked shaft.—The same rule holds good as regards the
diameter of a shaft with cranks forged on in one piece, and plain
cranks shrunk on a straight shaft. When the cranks of two engines
are placed at right angles to each other, the shaft should have the
same area as a single engine having the same force exerted on the
piston, the length of the crank from centre to centre being identical.
To find the diameter of the shaft, multiply the length of the crank
in inches by the total pressure on the piston (i.e. steam and vacuum),
and divide the sum by I2O6; the cube root of the quotient will be
the diameter of the shaft. The collars at the bearings for large
diameters may be I inch. The length of the two outside journals
is generally equal to twice the diameter of the shaft at the journal.
The middle bearing is made longer according to the distance
between the frames for supporting the shaft. The crank pin is the
same diameter as the journal; the distance between the jaws of the
522 - MODERN STEAM PRACTICE.
crank is ſound by multiplying the diameter of the journal by 87;
the thickness of the cranks in the line of the length of shaft is found
by multiplying the diameter by 8, and the breadth equals the
diameter over the collars. All the collars should be made with a
bold radius at the journals, for shafts generally give way at the
sharp corners after long running.
Cross/lead and guides.—The diameter of the crosshead for return
connecting-rod engines is found by dividing the total pressure on
the piston by 14OO, the quotient is the area in square inches. The
width of each block for taking the upward and downward thrust
of the connecting rod equals the diameter of the crosshead, and the
length is twice the diameter. The blocks are of brass or cast iron
lined with white metal. The depth of the top motion bars or
guides equals three-fourths of the diameter of the crosshead. Some
engineers allow clearance between the blocks and guides at the top,
depending on the weight of the crosshead and adjuncts to neutralize
the thrust; one-eighth of the total pressure on the piston can be
safely taken for calculating the bolts; the motion bar being taken as
a beam loaded at the middle, having a section of an I form, or centre
rib, with flanges at the top and bottom. Of course the thrust varies
according to the angle of inclination; it is less with a long than
with a short rod. From four and a half to five times the radius of
the crank, or the length from the centre of the shaft to the centre
of the crank pin, is about the average length for the connecting
rod.
Main frame.—The main framing is subjected to direct tensional
and compressive strains, and to a certain extent also to twisting
stress. As the cohesive strength of cast iron is less than that of
wrought iron in the ratio of one of wrought iron to three of cast iron,
the combined sectional area of the framing should not be less than
three times the area of the piston rods; but when we consider that
the framing forms the backbone of the structure, and may be sub-
jected to tensional, compressive, and twisting strain at one and the
same time, more area is required. When of an I section, the centre
web varies from 7% inch for small to 134 and 2 inches for heavy
engines; the flanges for bolting down to the keelson, cylinder, and
condenser, one-fourth more than the centre web; and all the other
flanges one-eighth less than the centre web. The breadth of frame
equals the diameter of the shaft at the journals. The depth of the
top limb for bolting to the cylinder equals the diameter of the
MARINE ENGINES. 523
shaft, and that of the bottom one at the cylinder is one-fourth less
in depth; the limb for bolting to the condenser may be made a
little more than one-half of the diameter of the shaft. The various
forms of framing have been already noticed. The thickness of the
brasses at the bottom is one-seventh of the diameter of the journal.
The caps when of wrought iron are one-third of the diameter of
the journal, and when of cast iron one-half. The combined area
of the cap bolts is found by multiplying the combined area of the
cylinders by the total pressure of the piston, as for the piston rods,
&c., dividing the result by 40OO. The brasses are recessed about
% inch in depth, and filled in with white metal, the brass surface
being about I }% inch all round for large shafts, with a bottom strip
running lengthways. -
Piston.—The piston has generally a depth of from one-fifth to
one-sixth of the diameter of the cylinder. The packing ring should
not be less than one-ninth of the diameter of the cylinder; its
greatest thickness one-fifth of its breadth, diminishing to the part
where it is cut through. The rubbing surfaces of the junk and
bottom rings can be made of about the same collective breadth as
the packing ring, with projections formed on the junk ring and
bottom of piston projecting from their respective thicknesses; this
tends to make the wear of the spring ring and piston more equal.
The ends of the piston may be somewhat less in thickness than the
cylinder; they are strongly ribbed, and have all the necessary bosses
cast for the piston rods. The bolts for the junk ring vary from
34 to 134 inch in diameter, according to the size; in some cases
they are merely tapped into the cast iron, in others nuts are inserted
in the body of the piston. The Spring ring is kept up to the
cylinder face with flat or U-shaped springs, recessed into the body
of the piston. Two pieces of cast iron are inserted between the
packing ring and the piston, which serve to keep the body and
packing ring central with each other; the pitch of these blocks is
about one-fifth of the circumference of the ring inside. (See p. 403.)
Air pump, condenser, &c.—The capacity of the air pump equals
one-eleventh part of the cubic contents of the cylinder for double
action, and double of that quantity for single action; the length of
the stroke being the same as for the steam cylinder. Thus the
area of the cylinder is divided by II or 5'5, as the case may be, to
obtain the area of the air pump. The lining of the air pump varies
from 3% to 34 inch in thickness. The depth of the air pump piston
524. MODERN STEAM PRACTICE. t
equals one-fourth of the diameter of the pump; the diameter of
the air-pump rod equals the diameter of the pump divided by 7.
The area of the foot-valve passages in the condenser equals the full
area of the pump, but for the head-valve passages more is allowed
which is found by multiplying the area of the pump by I-35; this
result is only for one end. The area through the gratings for the
foot valves should not be less than the pump area multiplied by 61,
and for the head valves ‘83 is the multiplier. Of course more area
in the passages and gratings may be allowed, as a large area reduces
the lift of the valves, and renders the wear and tear of the india
rubber less severe. The valve seats are secured to the condenser
by 34-inch stud bolts and nuts of Muntz metal. The capacity of
the condenser is generally about I'3 times that of the capacity of
one cylinder, when a condenser is fitted to each, placed side by side.
When the condenser is on the opposite side in relation to the
cranked shaft, the capacity can be reduced, as the eduction pipe
then forms a part of the condenser, and increases the total cubical
contents. The area of the main discharge pipe equals the area of
the air pump, or one-half the area for each. The thickness of the
condenser varies from 34 to I }4 inch; all the flat surfaces should
be strengthened with ribs in the casting. There should be an air
vessel formed in the casting, placed above the head valves, so as to
lessen the shock of the ejected water. The diameter of the snifting
valve varies from 2% to 4 inches, and it should be placed as low
down as possible, so that all the air, water, &c., may be ejected in
the act of blowing through.
Injection valve, &c.—To find the area of the injection pipe,
multiply the cubic contents of the cylinder in feet by '4, which
gives the area in square inches for each condenser; the bilge injec-
tion may be less than this. The former should be placed as high
up and the latter as low down as possible in the condenser.
Surface condensation.—The surface of the tubes, according to
Hall, should have about 2800 square inches for the Condensation of
6O,OOO cubic inches per minute, the quantity of cold water required
being about IO gallons. Some makers give about the same sq. feet
of condensing surface as there are sq. feet of heating surface in the
boilers (see p. 432). Of course, the pressure of the steam as it
enters the condenser is the point to study in considering the amount
of surface required; a very general rule is to multiply the total heat-
ing surface in the boiler by 75, which gives the number of sq. feet
MARINE ENGINES, 525.
of condensing surface. The air pump for the surface system may
be less than for the injection system, ranging from one-twelfth to
one-fifteenth of the cubical contents of the cylinder; it is, however,
often made of the same capacity as the injection system, in the
event of that system being adopted, in case of accident to the
surface condenser. - $ºr
Fecal pump.–The number of cubic inches of water required for
the boilers varies of course according to the evaporation of water
in the boilers. To find the water required, multiply the cubic
contents in feet of steam for one cylinder for an entire revolution
by the cubic inches of water required for the steam used, that is
, the quantity required to be boiled off, and the result will give the
cubical contents of the feed pump of the single-acting type. This
result is only for one cylinder, and generally double the contents
is allowed, so that in the event of one of the pumps getting out of
order the other one will be able to keep up the supply. The area
of the water passages in the grating, if india rubber valves are used,
is found by the same rule as for the air pumps; for brass valves,
divide the pump's diameter by I-3, which gives the diameter of the
valve. For the sake of uniformity, the bilge pump is the same size
as the feed pump.
Screw propeller.—The screw's disc, or the circle represented by
the diameter of the screw, should have an area of about I foot for
every 275 square feet of midship area or immersed section; while
the actual area of the blades may be put down at about I Square
foot for every 7 to Io square feet in the midship section. The
thickness of the roots of the blades for cast iron is found by multi-
plying the diameter of the screw by 55, this tapering to I 34 inch
at the point on the average. When the screw is made of gun-metal
multiply the diameter by 44, which gives the thickness at the root,
and all the other parts in proportion. To find the pitch of the
screw, multiply 6080, the lineal feet in a knot or nautical mile, by
the speed in knots per hour that is required, dividing the result by
the number of revolutions of the screw multiplied by 60 minutes,
and the quotient will give the pitch of the screw as it were working
in a solid nut. A certain amount, however, must be allowed for
slip. Deduct that amount from IOO, which we will name the divisor,
then multiply the pitch as already found by IOO, and divide that
quantity by the divisor: hence the formula—
* IOO—slip : pitch as found : ; ICO : actual pitch.
526
MODERN STEAM PRACTICE.
Angles on #- - - - - - - - - - - - - - - - - - -
Sides of §s - - - - - - - - - - - - - - - - - -
Wedge Box. . .
~5
Thickness t Kozake -º-º-;
- H rº-ºcºl cºlºr-tºo-lºv-iºurkcarºo H
in Boss. tº ºn º
Thickness rººke ko
- * * Ko
at Point of gº-sº F- Fs. º *... -º-º-º-º-º:
Blade. \cko Cºlº tºkotº-Ko P-1 ºt
º ko
Thickness a s ºf . Tºº Lº? … º.º. ºº, tº
at Root. : SY Q & cr) cr) ºr *t ºf sº- ur, ºr, \r, \o Vo Vo tº tº t-CO
g ... -N cºcobor-jºo —fºur-tº cºst cºor-ºcr-ºo-º-º-; tºor-ko
Yºhº; #3 orºžsº orºgoº,
*** - P-4
Blade. &: o – - - - - - - e, el & el & c. & to to to to
Width of .5 o stoo o stoo o ºrco o stoo o stoo o stoo o
Blade at
widest part. E & N s to so to sº st stur, ur, loso o so tº t-r-co
wº º 2: -ºn-4-H - ºr-º-º: cºst-ſº-tº cº-º-º-Fºlercºlºr-º-º:
O 21Cl & : <!- unºc VC ASSO ON ON O - CU & cry ºf ur, urovo tº OO
above Boss. * - Wºº hºt hºt ºt tº ºt tº bººt *
Thick - -: tº
ICKIleSS c; tºo r—$ocr—ºf ºp-4& ort ºf *{{ r—&cºlºr
cf Cutter. ºt - - - - tº S (N & S c & cols to to to
(N
Width of c: ºº ... ººº-º-º-º: fºbooyº-tº-lºv-ºo-ºoo lºc
Main Cutter. .5 S to coco st sº un uovo Vo Vo Vo tº rºco co on on on
Metal Ko t
between 3 tº Tºº-º-º-º-º-T ********
Flange and = - - ºg & S ºn 5 S to ºsº, sº st lf) lºr)
top of Üutter. to try
Metal round . . . tºo -ºo-ºo-ºº-ººr v-430 rºw-ºr-kW ºr ºf v-R}
hank. • - |- - - - - - - by tº & & el c, č, c, to try try
Diameter of &R -kº-Hº -(c.
v-tº- —º v-tº-ſeº v-tº-tºk v-4+
Shank of 5 ºvo No soo on Ö o el eq S tº in unºco co º
Blade. * * * * * * * * * * * *-* Y-4
Thickness ** T. -
º;. c r-ºllºo e-Pºº- * *::::::tºº-º-ºncºs t t
of Blade. oblº ºmit ºf
- . -98 -tºn -45 ~\ºn
P. a 9 o – to stºo o oso o – too o o, o, o o to
ange O
Blade. & O - - - - - - - tº tº S ºn tº el & c. to er) to
.ä tº . tººls ºc-ºn-tº-tº t-kcºlºr—&r-fºr-£cr-ºc tºº
Length of - to stºo co 2 s so o so, o o tour, o, o o
Boss. º
t; - - - - - - tº th en tº th eq to to to try to to sº-
e t;
Diameter | E on o ºbso o o so o o o too o o c \o o o o
of Boss. cº; – S S & & to to co “h ºf si <!- ur, ur, ºr, urºc vo wo
Diameter , ; \O F-Go ON O - N to St unvo tºod on O - to to st-
of Screw. Wºº- - - - - - - - - - - tº el & C S




Screw aperture—The length of the screw aperture
chant ship depends in a great measure on the configuration of the
screw propeller.
for a mer-
Dividing the diameter of the screw by 2.5 gives
ample room for the generality of propellers at present in use.
Screw shafting and thrust collars, pillow blocks, &c.—The pro-
peller shaft should have the same diameter as the cranked shaft.
The taper of the part for the screw boss should be about 1% inch
MARINE ENGINES. 527
for every 2 feet in length, the mode of fastening being a nut on the
end, with feather let into the shaft and boss. To find the area and
diameter of the lying shafting, divide the area of the cranked shaft
at the journals by I: 13, the quotient gives the area in Square inches;
and by a table of areas the diameter is easily found, always allowing
over rather than under, and even dimensions being preferred. The
thickness of the solid discs forged on the shaft is about one-third
the diameter of the shaft. A projection of 34 inch, and about
five-eighths of the diameter of the rest of the shaft, is left on, and
accurately fits into a recess bored out in the adjoining shaft, keeping
the shafts central the one with the other; the combined area of the
bolts for the coupling is found by multiplying the area of the shaft
by 35. A key is sometimes sunk into one of the discs and Secured
with screws, one-half of the key taking each disc; thus the shearing
strain is taken off the bolts, which can therefore be greatly reduced
in area. The thrust of the screw is received on a series of collars
accurately turned on the shaft. The combined area of the thrust
surface is found by multiplying the nominal horse-power of the
engine by 1:25, which gives the number of square inches of surface
in the whole series of collars, the length and depth of the collars
being one-eighth of the diameter of the shaft. The length of the
pillow blocks for the lying shaft is one and a half times the diameter
of the shaft. The length of the plate for the thrust block is about
six times the diameter of the shaft; it is well joggled at the ends
to prevent lateral movement.
Hand gear.—The rods must either be unnecessarily large in
diameter, or supported at the middle; the required strength very
rarely exceeds I inch in diameter. The joint pin is of the same
diameter as the ends of the rod, the diameter of the eye equals the
diameter of the pin multiplied by 2, and the depth of the eye equals
the diameter of the pin. This rule is for single joints, which should
always be used when convenient, because they are more easily
made; when double joints are used, the distance between the jaw
of the joint equals the pin's diameter, while one-half of the diameter
equals the thickness at the smallest part. Sometimes hollow rods
are adopted with advantage.
Bolts in cylinder cover.—The bolts vary in size from 5% to 1%
inch in diameter; the pitch from centre to centre of the holes is
generally about eight diameters. To find the combined area of
the bolts, multiply the area of the cylinder by the steam pressure,
528 MODERN STEAM PRACTICE.
divide the product by 2240, and then by the number of bolts
required, which gives the area of each bolt at the bottom of the
thread; adding the depth of the threads will give the full diameter
of the bolt. -
Turning gear.—The arrangement is generally a worm, working
in a wheel fitted to the end of the cranked shaft, the diameter of
the wheel being about 334 times the radius of the main crank, the
pitch of the teeth being 2% inches. The diameter of the worm
equals one-sixth of the diameter of the wheel.
Safety valve, waste-steam pipe, &c.—For every square foot of
fire-grate surface, allow 5 of a square inch, this multiplied by
the nominal horse-power gives the total area of the valves; then
dividing by the number of boilers gives the area of one valve for
each. Two safety valves are, however, better than one; and it
would appear that one-half of the area is required for each, but the
practice is to give two valves of the combined circumference of the
large one, on the ground that no more steam can escape with a
certain lift than the circumference of the valve will admit of. If
there were four boilers, of course there would be eight valves: the
main waste-steam pipe for these will be eight times the area of one
valve, or the combined area of all the valves; while the branch
pipes will be reduced in size according to the arrangement of the
valve chests. (See “Report on Safety Valves,” at p. 462.)
Copper steam pipes.—The steam pipes, blow-off, bilge, and waste-
water pipes, as used in the royal navy, are not less than % inch in
thickness; feed and injection pipes fºr inch, and waste-steam pipes
% inch in thickness. The diameters of the pipes depends on the
arrangement of the boilers, &c.; when four boilers are used, for
instance, the stop valves and branch pipes are one-fourth of the
area of the main steam pipe. The blow-off pipes are generally
about 3 inches in diameter. The main feed pipe should equal the
diameter of the feed pump, when plungers are used of the same
stroke as the steam piston; but when the pump is situated a long
way from the boilers, more may be adopted. The branch pipe and
non-return valve on the boiler is generally about 2% inches in
diameter. -
Ringston valves, blow-off and injection cocks. – The following
table gives the number and diameters generally adopted, but of
course these are regulated entirely by the arrangement of the
plping:—
MARINE ENGINES. 529

Horse- g BI ff St -> Iniection Stop:
power. Kingston. %. op Kingston. j Cocks. p;
No. inches. | No. inches. | No. inches. | No. inches.
6o | I | 3% | 2 || 3 || 1 || 5 || 2 || 3%
8o I 3 2 3 I 5 2 3%
IOO I 4. I 4. I 4. I 4
I5o I 3% I 3 I | 3% | 2 | 3%
2OO 2 4. 2 4. 2 4. 2 4.
3OO || 2 || 4 4 || 3 || 2 || 5 2 5
Flanges for copper pipes.—
Diameter of pipe Diameter of flange Diameter of pipe Diameter of flange
in inches in inches. in inches in inches.
1% F 4 7% = II
2 - 5 8 ~ II}%
2% F 5% 8% - I2
3 = 6 9 - I2 %
3% = 6% 9% - I3%
4. = 7% Io = 13%
4% == 8 IO% == I4%
5 == 8% II = 14%
5% F 9 II 7% - 15%
6 ~ 9% I2 == I5%
6% - IO I2% -: 16%
7 ~ Io94 I3 - I7
Sometimes for large diameters a raised ring is cast along with the
flange for bolting the pipes together, to which the copper pipe may
be securely rivetted; in other cases they are simply brazed on,
having a raised bead left on the flange to give a better hold.
LOCOMOTIVE ENGINES.
In this form of the steam engine, which has now advanced to a
high degree of perfection, the agency of steam is employed in the .
simplest form in which it is capable of producing power, namely,
by the mere excess of its pressure above that of the atmosphere.
The reason why the more economical process of condensation is
inapplicable in this case is obviously the increase of weight and
complexity attending the use of that process, both of which should
be avoided as much as possible in a machine which propels its own
weight at an immense velocity over a road composed of yielding
materials, all more or less liable to wear and tear from the effects of
momentum and friction. The qualifications for a perfect locomotive
are not easily reconcilable with each other, and demand the utmost
skill, combined with long experience, on the part of the maker.
We have said that lightness and simplicity of parts are desirable;
but these, on the other hand, must not interfere with the safety and
the economical working of the engine. Its stability must be
insured by the position of the wheels and the centre of gravity; and
every available means must be adopted for increasing, first, the
evaporative power of the boiler, and secondly, the mechanical effect
of the steam, without unduly increasing the weight and cost of the
apparatus. It is evident that any increase in the economical work-
ing of the locomotive effects a twofold saving, namely, in the cost
of the fuel and in the weight to be carried. Hence the steam is
worked at a very high pressure (about I 50 lbs. above the atmos-
phere), and is cut off and expanded in the cylinder.
It is well understood that railways owe their origin to the
necessities of the trade in coal, and that the improvement of the
engine followed gradually upon the improvement on the road on
which it was constructed to run. Among the names most con-
spicuous for the introduction and improvement of the locomotive
engine stand those of James Watt and his assistant William Mur-
doch, Richard Trevethick, Mr. Blenkinsop of Leeds, the brothers
Chapman, Timothy Hackworth, and George Stephenson.
LOCOMOTIVE ENGINES. 53 I
Under this section we shall first treat of the Locomotive proper
and its Tender, as used on railways; and then notice various forms
of Engines used for traction or haulage of machinery and road
traffic, Portable Engines employed for driving agricultural ma-
chinery, Steam Rollers for roads, &c.
COMBUSTION IN THE LOCOMOTIVE.
THE STEAM BLAST-FIRE-BOX AND COMBUSTION CHAMBER.
The successful development of the locomotive engine has been
mainly due to the introduction of the steam blast, or an application
of part of the motive power for effecting a rapid and intense com-
bustion of the fuel in the fire box of the boiler. This is produced
by blowing the waste steam from the cylinders into the chimney,
thus causing a partial vacuum, which is filled up by the air rushing
through the fire box, carrying the flame and heated gases through
the small tubes placed in the body of the boiler. By this means
the water is exposed to a number of highly-heated surfaces; the
thinness of these tubes adding greatly to their effectiveness in pro-
ducing steam. The fire
box, however, is un-
doubtedly that part of
the boiler where the
water is boiled more
quickly, more especially
at the top. This is due
to the material of which
it is composed—namely,
copper—being a very
good conductor, keep-
ing quite free from in- Fig. 379.—Diagram showing the Mechanical Action of
crustation, and the Con- the Blast. &
centrated and intense ***.s.l...”.”
vertical heat, caused by
a due admixture of the oxygen of the atmosphere, forced in a
measure amongst the live fuel. The practical limit to be arrived
at is, that the blast must not be too powerful, so as to lift and
carry off the fuel through the tubes, and then up the chimney

532 - MODERN STEAM PRACTICE.
to waste—the power of the blast that is required depending greatly
on the quality of the fuel. , -
The mechanical action of the blast is very simple. The waste
steam from the cylinders is led into a pipe concentric with the
chimney. The end of the pipe should be quite
straight, so that the expanding steam may strike
equally on the sides of the chimney, as at E. E.;
and it is of the greatest importance that the
pipe should be placed exactly in the centre of
the chimney. It is evident that when the steam
is led through bent pipes, placed on each side of
the smoke box, that the blast is imperfect, owing
to the steam striking alternately on the sides of
the chimney. So it becomes imperative that the
blast pipe should be made quite straight at the
end; thus the expanding steam strikes equally
all round the chimney, producing a much better
result. The blast pipe should taper from the
Fig. 386–Disadvantage of under side upwards, and should be suddenly
Bem was re- contracted at the orifice. Sometimes various
A, Blast pipes. B, Chimney. º te e -
sizes of nozzle or top pieces are provided; they
are generally made of copper, and secured to the cast-iron pipe with
a set screw. It is likewise preferable to braze a ring of brass on
the top, and turn it out correctly to size, thus providing -
a smooth and accurate aperture for the escape of the
Steam. - -
When the engine is not in motion a separate plug
valve is used, which is fitted inside of the chimney with
a pipe connection, communicating with the boiler. By
this means the fire can be urged by simply blowing
steam up the chimney directly from the boiler, inde-
pendently of the blast pipe. Of course this separate
valve is only used as a means of creating a circuit rº-r-
when the engine is not in motion, or in the act of of Blast Orifice.
raising steam quickly when the fire is kindled, a few º: -
pounds of steam pressure in the boiler being neces- -
sary, which is not considered as wasted when used for this pur-
pose. -
In order to still further increase the combustion of the fuel in
the fire box when the engine is in motion, various mechanical


LOCOMOTIVE ENGINES. 533
contrivances have been tried, and none with better results than
independent steam jets fitted to the fire box, forcibly inducting air
by steam pressure amongst the incandescent fuel. With this object
in view, the front and back or sides of the fire box are fitted with a
row of tubes, placed at a convenient height above the fire bars. A
steam pipe is fitted at the front, side, and back of the fire box,
having a nozzle connected with each hollow stay or tube, the
apertures being ºr inch in diameter. A vertical pipe is fitted to
this steam pipe, running to the top of the outside of the fire box,
having a plug tap for regulating the supply of the steam. It has
been proved by experiment that this contrivance greatly prevents
smoke nuisance when coal alone is used, and effects a material
saving in fuel. A much simpler plan, however, has been success-
fully adopted in coal-burning engines fitted with the ordinary fire
box: it consists of a plate, easily removed, fitted to the aperture
or fire door, and which is inclined downwards. By this means the
current of air entering by the fire-door aperture passes downwards,
instead of taking the direct course through the tubes, thus meeting
the flame and heated gases, and providing the necessary oxygen to
effect complete combustion.
The ordinary fire box of the locomotive-engine boiler has been
modified in various ways to effect a thorough combustion of the
fuel, and likewise to prevent smoke nuisance when coal is used.
All of the following schemes depend more or less on a free admis-
sion of air, with or without the use of a separate combustion cham-
ber, in connection with the ordinary fire box. In land-engine
boilers the air is admitted beyond the fuel, through apertures formed
in the bridge at the back of the fire bars. Mostly all the mechani-
cal contrivances introduced in the locomotive boiler aim at attain-
ing the above objects by similar methods, namely, dividing the fire
box by means of water spaces, formed of the same material as the
fire box, to which latter air is admitted as in the ordinary land
boiler.
The first example we will notice has two sets of fire bars laid at
an inclination, having over them a hanging bridge, provided with
an air pipe at the top. This plan was introduced for burning coal
in combination with coke; the large grate was for the coal, and
the small one, or fore grate, for the coke. Coal alone was charged
on the hind grate, and Coke on the fore grate, the design being to
deflect the flame and heated gases by the hanging bridge over the
534.
MODERN STEAM PRACTICE.
incandescent coke, thereby consuming the smoke and gases. By
F
Fig. 382.-Combined Coke and Coal Fire Box, tried on the
. Liverpool and Manchester Railway.
A, Fire box. B B, Fire bars. C, Hanging bridge. D, Air pipe.
E, Dudy of boiler, showing tubes. F, Manhole. G, Furnace door.
the arrangement of in-
clined bars the coal gra-
vitated,
easily pushed forward,
to make room for fresh
charges.
correct in principle, as
the dead coal
always be pushed gra-
dually forward, and when
this is properly attended
to, smoke is greatly pre-
vented in all furnaces.
The proportion of fuel
used on the Liverpool
and Manchester Railway
was two-thirds coal and
or was more
This is quite
should
one-third coke.
Another example on the same railway
Fig. 383-Fire Box, arranged for Coal Burning, with Combustion
Chamber. Liverpool and Manchester Railway.
A, Fire box. B, Combustion chamber. C, Perforated pipe. D, De-
flecting plate. E, Body of boiler, showing tubes. F, Manhole.
G G, Dampers, H, Furnace door.
has been tried, giving
favourable results, the
fire box being ar-
ranged for burning
coal. In connection
with the ordinary fire
box a second combus-
tion chamber was in-
troduced, which was
divided from the fire
box by a vertical water
partition, containing a
number of short tubes
for the passage of the
flame and gases. Air
was admitted into the
Combustion chamber
through vertical per-
forated pipes carried
up from the bottom.
A deflecting plate was likewise fitted to the combustion chamber,



LOCOMOTIVE ENGINEs. 535
thus delaying, as it were, the passage of the gases through the tubes
in the body of the boiler, and which we believe gave very favour-
able results. Of course it is essential that the bottom of the com-
bustion chamber should be perfectly air tight, means being adopted
for regulating the supply of air into the chamber up the vertical
tubes.
Various other arrangements were tried on different railways,
amongst these step grates, designed so as to admit a plentiful
supply of air through the grate (Fig. 384). When the bars are
stepped, or laid on an inclination, the fireman arranges the fire so
that the live coal is al-
ways at the foot of the Á Å
incline, while the dead A / A
or fresh fuel is at the A /
top, near the fire door;
thus the gases evolved
pass over the incan-
descent fuel, and with
a due admixture of air
are more readily con-
sumed. This plan
works very well with
free open coal, but with
bituminous coal clinker
forms, stopping up the ſº Fig. 384.—Step Grate. ; :
space between the fire ***...*.***
bars, and consequently
burns them very soon. In some arrangements of step grates a
movable grate is placed at the foot of the stepped bars, which can
be readily opened for the removal of clinker and ashes.
Another plan (Fig. 385) was tried, providing a much larger area
of fire grate, burning the fuel more slowly, and giving a plentiful
supply of air through the grate, and through hollow stays on the
front and sides of the fire box, the fire box being divided up the
middle by a water space, and carried inside of the barrel of the
boiler to a considerable extent. By this means a large top surface
was obtained, with the advantage of having a combustion chamber
at the back, common to both furnaces. This plan, by careful alter-
nate firing, no doubt tended greatly to consume the smoke of
itself. A curtain plate has in some instances been added with

§
@
Fig. 385.-Long Fire Box. Longitudinal and Transverse Sections.
* Fire box, B, Combustion chamber. C, Tubes in the body of boiler. D, Smoke box and chimney. E, Manhole, F, Furnace door.


LOCOMOTIVE ENGINES. 537
advantage, which receives the full charge of air from the open door-
way, the air being distributed through a number of small holes in
the front of the curtain plate.
Other methods have been tried to effect complete combustion.
One method (Fig. 386) consists of a small fire box placed at the
back of an ordinary fire box; this plan is introduced for burning
coal and coke, the latter being placed in the large fire box. The
coal being consumed in the auxiliary fire box, the smoke and gases
\S-2)
E
Fig. 386–Auxiliary Fire Box. A, Small fire box, B, Fire box, c, Fire tile. D, Body of boiler
showing tubes. EE, Dampers. F, Furnace door.
evolved pass through small short tubes into the main fire box, and
are caused to make an upward direction through the interposition
of a fire tile, thus passing over the entire length of the incandescent
fuel in the main box before entering the small tubes in the body of
the boiler.
Another method was designed to burn coal alone. The fire
grate, as in a previous example, is large, and is divided by an
inclined water space into two compartments, having a separate
door, fire grate, ash pan, and damper for each; the largest grate
being at the back, near the foot plate. The flame and gases from
this fire box rise, and, being met by a fine current of air entering



§
4?
f
******** * * * * *
zºº X 2:77). Arºº
zºv ii.,’X.23°., ii.,’X, <s. 2"
*S*iº,” * S.J., z', Ş2%. º
*
Fig. 387.-Fire Box and Combustion Chamber, fitted with Fire-brick Tiles. Longitudinal and Transverse Sections. -
a A, Fire boxes. B B, Water spaces, c, Arch of brickwork. D, Combustion chamber, E, Tubes. FF, Furnace doors. G. Manhole, H H, Dampers.




LOCOMOTIVE ENGINES. t 539
the perforated fire door, pass through a perforated arch of brick-
work into the front chamber. In the second grate the coal is
burned slowly, the combustion being regulated by a careful admis-
sion of air through the damper. This arrangement also includes
a second combustion chamber fitted inside of the body of the boiler,
in which are placed perforated fire bricks at a convenient distance
from the tubes in the body of the boiler. These fire-brick tiles
receive and retain a portion of the heat when the fire is quite clear,
and give off a portion of the retained heat when the fire is green,
thus acting as equalizers of temperature. In some instances the
combustion chambers have no fire bricks placed inside, the flame
and gases from the fire box simply passing through short tubes
forming the division between the fire box and combustion chamber,
the latter being divided by a vertical water space. A door is fitted
underneath the combustion chamber for cleaning and repairs.
Inclined bars have also been used, in combination with a curved
diaphragm plate, fitted with tubes and a transverse water tube, the
E.
Fig. 388.-Inclined Fire Grate, A, Curved diaphragm in the fire box. B. Water tube. C, Tubes
in the body of boiler. D, Furnace door. E. E. Dampers.
latter deflecting the flame and gases (Fig. 388). The gases having
free passage through the tubes in the diaphragm, mix with the
fresh air admitted. This plan does not seem to have met the

54O MODERN STEAM PRACTICE.
designer's wish, owing, we have no doubt, to the excessive cooling
surface, and the restriction and obstruction of the top of the main
fire box, where the vertical heat is most beneficially utilized in the
production of steam. f
Another example of inclined bars, which differs materially from
the foregoing, and which has been successfully carried out, may be
noted. The fire box is divided by a longitudinal water space forming
two separate fire boxes, uniting in one at the tube plate (Fig. 389).
By this means the fires can be worked alternately, that is to say,
Fig. 389.-Inclined Grate, with Long Run. A, Fire box. B, Combustion chamber.
c, Tubes in the body of boiler. D, Furnace door.
when the one fire is bright the other is provided with fresh fuel,
which slides forward on the incandescent fuel. The smoke and
gases passing over the bright flame, and likewise meeting the flame
from the adjacent furnace, are by this means effectually consumed;
and it will be seen that the top surface of the fire box is better
adapted for the production of steam than that of the foregoing
example. There is a fire-brick lump introduced at the bottom of
the inclined bars, which acts as an equalizer by giving off its heat
during the act of firing, and adds to the efficiency of the boiler.
Indeed, many examples of boilers of all descriptions have been
found to be greatly improved by the introduction of these fire
bricks.

LOCOMOTIVE ENGINES. . 54. I
. . In another arrangement, with the view of giving greater length
to the run of the flame in the
fire box, a transverse water par- F
tition, and in some instances, a
fire-brick arch, was introduced,
secured to the tube plate below
the tubes, and inclining up-
wards, towards the furnace door
(Fig. 390). By this means the
flame and gases are retained for
a longer period in the fire box;
and to assist combustion air is
admitted through stay tubes
in the front of the fire box,
as well as through small holes
in the fire door. - E
Another plan having the same
object in view has been tried, in a, Fire box, B, Fire-brick arch. c. Tubes in the body
which the main difference con- of boiler. D, Air stay tubes. E, Damper. F, Man-
sists in the fire-brick arch being * * ****
made shorter than in the pre-
vious example. Some consider this an advantage, as the vertical
Fig. 390.-Fire Box fitted with Transverse Partition.
Fig. 39r.—Tubular Stays, with Slide; Transverse and Longitudinal Sections.
A, Fire box, B, Fire-brick arch, c, Tubes in the body of boiler. D. Air stay tubes, E, Furnace door.



542
MODERN STEAM PRACTICE.
flame acts on the crown of the fire box more beneficially. In
º
º
§
O
<!
C
N
%
ŽS$
C
º * zºrrº
i
|
;
|
CŞ a !
N
i
i
i
|
i
all these examples having stay
tubes placed in the wall of the .
fire box, it is necessary to fit
sliding bars so as to regulate
the supply of air necessary to
effect complete combustion
with the different kinds of
coal used, or to admit more
or less air as may be re-
quired with the same kind of
coal, owing to atmospherical
changes.
In some railways a long
elliptical fire box has been
adopted (Fig. 392), having a
fire-brick bridge at the back
similar to the Cornish boiler,
through which air is admitted
by a number of apertures.
There are also hanging water
spaces fitted to the crown
of the fire box for deflecting
and mixing the gases, thus
detaining the flame in its
passage to the tubes placed in
the body of the boiler. Stay
tubes are likewise placed in
these hanging bridges, which
greatly strengthen them, be-
sides affording free passage
for the flame and gases, and
which seem fully to meet the
views of the designer.
Another plan has merely a
long elliptical fire box, having
a diaphragm of fire brick
placed at the back of the fire
bars, the flame passing through
suitable openings left in the diaphragm. This plan has the advan-


A, Fire box.
t
Fig. 393—Long Fire Box and Combustion Chamber. End View and Longitudinal Section.
B, Diaphragm of brick, c, Combustion chamber. D, Tubes in the body of boiler, E, Damper for admitting air into the
combustion chamber. F, Furnace door. G, Manhole.

544 MODERN STEAM PRACTICE.
tage of a separate combustion chamber, to which air is admitted
through a damper placed at the bottom of the diaphragm.
Steam-inducted currents of air have been successfully adopted
for the prevention of smoke, the air being forced through stay tubes
placed on the side walls of the fire box, eight of these hollow
stays being placed on one side and seven on the opposite side.
By this arrangement the currents
r of air (proceeding from these stay
tubes) do not interfere with each
other, as would be the case were
the tubes placed exactly opposite
each other, when the current of
the one impinges against the cur-
/ rent of the other, whereas in the

F
B
—o- : arrangement shown the current
| passes across the whole width of
O # ===== 2-4 - the fire box. The air can be
U / \ inducted into the fire box at an
_2^ angle by merely inclining the stay
>— tubes, and the arrangement is
fitted with steam pipes and noz-
zles, or small jets, as has been

g == = already described. This plan has
Uſt-c ce many advantages, the principal
B = A ==He of which are, the easy mode of
|H== |E regulating the supply of air to
*- == =H- suit the requirements, and that
Sº there are no mechanical difficul-
ties in keeping the apparatus in
efficient working order.
- Steam highly superheated has
been blown over and through the coal in the fire box for the sup-
pression of smoke, and when this plan is carried out properly it has
been attended with success so far as the smoke is rendered nearly
invisible; but there can be no doubt that unless the steam is highly
heated, in combination with fine rapid streams of air passing through
the fire door, that the mere fact of blowing raw steam over or
through the fuel damps the fire, and consequently retards com-
bustion, rendering it both more expensive in fuel for the production
of steam, and keeping such apparatus in efficient working order.
Fig. 394.—Steam-inducted Currents of Air.
A, Fire box, B, Steam pipe and jets. cc, Tubes.
LOCOMOTIVE ENGINES. 545
It is evident that in all the foregoing examples the main
thing that has been studied is the utilization of the smoke and
gases in the production of steam, by a due admixture of air passing
into or inducted into the furnace or combustion chamber. It must
be borne in mind, however, that a little smoke may issue at the
top of the chimney with the most perfect arrangements, when the
engine is not working; but when the engine is in motion, the vapour,
erroneously termed steam, issuing from the blast pipe, completely
annihilates the smoke. This is easily explained: the vapour when
seen is of a snowy whiteness, and we all know that a little dirty
water can be made much clearer with a copious admixture of pure
water; the same with the smoke. It gets mixed up in the chimney
with the vapour from the blast pipe, and the latter absorbs the
smoke and becomes more or less coloured with the sooty particles.
Smoke nuisance at railway stations is of more importance to get
rid of. This is accomplished by turning on the blow pipe placed
in the chimney, the primary use of which is to urge the fire while
the engine is not working, supplying oxygen, so necessary for
combustion, by forming a partial vacuum in the chimney as already
described.
It is allowed by all that careful firing is the chief practical diffi-
culty to attend to in effecting the complete combustion of the gases
and the prevention of smoke. The fuel should be supplied at short
intervals, in small quantities, equally distributed. With inclined
grates the fuel is laid on near the fire door, and is fed on the grate
per se by gravitation; thus the stoker's duty is comparatively easy
compared with the ordinary kind of fire grate lying quite flat. In
fact, with inclined bars the continuous forward motion of the fuel
keeps the fire grate always covered, and is the nearest approach to
continuous firing with travelling fire grates, without the incon-
venience of such mechanical contrivances, not at all to be desired
in the locomotive engine, although for other purposes moving fire
grates answer admirably.
It is of primary importance that the fire box of a locomotive-
engine boiler should be so constructed as to allow of a copious
supply of air above the fuel for the combustion of the gases, and
that the air should freely mix with the gases to give the greatest
effect. To attain this object, length of fire box, breaking up of
the flames by the interposition of fire tiles, fire-brick arches, baffle
plates, and other similar contrivances, are effectual, all tending to
* 35
546 MODERN STEAM PRACTICE.
delay or lengthen the run of the flame and gases in the fire box
before entering the tubes in the body of the boiler. It must be
likewise borne in mind that the air should be admitted at a high
temperature to attain the greatest measure of economy; this has
been effected in a variety of ways. Some have placed an air
chamber in the smoke box, in connection with tubes carried along
to the fire box; by this means the air is heated before passing into
the combustion chamber. Others have placed tubes, carried from
the front of the smoke box through the water space in the boiler;
thus the air is partially heated before entering the fire box. This
plan slightly tends to reduce the temperature of the water in the
boiler, and consequently the steam pressure. Auxiliary furnaces
for heating the air, as likewise fire-brick tiles placed in the com-
bustion chamber, have been carried out with a measure of success.
A hot-air blast, promoted by the steam blast in the chimney,
is far more economical, and tends more to effect the complete
combustion of the smoke and gases, than simply admitting currents
of cold air, however finely they may be spread over the surface
of the incandescent fuel where the heat is the greatest. With
air inducted by Steam jets the air is partially heated in its passage
through the short tubes placed in the walls of the fire box;
and there can be little doubt that if the steam was superheated
before passing through the jets a greater measure of economy
would be the result. The tubes to carry out this plan may be
2 inches in diameter, and their combined area should give 4 inches
of tube area to every square foot of fire grate, which of course can
be reduced or regulated according to the requirements by means of
the sliding bars, worked by hand from the engine platform. This
plan of steam-inducted currents of air is simply a number of
miniature nozzled steam blast pipes, similar in action to the main
steam blast placed in the chimney; the action of the one is almost
identical with the action of the other, each having the power of
inducting the air into the fire box. The former, however, forces
the air in currents of more or less intensity across the fire box, as
may be required. Thus it is thoroughly mixed with the gases
immediately where it is wanted; and it is remarked that where the
fuel lies in the line of these currents it is scooped or grooved out—
a convincing proof that the admission of air freely above the fuel,
or even partially through it, is the one effectual way to cause
complete combustion.
LOCOMOTIVE ENGINES. 547
The practical working of the apparatus now claims our attention.
When a sufficient area of tubes is provided it is not necessary,
under ordinary circumstances, to turn on the steam jets while the
engine is running, as a sufficient quantity of air will be drawn into
the fire box through the tubes by the action of the main steam
blast placed in the chimney; but when the vapour issuing from
the chimney appears dense, it is evident that the combustion of
the smoke and gases is not perfect in the fire box, and the steam
inductor can then be turned on with advantage. In the same way,
when approaching stations, and the steam is turned off the engine,
combustion receives a check owing to the blast having ceased, and
although the fire is burning with great intensity, smoke may issue
at the chimney, which can be prevented by turning on the steam-
inducting current, thus providing the necessary oxygen for con-
suming the smoke in the fire box.
The problem for effectually utilizing coal in the locomotive-boiler
furnace—carrying out complete combustion, so far as practicable—
is thus solved by the free admixture of heated air with the smoke
and combustible gases, the air being inducted into the fire box at
or near the surface of the fuel.
THE BRITISH LOCOMOTIVE.
CONSTRUCTION OF THE BOILER AND BOILER MOUNTINGS.
In the practical construction of the locomotive boiler the fire
Öor is of the first importance. Its outside shell is made of iron,
and the inside shell or fire box proper of copper, or in some in-
stances of iron. The fire box proper is surrounded with a water
space, communicating freely with the other internal water spaces
in the boiler. The union between the fire box and the outside
shell at the bottom is effected by means of a wrought-iron frame of
a square section. This frame is drilled with holes to correspond
with the rivet holes in the plates, all of which are rivetted together
and made perfectly steam tight by caulking the edges of the plates.
Sometimes a U or other section formed of boiler plate is adopted,
as the long rivets which must be used with the solid form are liable
to leak. The flat sides of the fire box and outside shell, being
548 MODERN STEAM PRACTICE.
exposed to the full boiler pressure, are not of sufficient strength to
resist the stress; and as the strain is in opposite directions, screwed
stays are introduced, binding the inside and outside shells together.
These stays are generally made of copper, and are pitched closely
together; after being screwed hard into the holes tapped for their
i
-}:
|
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|
i
|
ºoz---"
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:
i
reception, their ends are rivetted over, thus materially increasing
their holding power. They are screwed for their entire length;
when so made it necessarily takes a long time to screw them into
the plates. The stays are sometimes turned down at the middle
(Fig. 397), making their diameter smaller in the middle than
at the ends, and so dispensing with the thread except at each end,



LOCOMOTIVE ENGINES. 549
and - giving elasticity to the stay. This to a slight extent may be
advisable, but it should be borne in mind that the middle part must
Fig. 396.-Plate of
a U form for the
bottom of Fire
Box.
A, Fire-box plate. - e . .
B, Outside fire-box Fig. 397.-Fire-box Stays.
plate. C, U piece. A A, Plates. B, Parallel stay. C, Curved stay. D D, Screwed parts.
be of sufficient strength to resist the direct pressure, and we
believe that the elasticity of stays in narrow water spaces is but of
little moment. The unequal expansion of the fire box, however,
over that of the outside shell must throw a greater bending stress on
the top stays than those at the bottom; the ends of the stays,
therefore, to meet the strains imposed, should be of larger diameter
than the middle of the stay, and the extra cost of their manufacture
is balanced by the ease and less time taken to screw them into the
plates. Of course the direct cohesive strength of all stays subjected
to tension is measured by the diameter of the stay at the bottom of
the thread, and when the threads are turned off to the diameter at
the middle of the stay, the cohesive strength remains the same,
while the elasticity is greatly improved. The top of the fire box
must necessarily be strengthened with a very different form of
stays, as it would not be convenient to connect it to the top of the
outside shell in the same manner as the sides, although in some
instances long screwed stays have been tapped through the top of
the outside fire box and the crown of the inside one. Therefore
the top is prevented from collapsing by means of solid bars of
wrought iron, placed on edge along the top of the fire box, with
projections forged on for resting on the edges of the plates
forming the fire box. The bearing surfaces, in some instances,
are merely the breadth of the bar iron; but as the power to
resist compression in copper is very low, about 3 tons per square
inch, it is obvious that the bearing surfaces should be made of
sufficient area to meet the requirements. These bars have bosses

§
.i
* * * * * * * * * *
;
sº
|
:
Nº.
=
#
|
É
ſºº
#º
Fig. 398. —Boiler, showing Stays. Longitudinal Section and Plan,
A. Fire box, B, Body of boiler, c, Hole for dome. D, Manhole. EE, Longitudinal stays. F, Stays between front and back of the outside shell of fire box.
- G, Beam stays on the top of fire box. - -- .






LOCOMOTIVE ENGINES. 55 I
forged on at short intervals, which are bored for the reception of
stay bolts passing through the top of the fire box, deep washers
Figs. 399, 4oo.—Stays for top of Fire Box.
A, Plate stay. B, Stay forged solid. c c, Palms.
being interposed between the plate and bottom of the bars, while
in some projections are left on the forging. By this means the
top plate of the fire box is drawn tightly up against the bottom of
the beams or stay bars, and a bearing is secured at short intervals
along the entire length of the stays. By this arrangement the
strain on the plate is not too great, otherwise the plate would be
drawn up, which these washers effectually prevent, and a free cir-
culation of the water under the stays is effected, preventing the
plate being injured by the intense heat. Sometimes palms are
forged on for rivetting to the outside shell of the fire box and body
of the boiler. -
. In some examples the stays are made of wrought-iron plates
rivetted together, and indented where the bolts pass through. As
a means of staying the top of the outside shell, vertical bars are
introduced, secured to the beams on the top of the fire box by a
joint and pin taking a lug forged on the beams, while the top end
is secured to a T iron bar rivetted to the shell, the pin for the joint
passing through the mid feather of the T iron. Longitudinal stays
secure the smoke-box tube plate and the outside shell of the fire
box, as shown in Fig. 398. - -
The next detail in connection with the fire box is the junction
of the apertures cut out in both of the shells to form the fire door-
way. This was formerly effected by means of a solid bar of iron
around the opening, which is generally elliptical, securely rivetted
between the inside and outside plates. This plan necessarily en-
tailed very long rivets, and sometimes gave great trouble owing to
leakage. To obviate that objection, as likewise to obtain a free

**.
552 MODERN STEAM PRACTICE.
water space at that part of the fire box, the junction between the
shells has been improved by the introduction of a distance piece
formed of plate iron, flanged for rivetting to the inside box, while
an angle iron is worked all round the mouth-piece on the outside,
being properly rivetted to it and to the outside shell. To form
Fig. 4or.—Fire-door Opening. Fig. 402.—Fire-door Opening.
A, Inside plate of fire box. B, Outside plate of A, Inside plate of fire box. B, Outside plate of shell
shell of fire box. C, Furnace doorway. of fire box. C, Furnace doorway. D, U piece.
the openings for flues between the fire box and combustion chamber,
where such a chamber exists, the distance pieces between the fire
box and the combustion chamber must be of a U section, of plate
iron, interposed between the plates of the fire box and chamber, as
in Fig. 402, so that they may be in contact all round with the water,
otherwise the intense heat of the fire box or chamber would burn
such portions of the distance pieces as were not thus protected.
The fire door is made of plate iron, hinged to the outside shell of
the fire box, and is provided with a latch for shutting it close.
There is a baffle plate fitted inside, which is kept apart from the
door with ferrules and rivets, forming an air space, thus protecting
the door from the intense heat of the furnace.
The next constructive detail with reference to the fire box is the
manner of securing better work and facility for cleansing at the
bottom corners. With this object part of the outside shell is cut


LOCOMOTIVE ENGINES. 553
out at the corners, and a thicker forged plate worked on, having a
raised boss with tapped hole for the reception of a sludge screwed
plug, which would be otherwise difficult to adjust. There can
be no doubt that these sludge taps placed at each corner give great
facility for cleansing these contracted water spaces from deposit by
means of a water hose.
On the top of the outside shell a short branch piece is worked,
made of plate iron, flanged for rivetting to the shell, and fitted with
an angle iron at the top. This aperture in the shell is to allow the
steam to enter the steam dome or receiver when so fitted, or for
the reception of the plate on which the safety valves are placed.
This plate also forms the manhole door, and can be taken off to
admit of inspecting the inside of the boiler. In working the plates
of the outside shell, the front and back ones are flanged for taking
the top and side plates; the flanged corners should have bold
curves, and should not be worked square, as that form greatly
distorts the fibre of the iron, and consequently weakens the strength
of the plate. Of course all these flanged plates must be drilled, or
punched by a hand machine termed a bear. All the rivetting up
should be executed between the outside and inside fire boxes, before
the holes are drilled through both shells for the reception of the
screwed stays already referred to.
It is necessary to fit an ash pan underneath the fire bars. The
use of this pan is chiefly to prevent the cinders and live coal
from falling on the line, more especially on viaducts which have a
flooring of timber, as in some cases bridges have caught fire from
the live coal falling from the fire grate. This ash pan is secured to
the outside shell, and is fitted with a damper for regulating the
supply of air to the furnace when the engine is running, or for
shutting off the supply when the engine is standing, as may be
required. In some instances dampers are fitted to the front and
back, more especially in countries subjected to great falls of snow.
This is very desirable when engines are run tender-first for a
considerable journey, in which case the front damper can be shut,
and the back one opened, for, with much snow on the line, if the
front damper was not closed the ash pan would get choked with
the snow. In this case the hind damper admits the air under-
neath the fire grate, but it of course cannot act so beneficially in
promoting a rush of air underneath the grate as the front damper.
With the engine running at a high speed the pressure of the air
554 MODERN STEAM PRACTICE.
against the moving surface provides a powerful blast, which, with
the front damper open, affords a very effectual means for supplying
air to the fire grate. , -
The fire bars of the locomotive boiler are formed of wrought iron
of a thin deep section, and are supported by a wrought-iron frame,
which should be fitted with hinges or otherwise, so that it can be
dropped easily for the removal of clinker. -
The shell of the boiler is of a cylindrical form; a ring of angle
iron is worked on at each end for rivetting it to the outside shell
of the fire box and front tube plate respectively. In some cases the
plates of the outside shell of the fire box are flanged, to which the
shell of the boiler is rivetted, thus
dispensing with the angle-iron
ring.
The longitudinal joints of the
shell are usually double rivetted,
and the circumferential joints single
rivetted; but others have single
rivetting for the longitudinal and
circumferential laps. The rivets are
34 inch in diameter, pitch 2 inches,
for plates from 3% to 3% inch,
while for thinner plates the pitch
is 134 inches, and for rivets +} inch
the pitch is 15% inch. The holes
are all punched, and in punching
they assume a conical form; the
Figs. 403, 404, 405.-Rivets. small ends being placed together,
a Rivet hole formed conical in the act of the rivet when properly filling the
punching. B, Countersunk holes. C, Joint tº;
spread out. hole becomes a double cone, which
greatly strengthens the rivetting
and stiffens the joints—converging the line of strain through the
plates. The rivet holes are sometimes countersunk, and when the
rivets are made accordingly the strength is greatly increased, for
should the head be destroyed by corrosion the countersink will
hold good. As the joints in single rivetting are liable to twist,
the plates are sometimes spread out, getting the line of strain more
directly through the line of plating.
There can be no doubt that the longitudinal seams ought to be
much stronger than the transverse ones. To attain this object
2 \
















LOCOMOTIVE ENGINES. 555
the plates are made to butt together, and fitted with strip iron
double rivetted, thus having four rows of rivets. A small piece is
worked on the ends of the strips in the inside, making them very
strong at that part, and much more easily caulked. The double-
rivetted welt joint, made of Lowmoor plate, is capable of bearing a
strain of nearly 9000 lbs. per square inch of sectional area, and as
the longitudinal seams have to bear a stress of about double the
other seams, the double-rivetted longitudinal joints are nearly equal
in strength to the other joints single rivetted, and in practice may
be taken at equal value. -
The plates for the shell are all planed on the edges, and ar
slightly bevelled for setting up, the caulking making them quite

| ~,
aſ –
S-7 G
Fig. 406.—Lap Joint.
A A, Exaggerated effect of caulking.
flat. Great care must be taken in this operation, as undoubtedly
the caulking has a tendency to buckle the plates, thus weakening
the joints. Scarf-welded joints have been successfully introduced.
The plates are planed on the surface to fit each other, and are then


--~
Fig. 407.--Scarf-welded Joint.
A, Scarf plates apart. B, Scarf complete.
heated on both sides, and hammered as in ordinary welds, very
little hammering being required. When the work is properly
executed, this is no doubt the strongest way of uniting boiler
plates; moreover, the reduction of weight and the non-liability
to leakage is greatly in favour of this plan in its application to
shells or other boilers.
The steam chest is a short round barrel, placed at the centre of
the top of shell or at the front near the chimney, and in some
556 MODERN STEAM PRACTICE.
instances on the top of the outside fire box. A short piece is
flanged and rivetted to the top of the fire box; on the top of this
piece an angle iron is worked, which is turned on the top surface.
[] miſ- [...]
i
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i
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;
i
:
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& Tº Tº
for jointing to the turned angle-iron surface on the steam chest,
the two flanges being bolted together, and these can be readily dis-
jointed, forming a manhole for inspecting the inside of the boiler.
When the steam chest is placed on the shell an angle iron is worked
on it at the bottom, and securely rivetted to it and the shell; on
the top of the steam chest a cast-iron plate, on which are the safety
valves, is fitted. This can be taken off at pleasure for inspecting
the stop valve and other parts of the boiler. In such an arrange- -
ment it is usual to fit a manhole door on the top of the fire box, on
which the steam whistles may be placed.





LOCOMOTIVE ENGINES. 557
On all the parts of the shell where the check-valve boxes for the
feed pipes are fitted, forged plates having raised bosses are securely
rivetted to the shell. By this means the joints for the check-valve
boxes are made on turned surfaces, instead of fitting the flanges to
the curved plates of the shell—a plan which secures good joints,
and greatly facilitates the jointing and disjointing of all the valve
boxes, plug taps, &c.
The brass tubes are generally 2 inches in diameter and from
IO feet to I2 feet in length, with a thickness of from 9 to 14
wire gauge, or nearly 96 inch thick. The arrangèment of the tubes
is of the highest importance. Sufficient room should be given for
Fig. 409.—Arrangement of Tubes.
A, Free circulation at sides. B B, Contracted at sides.
the free circulation of the water. It is obvious that with a large
water space between the tubes and the side of the shell of the
boiler, the water has a better circulation than when the tubes are
packed too closely; and that small water spaces between the tubes,
in combination with a mass of tubes, tends greatly to decrease the
evaporative power of the heating surface, as delineated in the circle
having the largest number of tubes. The holes in the front plate of
the fire box, and tube plate in the front of the shell, being all set out
accurately, arranged zigzag or triangular and not above one another,
as in marine boilers, having water spaces between from 3% inch or
5% to 1 inch, are then drilled for the reception of the tubes. These
are driven tightly in, and then expanded with a tool for the purpose;
the ends are then rivetted over, making them perfectly steam tight.
They are rendered secure by driving in wrought-iron ferrules at the
fire-box end, while every six or so of the tubes at the front end
are likewise ferruled; but some are not so, giving free passage for
the soot and small cinders. Thus the tubes, being firmly held at
the ends, act as stays, tending to prevent the tube plates being
forced outwards by the pressure of the steam. However, long
tie stays must be placed above the tubes, running the entire length

558 MoDERN STEAM PRACTICE.
of the boiler, between the back plate of the fire box and the tube
plate in front of the shell. Gusset stays are sometimes applied in
the angles of the fire-box shell, uniting the flat plates with the
cylindrical portion of the boiler; thus the through tie bars may be
dispensed with—those gusset plates being likewise fitted to the
tube plate in the front of the shell.
The smoke bor is usually made cylindrical. It is formed of
34-inch plate iron, rivetted to the flanged tube plate on the
:23 shell, this plate being carried
* * down for securing the back
flanges of the cylinders. The
front plate of the smoke
box may be flanged, or an
angle iron worked at the
corner for rivetting to the
shell of the smoke box.
The door for the smoke
box should be of sufficient
diameter to admit of the
tubes being angled with the
holes drilled for their recep-
tion; the hole in the plate
is turned out with a slight
bevel, and the door is accur-
ately turned to fit, an angle
sº sº, sº tº as sº * * * * iron being worked inside to
Fig. 4ro.—Smoke-box Door. stiffen the plate, and prevent
'A, Smoke-box door. B B, Hinge plates. c, Handle. it buckling with the heat;
D D D, Sliding bolts. E, Inside plate. tº ſº tº tº
an inside plate is likewise
fitted to the door for its protection. The door is secured in its
place with generally three sliding bolts, jointed to a central disc
plate, worked by a handle placed outside of the door, the door being
hinged to the end plate of the smoke box, with one long bolt taking
both of the hinge plates and studs secured to the smoke box.
The chimney is usually made single, but at times an inside tube
is introduced to prevent condensation and preserve the full force of
the blast. The tube generally tapers from the bottom upwards;
thus the steam from the blast pipe expands in its upward course,
consequently the vapour and smoke issuing from the top are not of
such density as at the orifice of the blast pipe, where the chimney

LOCOMOTIVE ENGINES. 559
is contracted. The inside of the smoke pipe should be quite plain;
the rivet heads should be countersunk into the plate covering the
joints, so that there will not be any obstruction to the passage of
the steam and smoke. The outside covering can of course be
rivetted in the usual manner; it is secured to the top of the smoke
box by a short flanged plate rivetted to the chimney, and bolted
to the smoke-box shell. At one time the top of the chimney was
ornamented with a finely curved cap made of copper, which was
kept bright, while others were formed of a wrought-iron plate, and
as such presented a very neat appearance; but as the top of the
chimney, when properly formed, stimulates the draught passing
through the fire box
when the engine is run-
ning fast, it is of import-
ance to form the top
with this object chiefly
in view ; and we cer-
tainly consider the
plain top, cut quite hori-
tº - Figs. 411, 412,413.-Chimney Tops.
- zontally, 1S the best form A, Curved top. B, Plain top. c, Curved top with part bevelled off.
that can be adopted,
slicing the air, as it were, cleanly, while with the curved form the air
impinging against the top is thrown downwards. Some have
bevelled the top backwards to facilitate the escape of the vapour and
smoke, and assist the draught, never taking into consideration that
when so formed, with the engine running backwards, a downward
current of air passes into the chimney, tending to impede the
draught; moreover, a strong side wind must necessarily affect the
draught with such a form.
The ash pan is made of plate iron 34 inch in thickness, framed
with angle iron, having a band of flat iron at the top. The depth
should be at least from 9 to IO inches, so as to hold a large
quantity of ashes, giving a sufficient air space above the ashes for
the admission of air underneath the furnace bars. It should fit
closely to the bottom of the fire box, otherwise the draught will be
impaired. The ash pan is sometimes fitted with dampers at the
front and back, as already explained, the damper being a flat plate
hinged at the top, and closing accurately the aperture when shut.
It is fitted with a lever and rod, by which it is opened or shut from
the platform; and can be used either to stop the draught by shutting

560 MODERN STEAM PRACTICE.
it completely, or nicely to adjust the quantity of air required under-
neath the grate. It is generally bolted or rivetted to the fire box
with straps for that purpose, and sometimes a small door is fitted
at the bottom to allow the ashes to fall down, thus conveniently
clearing the ash pan. A disc damper should be placed at the crown
of the smoke box to damp the fire effectually at that end. Venetian
dampers have been successfully applied, covering the ends of the
tubes in the smoke box, while some are contented with placing a
plate on the top of the chimney, which must be removed before
starting the engine. Undoubtedly the locomotive boiler furnace
should be damped at both ends when required, which is practically
carried into effect with the damper on the ash pan, and otherwise
in the smoke box or chimney.
The fire bars are of wrought iron from 5% to 1% inch in thickness;
the latter size is thinned at the bottom edge to about one-half of the
thickness. The general thickness adopted is from 56 to 34 inch,
with equal air spaces between them; this thickness being found best
in practice, as the bars are not so liable to twist, being more easily
kept cool. They should not be thinned when of this thickness,
but merely chamfered on the lower edge for the free admission of
air. For bars of 3 feet long and under, the depth varies from
3 to 4% inches; when of greater length they must be made in two
lengths, or supported at the middle with a cross bar. The bars are
cut and flattened at the end, with raised pieces forged on the sides,
so that they may be kept apart the necessary width for the admission
of air. The frame on which the bars rest is made of wrought iron,
1 by 1% inch deep, fitted all round the bottom of the fire box quite
close up to the rivet heads, and is held up with studs rivetted to
the fire box. Some place angle iron for supporting the bars,
which is rivetted to the fire box, and notched for the bars, by
this means keeping them apart without any forged projections on
the bars. When the bars are not put in one by one it is preferable
to hinge the whole grate, so that they may be dropped down entire,
as sometimes a few of the bars may be choked up with clinker or
impure matter from the fuel, and consequently if only a few were
hinged there might be a difficulty in dropping them.
We give a very good plan adapted for a double fire grate (Fig. 414).
The frames for holding the bars are slightly inclined, and rest on
projections rivetted to the fire box, and at the bottom end projections
are forged on the frames, which rest on projections forged on a bar
LocoMotive ENGINEs. 561.
*ºrº
* * * * * * * * : s , , ss
• * * * * * * *
º
*
*
&
Fig. 414.—Arrangement for Lowering the Fire Bars.
A, Fire box, B, Foot plate. C, Fire bars. D, Handle, rod, lever, &c. E, Ash pan.

- 36
562 MODERN STEAM PRACTICE.
running across the bottom of the fire box. This bar is made to slide
in suitable hanging pieces rivetted to the fire box, and at one end
there is a bell-crank lever having a rod and handle passing up to
the foot plate. When the bars require to be dropped the handle
is pulled up, and the pin on the end of the bar having been removed
it is drawn past the projections, and then the frames and bars fall
down. In this arrangement there are no hinges, and consequently
less liability to derangement. *
The brackets for supporting the boiler from the frame are gene-
rally made of plate and angle iron; at the smoke-box end and
body of the boiler, these brackets are rivetted to the frame, but at
the fire-box end the boiler is free to expand, sliding as it were
on the frame, yet firmly held thereto with bolts and nuts. The
bracket on the body of the boiler should not be made too rigid,
otherwise a severe strain would be thrown on the framing. The
plate bracket should be of a certain elasticity, to yield to the
expansion and contraction of the boiler. Unless this is provided
for, rupture may take place in the seams of the boiler. Sometimes
the boiler merely rests on this bracket, without being rivetted.
The brackets for the smoke-box end are simply extensions of the
tube and front plate, stiffened with angle iron, when the arrange-
ment of the machinery will admit of this; and in some there is
simply an angle iron rivetted to the smoke box, which is carried
down square at the sides, with an inverted angle iron rivetted to
the frame, and the two secured with bolts and nuts. The bracket
for the body of the boiler is of plate iron, secured to the under side
of the boiler and to the main framing; while for the fire box some
provision must be made for the expansion and contraction of the
boiler.
To prevent radiation and condensation of the steam in the boiler
it is covered with a non-conducting material, consisting of felt
wrapped round in several plies, having wood-lagging over all, con-
sisting of pine battens grooved and tongued, and secured to wooden
rings which are fastened to the boiler with screws; over the lagging
is placed sheet iron, which is banded at the transverse joints with
hoops of the same material, to which lugs are rivetted at the ends,
which are bored out and tapped for the tightening-up screw, thus
holding the felt and covering boards firmly in position, the parts
lagged being the body of the boiler, the top and sides of the
outside shell of the fire box, and the dome.
LOCOMOTIVE ENGINES. 563
The steam pipe inside of the boiler is made of copper about
% inch in thickness, having brass flanges soldered thereto for
making the joints, the flanges being sometimes grooved and filletted.
The pipe is held up with straps rivetted to the crown of the boiler
where necessary, and in most locomotives is carried up inside of the
dome, with the object of getting the steam made as dry as possible;
while with some arrangements there is no dome, the steam pipe
traversing the entire length of the boiler, the pipe having a number
of slits cut out in it. By this means the steam is taken into the
pipe immediately over the parts where it is generated; thus drier
steam is obtained. However, the general practice is to provide
a steam dome, having the pipe carried to the top, on which is fitted
the regulators, made of brass. Circular-disc regulators have been
adopted, rotating on a centre pin: this plan is
not much in use, as the surface wears un-
equally, the circumference of the disc plate
having a greater travel than the centre, con-
sequently more wear must occur at the edges.
Flat gridiron valves sliding over ports are
very generally adopted, fitted to the top of the
steam pipe inside of the dome, or placed directly
on the cylinders in the smoke box; the former
position is to be preferred, as with the latter
there is a constant pressure of the steam in
the pipes in the smoke box, tending to leak-
age. The fewer joints to keep tight in so
complicated a machine as the locomotive engine
the better. An improvement on the former B
plan consists in placing the regulator in a cast- Fig. 4:5–Gridiron Regulator.
iron box, bolted to the tube plate on the end *.cº. ... B, Grid-
of the steam pipe. By this means, when the ſº
engine is standing or the valve closed, the pipes in the smoke box are
relieved from the pressure; the rod for working the valve passes
through the inside pipe, and is actuated by a lever directly, the rod
being provided with a stuffing box fitted to the back plate of the shell
of the fire box. There is no steam dome in this example, and the
pipe is slotted with a number of apertures for taking away the steam
immediately over the parts where it is generated. However, the ar-
rangement suits equally well when a steam dome is fitted, having a
pipe at right angles for taking the steam from the top of the dome.


564 MODERN STEAM PRACTICE.
When the engine is standing, or the valve shut, the pipe is not sub-
jected to pressure, the only part subjected to pressure being the cast-
iron box. Double-beat valves have been arranged in a similar way to
the foregoing, having a screwed spindle for opening the valve, which
is actuated by a lever, handle and rod; the latter passes through
the centre of the steam pipe, and has a boss forged on it, which
has a Square hole. This receives a square part on
GH the spindle, sliding freely thereon; thus by turning
the handle the valves are opened and shut by the
screw cut at the end of the valve spindle. Another
method for direct-action regulators has a brass
circular box bolted to the back
of the fire-box shell, having a
circular cylindrical valve with a
conical seat at the end. The
– handle for actuating the valve
works in a spiral segment; the
handle being turned presses
against the side of the spiral
5
Fig. 416.--Double-beat Valve Regulator.
a, Valve chest. B, Double-beat valve. C, Screw on the spindle. D, Rod. E, Stuſſing box.
F, Regulator halidle.
segment, thus pushing the valve firmly against the seat; and on
being turned the other way the handle bears on the opposite side
of the segment, thereby opening the valve. With this arrange-
ment the inside steam pipe is subjected to the steam pressure,
tending to collapse it, that is to say, when the valve is shut. '
Double-beat valves arranged vertically are very generally used







LOCOMOTIVE ENGINES. 565
for the regulator; a strong cast-iron pipe is fitted to the steam
pipe, at the top of which a & - •
short piece is bolted for the H.
seating, and is firmly held --
}* * s
º
* : *
** F.3 ° --
in position with a strap, fitted |F).
to some convenient part of ºf EºN WE
the boiler; the pipe having |EFA tº
an expansion joint with stuf- #3) 2. \
fing box and gland at the | i. i.i.H.
bottom, for taking the hori- O
zontal copper pipe passing
along to the cylinders; thus
it can freely expand and Con-
tract without straining it.
The valve has a jointed rod
passing downwards to a le-
ver, which is keyed on the
shaft which passes through
the stuffing box on the end
plate of the fire-box shell,
the other end being sup-
ported with a boss cast on
the vertical pipe, and which
is bored out for its recep-
tion, a plain handle with
quadrant and set screw or
pin, for holding the valve up,
being placed at the outer end
of the shaft. -
The steam pipes in the
smoke box when made of
copper are about #, inch in
thickness; this is to allow
for the wear by the action
of the cinders. Sometimes
cast-iron pipes are substi-
tuted, and should be at least
5% inch in thickness, but
copper pipes are preferable, -
as the cast iron is liable to deteriorate from corrosion. As the
* * * * * * *
E
i
;
§
|
i
:

566 MODERN STEAM PRACTICE.
steam pipes in the smoke box are made of a bent form, it is not
necessary to provide any expansion joints; they are simply bolted
to a cast-iron branch fitted to the end of the tube plate, while at
the bottom end they are bolted to flanges cast on the cylinder
branch pieces. -> -
The blast pipe is generally made of cast iron, although sometimes
copper is used. It tapers in a gradual manner from the bottom
upwards. The best arrangement for inside
cylinders is one central pipe taking both of
the cylinders; it is usual to make the nozzle
of copper, which is secured to the top of
the cast-iron pipe with set screws. The
blast orifice should be quite smooth and
true; sometimes a brass ring is brazed on
the copper piece, or in Some a flange is se-
cured to the top of the pipe, and which is
Fig. 418.-Blast Pipe. Fig. 419.-Blast-pipe Orifice.
A, Blast pipe. B, Copper nozzle. A, Blast pipe. B, Flange, c, Hole bored out.
accurately bored out, so that there is a true and smooth surface for
the exit of the steam. It is of the utmost importance that the
blast orifice should be exactly in the centre of the chimney, blowing
the waste steam in a true vertical line; otherwise, should the waste
steam be blown against one side of the chimney it tends to impair
the exhaust, or partial vacuum, formed in the smoke box, and con-
sequently the draught through the boiler is slightly affected.
With outside-cylinder arrangements there is a blast pipe fitted
to each cylinder, meeting a branch piece at the top, which should
be quite straight for a short length vertically, otherwise the waste

LOCOMOTIVE ENGINEs. 567
steam from the bent pipes, curved to the sides of the smoke box,
will strike alternately on each side of the chimney, thus tending to
impair the draught through the fire grate and tubes placed in the
body of the boiler. In modern practice the blast orifice is a con-
siderable distance from the crown of the smoke box, just above the
top row of tubes: this has been found, with a wide spreading
funnel, or even with the usual taper, to create a superior draught
with a wider blast orifice, and is now commonly adopted.
There are generally two safety valves provided, placed on the top
of the steam dome, or on the manhole door situated on the top of
* * * * * * * * * * * * * *
2
%
ſ/
V
%
ſ
S
#—s. sº
*** * * * * * * * * * - - - - - - - - - - - - - - - º Aº, - * * * * * * * * * * * * * * * * - 4 - > - - - - - -
Fig. 420.-Safety Valves.
A, Dome. B, Cast-iron top for dome. C, Safety valves and seats. D, Lever. E., Stud for lever.
the fire-box shell. In the latter case a third valve may be fitted on
the top of the steam dome on the boiler, which is loaded directly
by means of a spiral spring placed on the top of the valve, having
two screwed columns or long stud bolts and nuts, taking a cross
bar which is placed on the top of the spring, and then screwed
down with the nuts until a certain and constant pressure on the








568 MODERN STEAM PRACTICE.
valves is obtained to resist the internal steam pressure. The other
safety valves are fitted with a lever and spring, which can be
regulated with a thumb screw to any pressure within range of the
Salter balance fitted with a helical spring, graduated to indicate
I lb., 5 lbs., &c., intervals of pressure; the spring is so adjusted
that a weight of I lb. attached to the balance would move the index
to I lb. as marked by the scale, the lever being so proportioned to suit
the area of the valve that a pressure of I lb. indicated by the scale
gives I lb. per square inch on the valve. The valves formerly much
used were conical spindle ones, with the bearing surface bevelled to an
angle of 30°. Some makers round the point
of contact on the valve, and although they
are not so liable to gag in locomotive prac-
tice Owing to their being frequently opened,
still they are objectionable, as they do not
Fig. 421. —Safety valve with point give so free a passage for the steam as the
of contact rounded.—A, Valve seat. § t tº
B, Valve. C C, Part rounded. flat-disc valve or the spherical one. The
- former has been arranged in a variety of
ways; one good form being an inverted cone with a flange at
the base which bears on the seating, the two surfaces being accur-
ately turned, and then ground together to make them perfectly
steam tight, the thrust pin on the lever bearing on the internal
apex of the cone, the valve
being cast hollow for that pur-
pose. The annular flat-sur-
face valve (Fig. 422) differs
materially from the ordinary
ones and from the foregoing,
inasmuch as the steam, be-
sides escaping round the valve
§
§
º
Fig. 422.-Annular Safety Valve. when raised, escapes also
A, Valve. B, Seat for valve. C, Spindle. D. Lever. .
E. Stud for lever. through an annular aperture
- - cast in the valve, thus posses-
sing the advantage of two edges, instead of one edge as in the ordinary
disc valves, for the steam to escape by, and consequently with a given
diameter, and the lift of the valves of both kinds being equal, the
annular valve will pass about double the quantity of steam, while
the area exposed to the steam pressure in the boiler being much
less, the holding-down load is reduced in proportion. The spindle
is hollowed out for the reception of the thrust pin, as in the previous







LOCOMOTIVE ENGINES.
569
example, and in both examples the valves are frictionless in the
act of lifting, which is the main thing to be studied in safety-valve
arrangements.
valve has been designed, fitted
with a lever and spring balance.
All the bearings are of the ball-
and-socket description; thus free-
dom of action is secured, while
the tendency to corrode or stick
is rendered nil. The ball is gen-
erally cast in gun metal, and the
seating of brass. This valve has
the advantage that the ball may
be turned into any position to
suit the wear.
Various forms of direct spring-
loaded valves have been success-
fully adopted; one form consist-
ing of a large plate 12 inches in
diameter, loaded with a number
formly around the centre of the
springs resting in cups on the valve,
while the large flat surface at the
top bearing on the covering plate
renders the action quite true, and
as there are no spindles connected
to the outside springs there is no
liability to jam. So large a valve
is not really required for the loco-
motive boiler; but the principle
can be carried out with one small
valve having a central volute
spring.
Although there may be a differ-
ence of opinion as to the propor-
tion which the working pressure
of a boiler should bear to its ab-
To carry this more fully into effect the ball safety
Fig. 423.-Ball Safety Valve with Lever and Balance.
B, Seat for valve. c, Lever.
E, Salter spring balance.
A, Ball valve.
D, Stud.
of volute springs, arranged uni-
valve, the bearing surface of the
i
Sº
2
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º
º
AEP –st-T º
N-
%2.
fi
ă§
S.
Q.
;ºº
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;
§
§
º
fi
s
Sº
N
§§%
%2
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Z
ſº
à
Fig. 424.—Safety Valve directly loaded with Springs.
A, Plate valve. B, Seat for valve. C, Covering
plate. D D, Screw studs for adjusting the springs.
E E, Volute springs. F, Lever, G, Spindle.
solute strength, it will doubtless be admitted that the greater the cer-
tainty of a safety valve opening at the required pressure, and the
greater its range of lift under a given excess of pressure, the less will
























57O MODERN STEAM PRACTICE.
be the excess of strength required. If a perfect safety valve could be
made—that is, one which will absolutely prevent the boiler to which
it was applied from being subjected to a higher pressure than that
to which the valve was adjusted—it would of course be conducive
I
Yº...... -------Y Section at YY.
Š
<$ -
s: §º: āş Ø
- §§§ §§§
Z. . . . . . . . Fºllſ' SN. " " " ' " " " " ' "Z (ºg) ºf hº
* sº
Section att Z.Z.
** * N
| : N
A. A. S((*)
º
§§§§
Ş
#
Fig. 425.—Pillar with Safety Valves and Central Spiral Spring.
A A, Pillar. B B, Central part for spring. C C, Valves. D, Crosshead. E, Hand lever, F, Spring.
G, Screwed spindle and nuts. H, Shackle. I I, Plate screwed into the top of pillar.
in a high degree both to the safety and durability of such boiler.
The following arrangement goes far to meet the requirements, the
only friction while lifting being from the valves themselves, and
which may be entirely avoided by the substitution of spherical














LOCOMOTIVE ENGINES. 571
valves. A pillar consisting of one casting, which answers the pur-
pose of the manhole door, is bored out at the top for the reception
of the valve seatings, two in number. The valves are loaded by
the spring placed in the central box, which is secured to a crosshead
taking both of the valves, the crosshead being elongated to serve
as a handle, to enable the driver or engineman to ascertain the
working condition of the valves. The spring is made of sufficient
strength to resist the pressure on both valves, and is adjusted by
the nut on the top of the crosshead. The shoulder on the underside
of the crosshead should be drawn hard up when the maximum load
is put upon the valve. To prevent the valves being blown away
in the event of the spring breaking, the shackle fitted to the lower
part of the crosshead for taking the spring has two projections
formed on it, projecting beyond the slot in the cap which is screwed
into the top of the pillars. The valves, being equally loaded and
of equal size, will be simultaneously lifted with the cross bar when
the steam pressure exceeds the proper limit, and the spring will be
elongated through a range equal to the lift of the valves, and no
more; so that, except when the engineman is testing the action of
the valves, there is no movement in the joints of the apparatus, and
therefore no friction. A spring of 56-inch round steel, and about
seven coils, is sufficiently strong to load two 3-inch valves to 80 lbs.
pressure per square inch, and in order to load them to this extent
the spring will have to be stretched about 134 inch, or 218 inch for
each successive increase of IO lbs. pressure per square inch. In the
example we have delineated the spring is of smaller diameter than
the above, and consequently lengthened to make up for the reduc-
tion in diameter. Another arrangement shows the application
of the volute spring, which is placed in a shallow well in the man-
hole cover and adjusted by four nuts, which force down a cover plate
placed on the top of the spring, and so compress the spring until the
requisite pressure is obtained. Packings are then fitted between
the cover plate and the manhole lid to prevent any extra pressure
being applied. It is evident that, under any form, the valves cannot
be easily tampered with; and a brass funnel may be placed over
them in the ordinary way. Several of these valves have been at
work, proving highly satisfactory. They were found to be very
sensitive, having such freedom of action as to get into a state of
vibration, producing in some cases a musical note when at the point
of blowing off; and they allow the steam to blow off more freely
t
572 - MODERN STEAM PRACTICE.
than other safety valves under a given excess of pressure. The
arrangement of the two valves under one lever is not new, but the
E|)
§||º]]|| I) §lſº Z, -
§llº!||N- Niště
§§§ ſº §NAM
|||||||||||||||N
U/ §
JE
Dº)
Fig. 426.-Safety-valve Box with Central Volute Spring.
A A, Valve seat. B B, Centre part for spring. C C, Valves. D, Crosshead. E, Hand lever.
F F, Plate with bolts for holding down the spring.
object in the above arrangement is to increase the liſt of the
valves, making it equal to the full extension of the spring, giving
great freedom for the discharge of the steam, and preventing it
rising above a dangerous pressure, and also to dispense with
the spring balance. The point of attachment of the spring is rather
below the level of the points bearing on the valves, so that in the
event of one valve lifting before the other it is overloaded, the
other being proportionately relieved, thus tending to secure their
simultaneous action. There is no scale attached; the spring is
adjusted originally to the maximum pressure intended by measuring
the amount of elongation or compression under a given load, and
by adjusting the screw to within 2 or 3 per cent. of the compression
or elongation produced by the desired pressure. The valves are
tested previous to being used, by comparing them with a pressure
gauge attached to the boiler.
The zwasſe-steam funnel for covering the safety valves is made of
thin brass, and is kept highly polished, giving the engine a smart
appearance. It takes in both of the valves, delivering the waste
steam at sufficient height so as not to interfere with the free vision
of the driver. It is made tapering from the bottom upwards,
ending in a plain circular moulding at the top, and spreading out







































LOCOMOTIVE ENGINES. 573
at the bottom with bold curves to suit the curve of the fire box;
at the top it is suddenly contracted with a funnel-shaped piece
brazed thereto, having a hole of only sufficient diameter for the
escape of the steam, a plate being brazed at the top embracing the
outlet and extreme diameter of the moulding. All these funnels
“should be as plain as possible, as they are more easily kept clean,
no corners being left with beads or small mouldings for dust to
collect. They serve the purpose of protecting the safety valves
from injury, and when the valves are loaded directly, and so covered,
they are not easily tampered with.
The covering dome for the steam chest is generally of cast iron,
spherical at the top, and when the safety valves are fitted on the
top of the steam chest a curved outlet is formed on the dome for the
escape of the steam. The bottom is finished in a similar way as
the waste steam funnel, with bold curves embracing the body of the
boiler, to which it is securely bolted with stud bolts and nuts.
Sometimes these covering domes are made of brass, kept highly
polished, and present a very handsome appearance; but we consider
it preferable to have them made of cast iron, and properly painted,
as the large brass surface is difficult to clean, and in the act of
doing so the paint on the body of the boiler gets rubbed off, and
soon becomes shabby. In like manner we consider all the mould-
ings on the body of the boiler should simply be painted, for when
they are highly polished extreme care must be taken when cleaning
is going on; in fact a locomotive should be cleaned down very care-
fully, for when the paint gets rubbed off, like an ill-groomed horse,
it is not at all nice looking. The steam horse well kept is most
pleasing to the eye, and is certainly, as a whole, the greatest
triumph in steam machinery.
The water gauge placed on the outside of the fire-box shell is
for showing the height of water above the crown of the fire box
and tubes. It consists of a glass tube 3% inch internal diameter
and Wé inch in thickness; it should be properly annealed to resist
the sudden and varying temperature it is subjected to. The
ends of the tube are made steam tight, with hemp and a screwed
gland; the stuffing box at the top end allows of the expansion of
the glass tube, while the tube rests on the bottom one. By this
means the glass tube passes through the hole at the bottom of the
stuffing box at the top end, and thus freely slides with the expan-
sion and contraction without compressing the hemp packing.
574 MODERN STEAM PRACTICE.
The connections simply consist of a branch piece at the top and
bottom of the glass tube, having a flange for bolting to the flat part
of the fire-box shell, fitted with a plug tap between the glass and
IG
2% º
Fig. 427.-Glass Water Gauge.
A, Top piece. B, Bottom piece. C, Glass tube.
the boiler, with a screwed cap for putting in a fresh tube, and a
screwed plug in a line with the passage through the plug tap. By
this means a rod can be passed through to clear away any deposit.
The packing glands for the glass tube are provided with a loose
ring, which is screwed down over the packing with a screwed gland.
The plug taps are required in the event of the glass tube becoming







LOCOMOTIVE ENGINES. 575
}
fractured, thus providing a means of preventing a rush of steam, as
they can be instantly shut when required. There is a plug tap at
the bottom, in a line with the glass tube; this is the test tap for
showing if all the passages are in free communication with the
C
2–ºm
<------
Fig. 428.-Water Gauge. Plug Taps.
A, Plug tap. B, Handle. C, Screwed part.
steam and water space, so necessary for truthfully working of the
apparatus. The range of the index in connection with the tube
varies from 9 to Io inches, the general working height of the water
above the crown of the fire box being from 5 to 6 inches. Three
additional plug taps are screwed into the
fire-box shell; the bottom one should be .
placed 3 inches above the crown of the fire ſh
A
O
—x'O
º |
box, while the top one should be tapped in | ſº |
6 inches above it. These plug taps are used fillſ,
in the event of the glass tube breaking. An Fiji!-44.]],
experienced driver can at once tell by open- *|| | p
ing them whether there is enough water over H|H| ..] a
the crown of the fire box. When the gauge ſ ". |
is fitted to the side of the fire-box shell it is || :
connected with a brass pipe, having distance HH !
pieces of cast iron fitted to the curve of the As
box, the three additional test taps being | 61 Ot
tapped into the brass pipe, having the main |
gauge connection at the top and bottom of
the pipe. This pipe is closed at the ends
with screwed plugs, which can be removed
for clearing it from deposit. -
- º º Fig. 429. —Glass Water Gauge and
The pressure gauge indicates the difference connections—a, Top part, ,
e Bottom part. c, Glass tube and
between the pressure of the steam in the . . .
boilerand theatmospheric pressure. One form
consists of a curved flattened tube, into which the steam is admitted,
and which becomes more or less curved according as the pressure
Q
º













576 MODERN STEAM PRACTICE.
is less or greater. For it is a law of nature, that bent tubes under
internal pressure have always a tendency to become straight. The
tube has an oval section, is fixed at one end, and in communi-
cation with the steam in the boiler; the other end is filled up, and
has a connecting rod attached to a lever, with toothed quadrant
and pinion, the pinion spindle carrying the index handle, which
revolves in the centre of a disc plate, marked round the circumfer-
ence to indicate the pressure in pounds per square inch, the whole
being inclosed in a suitable box. It is fitted to the cab, or weather
protecting plate, having a U-shaped wrought-iron pipe connection.
Water lodging in the bend, or oil poured in, prevents such delicate
instruments from becoming overheated with the steam so necessary
for their proper action.
The steam whistle is placed at the back of the outside fire box,
or on the manhole door on the top of the box. It consists of a
plug tap screwed into the door, which is in connection with an
annular chamber, the steam escaping through a narrow annular
aperture, blowing against the edge of the bell, which is generally
from 3 to 3% inches in diameter and 2% inches in depth. It is
usually cast in hard brass, this size producing the musical note
D natural, which is sounded with about 8o lbs.
of steam pressure, higher pressures giving a
much shriller sound; and as the fulness of
tone is affected by the pressure, the driver
must open the aperture cautiously, or wire-
draw the steam through the tap to give the
full note when the pressure exceeds 80 lbs.
When the handle is not within reach of the
driver, a lever is substituted, with a con-
necting rod and handle passing through the
weather plate, fitted to the back of the fire.
box. -
The guard's zwhistle is of the same con-
struction, but the bell is made larger, about
... - 3% to 4 inches in diameter and about 5 inches
Fig. 439–Guard's Steam Whistle in depth. This gives a much lower note,
**** which is easily distinguished from the ordin- -
ary whistle. Instead of the plug tap, a valve
having a screwed spindle is sometimes used, which is worked with
a suitable handle, or lever and connecting rod. This plan has the

LOCOMOTIVE ENGINES. 577
advantage of being better able to adjust the volume of steam, so as
to produce a clear note, according to the steam pressure in the
boiler.
The blow-off plug tap or valve fitted to the bottom of the fire-box
shell, to blow off foul water and sediment, is usually
from I }% to 2 inches in diameter. It consists of a
solid plug tap, or a hollow tap inverted is used,
with a rod and handle fitted to the small end of
the plug, worked directly from the engine plat-
form. Screw plugs for sludge apertures at the
corners of the fire box are 2 inches in diameter, ...
e gº Fig. 43r.—Blow off, Hol-
screwed into a plate having a boss forged thereon. Tºw Tap-A, Hollow.
The plugs should be made of hard brass to prevent . cº- B, Seat
corrosion, and should have a strong square part
cast on for taking the strain of the screw key. When fitted to the
sides of the shell of the fire box, on a level with the crown of the
inside fire box, so that a water- -
hose may be inserted, washing
away any sediment collecting,
a good form of sludge door is
simply al brassflanged pipe piece sº
(Fig. 432), having a screwed cap, .B %
with Square piece cast on for Fig. 432.-Sludge Hole.
applying a SCTCW key, as in a *. Sludge pipe B, Screwed cap. c. Square part
- tº for unscrewing by.
water hydrant. This plan has
a free opening, the screw being cast on the outside, and as such
the screw is protected from injury from the tools used in clearing
the deposit which lodges at the bottom of the fire-box water
Space. -
Heating plug valves are fitted to the shell of the fire box, being
located above the water line in the boiler. They are used for blowing
the steam into the tender or tank for heating the water, but only
when the engine is standing, or when there is a surplus of steam in
the boiler that would otherwise blow to waste.
The pipe fitted to the heating-plug valves for leading the steam
into one or both of the suction pipes for the pumps is of copper,
I inch in diameter, and is connected with couplings to the valve
and suction pipe, the pipe having a slight bend to facilitate
making the metallic joints, which are screwed firmly together.
These heating cocks and pipes are only fitted when ordinary pumps






37
578 MODERN STEAM PRACTICE.
are used for forcing the water into the boiler, but when an injector
is adopted they are dispensed with.
The lubricating plug tap for the steam-regulating valve, slide
valve, and cylinder, is fitted in mostly all instances to the top of
the Smoke box, with a pipe connection to the regulating valve, the
oil flowing from thence into the cylinder, or other-
wise carried along with the particles of steam.
It simply consists of a hollow conical plug, into
which oil or melted tallow is poured through a
hole in the shell. The plug has a handle con-
nected to it in the usual way, so when the valve
Fig. 433.-Lubricating Plug is filled it is turned half round, until the opening
Tap for Steam Valves,&c. comes opposite the pipe, when the oil gravitates
A, º * into the regulating valve chest, and thence into
y * the cylinder.
A hand rail of iron, or iron sheathed with brass, is fitted to the
body of the boiler, secured with stud eyes screwed into bosses
forged on plates, which are rivetted to the shell. This hand rail
should likewise be fitted across the front end of the smoke box, to
insure safety when passing along the framing while the engine is
in motion.
A stud for the forward lamp is rivetted to the top part of the
front of the smoke box; these lamps have a powerful light, and are
aided with a reflector, so as to show for a considerable distance
whether the line of railway is free from obstruction.
CONSTRUCTION OF THE ENGINE, &c.
Cylinders, covers, and glands.-The cylinders, whether placed
inside of the smoke box, or, as in more modern practice, between
the frames, and in a variety of examples outside of the frames,
are arranged horizontally in some engines, and inclined in others.
With the inside arrangement the inclination given to the cylinders
and machinery is simply to obtain the necessary clearance above
the axle of the leading wheels, when of the same diameter as
the driving wheels; while there is no such necessity when the
cylinders are placed outside of the framing, the angle given to
the cylinders and machinery being a matter of opinion with
the various designers. As regards the inclination to be adopted
in connection with the general arrangement—when the leading

LOCOMOTIVE ENGINES. 579
wheel axle is fitted with outside bearings, with springs on the
top of the axle box, the inclination must be greater, so as to
effect the necessary clearance above the springs; while in those
arrangements having only inside bearings for the axle of the
leading wheels, the cylinders are generally arranged horizon-
tally, by which the pattern-making becomes much more easily
executed, while there is evidently a saving in fitting up, and the
weight is kept lower down, with the advantage of direct action in a
horizontal line through the framing. The cylinders are of hard
cast iron, and in some instances wrought iron has been employed,
but it is evident this material is very costly. Toughened cast iron
has been used with advantage, being a mixture of cast and wrought
iron. -
In former practice the cylinders were arranged inside of the
smoke box, holes being cut in the prolongation of the tube plate,
as well as in the front plate of the smoke box. The arrangement
was very compact, but the labour of fitting up was expensive, while
the disadvantage of attaching the machinery to the boiler soon
became evident from the expansion of the latter, causing a severe
strain to those parts rigidly held by the boiler and connected to
the framing. To overcome these difficulties the framing is arranged
to take the cylinders between the two horizontal plates running
the entire length of the engine, thus in a great measure keeping
them independent of the boiler. The cylinders are cast open at
the ends in some, while in others the back end is partially closed,
greatly strengthening the casting, only leaving an aperture of
sufficient size for the boring bar to pass through. All the passages
or ports and valve casings are cast along with the cylinder, as
likewise the side brackets, which are well ribbed in the casting,
and which form a strong junction between the cylinder and framing.
The weight of the cylinders rests on the top of the frames, a projec-
tion being left on the casting for that purpose; thus the cylinders
can be fitted to the framing quite independent from the boiler,
which may be in the process of manufacture. The cylinders are
joined together on the centre line, with flanges at the top and
bottom running the entire length, the exhaust passage being placed
at the top immediately over the exhaust ports. In this arrange-
ment there are valve doors fitted to the front and back, the latter
having stuffing boxes and glands for the valve rods, while the
former is fitted with stuffing boxes and glands to take the ends of
58O MODERN STEAM, PRACTICE.
the valve rods acting as guides in maintaining a true line of action.
In other arrangements there is only one door at the front, while at
the back the stuffing box for the valve rod is cast along with the
2
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Figs. 434, 435.-Cylinders.
a A, Cylinders. B, Valve. C C, Steam ports. D D, Exhaust passages. E, Regulator and chest.
F, Back cover. G, Stuffing box for the valve rod. H., Guide piece for the valve rod.
1, Front cover. K K, Main frames.
cylinder. The front cylinder cover is of the usual construction,
and is generally bolted to the cylinder flanges with stud bolts and
nuts; while the back cover is of smaller size, fitted with stuffing
boxes, bottom brass, and gland, and secured to the cylinder in like
manner. The generality of back covers have also projections cast


















LOCOMOTIVE ENGINES. 581
on for taking the motion bars, as shown by Fig. 436. There is
one regulator common to both cylinders, having the passages cast
along with one of the cylinders, while the other one is left plain, the
H
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re)
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2
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2.
I
Fig. 436.-Back Cover for Outside Cylinder.
A, Cover. B, Piston rod. C, Stuffing box and gland. D D, Motion bars,
valve casing being a separate casting bolted to the cylinder. In
some examples with inside cylinders the main steam valves are
placed on the top, with separate valve-casing covers for each cylinder.
Although for all arrangements, whether horizontal or inclined, the
framing forms the chief mode of attachment for the cylinders, some-
times they are likewise let into the tube plate and front plate of the
smoke box, the sides of the smoke box ending on the top of the
framing. •
For outside-cylinder arrangements the framing affords the sole
means of attachment. When Small leading wheels are adopted,
and in some cases with large wheels of the same diameter as the
drivers, the valve casing is placed on the side, towards the centre
line of the engine, and passes through an aperture formed on the
framing, to which it is securely fastened with bolts and nuts passing
through flanges cast on the cylinder. The centre line of the valve
spindle in the above example is in a line parallel with the cylinder,

582 MODERN STEAM PRACTICE.
but if large leading wheels are adopted it is necessary to incline the
rod to obtain the necessary clearance above the axle. In all these
examples the steam ports are much longer than in ordinary arrange-
ments, but at the same time some are shorter than others, provision
being made by the slide valve so as to make them as short as
practicable. To reduce them to the usual length they may be, and
are arranged on the top of the cylinder; but this plan necessitates
an indirect motion for the valve gearing—that is to say, when the
valve is placed horizontally; but in many arrangements the valve
is inclined, while the valve gearing is direct, although not in the
same horizontal line as the cylinder.
The valve casing is sometimes cast along with the cylinder,
having a door conveniently arranged with a view to its being easily
removed; while in other examples the casing is a separate casting,
bolted to the cylinder with long stud bolts, the same bolts taking
the cover. The cylinder covers at the front end are sometimes
recessed, having an L section of piston to suit, and which passes
into the recess, while others are recessed at both ends, having a
T section given to the piston. By this means the cylinders and ad-
juncts can be made a little shorter, which may be considered by some
an advantage, but the main advantage consists in the piston, which
is greatly reduced in weight by using any of the above sections.
The inside length of the cylinder, between the cover and the
back end, is equal to the length of the stroke, to which is added
the thickness of the body of the piston, and the clearance at each
end, which is usually 3% inch, and in some 3% inch is allowed.
This is necessary to allow for the variations in the length of the
connecting rod, due to the wear and other causes affecting the
position of the piston in the cylinder: in the event of the water
in the boiler priming over also, some space must be left to get rid
of it, otherwise the ends of the cylinder would be unduly strained.
The steam ports are of a rectangular form, cut square in at
the corners in most examples, while some are slightly rounded
at the corners; the face generally projects above the metal of the
port 3% inch, to keep the valve clear of the metal on port, as
likewise to allow for wear. The steam ports run partly into the
covers at both ends; by this means the piston does not travel past
the edge of the port too much at the end of the stroke.
All the joints are metallic; they are planed all over and then
scraped, to make them perfectly steam tight, and when finally put
LOCOMOTIVE ENGINES. 583
together receive only a thin coating of red lead prior to tighten-
- ing up the bolts. - - - -
For valve chests exposed to the action of the smoke and dust
collecting in the smoke box, brass nuts of considerable depth are
to be preferred, the nuts so formed as to in- - sºr
close the point of the bolts. Those nuts having ( Nº.
no tendency to corrode are preferable to iron §§
ones, as they do not strain the bolts when N
taken off, being very easily unscrewed.
In order thoroughly to provide for the lu-
2.
§
s
B
§
N|
º
t
--
si
ko
j
brication of the piston and valve rods, cups \ \, Ko A
are sometimes formed in the brass glands, Sj. 2.
fitted with a hinged cover. The stuffing box : l,
has the usual brass lining piece at the bottom; * @-4
both it and the gland are hollowed out at the | i
end bearing on the packing: thus when the *i;
packing is pressed up it is forced out against |
the rod. Two stud bolts and nuts are required ſº. º
for each gland. The valve rod passes through L T | fºllº
the front of the steam chest, and is guided by Fig. 437–Gland for Stuffing
means of a stuffing box and gland, and in . .”.”
• - º A, Gland. B, Oil cup.
some instances works in a brass tube, closed
at the end, the tube being bolted to the steam chest. With this
arrangement there should be a small hole cut where the rod bears
on the neck of the tube,
so as to allow water ac-
cumulating to be ejected,
which would otherwise
eventually rupture the
tube. -
A plug tap is fitted to
the bottom of the cylin-
ders at the front and back,
placed at the lowest part,
so that any water accu-
mulating may be run off.
Their bore is usually I's
or 54 inch in diameter; they are fitted with spindles and levers,
with a rod passing along to the starting platform. These taps are
generally left open for a considerable time after the engine is started;
Fig. 438.-Gland for Stuffing Box of Valve Rod.
A, Gland. B, Oil cup.




584 MODERN STEAM PRACTICE.
the cylinders being of course cold, condensation will take place,
and the water accumulating is forcibly ejected along with the
steam. As a considerable waste of steam
takes place, the bore of the taps is made small
to prevent excessive loss.
A plug tap is likewise fitted to the lowest
point of the valve casing, which should be
opened prior to starting the engine, or when
| the water from the boiler primes over, thus
tending to keep the water out of the cylinders.
The engine driver can easily detect when
priming is going on while the engine is run-
ning, and should always have the means of
opening the plug tap from the platform, in a similar way as the
small taps fitted to the bottom of the cylinders.
Grease cups should be fitted to each top corner of the cylinder.
They are provided with a plug tap at the bottom, which is screwed
into a hole tapped in the cylinder. This plug
tap carries a close cup, fitted with another plug
tap at the top, through which the melted
tallow can be run into the cup while the engine
is in motion, for the lubrication of the piston
and cylinder, the tap for the escape of water
in the cylinder being shut. There is another
grease cup for lubricating the regulating valve,
steam valve, and piston, which is fitted to the
top of the smoke box or side of the smoke
box, as already described.
The main slide valve is generally of cast iron. Sometimes brass
valves have been adopted, the cylinder faces wearing better with
such valves. But when cast-iron valves are used, placed on edge,
they are found very efficient. The valves are of the short
D description; the valve rod or spindle for working them in con-
nection with the valve gear has a strap forged on, embracing the
whole of the valve, leaving it free to move towards and from the
face of the cylinder, the valve being held to the face with a light
steel spring, Secured with stud bolts and nuts to the valve rod.
Sometimes the strap embracing the valve is not in a line with the
rod, but is bent in the forging to suit any peculiarity in the arrange-
ment of the valve gear. It is an object with high-pressure steam
i.
s
Fig. 439.-Cylinder Plug Tap.
A, Plug tap. B, Rod.
Fig. 44o.—Grease Plug Tap.
a A, Plug taps, B, Cup.









LOCOMOTIVE ENGINES. 585
to relieve the valve from the pressure; with this in view rings
properly packed have been fitted to the back of the valve, thus
placing, as it were, the valves in equilibrium, or relieving them
ſº * * * * * * * --- 6.7. -- - - - - - - -
* * 23%--------------4--- 3 •- -º
º g"Tº
sº. N. -> to IB
: ** §
1% ºf
:
Fig. 441.—Slide Valve and Rod.
a, Slide valve. B, Valve rod. C, Spring. D D, Stud bolts.
greatly from the pressure, reducing the wear and tear, and making
them much more easily handled.
A very general plan consists of a separate disc plate and packing
ring (working steam tight against a central plate in the steam
chest), which is secured to the back of the slide valve: thus the
pressure of the steam, acting as it were in opposite directions, tends
to relieve the valve from pressure. At the same time, the arrange-
ment allows for the wear of the valve. -
Another plan well suited for the locomotive engine consists in
casting a short cylinder along with the valve, and situated behind
it, which is accurately bored out for the reception of a thin packing
ring. This ring is turned slightly larger, and is cut through at one
part, and sprung in the cylinder: thus it forms as it were a piston
ring, fitting steam tight into the cylinder, while at the same time
the thin edge is pressed up against a fixed plate, with steel springs
placed between the ring and the valve. A round pin is let into
the valve, a hole being bored in the spring ring to receive it, to




586 MODERN STEAM PRACTICE.
prevent the ring turning round. A hoop is forged on the valve rod
for taking the cylindrical part of the valve, thus forming a loose
connection between the valve and the rod.
#
E - - -
F , -
• *
... • *
-
**.
**
º-* .
;
#
W.
&
K
i
<
.
3
>
Figs. 442, 443–Eccentric, Expansive Link, &c.
A, Eccentric. B B, Pins and cotters. cc, Set screws. D, Strap. E. E., Snugs and bolts. F, Oil cup.
G, Rod. H H, Links. I, Slide Block. K, Lifting rod. L, Guides for valve spindles. - -
.*





LOCOMOTIVE ENGINES. 587
Valve motion.— Double eccentrics and link gear are generally
used for giving motion to the steam valves, the parts pertaining to
these consist of sheaves, straps, rods, links, sliding blocks, lifting
links, guide bar and block, weigh bar and lifting arms, with balance
arms, and reversing rod, lever, and quadrant.
The eccentrics are of cast iron, made in two pieces secured toge-
ther with pins and cotters, having a groove and feather for prevent-
ing any movement sideways. The eccentrics are held in position on
the shaft with two set screws and jam nuts. The working surface
in the example shown (Fig. 442) is turned with a raised flat part or
ridge fitting into a corresponding recess in the strap, which is
usually cast in brass, with lugs cast on for holding the strap
together, with one bolt and two nuts for each. There is likewise an
oil chamber cast on the forward half of the strap, and the strap
may be ribbed to give greater strength. A T piece is also cast on
the forward strap for taking the end of the eccentric rod, which is
secured thereto with two bolts and two nuts for each. The rod
has a T piece forged on for connecting to the strap, and a double
eye for taking the link, which is of the open solid kind, coupled on
the centre line, this plan necessitating a greater throw for the eccen-
tric than the travel of the valve. The radius of the link is the length
from the centre of eccentric rod to the centre of the link, the open
part being accurately slotted out for taking the sliding block, which
is made of steel, having a hole bored in it for receiving the pin
passing through the jaw of the valve rod. The link is hung from
the top, with two lifting or suspending rods, one on each side, on
which a part has in some cases been forged on, acting as a guide to
the link, but this is not much adopted in modern practice. The
guide bar on the valve rod is square, with guide blocks secured to
a plate, bolted to the top of the motion bars; these guide bars are
introduced to prevent any twisting strain on the valve spindle.
In the next arrangement under notice the eccentric working Sur-
face is circular, and is held in position on the axle with one set screw,
having a wrought-iron nut let into the cast iron. The straps are
divided at an angle to the line of the rod, with oil cup cast on the top
fitted with a hinged cover. The rod is formed with a dove-tailed
piece, let into the strap, and securely rivetted thereto, while the link
end of the rod has a fork forged on for taking the link, fitted with a
plain pin, which is held in position with a split pin bearing on a
loose washer. The expansion link is of the former description,
588 - MODERN STEAM PRACTICE.
suspended from the bottom with two side rods. Instead of the
valve rod being guided with a v or square piece in a line with the
rod, the sliding block is fitted to a rod, oscillating on a pin close
up to the gland, and suspended with the vertical oscillating links,
hung from brackets attached to the body of the boiler.
Fig. 444.—Eccentric and Rods.
a, Eccentric. B B, Pins and cotters. C, Set screw. D, Strap. EE, Snugs and bolts,
F, Oil cup. G, Rod
In some arrangements (Fig. 445) the straps and rods are forged in
one piece, working on cast-iron eccentrics in this example; the pump
is worked from a pin on the back-going eccentric rod, having a bent
rod for clearing the axle of the driving wheels, an arrangement not
at all to be desired, although by this means a longer rod is obtained,
which tends to lessen the thrust on the plunger gland. The link is
arranged with lugs forged on for taking the eccentric rods, and the
link is suspended between the two, with side links oscillating on pins
forged on a piece bolted to the link. All the joints are provided
with oil cups forged on as shown. The sliding block for the link
is fitted as in the previous example to a rod, oscillating on a pin
passing through a crosshead, fitted to the valve rod; the rod being
supported by a jointed link hung from a plate bolted between the
main frames. -
In all the preceding arrangements the links are of the lifting

LOCOMOTIVE ENGINES. .
589
ng
i
some are, however, stationary, while the connect
2
º
ription
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In the example under
link on the valve rod moves up and down.

590 MODERN STEAM PRACTICE.
Tº
k1; .ii.
t S--—Fittº-
k. Agº" N : : /
tºº
A, Eccentric. B B, Pins and cot-
ters. CC, Set screws. D, Strap. EE,
Snugs and bolts. F, Oil cup. G, Ec-
centric rod. H, Link. I 1, Snugs for
the eccentric rods. K K, Suspending
rods. L, Sliding block. M, Valve
rod.
Figs, 447, 448, 449, 450,--Eccentric and Strap, Expansive Link, Valve Rod, Link, and Sliding Block




LOCOMOTIVE ENGINES. 59 I
notice the eccentrics are of cast iron, and the strap and rod of
wrought iron. The link is of the double description, rivetted
together and suspended with two hanging links from a bracket
secured to the boiler. The
connecting link is forked at
one end, taking a crosshead,
which works in suitable i * *º 2
guides. The sliding block is A
of course double, made in
One piece, with a part cut out
at the middle for the end of
the connecting lever held in
position with a pin passing
through the block. There is
a boss on the lifting link, a
short distance from the end that takes the sliding block for securing
the link for the up and downward motion. In some examples of
valve gear it may be necessary to bend the valve rods and eccentric
rods to clear the axles; this may be arranged as delineated.
A modification of the link motion more recently introduced is
illustrated by Fig. 452. The expansive link is straight; the sliding
4.
jºiſ.
Fig. 451.-Valve Rod and Eccentric Rod.
A A, Axles. B, Valve rod, c, Eccentric rod.
" ******* -----
e." 's
." *.
.." *.
*... ..~"
Fig. 452. —Straight Link Motion.
A, Eccentrics. B B, Eccentric rods. C, Straight link. D, Connecting link.
E, Connecting link. F, Radius rod.
block is carried on a radius link, placed between the main link and
the valve rod; both are connected to a long and short lever on
the weigh shaft, so arranged that the one travels up and the other
down, and vice versa, meeting each other at half lift, the greatest
vertical motion of each being only about half of that given to other
link motions. Single eccentrics have been used for each valve,
the reversing and expansion motion being obtained by means of
spirals and wedges. Figs. 453 and 454 give a general idea of the
arrangements; the angular position of the eccentrics being al-




592 MODERN STEAM PRACTICE.
tered laterally with spirals on the axle, and transversely with -
wedges.
|
Fig. 453.-Single Eccentric with Lateral Movement.
AA, Eccentrics, B, Sheave for altering the position of the eccentrics. cc, Cranks.
C
-
A A
Fig. 454.—Single Eccentric with Transverse Movement.
A A, Eccentrics. B B, Wedges. C C, Cranks.
The guide bar for connecting the link motion with the valve
------as------- .............axiºm . spindle is of an elonga-
E-----4%- 8% ††, ted V section at the top
and bottom ; some are
Qs> made of a square section,
i with the V at the top and
—- $ bottom, which works in a
Tº ſº guide blockof brass, which
2–U is generally bolted to the
back steadinent forcarry-
ing the motion bars. The
guide bar has a jaw forged
on at one end with a pin
for taking the link and
carrying the sliding block,
and at the other end there
is a socket for the slide-
valve rod, which is secured
with a cotter. The guide
A, Guide bar. B, Socket for the valve rod. c, Eye for the link. tº e : - - -
D, Guide block. E, Motion bar steadinent. block is fitted with a COver,
ſº-
Fig. 455.-Guide Bar and Block for Valve Spindle.








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B B B, Link levers, c, Rod lever
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Fig. 456–Reversing Shaft, &c.
P, Reversing rod.
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A, Shaft,


594 MODERN STEAM PRACTICE.
with collar bolts for securing it to the angle iron on the steadi-
ment, the bolts being prolonged at the top for taking the cover,
and are fitted with nuts and jam nuts. In some examples
with lifting links the guide bar and blocks are dispensed with,
the sliding block in the link being carried by a connecting rod
jointed to the valve rod; this connecting link has a jointed arm
which is suspended from a pin passing through a bracket bolted
to the under side of the body of the boiler, this arrangement re-
quiring no further guide, the connections vibrating with the motion.
When the link is stationary the sliding block in the link is carried up
in like manner, the connecting rod for carrying the sliding block
in such examples is raised and lowered with a connecting link and
arm, and it is necessary to guide the valve spindle in such an
arrangement, as the connecting rod lies at a considerable angle;
it may be simply guided with a prolongation of the valve spindle,
passing through a bracket bolted to the framing, as with outside
cylinder arrangements, or any other convenient and simple guide
can be used, according to the design and position of the valve
gear.
The weigh bar or reversing shaft (Fig. 456) is quite parallel in some
examples, and is carried up with brackets bolted to the main fram-
ing, the brackets being in the form of pillow blocks, having covers for
the weigh-bar journals, while in other cases the brackets have merely
solid eyes, and the weigh bar is held in position with loose collars
pinned on. The lifting arms, weight arm, and reversing arm are
separate forgings, which are keyed and pinned on the weigh bar.
In some arrangements two lifting arms are provided, while in
others there are three lifting arms and it is now the general practice
to forge them on with the weigh bar as well as the weight arm,
which is weighted for balancing the motive links, &c., as likewise
the reversing arm—all of which, along with the weigh bar, form
one solid forging. The reversing rod has a plain flat section, and
is fitted with joints at the ends for taking the reversing lever
and arm of the reversing shaft.
The reversing lever is a simple lever, having the fulcrum between
the end and the handle, as shown in Fig. 457, the stud for carrying it
being bolted to the framing, or to the quadrant as the case may be,
the lever being held in position with a loose washer and pin; it is pro-
vided with a detent which is fitted with a spring for holding it in the
quadrant. The quadrant is simply two curved plates, which can
LOCOMOTIVE ENGINES.
595
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Fig. 458.—Reversing Lever and Quadrant
A, Lever. B, Bracket on the foot plate. c, Quad-
rant. D, Detent rod. E., Joint for reversing rod.
E
A
Z.
C) {
D, Detent
Fig. 457.-Reversing Lever and Quadrant.
B, Fulcrum. c, Quadrant.
rod, E, Detent lever. F, Reversing rod.
A. Lever.



596 MODERN STEAM PRACTICE,
be variously arranged to suit the framing, or that part of the boiler,
or foot plate, to which it may be bolted; the top edge has a number
of slots cut in it for holding the starting lever in position when
cutting off the steam at the different grades of expansion.
The piston consists of three important parts, namely, the body,
the junk ring, and the packing ring or rubbing surface, but in some
the junk ring is dispensed with. The body may be of cast iron or
brass; brass is to be preferred, owing to its lightness, and not
being so liable to rupture as cast iron. The junk ring is made of
the same material as the body of the piston. Packing rings of
cast-iron, brass, and steel rings have been used with advantage.
Brass rings work smoothly, and effect but little deterioration on
the surface of the cylinder, but they wear rapidly and require
frequent renewal. Cast-iron rings are the most durable, and when
properly fitted and well attended to when first put in, give but
little trouble, working smoothly and keeping the cylinder surface
in good condition,--that is to say, when the cylinder is cast in hard
metal, but when the metal is soft the packing rings should be of a
composition of 2% oz. tin and 34 oz. zinc per pound of copper:
this is found to answer well, keeping the cylinder surface highly
polished. The packing rings should be easy in action, as the
cylinder has a tendency to wear oval, owing to the weight of the
piston. Packing rings cut in four segments accommodate them-
selves better to the unequal wear, and cause more equal friction on
the rubbing surfaces, than a ring cut at one point; as the rings,
having a wedge piece and spring for pressing them up against the
cylinder surface at each division, four wedges and springs will in
the former case be used, whereas when the ring is cut only at one
point the wedge must be pressed up with greater force, which, acting
on one point, must produce unequal friction, the point where the
ring is cut being that of greatest friction, while that of least friction
will be directly opposite. It is customary, therefore, to make the
ring thicker at the part where it is cut to allow for the wear, and
gradually tapering to a less thickness directly opposite the wedging
pieces. It has been found practically that the four segments
equalize the pressure on the surface of the cylinder, the rubbing
surfaces wearing equally; whereas when the ring is cut at one point
the wear is greater at that point, while the single ring is not so
durable. Single rings are sprung into the cylinder, consequently
they act partly with their own elasticity; therefore, the wedge does
LOCOMOTIVE ENGINES. 597
...'
not require to be pressed up so hard at first, until the inherent
elasticity is nil, and then the wedge and spring are pressed up
accordingly. The springing of the ring is effected by turning it
nearly 9% inch larger in diameter for ordinary pistons; a part is
then cut out, so that when the ring is compressed the joint is
hard up, the ring fitting tightly into the cylinder: the part cut out
need not exceed 3% inch or so. The ring when new of course acts
with its own elasticity, the expansive force being more uniform
Figs. 459, 460, 461, 462.-Piston Rings, showing the Wedge Pieces and Springs.
A, Piston rings. B, Wedge pieces. C, Spring with set bolts and nuts.
throughout the ring; it is then in its best working order. As it
wears the elasticity is destroyed, and the ring is expanded by the
wedge and spring, which tends to throw the strain on one point,
locating the wear of the surface at that part of the ring and cylinder
surface. When single cut rings are adopted they should be sprung
against that part of the cylinder which has the least wear. Taking
the weight of the piston into consideration, least wear must take
place on the top surface of the cylinder; and when two rings are

598 - MODERN STEAM - PRACTICE.
used, which is generally the case, the wedging pieces should be
placed on each side of the vertical centre line, thus tending to keep
the cylinder truly cylindrical. The wedge should be made at an
angle of 70°, thus securing free action laterally and radially. When
made sharper it is more powerful in pressing out the ring, but
has a tendency to gag it; while with a more obtuse angle the
range is shorter, the thrust being reduced, and the radial thrust
given by the spring is increased, throwing more stress on the ring
and cylinder surface. The springs are in one continuous piece, or
short springs are adopted for packing rings, cut at one point; but
when more wedging pieces are introduced, the ring being in seg-
ments, four or more springs are required, just depending on the
arrangement. The set Screws are generally fitted with jam nuts, the
screw passing through the spring, or in Some it is screwed into the
spring and held in position with jam nuts. The packing rings are
concentric in Some cases, while in others eccentric rings are adopted,
the latter being cut at the thickest or thinnest part. When cut at
the thickest part, they wear better and last much longer than those
cut at the thinnest part, while concentric rings seem to answer all
the requirements. However, we certainly prefer, with single cast-
iron rings, the wedge fitted to the thick part of the ring, as has
already been described, taking into consideration the unequal wear
of the cylinder surface due to the weight of the piston and adjuncts.
. The weight of the piston
is sometimes carried up, by
having a metallic piece in-
serted between the rings and
the body of the piston, which
is located at the bottom side
bearing on the bottom of the
cylinder; thus the body and
rings are kept as nearly as
practicable in their original
position. -
º (: 3.
Fig. 463,-Piston with Packing Ring in Four Segments. tº +
A, Piston. B, Junk ring. C, Packing ring. D D, Springs The various arrangements
with set screws. E, Cotter. F, Piston rod.
of pistons now claim our
attention; the example under notice has one packing ring, cut into
four segments, the ends of which are half-lapped, fitted with tongues
to make them steam-tight. The wedges are cut at an angle of 122°;
their radial movement being small, they never rub on the cylinder

LOCOMOTIVE ENGINES. 599
surface, and do not therefore tend to form ruts. The ring being
cut in four segments, the action of the wedges is very free, superior to
that of a single sharp wedge acting on a single ring cut at one part,
while the wedges work more truly as the rings wear, differing less
from the angles of the openings. The spring for pressing the
wedges up to the packing ring is continuous, bearing on the four
bosses for the bolts of the junk ring, which are formed on the
body of the piston; by this means should any of the screws get an
extra turn, the pressure is in a measure transmitted, and better
diffused amongst the others. The body and junk ring, for securing
the packing rings, are of brass, and the packing ring of cast-iron,
the piston rod being secured with a plain cotter, passing through
the central boss cast on the body of the piston.
Another form of piston materially differing from the foregoing,
has two packing rings, with one wedge, spring, and set screw for
B Š% A *
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Fig. 464. Piston with two Packing Rings, with Collars formed on the Piston Rod.
a, Piston. B, Junk ring. C, Packing rings. D, Wedge piece. EE, Springs with set screws.
F F, Tapped holes for bolts for junk ring. G, Piston rod. H., Collars on piston rod.
each, the springs being continuous. The junk ring is made of extra
thickness, with five holding bolts, with holes tapped into the body
of the piston, which is made of cast iron. The piston rod is secured
by means of collars formed on the rod, which is firmly held with
the junk ring. This plan has its advantages as there are no parts
to shake loose, while there is no strain on the junk-ring bolts, the
steam pressure being taken on the collars—the piston too can
be turned round, by simply slackening the bolts, thus altering
the rubbing surface and equalizing the wear. &

6OO MODERN STEAM PRACTICE.
Another arrangement with two packing rings, fitted with wedges.
has a short spring and set screw, the ends of the spring bearing on
Fig. 465.-Piston with two Packing Rings, with short Springs for Wedges.
A, Piston. B, Junk ring. C, Packing rings. D, Wedge. E, Spring with set screw.
§:
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Figs. 483,467.-Pistons with Concentric Ring, and Concentric Spring Ring.
A, Piston, B, Jusik ring. C, Packing ring. D, Concentric ring. E E, Springs with set screws.
+. FF, Bolts for junk ring. G, Cotter for piston rod.




















LOCOMOTIVE ENGINES. 6OI
projections cast along with the spring rings. The body, junk ring,
and packing rings, are of cast iron ; the bolts for the junk ring
are screwed into brass nuts let into the body, the piston rod being
firmly secured with a split cotter. There is a wrought-iron rest
pinned to the body, for keeping the body and packing rings central
with the cylinder.
With the view of diffusing the pressure on the packing rings, a
pair of brass rings have been adopted cut at one point, inside of
which is a concentric spring ring, on which springs and set screws
are brought to bear, thus diffusing the pressure all round the pack-
ing rings, and as these are of brass, the friction is thus reduced.
The action of the concentric spring ring, in this case, differing
from the foregoing examples, is needed, inasmuch as it acts of
itself as a spring keeping the two packing rings equally up to the
face, which would not be the case were the small springs acting
directly on the packing rings. The body and junk ring are of brass,
the piston rod being fitted with a screwed end, which is screwed
into the piston, and has a pin passing through the body and rod.
In one of the examples under notice the piston is parallel, while
in the other one the body is deeper, thus giving a better hold for
the piston rod, and it will be noticed in both arrangements that
snugs are cast on the body, through which the set screws for the
spring pass. We consider that these pistons are excellent examples
of their class, and the packing rings when of brass, as these are, will
undoubtedly wear much longer than others.
Another very good method (Fig. 468) for diffusing the pressure, as
applied to single cut rings, is to have a circular steel spring, bearing
uniformly on the entire circumference of the packing rings, the spring
acting between the rings pressing them up to the surfaces of the
piston flanges, as well as the cylinder surface, and supplying of itself
the necessary range of elasticity. The rings are cut obliquely on their
faces, thus preventing grooves being cut in the cylinder surface;
the piston rod in this example is secured by a plain cotter. All
pistons should be fitted with some means for preventing the bolts
in the junk rings working backwards. A plate is shown in this
example which bears on the side of the bolt heads; it is
secured with two stud bolts, and two stud pins also pass through
it, having a split pin bearing on the top of the plate. All the
rubbing surfaces of these pistons are turned and rendered per-
fectly steam-tight by scraping them; formerly they were ground
6O2 MODERN STEAM PRACTICE.
with emery, but the plan was bad, inasmuch as the small gritty
particles became imbedded in the metal, causing great friction and
ſº
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Fig. 468.-Piston with Circular Steel Spring, &c.
A, Piston. B, Junk ring. C, Packing rings. D, Circular steel spring. E, Cotter for the piston rod.
deterioration of the surfaces. When all the rings are adjusted,
and properly finished on their surfaces, thin slips of paper are
introduced, and then the junk ring is screwed hard up; by this
means the rings are held firmly in position, and then the outside
circumference of the piston is finished in the turning lathe, this
being required as the last operation, since in the course of fitting up
the surfaces are liable to get damaged.
In order to reduce the weight of the piston,
and likewise to reduce the number of parts,
Self-acting steel packing rings have been suc-
cessfully adopted, working longer than the
more complicated arrangements, giving less
trouble for inspection, and requiring but little
repairs. Several good examples of these steel
packing rings have been in use; they are
chiefly of two types, first, spring packing rings,
depending on their own elasticity, and secondly,
Fig. 469–Piston with a series those depending on the pressure of steam ad-
.*.*.*... mitted behind, or within the ring, to keep them
A, Piston. B, Steel springs. e
'... ºn .i.amai." up to the cylinder face. In the example under
notice (Fig. 469) the piston is a solid casting, the
packing rings consisting of a series of steel springs + to ºr in. square.
They are made in one piece, and cut with a saw at one point, and are


LOCOMOTIVE ENGINEs. 603
simply extended and sprung into grooves turned on the circumference
of the piston. These plain rings work for months, and last as long
as they can hold together, or until they are nearly worn through.
Another form of packing ring, for solid pistons, consists of
a flat cast-iron ring 1% inch
wide and # inch in thickness;
the ring is made steam tight
where cut with a tongue ri-
vetted to the body of the pis-
ton, and let into slots cut in
the ends of the ring, the ring
being extended and sprung
into the groove, turned in the
piston. This piston is very
light, and is well calculated
to meet all the requirements.
Pistons depending for their
efficiency on the steam being admitted behind the packing ring are
constructed in a similar way; the ring, however, is made deeper, and
not so broad on the rubbing surface—a small hole being bored in
the body to allow the steam behind the ring.
In these latter examples the piston rods are
Secured to the body by a nut, screwed on to
a thread cut on the end of the rod.
Piston rod, crosshead, and motion bars.-Pis-
ton rods are generally made of Lowmoor iron
or the best scrap iron, although steel has been
largely used in their construction. The part
fitting into the piston has a taper of about
I in 8 or ; inch for pistons 4 inches deep.
They are generally secured with a split cotter
passing through the boss, which is strength-
ened for that purpose; while in some the rod
is screwed at the end, and the piston secured 4TRiº TEEET2
with a single nut, having a round split pin Fig. 471. –Piston with Single
passing through the nut and rod, thus prevent- Ring, with Steam behind.
ing the nut turning backwards. Sometimes the A. .."...º.º. *
piston rod is forged along with the piston, and
consequently requires neither cotters nor nut; this plan, however, has
not been very generally adopted. Piston rods with flanges forged
| | | D
Fig. 470.—Piston with Single Cast-iron Ring.
A, Piston. B, Packing ring. C, Piston rod and nut.


6O4 MODERN STEAM PRACTICE.
on, form a very good attachment, being very secure, having no
parts to work loose, while the pressure is taken on the flanges, thus
making this mode for securing the piston on the rod complete in
its simplicity. The piston is held in position by the junk ring, the
pressure on the back end is taken
directly on the flange of the pis-
ton rod, while on the front end
the strain imparted to the junk
ring is simply due to the fric-
tion of the piston.
Figs. 472, 473.−Crossheads and Guide Blocks.
A, Crosshead. B B, Guide blocks. C, Piston rod and cotter. D, Gudgeon.
E, Pin for taking pump ram.
The crossheads are of wrought iron, having a part bored out for
receiving the piston rod, which is secured with a nut in some cases,
and a cotter in others; the taper of the rod fitting into the crosshead
need not be so much as that for the piston, I in 20, or even I in 30,
being sufficient. Crossheads are arranged in two ways; the best
arrangement, we consider, is that in which the crosshead is adapted.
for single-ended connect-
ing rods, with motion bars
on each side. The cross-
head is of a forked shape,
with holes bored through
for the reception of the
Fig. 474.—Crosshead for Single Motion Bar. gudgeon, for taking the
A, Crosshead. B B, Motion bars, c, Piston rod and cotter, end of the connecting rod
- D, Gudgeon. tº º &D y
which is driven tightly
into its place, having flat keys let into it for holding it in its position,
preventing it turning round. The gudgeon is longer at one end than
the other, the short end is simply for one of the sliding blocks, while






LocoMotive ENGINEs. 605
the long end likewise takes the pump ram. Crossheads for single
motion bars are generally made in one piece, bored out for the recep-
tion of the piston rod, which is secured with a cotter in some, and a
cotter and washer in others, the rubbing surfaces are steeled, and
planed out with cross gutters, cut out for lubrication. The connect-
ing rod is forked in mostly all examples. When the crossheads are
shallow the rod requires to be forked for a considerable length, to clear
the ends of the motion bars, but when made of sufficient depth it is
only forked to clear the crosshead; a sufficient depth is left between
the motion bars, for the connecting rod to work within them. Some
of these crossheads are made to receive a single-ended connecting rod;
the plan, however, is bad, as the connecting rod is shortened, the point
of attachment being overhung and nearer the crank pin, while the
line of action taken on the motion bars is not so perfect, and
cannot act So well as when the pin for taking the connecting rod
Fig. 475.-Crosshead with Cast-iron Guides lined with White Metal.
A, Crosshead. B B, Cast-iron guides. C, Piston rod and nut. D D, Gudgeon.
is placed central with the slides or crosshead. The crosshead
in many examples is fitted with cast-iron guides, which in some
are lined with white metal, but cast
iron of itself works very well on
iron motion bars, and is preferable
to steeled guides, as the latter are
uncertain, tending to cut the motion
bars. These guide pieces are bored
out, taking a pin at the top and
bottom, which are turned on the Cross- Fig. 476.—Crosshead with Cast-iron Guides.
head, no other fixture than this being A, Crºsshead. B B. Guides, c, Piston
rod and cotter. D D, Gudgeon.
necessary. In the two examples we
give it will be noticed that the piston rod is secured to the
crosshead, with a nut in the one, and a cotter let in obliquely in


6O6 - MODERN STEAM PRACTICE.
the other. In some examples there is an oil-receiver formed on
the brass or cast-iron guides for holding oil for the lubrication of
*. - - the crosshead, while in
others provision is made
on the motion bars. The
guide blocks have occa-
sionally been secured to
the crosshead with stud
bolts, this plan being adop-
ted when blocks have been
made of extra length, and
affording a secure attachment under the circumstances. In mostly
all these examples the part taking the piston rod is turned, and all
the other parts planed or slotted in the machine.
Fig. 477,-Crosshead showing Oil Receivers.
A, Crosshead. B B, Oil receivers. C, Piston rod and cotter.
|- *
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- A
H
. ().
C.J. Tº C
El Hº -
* Fig. 478. –Crosshead with Guide Blocks secured with Bolts.
a, Crosshead. B B, Guide blocks. C, Piston rod and cotter. D, Eye for pump ram, E, Gudgeon.
The motion bars (Figs. 479, 480) are made of scrap iron steeled or
case-hardened. Sometimes solid shear steel bars have been adopted,
while cast-iron has been used with great success. The motion bars
now generally adopted are of a flat section, and are secured with bolts
to the back cylinder cover seats, with side joggles cast on the cover
for their reception; the back end taking the blocks, which are forged
along with the motion plate, or rivetted thereto, the motion plate
being secured to the longitudinal frames of the engine. Sometimes
the motion bars are not connected to the cylinder cover, but are
secured to a front and back motion plate, which is bolted to the
longitudinal framing, flanges being ſorged on the motion plates for
that purpose. Thin strips of brass or copper are placed between
the motion bars and their seatings; by this means the wear on the
crosshead guides is adjusted by simply filing a little off the lining




LOCOMOTIVE ENGINEs. 607
pieces. When cast-iron motion bars are adopted they are some-
times fitted with a clip at the cylinder end, with a flange cast on the
back end for bolting to the motion plate, and the bar is strengthened
with a vertical feather cast along with it, tapering from nothing at
the end to a sufficient depth at the middle of the bar, this being
required, as the cast-iron is not so well calculated for taking the
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strain. Attempts have been made to dispense with the crosshead
and motion bars, this being effected by means of a prolongation of
the piston rod, which is forged along with the crosshead and piston
rod proper, the rod working in a long boss, which is secured to
what would otherwise be termed the motion-bar plate. The piston
rod requires to be of extra diameter for taking the strain, and a


608 MODERN STEAM PRACTICE.
hollow or tube section has been adopted; this plan for guiding the
piston rod in a true line necessitates a long fork on the connecting
rod. This peculiar arrangement, as applied to the locomotive
engine by Messrs. Sharp & Stewart of Manchester, has not found
much favour. It is, however, decidedly more cheaply executed
than the ordinary motion bars and adjuncts, but we think it
should be confined to agricultural engines, moving at a slow rate
of piston.
The plate for carrying the back end of the motion bars is forged
in some instances, with provision for carrying the end of the pump;
and has flanges at the end fitting against the longitudinal frames,
to which it is securely bolted. In other arrangements the motion
plate is formed of plate iron, with angle-iron flanges for securing
it to the main framing. It is generally made of considerable depth,
with holes cut out for the connecting rods and eccentric motion
rods, and sometimes the plate is carried up and securely rivetted to
the boiler, in fact, forming the support for the boiler; this is to
be preferred to the old method, having the boiler brackets bolted
thereto, and likewise to the rigid framing, as the plate is not so
rigid, yielding to the expansion and contraction of the boiler. The
motion plate for outside-cylinder arrangements is carried beyond
the framing, extending the whole width across the framing, with a
long hole cut out for the wheel coupling rods, working through the
plate extending from nearly the centre of the boiler to within a few
inches of the rails. -
Connecting rods—Much attention has been paid to the con-
struction of the connecting and the coupling rods. The body and
the straps are of scrap iron, with brass bushes and steel cotters.
The length of the connecting rod from centre to centre should be
six times the length of the crank, and even longer when convenient,
shorter connecting rods throwing an undue strain on the motion
bars, causing much friction. In former examples the body of the
connecting rod was turned, but this plan, although cheaper, was
objectionable. Flat sections are now universally adopted, as that
form gives rods much stiffer, and better calculated to take the severe
strains they are subjected to. Long forked connecting rods should,
as far as practicable, be discontinued, as forked ends are not nearly
so strong as plain ends; short forks, however, are extensively
adopted, and are not so objectionable, although we decidedly prefer
single ends.
LOCOMOTIVE ENGINES. 609
For inside-cylinder arrangements each end has a butt forged on
the body, which is planed for the reception of the strap, the bushes
being placed between the butts and the loop ends of the straps.
The latter are tightened up with jibs and cotter, by this means
adjusting the wear on the bushes. The cotter is held with two
side screws for the large end and a single set screw for the small
|
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end, and for further Security split pins are inserted in holes on the
bottom end bored at a short distance from each other. In other
examples the cotter is prolonged and cut with a screwed part which
passes through a hole in a prolongation of the jib ; by this means
the cotter is held in position with jam nuts. The bush and grap at

6IO MODERN. STEAM PRACTICE.
the large end are square, surface thereby being gained for taking the
thrust. The butt has a large hole cut out, for lightening it, tending to
reduce the balance weights placed on and between the spokes of
the driving wheels. The bush for the small end of the rod is tight-
:
ſ
:
§|
:
:
i
i
ened up with a single key and jibs, with side nut for holding the key
in position, as likewise a split pin on the under side. In another
example (Fig. 482) the small end is forked; the bushes at both ends
are lined with white metal; the ends of the bushes are not square, but

LOCOMOTIVE ENGINES, 6II
are fitted into parts cut out in the connecting rod and straps, like an
ordinary pillow block for land engines. The strap on the large
end is tightened up with jibs and a single cotter, and at the forked
ends with a single jib and cotter, having set screws and split pins as
before. The cups for lubricating the crank pin and gudgeon for
the crosshead are forged on, and fitted with a siphon pipe and
cover to prevent the oil being thrown out with the rapid revolving
and reciprocating motion the connecting rod is subjected to.
Owing to this rapid motion it is found advisable to secure the
strap at the crank end with two bolts and two nuts to each bolt,
-º-
3.
CN
- sº D te T/ s . .
§ {G}º EG) tº ' || --El (O); ºft
# y T = * , |\.2 tº
| UD
;
49.
y
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Fig. 483.−Connecting Rod with Fixed Strap, having Bolts passing through the Strap and Butt.
A, Crank end. B, Crosshead end. C C, Butts. D D, Straps. E, Jib and cotter. F, Cotter
G, Bolts and nuts. H H, Brasses. I I, Oil cups.
thus binding the strap and butt firmly together; there is a single
cotter bearing on the bush for adjusting the wear, the set screws
for holding the cotter in position being screwed into the strap, the
small end in this example having a cotter and two jibs for the bush.
The siphon cups are forged on the straps, and the cover is fitted
with an internal plug bearing on it, and which is held up
with a light spiral spring. In another plan for holding the strap in
a fixed position two sets of jibs and keys are adopted, with joggles
formed on the large butt (Fig. 484). One set draws the strap into
the joggle, where it is firmly held, the cotter being secured with set
screws and split pin, while the other set bears directly on the bush,
and are only used for adjusting the wear. The siphon cup is
forged on the large strap, and the small end is provided with a brass


612 MODERN STEAM PRACTICE.
Cup screwed in the strap, which is an advantage when the cup
requires cleaning; but it is preferable to forge them on the large
ends, owing to the violent motion, which is liable to shake brass
cups loose. The slightest derangement in this important part will
with an attentive driver cause a stoppage, perfect lubrication of the
B IB
F-X-
Fig. 484.—Connecting Rod with Fixed Strap secured with Jib and Cotter.
A, Body of connecting rod. B B, Brasses. C C, Straps. D, Jibs and cotters. E E, Oil cups.
crank pin being necessary; and indeed all the moving parts of a
locomotive must be plentifully supplied with oil or other lubricant.
In some examples (as Fig. 485), not at all to be commended, dove-
tailed pieces are let into the strap and butt, with a single bolt for secur-
ing them, passing through and through. It is evident that the dove-
tail weakens the strap, and when the strap becomes loose it is sure to
fracture at the weakcst part; we therefore consider that the joggles
formed on the butt are to be preferred. Some of the crank-pin bear-
ings are rounded with the bush bored out to suit, while all the bearings
should be well rounded at the corners, thereby materially strength-
ening the shaft. Various other forms of connecting rod ends have
been applied in practice; amongst these we note an example entirely
doing away with the straps (Fig. 487). The large end is cut out em-
bracing three sides of the bush, which is held in position with a plate
on the underside, and bolts passing through the butt, the bush being
adjusted with a single cotter. The small end of the connecting rod
is forked, and is fitted with a long bush, with jib and cotter for
adjusting the bush. In other examples for small ends the wear of

LocoMotive ENGINEs. - 613
SRF
º
j'O?S
:
i
:
fy
*
#
;
o
:
l
Figs. 485, 486.-Connecting Rods with Dovetailed Piece let into the Strap, and Rounded Bearing
for the Crank Pin.
A, Crank end. B, Crosshead end. C C, Butts. DD, Straps. E. E., Jibs and cotters. FF, Dovetailed pieces.
- G. Bolt. H H, Brasses. 1 i, Oil cups, kk, Set screws. L, Rounded bearing.













i
614 - MODERN STEAM PRACTICE.
the bush is adjusted with a wedge with screwed point and nut, the
end being solid and cut out for the reception of the bush (Fig. 488).
In order to reduce the clearance between the cotters and the
body of the boiler for inside-cylinder arrangements various forms
of connecting-rod ends have been adopted; in some the bush has
been adjusted with bolts and nuts, taking a cap bearing on the
bush, a T form of connecting-rod end being adopted with the distance
piece between the cap and end cast along with the bush (Fig. 489);
these connections have not been much used in the locomotive,
although they have been largely adopted in marine practice. *
C
I
i
—i.
v- H
HTT
-
-
-
-
-
-
-
*
-
-
-
--
*
--
--
-
*
l
§: . |J&
Fig. 487.—Connecting Rod with Solid End and Plate.
A, Crank end. B, Crosshead end. C, Butt. D, Forked end. E, Jib and cotter.
F. Cotter. G G, Bolts and nuts. H, Plate. I I, Brasses, k, Oil cup.
l
ſ
|-
Fig. 488. – Connecting-rod End with Wedge Fig. 489–Connecting rod End fitted with Cap
Adjustment. # --> and Bolts.
A, Solid end. B, Wedge. C. Oil cup. - A, Crank end. B, T piece, c, Body. D, Cap.
D, Brasses. E E, Bolts and nuts. F, Brasses.
Connecting rods for outside-cylinder arrangements materially
differ from those for inside arrangements with cranked shafts, the
end taking the crank pin being much reduced; it is generally
forged solid and cut out for the reception of the bush, which is






LOCOMOTIVE ENGINES. 615
adjusted with a single key, the end for the crosshead being fitted
with strap, jibs, and cotter as for inside-cylinder arrangements.
Ž
*A TI- Sºl I
Fig. 490.-Connecting Rods for Outside Cylinders.
A, Crank end. B, Crosshead end. c, Butt. D, Strap. E, Solid end. F, Jib and cotter.
G, Cotter and set screws. H H, Oil cups. I I, Brasses.
The crosshead end in some being single, while others are made with
a short fork for taking the crosshead, all the cups for the lubrication
§º
t SNS
| |-
nº TTE. T -
I r | tº]+
(# i(G):HE. º |
r ~2 - --
(ii) i |
Fig. 491.—Connecting Rods for Outside Cylinders.
A, Crank end. B, Crosshead end. C, Solid end. D, Butt. E, Strap. F, Jib and cotter.
r G, Cotter. H H, Oil cups. I I, Brasses.
of the crank pin and crosshead gudgeon are generally forged on
along with the butt and strap. In some examples straps are like-
wise used for the crank end, and in some forked ends have been
successfully adopted (Fig. 492), the bush being adjusted with a jib
and cotter; it is evident this form of connection is not so safe as
the solid ends or those fitted with straps; it will be observed that
the jaws of the fork are kept from springing with a tie piece, taking
the two set screws for the cotter. -






616 MODERN STEAM PRACTICE.
The rods for coupling the wheels should have the ends forged in
one piece; they are generally fitted with parallel brasses, having an
elongated flange on the same side as the cotter, which is adopted
for adjusting the wear, the cotters being placed each on the same
Fig. 492.-Connecting Rod for Outside Cylinder • e -- *
with Forked End. Fig. 493.-Coupling-rod End:
a, Forked end. B, Jib and cotter. C, Brasses. A, Solid end. B, Brasses. C, Cotter and
D, Oil cup. E., Tie piece. set screws. D, Oil cup.
side of the crank pins as the other; this is required to preserve the
true distance from centre to centre. The cotter is held in position
by two set bolts screwed into snugs formed on the butts, and by
a split pin at the under side of the cotter. Sometimes a metallic
piece is inserted between the bush and the cotter for taking the
strain. The lubricating cups are of brass, or forged on and bored
out, and fitted with siphon pipe having a cotton wick, by which
means a constant supply of oil is kept up, the lubricant falling on
the pin drop by drop. Without this appliance oil poured into the
cup would run to waste, and the pins would soon become serrated;
in fact, the simple application of cotton-wick siphons to the various
oil cups distributed over the locomotive engine tends in a great
measure to its success.
When the leading and trailing wheels are coupled to the driving
wheels, a joint with a pin is introduced; in some cases it is placed
between the driving and trailing wheels, while in others it is placed
between the driving and leading wheels. This joint is located close
up to the bushes, and is introduced to prevent the rod becoming
bent by the irregular vertical motion and vibration of the framing
and wheels, owing to irregularities in the permanent way.

LOCOMOTIVE
6 I ;
ENGINES,
~~ ~ ~★ →
Fig. 494.—Coupling Rods and Outside Crank Pins.
GG, Bodies of rods.
FF, Oil cups.
cc, Cotters and set screws. D D, Crank pins, E, Joint and pin.
B B, Brasses.
AA, Solid ends.


618 MODERN STEAM PRACTICE.
The pins for taking the rods are either fitted into holes bored out
in a solid part formed along with the spokes of the wheel, or
separate cranks are adopted. In some examples the 'ends of the
coupling rods are quite round, a simple eye being forged on the rod,
which is bored out for the reception of a thick round bush, which is
held in position with a washer and nut, the end of the crank pin
being screwed. In mostly all examples the body of the rod is of
a flat section, while in others it is turned, and in some the top
- and bottom are turned and the sides
C | | D flattened.
Coupling rods have been fitted
with straps, with two jibs and cotter
for holding the strap rigid, and a
single cotter for adjusting the wear
of the bush, which in many instances
is bored out to fit a spherical-shaped
pin. We certainly prefer the ends of
the coupling rods forged in one piece,
and such ends are universally adopted;
they are better calculated to meet the
ria os-cººrded violent motion these rods are sub-
a, Butt, b, strap. c. jib and cotter jected to. All the parts should be
D, Cotter. cº ** as rigid as practicable, with no part
. liable to shake loose.
Cranked arſe.—When the cranked axle is arranged with a main
outside bearing it must have a narrow bearing placed close up to the
&
:
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$
Fig. 496.-Cranked Axle.
A, Main body of axle. B, Crank pin. C, Inside journal. D, Outside journal.
E, Part for outside cranks. F, Part for wheel. G G, Crank.
cranks, as when the main bearing is outside of the wheels it is impera-
tive that the cranked axle should be supported close up to the





LOCOMOTIVE ENGINES. 619
cranks; but in many examples of inside-cylinder engines the axles
have no outside bearings, but simply a broad bearing with the side of
the brasses rubbing quite close against the flat sides of the crank.
This plan has been very generally adopted both for broad and narrow
gauge engines; it is certainly much simpler than the cranked axle
having outside bearings on the main framing and likewise narrow
bearings fitted to the horn plates; moreover the breadth over all
is greatly reduced, the outside coupling rods being placed quite
close up to the wheels. In manufacturing cranked axles a long
slab is hammered up, and then swaged down in the middle and at
the ends; the throws are then worked into shape, and the axle is
then twisted at the central part, until the throws are at right angles
with each other—the grain of the iron running across the throws;
by this method they are not so liable to split through. Some
cranked axles are bent with the aid of hydraulic machinery, a long
bar being heated and put into the machine; the throws are formed
with a die and mould, the die being pressed up by water power:
these axles give great satisfaction. When the axles are delivered
at the factory the throws are gen-
erally solid with the ordinary
method of construction; they are
then slotted out, and the axle is
then turned in a lathe. All the
corners of the bearings should be
well rounded, as the axle is greatly |
strengthened thereby. In some B
| 1–
the crank pin is turned of the
same diameter throughout with Fig or stars on inside car, A, Crank
bold curves at the corners, while in pin. B, Axle. C C, Straps.
others the pin curves from the -
middle to the sides of the crank; by this means greater strength is
obtained over those that are finished parallel. The ends of the crank
throws are rounded at the outside corners, thereby reducing the
weight, while others are left quite square, the extra weight being
balanced on the wheels. In some examples a wrought-iron strap has
been shrunk on each crank, with the view of binding the fibre of the
iron better together; this we consider may be to a certain extent advis-
able, although it adds more weight, which must be properly balanced;
on the other hand, when due attention is paid to the selection of the
scrap iron, with good workmanship, and with the improvements

62O - MODERN STEAM PRACTICE.
in manufacture, we consider these straps not at all necessary, and
they are but little used in modern practice. With plain driving
axles used for outside-cylinder arrangements the bearings are placed
inside of the wheels in a similar manner as for cranked axles, having
no outside bearings, while the crank pin is rivetted into a hole bored
out in a boss forged along with the wheels. When the wheels
are coupled together the crank pin has two bearings, one for the
coupling rods placed close up to the wheel, while that for the main
connecting rod is placed outside of it considerably overhung, throw-
ing a severe strain on the part, which, fitting into the wheel, is made
conical and rivetted at the end into a countersink, thus making it
very secure. The bearing for the coupling rod on the crank pin is
made larger than what is actually required for the other wheels,
simply to strengthen the pin for taking the strain imparted from
the steam piston and connections. The connecting rod in many
cases is held on with a collar forged along with the pin, while others
have a nut and washer, and some a plain washer with a pin passing
through it. There is likewise a collar turned on the pin between
the two connecting rods, when so fitted, for keeping the brasses
separate, as they would soon tear were they in juxtaposition.
Plain axles consist of four parts, namely, the body or middle, the
*-43.
C}
|
k
Fig. 498.—Carrying Axle.
A, Body. B, journal. C, Part for wheel.
parts for taking the wheels, the journals, and the parts for the
outside cranks. To combine lightness with strength, the axle
should taper from the middle to the raised parts for taking the
wheels, which should be of increased diameter to obtain a large
bearing surface for the eyes of the wheels; in the inside there should
be a shoulder for the nave of the wheel abutting against. When
fitted with outside bearings, the journals are reduced in size, while
the parts for taking the outside cranks are of greater diameter than
the journals. When the axle has only inside bearings all the parts are
generally of the same diameter, excepting the collars for the wheels
and journals. It is preferable, however, to make the part for taking







LocoMotive ENGINES. 621
the eye of the wheels of increased diameter to secure a larger sur-
face, the boss of the wheel in such cases rubbing closely against
the brasses in the axle boxes, while with collars the nave of the
wheel is kept the breadth of the collar apart. All the journals
should be finished with a tool in the lathe, leaving well-turned curves
at the corners. The old method of using emery to get a smooth
surface has for long been discarded, as particles of the emery got
imbedded in the iron, and soon played sad havoc when the engine
tº s:-----Centres of Bearings 6 2% ----------------- 4-
***...-7%.----. 7%.-->

º
-
*T-
* º & º T
e • : i" : :
*: wº * * *...* $º
C; B $ is $ § 4 $
. & i : * &
jº Lº–T
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Fig. 499. –Leading and Trailing Axle.
A, Body of axle. B, Journal. c, Part for outside crank. D, Part for wheel.
was started. When the wheels are coupled the journals should be
nearly of the same diameters, but this depends on the weight as
adjusted with the springs.
Axles are generally made of scrap iron drawn out at two heats.
When new iron is used it is taken from the puddling furnace, put
through a squeezer, then piled, heated, and rolled twice, and finally
heated, and swaged into shape. There is considerable difference of
opinion as regards the manufacture of axles from scrap iron, on the
one hand, and new iron on the other hand; scrap iron must neces-
sarily vary very much; the pile may be composed of a variety of
qualities of iron, such as old and new, hot short and cold short,
burned and raw; and in the process of heating, one part may be
burning while others are welding; thus it is difficult to pick out
scrap iron that combines all the necessary qualities so essential
in manufacturing a sound axle. The scrap iron generally adopted
in railway workshops is old tyres taken from the carriage wheels,
and this may be considered the best description that can be used for
such forgings. With ordinary scrap iron the pile requires to be
well drawn down in order to secure a uniform grain, as parts of the
pile may be drawn out while other parts may be upset. All iron
is subject to be either more or less burned or worked at too low a
heat; that, combined with bad workmanship, renders it difficult to
say whether new or scrap iron axles are to be preferred; we are
inclined to consider, however, that axles made from new iron of
622 MODERN STEAM PRACTICE.
good quality, and with first-class workmanship, are preferable to
those made from ordinary scrap iron of doubtful quality.
Wheels consist of four parts, namely, the nave, the spokes, the
inside tyre or ring, and the outside tyre. They are manufactured
in a variety of ways; some have wrought-iron rings and plain spokes,
with nave forged on, and some cast-iron naves, with spokes vary-
ing in section: the latter method, however, has now become ob-
solete. In modern practice the nave, spokes, and ring are built
up, and forged in one mass. The spokes are forged with wedge
pieces to form the nave, and T-shaped pieces for the inner tyre
or ring ; the ends of the
T pieces are bevelled; thus
when the spokes are put to-
gethera series of wedge spaces
are left to bewelded up. After
the spokes are forged they are
taken to the grinder to be
ground quite smooth, a re-
volving-stone being used for
that purpose. The spokes are
then put together, and are held
Nº º in position with a strap and
Fig. 5oo.—Wrought-iron Wheel.—A, Nave. screw; the nave is then placed
B, Arm. c, Inside tyre. D, Outside tyre. E, Rivet. on the fire and brou ght to a
welding heat; at the same time a thick washer is brought to a
welding heat in a fire adjacent, two smiths being required, one for
attending to the nave and the other to the washer.
The smith attending to the nave, when it is brought to a proper
heat, gives the screw on the strap an extra turn, thereby forcing the
series of wedge pieces more closely together. When both are ready
the nave is put on an anvil, and the washer is placed on it, and a
few strokes of a suitable steam hammer unite the mass; thus one
side is partly finished, a washer being required for each side, the
other is in like manner welded on; the nave is then dressed off with
hand labour. After the nave is completed the strap is removed
and a straight bar attached, with means of turning the mass over,
so that the wedge space in the ring or tyre can be filled up and
welded bit by bit. The spoke wheel is then taken and placed in
the turning lathe, and the ring turned with a plain surface, at the
same time the eye is bored out.

LOCOMOTIVE ENGINES. 623
The outside tyres of iron or steel are generally ordered from the
rolling mills in hoops entire, which are turned out with a plain
surface in the factory. Both spoke-wheel and tyre are then taken back
to the wheel shop, which should be adjacent to the turning depart-
ment, the Smith then heats the outer tyre in a furnace for that pur-
pose, the spoke wheel being placed in a circular trough. The tyre,
after being brought to a proper heat, is taken out of the furnace and
placed over the ring on the spoke wheel; the outer tyre having
expanded with being heated, is easily placed over the ring, and
water being let into the trough, it contracts on the ring and
firmly embraces it as it were in one mass. The wheel may then be
fitted to the axles, which have generally the key ways cut in each.
The keys are of steel, and are fitted accurately into the key beds,
and are then driven in with a sledge hammer. The wheels and axle
may then be taken to the turning shop and put in the lathe, the
centres on the axle being left on for that purpose; thus the trods
of the wheels are turned all over and finished off quite truly with
the journals, as the same centres for turning the journals are used
for turning the outer circumference of the wheels.
Six-wheeled engines have generally flanges on all the tyres, for
preventing the engine leaving the rails; but when more wheels are
adopted, with the driving wheels placed in a central position, it is
better to have the tyres for the driving wheels without flanges, so
that the engine can turn round sharp curves easily. A few tap bolts
are fitted to holes tapped through the inner tyre, and partly tapped
in the outer tyre; some are fitted with nuts which are screwed hard
up, and the point of the bolt rivetted over, while the bolt is put in
hot, and the point rivetted over.
Wrought-iron wheels for outside-cylinder engines have the bosses
forged along with the arms for taking the crank pin; weights for
balancing the crank throws, connecting rods, &c., are fitted to the
wheels inside of the inner tyre or ring, having side plates for keeping
them in position, which are held together with bolts rivetted over.
In some the balancing power has been put into the inner tyre, this
being forged of greater thickness at one part for that purpose.
Wheels of small diameter are sometimes made of cast iron, and
are suitable for waggons, &c. The usual practice is to cast the
nave, arms, and ring together, and fit the outside tyre of iron or steel
in the usual manner. The arms are made of a strong sectional area,
as likewise the ring; a T form of arm was formerly adopted, but
624 MODERN STEAM PRACTICE.
in modern practice solid arms are the rule, though some are made
hollow in the casting as well as the naves. Much attention has
been paid to wheel castings in order to prevent them cracking from
the unequal expansion of the cast iron. A wheel properly propor-
tioned in all its parts will give way if one part is cooled sooner than
another part; for instance, the ring being thinner than the boss,
_VT) ( / N_2^ T TM
> -ºº:
I . # |
*——6+ i--
s
| |
|
º §c
% §§
#
A, Nave. B, Arm. C, Inside tyre. D, Outside tyre. E, Crank pin and boss.
Fig. 5or.—Cast-iron Wheel.
contracts rapidly, the great body of metal in the nave being still in
a fluid state, which in cooling tears away from the rim; it was there-
fore found necessary to divide the nave, and afterwards fill up the
spaces with iron plates, two wrought-iron hoops being shrunk on the
nave, one on each side, similar to the fly wheel of a land engine.
Cast-iron locomotive wheels are now annealed in a kiln for that pur-
pose. A deep pit made of brickwork is heated red-hot, and while



LOCOMOTIVE ENGINES. 625
*
the wheel is red-hot it is taken from the mould and placed in the
kiln, which is then covered to prevent access of air; the wheels
taking three or four days to cool, must necessarily cool equally, and
this treatment prevents internal strain.
Sometimes large wheels are cast in a chill on the trod, and it is
a fact worth noting that the chill is not destroyed by the annealing
process, as no heat below that which the cast iron has when the par-
ticles taking the chill are solidified affects the peculiar hardness of
the metal. There are certain objections to chilled wheels: they
cannot always be cast of uniform diameter, and should the nave be
bored out eccentrically much harm will ensue by the wheels wearing
unequally. Besides, when such wheels are acted on by brakes, if
care is not taken to prevent their locking, flat places may be formed
on them by the brakes, which will prove very injurious, and the slid-
ing action will also cause the chill to get soft. These wheels, how-
ever, are much cheaper than those fitted with iron or steel tyres, and
have an advantage over the latter, inasmuch as when the line of rail-
way is rough the cast-iron chilled wheels are not liable to become
indented on the flanges, which sometimes takes place to such an
extent with wrought-iron tyres as to endanger the safety of the
engine. Wheels from 3% to 43 feet are sometimes cast in the plate
or disc form, thereby lessening the tendency to fracture. The
balance weight is cast along with the cast-iron wheels, whether
the disc or radial-arm form is adopted.
Outside cranks.--When the axles are fitted with bearings placed
outside of the wheels, with the wheels coupled together, wrought-iron
cranks are fitted to the ends of the axles, having one large key way
and two smaller ones for keeping the crank firmly on the axle.
The crank pin is forged along with the main body of the crank; when
six wheels are coupled together the width of the crank pin bearing
for the middle crank is made in excess of the other two to allow for
any lateral motion. The sides of the crank are quite straight from
boss to boss; thus they are more easily planed, and at the same time
the crank is much stronger. In other arrangements with inside bear-
ings for the axles, the crank pin for the coupling rod is let into an
eye bored out in a part forged on, or cast along with the nave of
the wheel. The part fitting into the wheel is tapered and securely
rivetted in. A set screw bearing on the side of the tapered part is
screwed into a hole tapped through the eye, thus preventing the pin
from turning; this can be done likewise with a short key let into
40
626 MoDERN STEAM PRACTICE.
the pin at the neck, which fits into a hole cut in the eye. On
the end of the pin a collar is turned for keeping the rod in
position, while others have
a screwed part at the
end, having a nut and
washer bearing on the
side of the brasses of the
coupling rod. When the
coupling rod takes the
crank pin for the piston
connecting rod, the for-
mer being next the wheel,
the pin is enlarged over
the others in order to
strengthen the pin, as the
overhang is considerable.
In some examples the
Fig. 502.-Outside Cranks. pins for the outside cranks
A, Crank pin. B, º º C, Eye of crank. are turned spherical, with
, KeyS.
the brasses in the rods
bored out to suit, thus the rod swivels as it were with the motion,
tending to throw less strain on the pins.
Framing and axle boxes.—The framing in all modern examples
extends between the front or buffer beam and the back or draw beam,
and is either double or single. With the former, suited for outside
bearings, the frame was originally composed of two thin plates with
wood between, held together with rivets, while the inside frame or
horn plate was wholly of wrought iron. -
When inside bearings are adopted the frame plate is of wrought
iron, a plain parallel beam of considerable width and thickness, to
which are fitted the horn plates for the axle boxes, but some have
the horn plates and stays forged all in one piece. The framing is
stiffened by the cylinders when placed between them at the front,
the motion bar plate forms another source of stiffening, then comes
a plate fitted between the frames in front of the fire box, while at
the back of the fire box, plating is arranged for taking the drag links,
and in some instances a casting is introduced, thus giving weight
for adhesion in the hind wheels, and also strengthening the framing for
taking the drag links, the pull and thrust being taken directly on the
framing. Double frames are likewise made entirely of wrought iron.
* e 2%. ,

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Fig. 503.-Plain Plate Framing.
A, Frame plate, B, Horn plate, c, Horn plates for the axle boxes. D D, Stays. E, Draw beam. F, Buſſer beam,
G, Guard, H, I.eading wheels. 1, Driving wheels, k, Trailing wheels,





623 MODERN STEAM PRACTICE.
The front beam for taking the compression strain, imparted
through the buffers, is generally made of wood fitted directly to the
frame ends, a flange being formed on the ends for bolting the beam
to; sometimes a plate is introduced between the beam and the frame
ends, an angle iron fastening being adopted to which it is firmly
rivetted. The wooden beam in some cases extends the whole breadth
across the light frame work and platform fitted on the top of the
framing for passing round the engine, but it is preferable to end the
beam at the longitudinal main framing, or otherwise bevel it from
that point to each end; thus the blow imparted through the buffers
is taken directly on the main framing, and cannot affect the light
angle-iron frame for carrying the foot plates; moreover, the beam
to a certain extent acts as spring beam for taking the shock. The
draw hook and chain in front of the buffer beam, which is used when
the engine is going backwards, is secured with an eye bolt passing
through the buffer beam and plate, having a nut bearing on the plate.
The hind or draw beam is generally of wrought iron secured to
flanges formed on the longitudinal frames; a framework of angle
iron and plates is rivetted to the beam, spreading over a consider-
able space under the foot plate between the main frames to which
it is securely rivetted; this framework carries the pin for the draw
shackle, and consequently, as the whole strain of the engine comes :
on this part of the framing in the first instance, it requires to be
strongly united to the longitudinal beams forming the main frame.
In some instances a framework of cast iron has been adopted,
carried from the draw beam forward to the back of the fire box.
An angle piece is rivetted to the fire box; by this means the boiler
is partly supported on the cast-iron framing, but in most instances
the angle irons are rivetted to the sides of the fire box, taking an
angle iron rivetted to the frame plates. The boiler has the power
of expanding and contracting without straining the main frame-
work, owing to the bolt holes in the angle iron being oblong, a very
important matter to consider in the construction of the locomotive,
for when the boiler is rigidly held with the framework without the
power of expanding, rupture must eventually take place at some
part, and more than likely in the body of the boiler. The other
frame brackets for supporting the body of the boiler are formed by .
a continuation of the motion-bar plates, and at the front end the
smoke box is secured to the main framing, the boiler expanding
from that point quite independent of the framing. -
LCCOMOTIVE ENGINES. - 629
When inside bearings for the cranked axle are used with outside
bearings for the leading and trailing axles, both of the frame plates
are in some examples made of wrought iron, having the horn plates
or plates for taking the guides for the axle boxes forged on; the
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Fig. 504.—Inside Bearing and Horn Plate.
A, Inside horn plate. B, Axle box. C C, Guides for axle box. D, Hollow distance piece and bolt.
- E, Spring. FF, Spring harness. G, Spring pin.
framing is stiffened with cross pieces between the two frame plates
at each side, and likewise stiffened between the two inside ones.
The buffer beam is carried across as before, the compressive strain
imparted through the buffers being in a more direct line with the
outside frame plate, to which it is securely attached, as likewise to
the inside frame, having a plate between the buffer beam and the
end of the framing.
The back end or drag beam is fitted as before with plate and angle
iron framing for taking the drag link, the framework being securely
attached between the two inside frames.
When the driving and trailing axles have inside bearings, and the








C3o MODERN STEAM PRACTICE.
leading axle has outside bearings, double frames are used, and when
the cylinders are placed outside, or between the two frames at each
side, the outside frame is made of reduced thickness from the
curved part of the horn plate at the top for taking the leading axle
to the hind beam. In front of the driving wheel a plate joins the
two side frames, to which the double-motion bars for the piston cross-
head are firmly secured, as they are also to the cylinder cover.
These double frames no doubt tend to make a much stronger
framing, although it is not desirable, with outside-cylinder arrange-
ments, to receive the shock of the buffer beam on the outside frame.
Double wrought-iron plate framing is likewise used for inside-
cylinder arrangements, having the driving and hind wheels coupled,
the leading, driving, and trailing wheels being fitted with outside
bearings, while an additional inside bearing in such cases must be
used for the cranked axle, supporting it quite up to the sides of the
Crank throws. s
Wrought-iron plate framing is now generally adopted for all
classes of engines; when so fitted the hind or drag beam is some-
times made of wood, with an outside plate running across and bent
in at the ends for taking the longitudinal beams, having a short
plate interposed between the beam and the ends of the main framing,
the part for taking the drag shackle being made of plate and angle
iron, securely rivetted to the two inside frames and to the drag beam
with angle irons, thus making a very secure attachment.
Por outside-cylinder arrangements the side frames in some
examples are connected together by one or more water tanks, of
which they form the sides, the whole being framed on angle iron,
with all joints rivetted and caulked the same way as a boiler. By
this arrangement, the tanks being an integral part of the framing,
great rigidity is secured. This principle is applicable to locomotives
variously constructed as regards the number and position of the
wheels. *
It is customary with outside-cylinder arrangements to make the
framing deeper at that part where the cylinders are attached, a hole
being cut out in the frame for allowing the valve casing to pass
through; some merely undercut the framing, while with inclined
cylinders, flanges are cast on for bolting to one or both of the frame
plates.
The axle guards, to which the guides for the axle boxes are
bolted, are forged along with the frame plates, or in separate pieces,
LocoMotive ENGINES.
631
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632 MODERN STEAM PRACTICE.
securely rivetted thereto. When the framing is composed of two
thin plates, with a wooden beam between them, the guards are
formed along with the frame plating; long guards so constructed
require to be well stiffened by the axle-box guides, which in some
instances are carried up between the plates into the timber, and
securely bolted through and through the frame plates and timber.
The guides are strengthened with flanges and bosses, having holes
cast through, and are securely rivetted to the guard plates; they
are also fitted with a distance piece and bolt underneath the axle
box, thereby preventing the guard plates from springing; in other
examples a tie bar with bolts is fitted to the guard plates. When
a wrought-iron single frame plate is adopted with two guard plates
rivetted thereto, guides of wrought iron are sometimes used of a T
section, which are securely rivetted between the guard plates, the
guards having a flat tie bar taking all the axles, and being inclined
upwards at the end, taking the under side of the buffer beam. When
the guard plates are forged along with the single frame plates the
guide plates are of wrought or cast iron securely rivetted thereto,
having a clip stay bar secured with bolts and nuts to the guard
plates. In some cases both the guard and guide plates are forged
along with the frame plate, thereby dispensing with rivetting,
the guide plate having a distance piece with bolt passing through,
with nut and jam nut, for securing the bolt. In others the guide
plates are cast together, having sides and top piece, with a boss on
the top, having a hole for the Spring-bearing pin passing through.
Sometimes one side of the guide plate is movable, with a wedge
adjustment, so that the wear of the axle boxes, caused by the
knocking action due to the working of the engine, can be
adjusted. •
The guide plates are planed on the surface and sides, and should
be quite parallel. The guard plates are likewise planed on the
edge, fitting accurately against the guide plates, which are likewise
planed on the part the guard plates fit against. In fitting up the
guide plates they should be screwed hard up against the guard
plates, and then all the rivet holes made fair prior to rivetting up.
The axle boxes are of cast iron with brass bushes; flanges are
cast on each side of the box, which bear on the sides of the guide
plates, thus guiding the axle box vertically; the working sides of
the axle boxes and flanges are planed, bearing against the planed
surface of the guide plates. With the springs placed above the
LOCOMOTIVE ENGINEs. 633
axle box, the whole weight is taken on the top, the spring-bearing
pin resting on the cast iron, a boss with a part cast out or bored
out being left on, forming a step
for the end of the pin. The sides
of the axle boxes are from 34 to
I inch in thickness; but when
the springs are underneath the
axle boxes the sides require to
be much thicker, as the weight
is taken through the sides. A
wrought-iron strap has been
used to strengthen the axle
boxes; the strap is bent over
the box, passing down on each
side, the pin for taking the
spring shackle passing through
the strap. Wrought-iron axle
boxes have been used; they are of course much stronger, but
they do not wear so well as the cast-iron ones; solid brass, and
Muntz metal axle boxes have likewise been adopted for underhung
spring arrangements, the brass sides being 1% inch in thickness,
but of course they can be made much thinner, when a wrought-
iron strap is likewise used.
The brass bushes for the axle boxes are quite circular, bored out
parallel in some, while in other arrangements the bearing tapers
from the centre, where it is small, to a larger diameter at the
sides, the journal being made accordingly. The bush should be
well fitted into the axle box at the top and sides; it is preferable
that the top surface should bear all over, but the sides may have
fitting strips, thus lessening the labour in fitting up. Flanges for
holding the bush in its place are cast along with the top bush,
and are likewise accurately fitted into the axle box. The bottom
bush is a mere shell of cast iron, fitted into the bottom part of the
axle box, and is held in position with two pins, passing through the
sides of the axle box and bush. The top part of the axle box must
be made of considerable thickness for taking the weight imparted
through the springs; it is formed with a circular seat for the spring
pin, but sometimes, two spring pins are used of a flat section. The
sides of the axle box project above the crown, forming a grease cup
for the tallow and oil used in lubricating the journals. The bush
|Fig. 507.-Brass Axle Box with Wrought-iron Strap.
A, Axle box. B, Strap. C, Shackle.

634 MODERN STEAM PRACTICE.
for the journals should be bored out about ºth of an inch larger
than the journal, as they are not so liable to heat when made a
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Outside Driving Axle Box. Inside Driving Axle Box.
Figs. 508, 509.-Axle Boxes with Tapered Bearing.
A, Axle box. B, Brasses. C, Oil cup. D D, Holes for siphon wicks. E, Boss and hole for spring pin.
little slack in the first instance. The grease chambers should be
fitted with two siphon tubes, which are screwed into the top part of
the axle box, and provided with cotton wicks, the wicks insuring by
capillary action a constant and steady flow of oil, or other fluid lubri-
cant; holes are bored through the bushes, and grooves are cut from
hole to hole in the brass, thus allowing the oil to flow along the top
part of the journal. Sometimes the grooves have been cut diagon-
ally from each hole; this plan is not so good as the former, as the oil
runs greatly to waste; whereas, when a groove is cut in the brass
along the top, the lubricant flows on the top of the journal, where it
is most required. $ I -
Sometimes a separate oil chamber is cast on the top of the axle
box, provided with a cover, and siphon tubes and wicks; and for
the leading and trailing axles, with the wheels uncoupled, the axle
box has an outside plate cast along with it, which prevents dust and
grit from destroying the surface of the journal. In some arrange-
ments the lubricating cup can be removed through the hinged cover
at the end, while the under shell is so constructed as to catch the
waste oil, thus providing a very efficient mode of lubricating the















LOCOMOTIVE ENGINEs. ... • 635
journal, the pin for the spring bearing upon the top of the chamber,
where the oil cup is placed. Sometimes the axle boxes for the
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Fig. 510. –Axle Box with Covering Plate. - Fig. 5x1.—Axle Box with separate Oil Cups, &c.
A, Axle box, B, Plate cast on. C, Oil cup. A, Axle box. B, Oil cup. c, Hinged cover.
D, Recess at bottom.
driving axle are fitted with wedge pieces between the flanges, one
on each side, acting as guide plates, but adjustable at pleasure,
these wedge pieces sliding on guides which are rivetted to the
frames. At the top and narrow end of the wedge a round part is
forged on, turned, and cut with a screwed thread, which, passing
through a hole in a bracket rivetted to the frame, the wedges are
adjusted and held in position with a nut bearing on the top and
º
Fig. 512.-Guide for Axle Box with Wedge Adjustment.
A, Axle-box guide. B, Wedge, c, Horn plate. D, Adjusting bolt. E, Set screw. F, Hole for the spring
pin, G, Tie bar.
bottom of the bracket. In another arrangement a single wedge is
adopted on one side, while the other side of the axle box has a
plain guide; the wedge piece is the entire breadth between the
flanges, and is drawn up with a screwed part, which is forged along
with the wedge as in the preceding example. In Figs. 512 and
512A is an arrangement of adjusting wedge and axle box fitted to
*









636 MODERN STEAM PRACTICE.
more recent engines. The guide is made all in one piece, and
securely rivetted to the horn plate. The adjusting bolt for the
wedge is at the bottom, the nuts bearing on the part forged on the
tie bar, while the adjusting bolt passes through a slot formed on
F F
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Fig. 512A.-a, Axle box, B, Top bush, c, Bottom. D.D., Pins for securing the bottom part.
E E, Oil cups. F, Spring pin. -
the guide. This example of wedge pieces is fitted by some
makers to the back of all coupled axles. The inside bearing used
for cranked axles, when fitted with bearings outside of the wheels,
is likewise fitted with wedges in some examples, one on each side
of the horn bar, having the guides forged thereon. The wedges are
cut with a groove which works in a feather on the guide pieces.
The tightening parts are forged on and cut with a thread, and are
longer than in the previous examples, passing up through elongated
holes on the top of the horn bar, having a nut and a jam nut for
each wedge. The jaws of the guide pieces have a long ferrule at the
bottom, with a bolt passing through, to prevent the jaws springing.
Springs and /arness.-Springs are flexible beams, composed of
thin steel plates, loaded at the middle, and free to move at the ends.
Ordinary springs are much deeper at the middle than at the ends.
This is required to obtain uniform flexibility throughout, the plates
decreasing in length towards the centre. Every part of a spring
should yield equally throughout. If any part of a spring is more
rigid than another part, it is between those parts that the spring
will give way, simply because the portion that is the most flexible
will become unduly strained. Springs that are properly constructed,
and loaded within the limits of their capacity for carrying weight,
deflect through equal spaces for equal additions of weight applied,
when the span is sensibly constant When the compass of a spring
is considerable the span or length of the spring must increase with
the weight applied. The elastic strength of a spring is measured
by the weight necessary to cause a given deflection, and vice versa.



















LOCOMOTIVE ENGINES. 637
The strength is measured by the greatest weight the spring can
carry without giving way; when over-weighted, the symptoms of
rupture consist in the greater apparent elasticity of the spring, or a
greater deflection under a given increase of weight, independently
of what may be due to an increase of length or span. That point
at which a decided change takes place is an index to the strength of
the spring. Ordinary springs, when loaded, are 2 feet 8 inches from
centre to centre, and when unloaded, 2 feet 7% inches from centre
to centre, and have a set of 5% inches from the point of suspension
to the top of the plates; the breadth of the plates is usually 4 inches.
The following table illustrates the constancy of the elasticity for
sensibly equal spans, and its slight increase as the weight carried
is increased is due to the increase of span:-
DEFLECTION UNDER GIVEN LOADS.–Span in working order, 30 inches.
2 plates of § inch in thickness; I4 plates of fºr inch in thickness—I6 in all, 4 in. broad.

Compass Measured Total Span Measured
Loads. to the Centre of Deflecti to the Centre of
- Suspension. €ſleCLIOI. Suspension.
CYytS. inches. inches inches
O 53 full. O 28;
35 5#. • * * 2.94%;
4O 51%. +: 29Hºr
45 51's full. # full. 293
5O 5 full. § 29.1%
55 4+; # full. 29%
6o 4 bare. # 29.1%;
65 43 full § 29# bare.
7O 4+; full. # 29# full.
75 43 I full. 29%
8O 44%; bare. ' I+’s full. 29#
85 44's full. I#s 29š
90 43 full. I+ 3O
95 41’s I# 3o full.
IOO 4t Iš 3OH's
after shak- 4$ I# (§ set). 3Oś full.
ing lever. - –-
It will be found that the flexibility is increased 2-6 times when
the span is a trifle over 30 inches. This extension is entirely due
to the weight applied and to the great compass of the spring. The
elastic strength of a spring is one thing, and its elasticity when
unduly loaded is another. The strength varies as the span or
length between the supports inversely, as the depth or number of
plates directly, as the square of the thickness of the plates, and as
the breadth of the plates; while the elasticity varies as the cube of
the span, as the depth or number of plates inversely, and as the
breadth of the plates.
638 MODERN STEAM PRACTICE.
The flexibility of the engine springs varies in practice from 34 to
I inch per ton of load, and in some is even as low as % of an inch.
Springs should be easy of action, and should be more or less flexible
to meet the requirements. The springs fitted to the axle boxes of
the leading wheels should generally have the least flexibility, as from
the severe strain due to the irregularities of motion of the engine,
and imperfections in the permanent way, their springs are very
severely tested. In a six-wheeled engine, having the centre wheels
as the drivers, the springs fitted to the driving axle boxes should
be made of great elasticity, so that the wheels have always a grip
on the rails, maintaining the full tractive load as equally as possible;
more especially as the load on the driving wheels being the greatest
the rails may yield with the weight, and partially lose a portion of
adhesion or traction due to more weight being thrown on to the
hind spring. The latter should be of great flexibility, so as to yield to
the driving springs when the wheels sink from unevenness or sink-
ing of the rails. At the same time the hind springs should be of
sufficient elastic strength to steady the motion of the engine.
In engines having the hind wheels coupled to the drivers, the springs
may have an elasticity of 34 an inch per ton of load. For
engines much overhung either before or behind 3% of an inch per
ton should be allowed for the elasticity of the springs. If the
overhang be behind it should be reduced to 36 of an inch per ton
of load; and in six-wheeled coupled engines, running at low speed,
the flexibility need not be more than % or fºr of an inch per ton
of load.
The springs most commonly adopted consist of steel plates in
close contact with each other for their entire length, with wrought-
iron eyes forged at the ends of the top plate, to which the links are
secured with a pin passing through a hole bored in the eye. This
form of spring from long practical use has been found to answer
all the requirements. In some places where there is not much
ventilation, and a good deal of moisture, as in the draw springs under-
neath the framing, close plated springs are not so good as open
springs, owing to moisture getting in between the plates, which soon
become rusty and stiff, and cease to act in a satisfactory manner.
The plates of the springs are kept fair with each other sideways by
studs punched up at the ends of each plate, entering and sliding in
slots in the plate adjacent. Modern springs have a longer part
punched in a similar way, fitting into a hollow in the plate adja-
LOCOMOTIVE ENGINES. 639
cent; this ridge and furrow gives greater strength for preventing the
plates moving either longways or sideways. The plates are likewise
held in position with a wrought-iron hoop shrunk on at the middle,
binding the whole together, and fitted with a boss and hole to take
the end of the spring pin, which bears on the axle box. The springs
are arranged above the axle in some cases and below the axle in
others, there being independent springs for each axle box; while in
others the trailing, wheels are sometimes fitted with one spring for
both axle boxes, arranged across the engine below the foot plate.
The springs are generally fitted with scroll or solid ends for taking
the links and pins, and in some flat ends are adopted.
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Fig. 513.−Spring with Plain Link Harness.
A, Spring. B B, Harness. C, Spring pin.
The most simple description of spring harness has one link let
into jaws formed on the solid ends of the plates, with a pin passing
through the eyes formed on the top plate, the bottom end of the
link being secured to the framework with a pin, supported with a
bracket rivetted to the frame. All these pins should be fitted with
a washer at the end, and a split pin passing through the main pin.
Another plan adopted for single wrought-iron frame plates has two
links, one on each side, with a raised boss at the bottom end, the
top and bottom being secured with a pin taking the links and the
spring at the top, and another the links and frame at the bottom
end. The spring pin for taking the thrust on the top of the axle
box is round in some, with a reduced part turned at the top, which
fits into a hole bored in the central hoop, and sometimes passing
through the spring and hoop, and Secured with a nut at the top. In
others, the spring pins are of a flat section, having two pins for each


64o MODERN STEAM PRACTICE.
spling, one on each side of the frame. These are guided by means
of a wrought-iron bracket rivetted to the frame, with holes bored to
suit the round pins, and a flat part formed in the bracket for the flat
pins, the bottom end of the pin resting in a part formed on the top
of the axle box. In other forms of spring harness adopted for solid
eyes, formed on the top plates, the links are made with a clip piece
at the top embracing the eye, thus no pins are required, the weight
being taken directly on the clips. *
When plain links and pins are adopted the spring, when once set,
cannot be altered; this is the only inconvenience attending so simple
an arrangement. It is considered, however, in many examples that
the spring harness should be so constructed that the spring can be
tightened up, as it were, or slackened at pleasure. With that object
in view a box form of link has been adopted, made with jaws for
taking the spring ends; the bottom part of the link is different, being
made with an eye and pin for passing through the framing. It is
likewise screwed for part of its length, having a nut which bears on
the bottom part of the top piece by simply turning the nut, when
the weight is on the spring. It can be shortened or lengthened as
required, by this means adjusting the spring to the greatest nicety.
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Fig. 514.—Flat-ended-Spring and Harness.
A, Spring. B, Shackle. c c, Shoes. D, Axle box.
When the springs are flattened at the end the link is simply a
round bar, with an eye and pin for the bottom end, and a raised




















LOCOMOTIVE ENGINES. 641
screwed part for the top end, which passes through an elongated
hole in the ends of the spring, the spring being adjusted with a nut
on the top, having a jam nut and split pin passing through the end
of the link, and in some a simple strap is indented in the ends, with
a pin for securing the strap to the framing. When flat-ended springs
are arranged underneath the axle (Fig. 514), the spring is connected *
to the axle box with two side links and pins, taking a snug on the
central hoop on the spring; a snug is likewise cast on the bottom
half of the axle box bush, which is made of extra strength to take
the strain. Shoes are fitted to the frame or horn plates, having
projecting flanges to prevent the spring moving sideways.
When transverse springs are adopted the spring harness is arranged
at the middle, the spring working in some cases between the trans-
L- hºmºsº
Fig. 515. —Transverse Spring.
A, Spring. B B, Axle boxes.
verse plates, which are rivetted to the framing, and the spring is set
up with a single nut and screwed piece forged along with the cen-
tral hoop. Volute springs have been used for the hind axles; the
vertical pin for taking the thrust on the axle box has a plate at the
top, recessed for two volute springs, one on each side on the top of
the springs; another plate is placed so as to bear on the small flat
end of the springs; a bolt passes through each end down the centre
of the springs, and through the bottom plate, these bolts passing
through holes in brackets which are rivetted to the main frame; the
bolts are screwed at the bottom, and the springs are adjusted with
a nut and jam nut on each. The thrust pin should be guided with
a bracket, placed quite close to the under side of the bottom plate.
These springs certainly occupy less space, but we prefer flat curved


- - 41
642 MODERN STEAM PRACTICE.
springs as usually constructed, as their action is easy, and better
calculated in every respect to meet the requirements. India-rubber
springs have been tried, but have proved a complete failure, as they
get crushed, and at times settle into a rigid mass; moreover they
are very quick in action, and are very destructive to the machinery.
and permanent way; in summer, also, they get soft, and in winter
hard, and should oil get near them they deteriorate rapidly. -
Compensating levers.--To make the action of the springs more
perfect, they are coupled together in some instances with com-

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Fig. 516.-Compensating Lever.
a 1, c, Springs. D, Compensating lever. a b, Links joining lever, c, Fulcrum of lever.
pensating levers. Thus the loads on the springs are equilibrated,
as any deflection in either spring from the motion of the engine
and imperfections in the permanent way is transmitted to the other
spring. The compensating lever is underneath the framing, and
may be arranged with a long and short end, or with the fulcrum
in the middle of the lever. In some arrangements the leading and
driving springs are so fitted, while in others the driving and trailing
springs are coupled to the lever, while others have only springs
fitted to the driving axles, the elasticity of the hind bearing being
transmitted from the driving spring through the compensating lever,
which is directly attached to the hind axle box with a link con-
nection, as shown in the American style of trussed framing.
When there is a moderate distance between the wheels, the centres
being say 5 feet and under apart, a single spring is placed between
the wheels, located on the top of the framing, as shown in Fig. 518,
fitted to the bogie in front (Fig. 519). In this arrangement the spring
itself is the compensating lever. The concussion from the wheels is
taken directly on the ends of the spring, while the deflection at one end
is transmitted to the other axle through the spring itself, the mechan-
ism thus being simplified, while the action is more perfect. For a
greater distance between the centres of the wheels a lever of the same
LOCOMOTIVE ENGINES. 643
span as the wheel centres is introduced, with pins bearing directly on
the axle boxes. The ends of the spring are linked to the framing,
ſ
Figs. 517, 518.-American Methods of Coupling the Springs,
A A, Springs. B B, Compensating levers.
while the butt of the spring is supported by the lever; thus equal
loads are put on the axles. In some cases the springs are inverted,
Fig. 519.-Inverted Spring and Compensating Lever.
A, Inverted spring on bogie. B, Compensating lever, C, Spring.
butting against the frame, and connected with links to the com-
pensating beams, the latter being jointed to the axle boxes. The
action is very easy, insuring a constant load on all the axles, but at
the same time it confines the spring base to one half of the wheel
base, which is injurious from the overhanging parts at each end.
Various other arrangements may be adopted; and sometimes the


644 MODERN STEAM PRACTICE.
link is fitted with india-rubber washers, placed between two metallic
ones butting against a swivelling piece, which is fitted to a jaw formed
at each end of the compensating lever, having a nut on the link for
O
×2-IſºSAN :
Fig. 520.—Inverted Springs and Compensating Levers.
A A, Springs. B B, Compensating levers.
adjusting the load; these india-rubber washers tend to soften the
action; the other links are fitted likewise with washers bearing on the
under side of the frame. • .
Bogie carriage.—The bogie carriage is introduced in front of the
engine to assist or ease the rubbing of the flanges of the wheels against
the rails in rounding sharp curves. It is placed underneath the main
framing, and is entirely separate from it, being free to move on a cen-
tral axis either way. In some six-wheeled engines the centre or
driving wheels are left without flanges, with the same object in view,
while in all engines the flanges for the centre wheels are reduced in
thickness, or, in other words, have more clearance from the side of
the rails. If the flanges were to grip the rails, the strain on the framing
would be very severe, and when the curve is very sharp the engine
might be thrown off the rails. The object of the bogie carriage is to
prevent this. It provides a long wheel base, combining the advan-
tage of an ordinary eight-wheeled engine as used for comparatively
straight lines of railway, with the advantage of a short wheel base,
when the curves are very sharp. In fact, the front bogie may be
swivelling into a sharp curve while the driving and hind wheels are
on a straight part of the line, as when crossing from one line of rails
to the other line at the points. The bogie carriage is a frame of
wrought iron carried on four wheels, with springs and axle boxes as,
in ordinary frames; two plates on edge pass transversely between .
the side frames, and are trussed with plates from the corners. At
the centre of the bogie, where the tie plates radiate from, a circular
boss is formed, which is bored out for taking a ball, thus forming a .
universal ball-and-socket joint, the ball being securely fastened with



LOCOMOTIVE ENGINES. 64
plate brackets to the under side of the boiler, and having a projec-
ºtion forged on, with screwed part and nut bearing on the under side
of the bogie frame; this pin has sufficient clearance in the hole to
suit the inclination of the bogie frame in either direction. The frame,
being pivoted on a ball, can more easily move in any direction.” In
this form of bogie the front part of the engine is entirely supported
Y I Aſ g (
• * f ‘Ef **** -
C " * -:
º
g
------------------------5.
Fig. 521.-Bogie Carriage. — a, Bogie frame. B B, Wheels, co, Springs. D, Centre of motion.
E E, Sliding pieces. F, Engine frame. :
on the ball. In some of the centre bearing description the ball is
dispensed with, and the load carried upon a broad flat circular seat;
others rotate on a pin with side sliding pieces fitted on the top of
the bogie frame, corresponding pieces being fitted to the main
framing of the engine, or to the carrying plate, so that the bogie
can move transversely and radially, while some sliding pieces are
*

646 MODERN STEAM PRACTICE.
cast along with the cylinder, and strongly bracketed in the casting,
and secured to the under side of the smoke box. These side sliding
pieces are quite flat in some cases, and in others are formed on an
obtuse wedge or double, incline for the transverse motion of the
bogie; the front part of the engine lifting, as it were, when the bogie
is striking a curve, the bogie being free to move I }% inch either way or
rather sideways, and sinking into the flat V-shaped piece when on a
straight part of the line. It is evident with this form of sliding side
piece, that the friction must be very great, and it is simply introduced
to maintain the bogie in an even line with the other wheels when
on a straight part of the line of railway. In some modern examples
(Fig. 52 I), mostly applied to American engines, the curves on some
of the American railways being very quick, the sliding pieces, fitted
to the main framing of the engine, rest on a segmental roller fitted
to the bogie frame on each side, the axis of this roller being secured
to the frame; with this provision the swivelling action is very easy.
Stops are generally fitted to prevent the bogie turning round too far.
Buffers, couplings, rail guards, sand boxes, &c.—The buffers,
fitted to the front beam or buffer beam of ordinary engines, and
likewise to the front and hind beams of tank engines, are of the
metallic description, consisting of a volute spring placed in a
cylindrical box bolted to the frame, having a telescopic piece cast
with a flange, and fitted with a wooden buffing piece. The spring has
a bolt passing through, taking the telescope piece and cylindrical
box, thus holding the spring and telescope piece in position; in the
act of buffing the spring is compressed, while the telescopic piece
slides in the box, sufficient clearance at the end being left to suit
the range of the spring. These springs are in some examples fitted
between the engine and tender. .
The engine is coupled to the tender with a rigid connection in some
cases and an elastic connection in others. With the former a right and
left-hand screw, having a bar for tightening up, is used; each screw
passes through a nut, fitted with journals, taking a link, which is
secured by a bolt passing through brackets on the engine and tender
beams; the bolts are prevented from lifting by means of split cotters
bearing on the under side of the brackets. The engine beam is fitted
with a cast-iron block having a convex surface, and on the tender
beam a block is fitted with a concave surface, both of the blocks
being rounded vertically; by this means they are enabled to take
the vertical and Swivelling motion of the engine and tender, the
LOCOMOTIVE ENGINES. * 647
blocks being drawn into juxtaposition with the right and left hand
screw. The tender is sometimes fitted with buffers, as on the front of
the engine, to steady the motion of the engine and tender; and
side-chain couplings are fitted in case of accident to the coupling,
* * * *
* *
* * *
•e
T " " -----...
&
* * * * * * -
-------
& is
! --- . . . S.
ºf 372 * -----6 *~~~3-;
$
Fig. 522.-Coupling between Engine and Tender.
a, Shackle and bolt on the engine beam. B, Shackle and bolt on the tender beam. c, Right and
left hand screw and handle. D, Block pieces. E. E., Brackets for draw pins.
thus preventing the engine getting detached from the train; in some
instances plain long links are substituted. -
In other arrangements the draw link is connected to a transverse
spring, which is extended as the strain or pull comes on it; with this
method the engine is drawn away from the solid buffing pieces, and
when the engine is suddenly reversed, as is the case at times, a
violent shock between the engine and tender is the result. There
can be no doubt that a rigid connection between the engine and
tender is to be preferred, the pull between these being solid and
inelastic, and side buffing springs being only used to steady the
motion. -
Another arrangement of draw gear consists of a plain bar, which
is connected to the engine by an elongated eye, and to the tender





648 MODERN STEAM PRACTICE.
|
and spring shackle by a plain eye; the transverse spring is fitted
with rods having buffing pieces at the flat ends, the rods passing
loosely through bosses on the tender end beam ; thus when the
engine and tender are drawn together a slight compression is given
to the spring through the buffing pieces, and the pin for the draw
shackle is then dropped into its place. This arrangement is rigid when
the engine is running, and when the engine is reversed the shock is
taken on the spring ends, the elongated slot on the draw bar allow-
ing for the compression. The safety chains, one on each side, are
simply single bars with an elongated eye for the engine end, and a
plain eye for taking the pin on the tender frame. This plan of draw
gear is a decided improvement on the foregoing example, as the
shock while reversing the engine is easy, and not at all destructive
to the machine; at the same time, when the engine is suddenly
reversed backwards and then instantly put forwards the strain must
be rather severe, so on the whole we prefer the rigid connection,
which remains so when the engine is going either way.
The draw bar and hook for tank engines are fitted with an india-
rubber spring, which is placed in a box secured to a wrought-iron
frame underneath the foot plate, the draw bar having a flange bear-
ing on the india-rubber, and secured to the rod with a cotter. The
spring, in some examples, is contained within a wrought-iron shackle,
having a round piece forged on for taking the spring, with a central
hole for the draw bar passing through. The shackle is held by
means of a round pin passing through a hole in the framework
underneath the foot plate. A shoulder is left at the hook outside of
the draw end or beam, and the draw bar is tightened up against
it with a nut bearing on a washer, which compresses the spring; by
this means the rod and shackle are made quite rigid, or, as it were,
drawn taut by the action of the spring. The draw chain in front of
the engine is likewise fitted with an india-rubber spring, which is
contained in a box bolted to the inside of the buffer beams, the
draw bolt being fitted with a loose washer and nut for adjusting the
draw gear. -
The rail guards are placed in front of the leading wheels, and
within a few inches of the rails; they are intended to push aside any
obstruction, such as large stones that may fall from deep cuttings,
upon the rails. The guards are made of wrought iron, and are bolted
to the framing, and in some cases to the buffing beam. In no case
should they form part of the framing. As the obstruction maybe heavy
LOCOMOTIVE ENGINES. 649
and bend or even break the guard in the act of displacing it, we
are inclined to think that the buffing beam is the proper place to
fix the guard, as the strain in displacing a heavy stone or other
obstruction would be confined to the wooden beam, which could be
easily replaced were it injured; whereas were the main framing of
the engine strained with the impact of the blow imparted through
the guard in displacing the obstruction, it would entail heavy repairs.
A thin scraper or brush is attached to the guard to clear Snow off
the rails. It has been proposed that the sheet-iron scraper should
be acted on by the springs, but this is an unnecessary refinement,
seeing that a snow plough in many instances is required to clear
the track. The thin scraper can only be of use to keep the top
of the rails free from snow, thus preventing the leading wheels
crushing the snow into a solid cake, on which the driving wheels
would slip. - *
Sand boxes are fitted to the framing of the engine, with a pipe
descending to within a few inches of the rails. This pipe should be
bent at the bottom backwards, so that the sand may be allowed to
drop gently on the top of the rails, and so get them properly
covered. Sand boxes are generally made too small, owing, we
have no doubt, to their unsightly appearance, as fitted to the fram-
ing. In some cases large sand boxes have been placed on
the top of the boiler, with a pipe descending on each side, so that
with one valve or tap the rails on each side are sanded simul-
taneously. The regulating valve is generally of the disc descrip-
tion, with two apertures for allowing the sand to pass through, the
valve being fitted with a spindle, lever, and rod, passing along to
the platform. In order to obtain sufficient bite for the wheels,
the rails being in a greasy condition, the sand must be clean and
sharp; moist sand will not do, so to free it from moisture and
obtain a hard gritty powder it must be roasted. A good plan for
doing so is by baking it in a fire-brick oven. In most railway-
locomotive workshops a furnace is kept burning, named the
“kindling furnace,” where at any moment the stoker can get a
shovelful of live coal to kindle the fire in the locomotive fire box,
and the sand for the rails used to be roasted on a griddle of cast
iron placed over this kindling furnace, but the frequent cracking
and breaking of the plate gave a deal of trouble, as the sand fell
into the fire. The roasting oven should be made entirely of fire-
brick; it is arched over the fire, the flame passing through flues
65o MODERN STEAM PRACTICE.
all round the oven, and then up the chimney. The door of the
furnace is made of cast iron, lined with firebrick, and fitted with a
chain and balance, the chain passing over suitable pulleys. As the
whole of the brickwork gets intensely hot, it is necessary to bind
the building with angle iron round the edges, secured with cast-iron
girders, with bolts at top and bottom running across the brickwork;
in this way the brickwork is prevented from cracking.
Foot plates should be of a ribbed or checkered pattern to give a
secure foothold, the plates being 3% of an inch or so in thickness
behind the fire box, and 3% of an inch in thickness all round the
top of the framework. The plates are secured to angle iron forming
part of the framing, or supported by brackets bolted to the frame,
and edged with angle iron, the foot plates and angle iron forming
the fender when no outside framing is used.
The foot space for the engine-man and stoker at the back of the
fire box is protected with thin sheet iron, supported by wrought-iron
pillars and rail, the pillars being secured to the framing. There
should in all cases be fitted a weather-protecting plate, covered in
at the sides and top so as thoroughly to protect the driver and
stoker, the plate being fitted with two round windows for looking
ahead. Indeed we consider that a cab should be fitted on all
engines in all countries, similar to those on the American engines;
but of course, for very warm climates, the protection should be
freely ventilated, or be, as it were, an open cab, consisting of
wrought-iron pillars, and top awning to protect the head from the
vertical rays of the sun. Hand rails should be fitted all round the
framing at the sides and front, formed of wrought iron, secured to
the boiler with round eye studs, screwed into a plate with boss piece,
which is rivetted to the boiler. -
Two iron steps are generally fitted to the framing for ascending
the foot plate at the fire-box end, and front steps may be fitted
when necessary, so as to facilitate the inspection of the machine.
Splashers are fitted on the top of the framing, inclosing the
wheels, which they should do effectually, so that there will be no
danger when passing along the foot plates when the engine is
running at a high velocity. They are formed of thin plates and
angle irons, with angle-iron flanges for securing them to the framing;
they are generally edged with strips, and should be constructed in
a tasteful manner. Of course the top of the arch should be kept
sufficiently clear from the flange of the wheel to allow for the action
LOCOMOTIVE ENGINES. 651
of the springs. Some ornament these parts with bright brass work,
we certainly prefer tasteful painting, as the brass work requires con-
stant cleaning to keep the machine nice looking.
Feed pumps and feed-water apparatus.-Feed pumps, as applied
to the locomotive, are of three descriptions, namely, long-stroke
ram pumps, worked from the piston crosshead; short-stroke ram
Fig. 523.— Feed Pump and Valve Chests of Brass.
a, Working chamber. b, Plunger. c, Valve chambers. d, Suction valve.
e, Delivery and non-return valves. J. Stop plug tap on boiler. g., Eye piece on end of plunger.
pumps, driven with an eccentric; and independent steam pumps,
having a small engine expressly for the purpose of supplying water
to the boiler; while the feed apparatus consists of the much-used
injector.
When long-stroke pumps can conveniently be applied they are
to be preferred, no matter in what position they may be placed. In
frosty weather all pumps are liable to get damaged from the water
freezing in the pipes, where the engine is exposed to the influence
of the weather overnight. It is highly necessary under these
circumstances to have a test plug tap fitted, to see if the pump is free
before starting the engine; a cock and pipe should also be fitted

652 MODERN STEAM PRACTICE.
to allow steam into the pump, to thaw the ice in cold climates;
but probably if the water was allowed to flow out of the pump by
the cock as already described, when the engine was in the shed at
the workshops, there would be no danger from freezing. When
the engine is running there is but little danger from frost, as the
circulation of the water from the tender can always be more or less
maintained. This motion of the water, partial as it may be, tends
to the prevention of accident in all pipes which are liable to be
damaged from the expansion of water when frozen. With inside-
cylinder arrangement the pump ram is worked directly from a pro-
longation of the gudgeon of the crosshead; the pump being fitted to
the main frame, the front end is fitted to the motion plate, and the
back end is bolted to the frame, flanges being cast on the barrel of
the pump for that purpose. These pumps consist of the working
chamber, the plunger or ram, the valve chambers, the suction and
delivery valve, and the non-return valve, fitted to the side of the
boiler, while, in some instances, although by no means general, a
plain plug tap has been fitted to the side of the boiler. We prefer
the self-acting non-return valve, although a plug tap may be fitted
between it and the boiler, to be shut off when the non-return valve
or other pump valves require inspecting when the engine is under
Steam.
The pump barrel should be cast of tough brass, but in many in-
stances toughened cast iron has been used. Muntz metal is now
universally used for the plungers, which are connected to the cross-
head of the engine by means of a wrought-iron eye, keyed to the
plunger, a hole being bored out in the prolongation of the eye piece
for receiving the part turned down on the end of the pump ram.
The eye is simply held in position on the crosshead with a set screw,
the point of the steel screw being indented into the gudgeon. When
cast-iron barrels are adopted, the stuffing box for the plunger is
fitted with a bottom ring and gland piece of brass; the latter should
have an oil chamber cast along with it for lubricating the ram, fitted
with a siphon wick. -
In the arrangement having the barrel of brass, the valve chest is
cast in one piece, containing the suction, discharge, and non-return
valves, which are of the ball description, having cages for the
guidance of the balls, which are cast along with the screwed caps
on the discharge and non-return valve chests, let into the chest
for the suction valve, and held in position with the flange on the
LOCOMOTIVE ENGINES. 653
suction pipe; all the yarious fittings are noted by letters on the
engraving Fig. 523.
In the arrangement shown (Fig. 524) the valve boxes of brass are
all separate for the suction, discharge, and non-return valves; but in
§
º
S.º
Sº&
5
º
|&
W
QC
%
s
à
#ºzº
K- *i.
§
É
&
§
i
º
:
2
Tá.
Fig. 524.—Feed. Pump with Cast-iron Barrel and Valve Chests of Brass.
A, Pump barrel B. Plunger and eye-piece. C. Suction valve box. 2, Delivery valve box.
E, Non-return valve box on boiler.
some cast iron is adopted for the suction and discharge boxes, and
they are cast along with the pump barrel. The cages are held in posi-
tion with a screw bolt and jam nut bearing on them, while the suction
cage is held in position with a flange when the valve box is of brass,
having a taper union piece and nut for the suction pipe. The non-
return valve box has a flange which fits the curve of the body of the
boiler; in modern practice this flange is quite flat, fitting against a
plate with a raised part, which is faced, the plate being rivetted to
the body of the boiler. The position of the non-return valve on the
body of the boiler is of the highest importance, it should be placed
as near the smoke-box end as convenient; the injected water should
be thrown into the boiler at that part where the temperature of the
surfaces exposed to the action of the flame and heated gases is the




















654 MODERN STEAM PRACTICE.
least. If the water is injected at the fire-box end, the tubes, being
greatly heated, contract, and draw out of the holes in the tube plate,
causing leakage; and, moreover, when cold water is injected into .
that part of a boiler where the steam is more readily produced, it
must have a tendency to reduce the temperature of the steam,
and consequently increase the consumption of fuel. Wherever
the non-return valve is placed the pipe between it and the pump
should be so constructed that it can yield with the expansion
Riº
ºzzº&CŞ
N
º
§
ãº
r
§
3.
§
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i
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32&xºtz
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- Aºzºa º -
**---- & &Rºxtºn º &%
**-------- *º §lº
** - - SSººzzº
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* * *
*** - -
* -- ~...~
- *** ---
**---
§ºº. ..., zºº.º.º.22% -
§Tºº
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N
Figs. 525, 526.—Feed Pumps.
A A, Pump barrels. B B, Plungers. cc, Suction valves. D D, Delivery valves.
E E, Non-return valves.
and contraction of the boiler, which can be easily done by giving
the pipe a round bold radius where it bends up from the pump to
the non-return valve box. Some form a U bend in the pipe. We
prefer the bold radius given to the pipe, as the water flows through
























LOCOMOTIVE ENGINES. 655
it more freely. At the same time the pipe is not so much strained
with the expansion and contraction of the boiler; and in fact this is
the only part where the expansion affects the machinery, owing to
the pump being attached to the frame, while the boiler is free to
expand independently of the framing. All the flanges on the valve
boxes should be of great thickness, more especially when of brass,
as with frequent jointing and disjointing the flanges would be bent.
And the bonnets or caps are liable to spring under the great pres-
sure they are subjected to when going at high velocity, unless they
are made very strong.
In other pump arrangements the valves have their webs with broad
surfaces for guiding the valve in the seating, as in Figs. 525, 526,
while others (Fig. 527) have guiding pieces with no webs, with stops
So as to limit the lift. A pet plug tap (Fig. 528) is fitted between the
discharge valve and the non-return valve; it is calculated to allow
§
NS NS
=º
àS
Fig. 527.—Feed-pump Valve. Fig. 528.-Pet Plug Tap.
A, Valve. B, Seat. A, Pet plug tap. B, Pipe.
any air or steam collecting between the valves to escape, as also to
test the action of the pump. This tap may be fitted directly to the
valve box, with rod passing along to the platform; in other cases a
pipe is fitted, having the tap close at hand near the platform. In
all pumps it is found a great advantage to have the space be-
tween the ram and the body of the pump as little as possible,
as a better vacuum is obtained in the first instance when no water
is in the pump, or in technical language the pump fangs more
readily. -
There can be no doubt that the pressure at the commencement
of the stroke is greatest on the ram, owing to the area of the valves
being greater on the top surface, and that the valve closes with con-





656 MoDERN STEAM PRACTICE.
siderable shock. With a view, therefore, to soften the action of the
valves, air vessels have been adopted on the suction and discharge
boxes, with cup valves working in a cage, similar to the ball-valve
arrangements, and it is found neces-
sary to limit the lift of the valves,
N
N
1. Alsº
º 3%
- à
- %AT&
º N N
§ § ſº
sº N
§ § Sºme
º § C
Sº
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Fig. 529.—Air Chambers. Valves. Fig. 530.-Non-return Valve and Box.
a, Non-return valve and box, B, Pipe from
A, Pump barrel, c, Ain vessel and suction valves,
pump. C, Expansion joint.
and D, Delivery valve and air vessel.
which varies from 36 to 34 of an inch. A valve with a greater liſt
must necessarily return with much greater velocity, giving repeated
blows, which soon injure the surfaces, but the blows can be greatly
softened by the adoption of air chambers, forming elastic cushions
that tend to relieve the pipes, while they also insure a steady flow
both into and from the pump. The non-return valve (Fig. 530) on
the cup principle is likewise adopted, the box being fitted with an
expansion stuffing box and gland; by this means the feed pipe
expands and contracts freely, thus forming a yielding medium
between the pump and the boiler.















LocoMotive ENGINES. 657
Short-stroke pumps, having a hollow plunger, have been used,
the plunger being actuated by an eccentric for that purpose;
placing the rod on the back eccentric for - s
the valve motion is a bad arrangement,
that should never be attempted. The
strain on these pumps is somewhat severe
owing to their large area; consequently,
when the eccentric for the valve has its
own legitimate duty to do, and likewise
to drive a pump plunger, the wear be-
comes very great, destroying in a mea-
sure the correct action of the main
steam valves, so it becomes imperative to
adopt an eccentric for driving the plunger
alone. -
Ball valves are sometimes adopted in
these short-stroke pumps, similar in con-
r
struction to those already described, and à
shown in detail. In other arrangements #
the valves are feathered, and are guided at #,
the top with a short spindle working in |*|†
a hole bored out in the cover for the valve Fig. 531.-Short stroke Feed Pump.
- º • º * > * : - to A, Pump barrel. B, Plunger and stuff-
chest; at the side of this guiding piece a “..."...s...".
very small hole is bored, through this the lºve surrºr
* & * * triC rod.
valve spindle ejects the water above it in
a gradual manner, forming a water-cushion for the valve liſting
*
Fig. 532.—Feed Pump with Feather Valve having a Spindle on the Top. Fig. 533.-Non-return Valve.
-a, Pump barrel. B, Plunger and stuffing box. C, Suction valve. A, Ball valve. B, Valve chest.
D, Delivery-valve box. E., Stud for the eccentric rod. c, Cage. D, Flange for
F, Oil cup. - bolting to the boiler.
.
against instead of striking against a stop, and which tends to soften


£2
658 MODERN STEAM PRACTICE.
the action. The plunger of the pump has a stud secured to the
plunger with a cotter, and in some a nut, while the eccentric and rod
are of the ordinary description, with cast-iron sheave, brass straps,
and wrought-iron connecting rod. The non-return valve connected
with the latter arrangement is of the ball type, with cage secured
to the cover by a single nut, while there is a stop cast along with
the cage for regulating the lift of the ball. In another arrange-
ment of short-stroke pump the jointed stud, placed inside of the
ram is so situated that the thrust of the eccentric rod is taken
on the gland and ring fitted to the bottom of the stuffing box
directly; by this means the pump
ram is not so liable to tilt. The
gland for the stuffing box shows
the arrangement of oil cup, which
is cast along with it for lubricating
sº the plunger.
A SL2" I. In fixing these pumps it is pre-
Fig. 534.—Feed Pump. ferable to keep them entirely clear
*.*.*.*.* of the boiler. They are generally
.. fitted to a vertical plate, the pump
is bolted on with the same flange as takes the gland bolts, the
pump being short requiring no other support. In this arrange-
ment the pump is placed in front of the driving wheels, while
in others, when it is placed behind the driving wheels, a flange
is cast on the bottom of the pump, which is bolted to a vertical
plate placed at a short distance from the fire box, which is
securely rivetted to the framing. With the view of giving greater
strength to resist the thrust of the plunger, the plate for bolting the
pump to has been placed on its side in the form of a beam, having
flanges cast on the pump at the side for bolting thereto. All these
different arrangements are preferable to fixing the pump to plate
brackets attached to the fire box and shell of the boiler, as the strain
is liable to affect the joints of the boiler, causing leakage.
Bal/-and-socket joints with a sliding pipe were at one time much
used for forming the connection between the pump and the tender,
fitted with screw couplings for readily connecting and disconnecting
the union between the tender and engine. A branch is made on
the pipe for fitting the heating pipe, with plug tap on the boiler for
allowing any surplus of steam to be blown into the tank for heating
the water; the steam being let into the tank when the safety valves
3.3.−rº -



LOCOMOTIVE ENGINES. 659
blow off, which mostly takes place when approaching stations; and
great waste of steam would occur when the train is detained at the
station were it not profitably utilized in heating the feed water.
ºº:
Bººz-Z, -, ºr
$º 2
Sºººººººº.
These ball-and-socket connections are very
expensive in first cost, and prove a continual
source of annoyance and expense in keep-
ing such fine fittings in proper repair. A
simpler connection is obtained by using “a
flexible hose, manufactured of canvas and
india rubber, with a coiled wire inside which
readily yields with the motion, and prevents
the flexible hose from collapsing, the union
being formed with a screwed coupling. The
flexible hose, however, is also a source of
trouble, as it soon deteriorates unless of
very superior manufacture. To remedy the
Fig. 535.-Union Pipe between practical difficulties in both of these con-
Engine and Tender. nections various plans have been tried: we
notice one that has given a measure of
success. The arrangement consists of two cylinders A A (Fig.
535), of brass or cast iron, one of which is bolted in the usual
manner to the feed pipe of the engine, and the other to that
of the tender; they are both bored out smooth and parallel;
B is a connecting tube of brass or cast iron, having the ends
turned, the part from C to D being parallel, and that from D to E
coned; the collars, F, are curved as shown; G G are elastic rings of
vulcanized india rubber, which, when at work, roll between the
cylinders, AA, and the connecting tube, B; II are light chains used
for the purpose of keeping the tube, B, in its proper position; they
are left slack to an extent of one half, the greatest amount of travel
required between the engine and tender. The advantages which
this arrangement appears to possess are its extreme simplicity, and


CGO : MODERN STEAM PRACTICE.
consequently cheapness both in first cost and current repair, and
the great durability of the only wearing parts, the motion of thes,
elastic rings when at work being a rolling instead of a sliding action.
Also the absolute tightness of the joints when the steam is blown
from the boiler into the tender tank, as the elastic rings, G G, are
then forced up the cone, D E, by the increased pressure, and are
prevented from blowing out by the collars, F, which are curved as
shown for the purpose of enabling the rings to adjust themselves
readily to their proper position when the pressure is removed, which
they do as soon as the engine is put in motion. The india-rubber
rings, G, are made slightly larger than the space into which they fit,
for the purpose of insuring a thoroughly water-tight joint; the
cylinders, A, are 3% inches inside diameter, and the tube, B, 2 inches
diameter outside; the ring is made 3% inches outside diameter and
1% inch inside diameter, the section of the ring being a circle
% inch diameter; of course these dimensions vary with the size of
the pumps. Wrought-iron hanging brackets of plate iron or round
forged bars are hung from the framing on the foot plate for supé
porting the ends of the pipes, placed close up to the screwed coup-
ling; they are fitted with a cap in some, and a strap bolt in others;
for readily connecting and disconnecting without distending the
flanges on the pipe.
The auxiliary engine or steam pump (Fig. 536) is sometimes fitted to
the locomotive as the only means of pumping the feed water into the
boiler, such as on short mineral lines where there are frequent stop-
pages; in such cases the ordinary feed pumps have been entirely
dispensed with. The steam pump is serviceable in all engines as
a means of pumping in the water when the locomotive engine is at':
rest. The steam pump possesses the advantage of being allowed to .
werk at a uniform speed, while the ordinary pumps have often to:
work unſavourably at a high velocity. The steam pump should be
so constructed as to take up little room, consequently the best form
of design is long and narrow; in the example given, the suction º
and delivery valve chambers are fitted with air vessels, which tend:
to soften the action of the valves, and equalize the flow into and ºr
out of the pump. The waste steam should be discharged into the 3
tapk on the tender, thus utilizing the exhaust steam in heating :
the ſeed water. * . . .';
|The injector is an instrument used for feeding the boiler, and cer-"
tainly is a very ingenious contrivance; the engraving (Fig. 537) shows...}
)
y
*LocoMotive ENGINEs. 661
“clearly how it is arranged. The central cone spindle is made adjust-
able so as to allow the exact quantity of steam to pass, while the
"outer cone pipe can also be adjusted for allowing the necessary
* * -
- *
Fig. 536.—Auxiliary Feed Pump.
A, Steam cylinder. B, Pump plunger. C, Inlet passage. D, Outlet passage. E, E, Air vessels.
quantity of water to pass around the annular space left between it
and the outer casing. This instrument works best with cold water,
and we are inclined to think that the water is simply injected into
the boiler by the velocity it acquires from the atmospheric and steam
pressure; in truth it works as a condenser. Were the water in the
tank at the boiling point, and the steam turned on from the boiler,
no water could be injected into the boiler from the tank; but the
water, being comparatively cold, will flow in. Now we consider this
is to be accounted for by the steam rushing against the cold water,
forming a partial vacuum ; the atmospheric pressure then comes to
bear, and the water is simply injected into the boiler by the atmo-
spheric and steam pressure. The valve shown on the underside is
to prevent the water in the boiler flowing out when the apparatus
is not working. A very large plug tap and pipe is fitted to the
boiler in comparison to the small water nozzle, and in fact the pipe
'is much larger than what is fitted to an ordinary steam pump, thus
giving a full command of steam for injecting the water rapidly into

662 MODERN STEAM PRACTICE.
the boiler. The suction pipe should be properly guarded in the
tank with a rose having very small holes, as the smallest hard
substance would lodge in the nozzle, and completely destroy the
action of the instrument. The only benefit in using the injector
seems to be its economy as regards repairs, which in ordinary
ºffs
& gº sº sº sº-º-º-º:
º
sº
sº - SS N
$23 º / § Š NSS$ 2.
º-s º §.3% =TüWiſiº jº
çº | S º º a
º Ş-SZŽz *gzºzzºğ§§§ -- †
º s's gºssº §§ -
Fig. 537.-Injector.
pumps are heavy. But we are of opinion that a steam pump or
auxiliary engine on the double-acting principle is far more econo-
mical as regards the steam required to throw a given quantity of
water into the boiler. The plug tap, as in fact all steam plug taps
worked by hand, should be fitted with a wooden ferrule fixed in the
handle; wood being a non-conductor, the handle always remains
cool, but if of brass or other metal, it at times becomes too hot
to grasp.
Feed-water heaters appear to have been applied with success to
locomotive engine boilers. The principle upon which these appli-
ances depend is the delivery of the feed water to the boiler at a
uniformly high temperature, such as 200° F. and higher, and the
freeing of the water from impurities. Exhaust steam is used, and
in some cases live steam from the boiler. The exhaust steam is
passed into tubes surrounded by the feed water, contained in a strong
casing, and after circulating, passes off. The water receives so
much heat from the surfaces of the tubes, and is afterwards further
heated by a coil of pipes containing live steam. Any matter pre-
cipitated as a deposit is received in a filter chamber containing char-
coal, and the water thus purified and heated passes to the boiler.
When applied to locomotive engines two pipes connect the heater
with the blast nozzle conveying the exhaust steam to and from the
heater; the water from the condensed steam being suitably drawn
off. This amount appears to be twenty per cent. of the whole used.




































LOCOMOTIVE ENGINES. 663
THE AMERICAN LOCOMOTIVE.
Details of boiler, fire boa, tubes, &c.—The fire boxes of American
locomotive engines are made large as wood fuel is greatly used
in these engines; they are of the usual form, strongly stayed at
the top with beam stays, which run longitudinally, and in some
transversely, care being taken that the ends of the bars rest on
the upper edge of the end or side plates. In addition to these
Fig. 538.—General Arrangement of Coal-burning Engines.
A, Fire box. B, Body of boiler. C, Smoke box. D, Chimney. E, Steam dome. F, Sand box.
G, Bell. H, Lamp. I, Cab. K K, Cylinders. L L, Valve casings. M, Guide bars. N, Eccentric
and link motion. N', Weigh shaft. O, Crank pin. P, Connecting rod. Q, Side rod. R, Cow-
catcher. S, Bogie wheels. T, Driving wheel. U, Trailing wheel. v., Platform. ww, Stays.
x, Tender. Y, Tender wheels. z, Springs. z', Brake handle.
bars the top of the fire box is stayed with vertical rods secured
to the bars and rivetted to the top of the outside shell. The
sides of the fire box have screwed stays, which are screwed through
the inside and outside shells, and then rivetted over at the ends.
Although these stays have been originally made of the best iron,
they soon become crystalline in texture, and rapid corrosion also
sets in; the former of these effects is attributed to the expansion
and contraction of the plates, causing a bending and unbending
strain, more especially at the top rows, where the expansion of the
plates is the greatest. Were the inside and outside fire boxes
expanding equally, there would be no cross strain on these stays;
but the inside fire box must expand more than the outside shell,
consequently the stays must bend and unbend, the bending taking

664
MODERN. STEAM PRACTICE.
The
stays in some instances have been turned down at the middle
of their length, thus securing some lateral strain without permanent
7/20% ºſé/S/2.
place when the fire box is thoroughly heated, and
injury.
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tish practice with
i
Br
ged as in
a separate crown plate, which is at times flanged downwards on two
The plates of the fire box are flan
sides, while in other
S the side plates are bent, and are of sufficient
length to form the cr
$
own, the seam of rivets being in the centre of
The junction between the inside and outside shells at
the fire box.
the bottom is made with a solid hoop fitted and rivetted between
ºy
the two shells. The fire boxes for wood burning are of iron plates
the sides are 4 inch thick, which has been found less liable to
$.








* ſº __k y | .* i •ſ
-- - - - - - o T &l s' 4. 5 g
AMERICAN PASSENGER FAST LOCOMOTIVE. (side ELEvation AND section.)
By the Baldwin Locomotive Works, Philadelphia, Pa., for the Northern Pacific R. R., 1882.
H

i
i.
;
;
AMERICAN PASSENGER LOCOMOTIVE. - AMERICAN PASSENGER LOCOMOTIVE. AMERICAN PASSENGER LOCOMOTIVE.
Half Elevation at Back, and Half Section through Fire-Box, Half Sections at Guide Yoke, and Reverse Shaft, Half Elevation at Front, and Half Section through Smoke Arch and Cylinder,
} (E.A.L.Dvºyri ST raccoratoricvis worrºs, iss2-)


LOCOMOTIVE ENGINES. C65
}
:blister than thicker plates; the tube plates fºr to 3% inch in thick-
ness, and the crown fºr inch thick, Lowmoor or Bowling iron being
preferred, both as regards soundness and facility for flanging,
although American iron is allowed to be stronger. -
The water spaces around the fire box, when wood is used as fuel,
are narrow, varying from 194 inch to 2 inches, while for coal burning
3 inches clear space is allowed. For promoting a free circulation
of the water a thin plate is placed in the middle of the water space,
parallel with the sides of the fire box; by this means an ascending
and descending current is maintained, the ascending current flowing
from the bottom between the partition and the sides of the inside
shell, while the descending current takes place between the parti-
tion and the outside shell. In some fire boxes suited for coal burn-
‘ing circulating pipes have been fitted, connecting the underside of
the barrel with the bottom of the water space, which tends to effect
a better circulation of the water; however, the best plan for doing
so is by making the water spaces of sufficient width tapering from
the bottom upwards.
The top of the outside fire box in some examples projects above
the barrel of the boiler from 9 to I2 inches, thus affording addi-
tional steam space and facility for inspection. It is connected with
a sloping plate to the cylindrical part of the boiler; in the latter
...the plating is what is termed telescopic, arranged in rings which are
largest at the fire-box end. The top of the outside shell in other
-examples is on a level line with the body of the boiler, and in both
instances steam domes are fitted, placed on the top of the fire box
in some, and body of the boiler in others. In cases where a large
dome of say 36 inches in diameter is fitted to the barrel of the
boiler, the hole cut in the plates is only 18 inches in diameter; this
-size is ample for inspection through the dome, and the barrel is not
weakened so much. The Smoke box is a continuation of the barrel,
and as the cylinders are fastened thereto the plates forming it are
of greater thickness than the body. Careful experiments on the
'strength of American boiler plates gives the following results:—
Process of Manu- Rough-edge Edge Filed Notches Filed in the Bar
. . . . facture. Bar. Uniformly. on each Edge.
Piled iron, .................. 23°7 tons. ...... 25 tons. ...... 28-24 tons.
Hammered iron, .......... 2I 2 × . . . . . . . 24'81 ..., ...... 26. I ,
Puddled iron,.............. 23'37 2, ... ... 228 , ...... 27.87 ,
with a reduction of say from IO to 15 per cent. Formerly the body
636 MODERN STEAM PRACTICE.
of the boiler was formed of plates 3% of an inch in thickness, with barrels
from 36 to 40 inches in diameter, for 80 to IOO lb. steam pressure;
this thickness has been reduced to 34 inch, and in some fºr of an inch,
in thickness for barrels 43 to 50 inches in diameter, carrying I2O to
130 steam lb. pressure, while the plates of the smoke box may be
taken at 3% of an inch in thickness as well as the tube plate in the
smoke box. There is no angle iron used in the construction of the
boiler, all the plates being flanged at the corners with a bold radius,
single rivetting being adopted throughout the entire boiler.
The tubes used for wood burning are made of copper, brass, and
sometimes of iron; with the former they are from No. 13 to No. 16
gauge, and are expanded in the holes with a tool for the purpose;
no caulking should be adopted, as the tube plates are much thinner
than in British practice, consequently not well calculated to bear
the strain in the process of caulking without injury both to the
plates and the tube, whose ends become brittle; in fact all boiler
tubes are now expanded in the holes with an expanding mandrill
for the purpose; ferrules are only used in the fire-box end; they are
made of wrought iron, and in Some instances cast iron is used, the
latter permanently expanding with the heat, keeps the tubcs tighter;
however, they require to be made thicker than the wrought-iron
ferrules, consequently the draught is partially impeded. The tubes
vary from I 34 inch to 2 inches in diameter, the latter being preferred,
with 56 of an inch distance between them; it is generally allowed
that tubes 2 inches in diameter make a better steam-producing
boiler than tubes 134 inch in diameter, the same heating surface
being presented in both cases. The tubes are preferred in vertical
rows to insure free circulation of the water, as well as allowing the
steam to rise freely.
The coals used in American engines are of the anthracite, bitu-
minous, and semi-bituminous kinds. The former contains but little
hydrogen, and is smokeless; bituminous coal produces much smoke,
and both kinds form clinker. The semi-bituminous coal is not
unlike Welsh coal. All the fire bars for coal burning should be
made so as to clear the clinker; with that object in view they are
fitted with a rocking apparatus that can be agitated when the engine
is running, thus loosening the vitrified clinker.
The problem of coal burning without smoke, as in British prac-
tice, may effectually be carried out by using the best kind of coal,
with frequent firing, and by making proper arrangements in the
LOCOMOTIVE ENGINES. 667
furnace for effectually mixing and igniting the gases and air, and
keeping the grate free from clinker.
The induction by steam of currents of air, as in British practice,
has proved the best and simplest mode of mixing the gases and air,
and will no doubt be found advantageous for American Coal-burn-
ing locomotive engines. º
The smoke box, as before stated, is a continuation of the boiler,
the tube plate is flanged, and the smoke-box plates rivetted thereto,
while at the door end a wrought-iron hoop is worked inside and
rivetted to the plates, while some have a hoop at the back end,
placed between the shell plates of the boiler and that of the smoke
box, thus greatly stiffening the smoke box for bolting the cylinders
thereto. The smoke-box door is generally circular, hinged and
fastened in a similar way to that in British practice, while some
have a segment of the circle cut away, which is hinged vertically
and fastened at the bottom.
The chimney of the American locomotive is a very plain affair,
but the spark arrester attached to it is peculiar. No arrangement
seems to work better than the conical deflector placed a few inches
above the ordinary chimney, which throws down the sparks into
the receiver surrounding the chimney, and from its large diameter
forms a characteristic feature of the American locomotive, present-
ing the appearance of a huge inverted cone, the top being covered
With a fine wire-gauze protection to retain the finer particles, as well
as to allow the smoke and steam to escape (see Fig. 538A, p. 664).
At the bottom of the receiver a door is fitted for the purpose of
raking out the accumulation of charred wood; and in Some a cast-
iron socket is fitted to the top of the smoke box for receiving the
small end of the receiver. The wire-gauze covering can likewise
be readily removed, and is held down with a jointed strap with rod
and catch. In other forms of spark arresters a series of curved
vertical vanes are placed beneath the conical baffle plate; by this
means the sparks receive a spiral motion, which tends to throw
them against the sides of the receiver, and by their own weight
they fall to the bottom, the smoke and steam passing through a
series of wire-gauze rings placed at the top of the chimney. This
form retained a greater portion of the sparks, and was mainly
introduced on those railways where the sparks are so dan-
gerous to trains freighted with cotton; however, the plan is more
complicated, and as wire gauze has a tendency to impede the
* 668 MODERN STEAM PRACTICE.
draught we certainly approve more of the former arrangement,
which no doubt will continue in use until coal finally supersedes
wood as fuel. -
The ash pan is similar in construction to those already described,
and is sometimes fitted with a door or damper at the front, while
others have one at the front and back, which can be opened at
pleasure from the foot plate by means of a jointed rod and handle,
with notches for keeping the damper open at any required position.
The fire bars are of cast iron; in Some cases cast in pairs, having
a means of rocking them to loosen the clinker; in others four or
more bars are cast in one piece, the bars resting on flat pieces of
iron fastened at the front and back end of the fire box.
The variable blast nozzle is used in mostly all coal-burning loco-
motives; it is placed in some low down in the smoke box, nearly on
... a level with the bottom row of tubes, while in others the blast orifice
is on a level with the top row of tubes.
The separate steam jet is likewise fitted to the chimney so as to
increase the draught while the engine is standing, and is used to
keep down the smoke at the stations by gently urging the fire, while
the steam, mixing with the smoke, makes the latter not so black in
appearance as it would otherwise be. Thus the smoke is partly
Consumed in the first instance by a rush of air through the grate,
urged by this separate blast pipe with steam taken directly from the
boiler, which, mixing with the smoke issuing from the chimney,
renders it less opaque, and being forcibly ejected into the atmosphere,
tends to Scatter the volume that would otherwise issue slowly and
densely from the chimney were not this appliance adopted.
Various contrivances have been adopted in order to equalize the
draught through the tubes, more especially for coal-burning engines.
In all tubular and other boilers, the heat naturally rises to the
highest parts, consequently takes the shortest course through the
upper row of tubes. To effect a better distribution the exhaust
nozzle has been placed on a level with the bottom row of tubes; a
pipe of about IO inches was placed over the nozzle, extending a few
inches within the base of the chimney, leaving an annular Space of
about 2% inches in width all round the chimney; by this means
the draught was urged through the openings at the top and bottom,
and consequently more equally through the tubes. While in
wood-burning engines a set of short pipes has been arranged one
over another in the form of a truncated cone, leaving annular
LOCOMOTIVE ENGINES. “ 669,
openings, through which the gases pass, the exhaust steam being
discharged from the lower part of the cone.
To prevent radiation, the boiler is covered over with pine wood,
termed cleading, over which is placed a covering of planished
Russian sheet iron, having brass bands highly polished where the
plates meet these bands; they are sometimes beaded or moulded,
American engineers priding themselves on the high finish they give
their engines.
The steam pipe, placed inside of the boiler, is sometimes per-
forated as in British practice, the openings in some being a triple
row of slots, each 3% inches long and 34 and 36 wide at the fire-
box and smoke-box ends respectively. With this arrangement the
regulator is placed in the smoke box, and can be more easily
inspected than when inside of the boiler. In other arrangements
the regulating valve is placed in the steam dome, an elbow branch
piece being bolted to the side of the dome, taking the steam pipe
passing along to the branch piece of the front tube plate; the steam
pipe in such instances must be made of sufficient strength to prevent
collapse. - -
Two safety valves are generally fitted, placed on the top of the
steam dome; while in others a separate casting is used; this is pre-
ferable, as with the former arrangement there is a greater tendency
to priming when the steam is blowing off; lever and spring balances
are generally used, as in British practice, for resisting the Steam
pressure on the valve, and they are arranged so as to be reached by
hand, as all safety valves should be; but unless experienced and
careful men are employed as drivers and firemen safety valves of the
lever kind may be tampered with in whatever position they may be
placed on the boiler. The safety valves are generally fitted at the
top of the safety-valve chest, while others are arranged on the cast-
iron cover, forming the top of the steam chest, and are carried suffi-
ciently high overhead, thus dispensing with steam funnels for carrying
off the steam. The covering for the steam dome is of polished brass
very elaborate in design; in some there is merely a bottom piece,
with a recess at top of moulding for letting in the wood lagging,
and which is secured at the top with a strap, the whole being
covered with Russian iron highly planished.
Glass water gauges are not generally adopted in American loco-
motive engines; sometimes gauges on the float principle are used
for indicating the height of water in the boiler, while others have
670 MODERN STEAM PRACTICE.
merely test taps, arranged one above another. From three to seven
of these taps are fitted, and an experienced man can tell, on one of
them being opened, whether steam is blowing off, or steam and
water combined, in which case it is seen that the water in the
boiler is so far above the crown of the fire box. When steam alone
is found blowing off, the next tap lower down is tried, and so on
until the limit is indicated below which it is not safe to work the
boiler. The pressure gauge is similar in construction to that
adopted in British engines, Bourdon's being generally preferred;
for a description see p. 575.
The steam whistle is larger than is used in British practice, the
bell being 4% inches diameter and 6 inches deep; instead of a
plug tap, a conical valve admits the steam into the annular chamber,
it is fitted with a spring, and when the whistle is placed on the top
of the steam chest, on the body of the boiler, or on the top of fire
box, it is fitted with a lever and rod passing along to the platform.
The whistle produces a sound deep and powerful, and is chiefly
used when the train is departing from and entering stations, as like-
wise signalling to the guard to turn on the break in cases of danger.
A mechanical means of sounding the whistle on approaching level
crossings has been carried out with a measure of success, consisting
of a worm wheel placed on any of the engine-truck axles working
a train of wheels which turns a drum, having catches for lifting the
valve lever on the whistle, the catches being adjusted to the distance
travelled over by the truck wheels of the engine. It is obvious that
this plan would work well on certain lines, provided no slip occurred,
and the truck wheels of the engine did not wear on the tyres, increas-
ing the number of revolutions for a given distance travelled over;
but as the wear must be very gradual, a provision for adjusting
the mechanism is all that is required on the part of the engineman.
A large bell weighing upwards of 200 lbs, is fitted to a stand
placed on the top and front of the body of the boiler, having a rope
passing along to the platform, which is sounded on approaching and
passing level crossings.
The head light is placed in a large lantern, fitted with brackets,
secured to the front of the smoke box, and is fitted with a parabolic
reflector plated with silver, the diameter varying from 18 inches to
22 inches, and about 16 inches in depth, concentrating and throwing
the rays of light directly along the line, enabling the engineman on
a dark night to distinguish objects for a considerable distance, Oil,
LOCOMOTIVE ENGINES. 67.1
and in some instances gas distilled from “burning fluid " is used
in the lamps, the latter improving the brilliancy of the light.
A sand box is fitted to the top of the body of the boiler, with
pipes passing down in front of the driving wheels, and is fitted with
valves, levers, and rods, passing along to the platform; by this means
the rails can be sanded simultaneously. These boxes are elaborate
in design, and in some instances support the bracket for the great
bell, by this means lessening the number of fixtures attached to
the body of the boiler.
The blow-off plug valves, heating and lubricating taps, are similar
in construction to those in British practice.
The hand rail is placed somewhat higher up than in British
engines, and passes along from the front of the cab, and across at
the front of the smoke box, the long studs or pillars for supporting
it being secured to the body of the boiler and to the smoke box.
Cylinder and slide valve.—The cylinders are generally arranged
outside of the framing, lying horizontally in Some and diagonally
in others, the inclination varying to suit the requirements.
The cylinders are of cast iron, and great attention is paid to
secure the best quality of material. They are cast open at both
ends, the bearing surface of the covers being outside of the
internal diameter, flanges being cast on for securing the covers
thereto. The steam chest is jointed to the cylinder, not cast
along with it as in British practice, thus simplifying the casting,
the joint being metal to metal, carefully faced and scraped, and
secured with bolts or studs in the usual manner. A port is cast on
the cylinder for the admission of the steam from the boiler, which
enters the valve casing through a rectangular port. The fastening
of the cylinders to the smoke box is effectually carried out by means
of brackets cast along with the cylinder, which have flanges for
bolting to the top of the framing, and to the underside of the round
smoke box, while some have the cylinders cast together.
In other examples a separate casting, termed a saddle, is placed
between the framing of the engine, and is curved to the round of
the smoke box, to which it is bolted, as likewise a flange rests on
each frame, both surfaces being accurately planed and strongly
secured together; a flange, turned downwards, takes the inside of
each frame, the whole making an extremely strong fastening
between the framing and the smoke box. The exhaust passage for
the waste steam is cast along with the saddle piece, whilst the
672 MODERN STEAM PRACTICE.
steam passage is let into the side of the steam chest. The cylinder
in this arrangement has a flange which rests on the top of the
saddle, and another, which abuts on the outside of the frame, to
which they are securely bolted.
In other arrangements the saddle is an open-ribbed casting, with
a flange curved to the round of the smoke box, the saddle being the
entire breadth between the frames, to which it is secured at the inside
and bottom, with suitable flanges cast thereon through which the
bolts pass; on the top side of the saddle vertical flanges are formed
in the casting to which the cylinders are bolted, the waste steam.
pipe in such arrangements being cast along with the cylinder.
Provision is made in the saddle for carrying the pin or surface plate
on which the truck or bogie is centered. The steam ports are
located on the top side of the cylinder, placed nearly centrally with
the line of the main connecting rod; a plain valve of cast iron is
used, this has been found to work very well when the cylinder face
is of hard iron; it is, however, found that these faces work unevenly
if not properly arranged, owing to the varying travel given by the
link motion when cutting off at different grades of expansion. A
steel plate has in some examples been screwed to the cylinder face,
having the ports cut therein; the valve is made of hard brass, all the
surfaces being properly phaned and scraped. When separate expan-
sion valves are used they are placed on the back of the main steam
valve directly, or work on a plate having ports to suit, this plate
forming a division across the steam chest. There can be no doubt.
that when the expansion valve is placed directly on the back of the
main valve the cut off or suppression of the steam is more perfect,
simply owing to less steam being admitted into the cylinder;
whereas, when the expansion valve works on a plate forming a
division in the steam chest, the steam chest proper must in each
instance be filled with steam, consequently waste must occur. It
must be borne in mind, however, that with the expansion valve on
the back of the steam valve the surfaces work unevenly, and this
is a drawback to their general adoption. Besides there can be no
doubt that with a proper link motion a plain valve is best suited to
work the steam expansively. The reduction of the working parts in
the locomotive engine should be a main object, but expansive valve
gear in many instances is very complicated, while the advantage is
doubtful, and the repairs in some arrangements are heavy.
The steam chest, as before stated, is a separate casting, bolted to
Ҽ

PASSENGER LOCOMOTIVE, BUILT BY THE BALDWIN LOCOMOTIVE WORKS, PHILADELPHIA, 1888.

||t
|
AMERICANTFASSENGER LOCOMOTIVE, BUILT BY THE BALDWIN LOCOMOTIVE works, PHILADELPHIA, 1888.
HALF ELEVATION AT BACK. - HALF ELEvATION AT FRONT.




LOCOMOTIVE ENGINES. 673
the flange on the cylinder with stud bolts, and having a round
collar bearing in a recess cut out in the top side of the valve casing,
the bolts projecting beyond for taking the casing cover, having nuts
and washers for securing the cover; the bolts are placed about
4% inches from centre to centre, and pass down through shields
cast in the valve casing. Were not such a precaution adopted, the
bolts would rapidly corrode when in contact with the steam and
steam currents continually passing through the casing. The
cylinders and steam chests are properly clad and covered over
with Russian sheet iron, and in some instances sheet brass highly
polished, and which may easily be kept so. The valve rod passes
through the back of the steam chest, having a suitable gland and
stuffing box, with proper means for lubricating the rod; the mode
of attachment to the valve is by means of a loose strap encircling it,
thus the valve accommodates itself to the wear; in some cases the
rod passes through the valve, and is prolonged at the back, working
in a tube piece bolted to the valve casing; the valve is adjusted by
nuts, a thread being cut on the rod.
The valve is lubricated by means of an oil or grease cup placed
on the top of the valve-casing cover, the lubricant finding its way
into the cylinder, keeping the rubbing surface thoroughly lubricated.
Plug taps are fitted to the underside of the cylinder, one at each end
for ejecting the water collecting from condensation and priming.
Valve motion.—To recapitulate all the various arrangements of
valve motion that have been used is needless, as the double eccen-
trics and single link for working the steam expansively are now
fully recognized by American engineers. The position of the steam
valve being generally on the top side of the cylinder, the motion is
more indirect than that usually adopted in British practice.
The shifting link is commonly used over that of the stationary
link, and the motion of it given by the double eccentrics is com-
municated to the valve by levers fixed on a short rocking shaft
placed on each side of the framing. The maximum admission of
the steam into the cylinder is about 90 per cent. of the stroke of the
piston, while the minimum admission is about 35 per cent of the
stroke of the piston; the valve having a throw of from 45% inches to
5 inches, the outside lap being from 5% of an inch to I inch at each
end, while the inside lap is nil; or, in other words, the edge of the
valve is in line with the inside of the port. Some even consider it
advisable to give a little clearance.
- - $3
674 MODERN STEAM PRACTICE.
Cast-iron eccentric straps are very generally used; they are
found to wear better than brass straps when the friction is not very
severe. The rods are of wrought iron, connected to the strap with
side bolts, a broad palm being forged on the rods, having a cor-
responding piece cast along with the front half of the eccentric
strap. The rods are attached to the link with a plain eye having a
pin of steel, and sometimes a bush of steel is placed in the link.
The link is usually of the solid description, formed of wrought iron,
case hardened. The snugs for taking the eccentric rods are at
the back of the link, and very rarely at the ends. In some examples
the link is of cast iron, and although the weight is considerable they
are found to work and wear satisfactorily.
The point of suspension is various, and is generally determined
by trial, which can readily be done with a full sized model; in some
the point of suspension is exactly in the centre of the link, both
vertically and horizontally, while in others it is a few inches above,
or an inch or so in front or behind the centre of the link. The
radius of the link, we consider, should in all cases be the exact dis-
tance between the centre of the link when placed vertically at half
stroke of steam valve and the centre of the eccentric. The weigh
shaft or reversing shaft, on which levers are placed in connection
with the lifting rod on the link, is very similar to those used in
British engines; the brackets for supporting it being bolted to the
top of the frame, one on each side. There are two lifting arms
keyed on, and one reversing arm, as likewise a weighted arm for
balancing the weight of the links, rods, &c.; in some instances a
spiral spring is used for this purpose, which can be placed on the
weigh shaft or at the foot plate according to the arrangement.
The reversing rod attached to the arm on the weigh shaft passes
along to the reversing lever and quadrant placed on the foot plate,
the quadrant being cut with suitable notches for taking the catch
on the reversing lever. When a spring is used at the platform
for balancing or easing the weight of the links, &c., in reversing the
motion, a coiled spring is placed inside of a hollow sheave or drum
which revolves on a central pin, the spring being held with a fixed
point at the spindle, and the other end secured to the drum; a band
connects the drum with the short arm of the reversing lever, so that
when the links are lowered the spring stores up force to ease the
labour of lifting them. As the trains in mostly all double-lined
railways run up on the right-hand line, the levers, and consequently
LOCOMOTIVE ENGINES. 675
the position of the engine driver, being on the outside of the double
line is generally on the right hand, while on some railways vice versa,
or, in other words, the engineman's position should always be on
the side of the engine next the platform of the railway stations, in
order that he may see distinctly the signals given by the guard or
conductor of the train.
Piston.—The piston commonly used in American practice is of
cast iron in the body, with a junk ring of the same material secured
: to the body by four or more bolts; the packing rings, two in number,
are made of a composition of 9 of copper and I of tin; they are cut
at one part, and the rings are lined or plugged with Babbitt metal.
A ring of wrought iron or cast iron, % inch in thickness, is
put inside of the brass rings, and between it and the body of the
piston small springs are placed with set screws for adjusting the
outward pressure against the surface of the cylinder. The inside
ring likewise tends to prevent the steam passing into the body of
the piston. Cast-iron packing rings, even when lined with Babbitt
... metal, have invariably been found to rut the surface of the cylinder.
Sometimes the packing rings are expanded with a single wedge as
in British practice, while self-expanding packing rings do not seem
to find much favour with American engineers. Wrought-iron pistons
have in a few instances been adopted with advantage, as there can
be no doubt that these pistons are light compared with the cast-iron
form, tending to reduce the weight of the reciprocating parts, and
consequently making the repairs less, when the permanent weight
is heavy; with the rapid reciprocation as in the locomotive engine,
the strain on the moving parts is very severe. In these examples
the piston is forged along with the rod, while for the cast-iron
pistons a simple key secures it to the rod, which is made conical,
and properly ground into the conical hole bored out in the boss. º
Piston rod, cross/lead, and motion bars.-The end of the piston
rod is made conical, fitting exactly the hole bored out in the boss
and ground together with it, making the union perfectly steam tight,
the piston rod being secured to the piston and crosshead with single
split cotters. The gland on the back of the cylinder for the piston
rod is packed with hemp, and in some metallic packing is used.
In the bottom of the stuffing box an annular metallic ring is placed,
surrounding but not nearly touching the rod; it is of a conical form.
with the larger opening at its outer end. Composition rings, cut at
one part and bored out to fit tightly against the piston rod, are
676 MOI).ERN STEAM PRACTICE.
placed inside of the conical metallic ring already described, the
outer diameter of the rings being turned conically. The gland is
screwed up pressing these rings closely against the piston rod, and
as the outer ring does not fill exactly the stuffing box, and the
gland is bored out somewhat larger than the rod, the packing rings
can thus accommodate themselves should the piston rod from wear
be not in the same centre line as the cylinder. The composition
used for the packing rings is 9 of tin and I of copper. Of course
the piston rod in the first instance must be quite smooth and per-
fectly parallel. The crosshead in a number of examples is of cast
iron, with the pin for taking the connecting rod cast on, and which
is turned with a tool for the purpose. The sliding block and cross-
head are cast all in one piece, and a snug is also cast on for taking
the pump ram. Wrought-iron crossheads are likewise used, and
certainly we prefer this thoroughly British mode, as they are much
lighter, reducing the weight of the permanent moving parts to the
minimum. The motion bars are of iron, of the double form, placed
on each side of the piston rod. When cast-iron crossheads are used
case hardening is not required, but when the sliding blocks are of
brass or composition metal the bars are case hardened, or steel
used in their construction. The width of each motion bar varies
from 3 to 4 inches, while the length of the sliding block is about
16 inches. The motion bars are secured to lugs cast on the
cylinder cover at the one end and to a bracket through which the
connecting rod works at the back end, the bracket being secured to
the framing and boiler. When no lining pieces with means of adjust-
ment are fitted to the crosshead thin 'slips of metal are placed
between the lugs on the cover and bracket, which are removed, or
as in British practice filed down to suit the wear of the crosshead.
. A lubricating cup is placed on the top motion bars for supplying
the rubbing surfaces with oil or other lubricant.
Connecting rod.—The connecting rod is formed, as in British
practice, flat on the sides, the middle part of the rod is rounded at
the top and bottom, with butts at ends for receiving the straps and
brasses; sometimes the middle part of the rod at sides has a semi-
circular groove planed out, thus reducing the weight, while the
section is very stiff. The brasses have all square ends, excepting
the outer half of the small end for the crosshead of the piston rod,
which is made curved, the flanges projecting on each side and made
the full width. of the strap. The brasses, with flat ends and flanges
. LOCOMOTIVE ENGINES. 677
so arranged, wear much longer than those with the ends circular
and the flanges narrow, being held much more steadily in position.
The straps are secured by two bolts, with nuts and jam nuts; the
cotter for tightening up the brasses bears on an iron plate let into
the brass, thus preventing the thin cotter from cutting the brass,
in which way it would soon become loose were not the plate
interposed between the brass and the cotter. A set screw bears
on the side of the cotter, a hole being tapped on the side of the
butt; by this means the cotter is held firmly in the slot. An oil
cup is placed on the top side of the strap, provided with a sipho
wick. -
The rods for coupling the wheels together are arranged in a
similar way with straps, keys, and brasses; the brasses are made to
form a close cap on the outside, by this means excluding dust and
grit; there are two bolts and nuts passing through the straps and
butts at each end, with a single cotter at the one end placed inside,
and at the other end a cotter both in the inside and outside ends of
the brasses; by this means the centres of the bushes can always be
adjusted to the exact distance between the centres of the wheels.
In order to reduce the overhang of the pins for taking the outside
rod, various arrangements have been tried to couple the wheels in
the same line as that of the main connecting rod. One of these
arrangements has a pin formed on the end of the strap for the
main connecting rod, taking the putside rod; but it is obvious that
this plan is highly objectionable, as by the oscillation of the con-
necting rod, the distance between the crank pins of the two pairs of
wheels is alternately lengthened and shortened, imposing a severe
strain on the crank pins. Another plan has the strap on the for-
ward end of the coupling rod prolonged and fitted with brasses for
taking the forked end of the main connecting rod; by this means
the rod is coupled a few inches in advance of the crank pin, and
although by this arrangement an indirect strain is imposed on the
bolts, yet the plan worked much better than the former one. A
third arrangement consists in making the forward pin longer than
usual, and the brasses circular at the middle and square at the
ends. The main rod is forked and provided with straps for taking
the square ends of the brasses, and fitted with bolts and keys.
The coupling rod is fitted with a strap, with bolts and keys, and
is coupled and worked between the forks on the main connecting
rod, the middle part of the main connecting rod brass being turned
678 MODERN STEAM PRACTICE.
for its reception. This form of direct connection recommends itself
as being correct in principle, and may be otherwise arranged in
detail to suit the views of the designer.
Wheels and axles, and crank pins.—Although cast-iron wheels
are much more liable to fracture, more especially in cold weather,
they are extensively used in American engines; but there can be
no doubt that wrought-iron wheels are preferable, their weight being
less, and having greater elasticity with less liability to fracture.
The driving wheels for goods engines, ranging from about 3% feet
to 4% feet in diameter, are made of the plate or disc form, similar
to those used for the bogie or forward-truck wheels. Driving
wheels 5 feet 6 inches or so in diameter have from fourteen to
sixteen arms cast along with the nave and inside tyre. As these
wheels are heavy, and the permanent way rather rough and rigid,
more especially in the winter months, the outside tyres are of great
strength, varying from 2% inches to 3% inches in thickness ac-
cording to the requirements, the latter thickness being used with
engines having 5 tons on a wheel; and even when those tyres wear
down to about 2 inches they stretch, become loose, and require to
be renewed.
Sometimes the front pair of coupled wheels, where of course a
bogie is placed in front of the engine, have no flanges; this is to
facilitate the engine turning curves; but in recent practice flanges
are put on all the wheels, while the engines turn as before curves
from 600 to IOOO feet radius, and run more steadily, and the
diameter of all the coupled wheels is better preserved, with seem-
ingly a slight gain in adhesion.
The nave of the wheel for receiving the axles was formerly bored
out conically and the axle turned to suit, the end of the axle being.
finished flush, over which was placed a brass plate; this plan is
highly objectionable, for should the wheel become loose on the
axle the covering plate hid the defect; and there can be no doubt
that a cone is a great source of danger, for should the axle become
loose the contact is at once broken. It is imperative that the hole
should be made quite parallel and cylindrical, and the raised part
of the axle turned slightly larger, the wheel being forced on the
axle with a powerful hydraulic machine; the axle then acts as a
mandrill, incorporating as it were the two metals together, the key
way being of course cut before the wheel is finally fixed.
The axles are quite plain. Some, indeed, are parallel bars with
LOCOMOTIVE ENGINES. 679
no collars turned on, while in others deep collars are left bearing on
the inside of the axle boxes, two being required for each axle.
The holes for the crank pins are bored out with a machine for
the purpose, and are not finished until the wheels have been placed
on the axle; by this means they are bored out with a boring bar
truly with one another; the hole is quite parallel, and the pin is
forced in with an hydraulic machine and rivetted over in the inside;
on the outside the hole is recessed about 3% inch, a collar being
left on the crank pin; all the other collars are formed on the
pin, no loose washers being used. The pin is made much larger
where it enters the wheel, as the overhang of the coupling rod is
considerable, and the pin requires to be strengthened accordingly.
Framing and axle bores, bogie frame, &c.—The framing very
generally adopted is that known as the trussed beam formerly used
by some British makers, but which has now become obsolete in
British practice. The bars forming the beam are about 4 inches
wide by 2 inches in thickness laid upon the flat side. The horns
by which the axle boxes are guided are forged on, and in some
instances a separate forging or a casting is bolted to the top bar,
forming part of the trussed beam. The bottom of the horns are
connected together with a flat bar which extends the entire length
of the framing, thus forming a trussed beam the whole length of the
engine. The framing is connected to the boiler with braces about
3 feet apart, which is calculated to stiffen the frame; at the same
time these braces must be so arranged as not to throw an undue
strain on the boiler plates, or otherwise the braces must yield with
the expansion and contraction of the boiler, more especially as the
boiler plates are not so thick as in British locomotives. These
intermediate braces are bolted firmly to the frame and are rivetted
to the boiler, broad palms being forged on the end of the tie braces.
At the fire-box end a long angle-iron piece is secured to the outer
fire-box shell, the boiler at the fire-box end being supported by
this means, the angle iron resting on the top of the frame, to which
it is secured by means of a strap which is bolted down at the ends
to the frame, provision being made for the free expansion of the
boiler, say 34 inch for the whole. The boiler is rigidly held at
the smoke-box end, but is quite free to expand towards the back
end. The screw bolts for securing the angle-iron brace to the fire
box pass through the water space, and are screwed and rivetted to
the shell of the inside fire box, and in some a nut having a con-
&
68O i MODERN STEAM PRACTICE.
cave face is screwed. A packing of canvas and red lead is placed
upon the bolt before it is screwed through the inner shell; the nut
is then tightly screwed against the inside plating of the outer fire
box, thus making a perfect joint. The plate-beam frame, 8 to
9 inches deep and I inch in thickness, so universally used in British
practice, is now adopted by American engineers; this form of frame
combines strength and simplicity, giving a ready means of attach-
ment to the various parts, and should have the horns, &c., forged
on the plate beam. -
The axle guards or horn plates, as has been stated, are welded on,
and in some instances cast-iron and wrought-iron pedestals are
bolted to the frame, while in the plate-beam frame they are:
forged along with it. The wearing surfaces of the axle boxes are
of cast iron, and sometimes of composition metal, and slide on
wedge pieces secured by bolts and confined with the flanges on
the axle box. These wedges adjust the wear of the boxes, and
coupled engines should never be without some such means of adjust-
ment. A good plan consists of a wedge or shoe piece of cast iron
embracing with flanges the side of the horn plate, presenting a sur-
face of say 5 inches. The flanges of the axle box extend upwards,
completely inclosing the opening between it and the under side of
the frame; they support a short roller above, on which the spring
rests, providing a fair bearing no matter what the inclination
may be. - * .
The brasses for the axle boxes are lined with anti-friction metal,
but this is not desirable in some instances, as grit and dust, finding
their way to the journal, soon destroy the rubbing surface. A com-
position of 97% parts zinc and 7% parts copper has been success-
fully used, the boxes in many instances being entirely cast with this
metal, no separate lining brasses being required. The best brass
bearings are made of a composition of 9 of copper to I of tin, which
gives great satisfaction. The lubricant generally used is oil, and
never grease, provision being made in the oil boxes for supplying
a constant drop by means of siphon wicks.
The front beam of the main framing is of wood, while the back
, or drag beam is formed by a frame of cast iron placed between the
longitudinal main frame pieces, to which it is secured; in other
examples the drag beam is constructed of wrought iron.
The engine and tender are coupled closely together, and a cast-
iron wedge with tapered plate is fitted on the back of the engine

AMERICAN LOCOMOTIVES.
Fig. 1. Lorngitudinal elevation of Freight Locomotive (wootten System, for anthracite),
on the Philadelphia and Reading R. R.
Fig. 2. Front elevation and Rear elevation.
Fig. 3. Longitudinal section. *
F;
7
sº- -
º-º-º-º-º-º-
Fig. 4. Fire Box: Rear View and transverse section.
Fig. 5.x Smoke Stack: Front View.
Fig. 6. Boiler: Transverse section.
Fig. 7. High-speed Locomotive (Formtaine System).
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H. & tº- ğ. Grºßsci-
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! (Sºlº)
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Fig. 8. Drawing of High-speed Locomotive (Forntaine System).
. Fig. 9. Elevation of Locomotive Tender (Forney System).
i Fig. 10. Plan of Locomotive Tender (Forney System).














LOCOMOTIVE ENGINES. 631
frame, which is screwed up tightly. Draw springs are never used
between the engine and tender, but a draw spring at the back of
the tender is at times adopted.
The front beam is generally stayed to the boiler at the smoke
box, and sometimes to the main framing; this is required to stiffen
the overhanging frame, which is projected in front to clear the
truck or bogie wheels. -
The bogie frame or carriage is similar in construction to those
already described in British practice; some are made with two
bearings for each axle placed inside of the wheels, while others have
four bearings, two inside and two outside of the wheels. The truck
has generally a central bearing, swivelling on a pin, and in some
a flat plate is used. In others swivelling takes place on a joint
several feet behind the smoke box; the truck has the ordinary Cen-
tral bearing pin, which drives the carriage forward along with the
engine. The back end of the truck frame is connected to a swivel-
ling joint in front of the driving axle by means of two radial bars.
When the engine is running on a straight line the truck is held
steadily in position by means of inclined seats, upon which the
weight of the forward part of the engine rests, and on taking a
curve the truck slides laterally on these seats, the axles and
wheels adjusting themselves radially or nearly so to the curve, which
is a considerable advantage, and the engine runs more steadily on a
straight part of the line with this arrangement.
Cowcatcher—The cowcatcher takes the place of the rail guard
in British engines; but it is more formidable in its character, as it
can remove quadrupeds straying upon the line, and with the train
going at 30 miles an hour it does so safely and with very little
ceremony. It is generally made of wrought iron in the form of a
coned wedge, consisting of a flat wedge-shaped bottom bar placed
a few inches above the rails, and extending across and a little
beyond the rails. A strong central brace connects the front of this
wedge-shaped bottom bar with the front beam of the engine,
while a number of bars about 5 inches apart placed horizontally,
and in some inclined upwards, likewise form braces between the
bottom plate and the side plate of the cowcatcher, and the forward
beam of the main framing as the case may be, thus forming a strong
guard, which is likewise stiffened with a rod on each side, connecting
the bottom bar with the main frame of the engine. The drag link
is a long bar connected to the central bar of the cowcatcher or to
682 MoDERN STEAM PRACTICE.
the front beam in a strong and substantial manner. There are no
buffers placed in front of the engine. (See Figs. 538,538A, p.663,664.)
Cab.-The cab or covering for the protection of the engineman
and fireman, which is placed over the foot plate, and partly over
the back end of the fire box, is in the form of a house, having
a curved roof, the clear height from the foot plate being about
6 feet 6 inclies. The frame work is strongly put together, having
windows at the front and sides; the front windows can be opened
at pleasure for the attendant passing through to lubricate the
machinery. Seats are provided with cushions, and in cold weather
a screen of canvas is hung up at the back end, so as to thoroughly
protect the men from the cold. As might be supposed these house
coverings are got up in superior style, both as regards architectural
design and the variety of choice woods used in their construction;
and along with the rest of the engine they are superbly decorated
and painted. (See Figs. 538, 538A, p. 663, 664.)
Inside of the “cab” there is placed a large gong or flat bell, fitted
with a spring hammer, so constructed that by pulling a trigger the
gong is sounded. A strong cord is attached to the trigger, and is
carried back throughout the train. Each carriage, or car as they
are termed in America, carries its own length of cord, which can be
coupled and uncoupled very quickly by means of spring hooks.
The cord is within reach of the passengers, and by pulling it gives
a stroke on the gong, which is the signal for stopping the engine,
and consequently the train of carriages.
Springs and equalizing beams.-The springs are very similar in
construction to those used in British practice. The ends of the
spring are formed flat, and the harness consists of a looped strap,
which is connected to the framing in the usual manner. In some
the top plate is made much thicker at the ends and hollowed out,
the spring harness or strap resting in the hollow, by this means
keeping the harness in position. The steel plates used in the con-
struction of springs are very seldom more than 3% of an inch in
thickness, and in some cases only ºr or % of an inch. Pintles or
spring pins are used for taking the bearing on the axle box, and in
some arrangements a roller is carried on the top of the axle box,
the flanges of the axle box extending upwards for this purpose;
the strap at the spring centre rests on this roller, which is calculated
to give a true bearing, with any inclination due to the working of
the spring when the engine is running.
LOCOMOTIVE ENGINES. 683
At the end of the spring which is connected to the equalizing
beam a slot is cut through the plates for taking a flat link, which is
secured with a key at the top, the bottom double link or hoop
taking the end of the equalizing beam. When the driving wheel is
placed in front and the trailing wheel behind the fire box, the pin
for the equalizing beam is carried on a bracket secured to the side
of the fire box and framing. With the view of increasing the elas-
ticity of the spring hanging blocks of india rubber are interposed
between the frame and the straps holding the springs, although this
material is never used for direct springs. In some examples the
equalizing beam is formed as a spring, with the view of giving
greater elasticity to the hanging arrangement.
Feed pumps, pipes, &c.—The stroke of the feed-pump ram is the
same length as that of the piston, the ram being secured to the
piston-rod crosshead with a single nut; the end of the ram passes
through a snug cast along with the crosshead. The pump is bolted
to the frame at the back end; and at the front or gland end it is
secured to the bracket plate for carrying the motion bars; this is
the plan usually adopted when the cylinders are placed horizon-
tally, and the pumps arranged inside, which is generally done. The
barrel of the pump is sometimes cast in brass, with a plunger of
wrought iron; but we certainly think that a cast-iron barrel and a
Muntz metal ram, such as used in British practice, is to be pre-
ferred, though there can be no doubt that a pump cast in brass is
more compact, and probably better able to bear the strain should
the water in the pump freeze in winter when the engine is cold.
The valves are usually of the cup form working in a suitable cage;
the lift of the suction valve is generally limited to 3% of an inch, and
the delivery valve from 3% of an inch to fºr of an inch rise. The
check valve on the boiler is of the same construction, and the valve
box is fitted with a gland and stuffing box for taking the pipe from
the pump.
The valve boxes both for the suction and delivery pipes are each
fitted with an air vessel; with the former it assists the water in its
passage to the pump, tending to fill the barrel more readily; while
for the delivery valve, the shock that is often felt and heard in all
quick-going pumps is reduced to the minimum, thus tending to
lessen the necessity for repairs, which are otherwise often required
in the feed pipes. The bottom of the suction branch on the pump
is fitted with a gland and stuffing box, so that the suction pipe may
634 MóDERN STEAM PRACTICE.
give with the expansion and contraction of the pipe, when the feed
water is warm or comparatively cold. There is always a plug tap
fitted to the boiler with pipe connection to each pump and feed pipe;
by this means steam is admitted into the pumps in the winter time
when they are in danger from the water freezing, as likewise the
steam can be admitted into the tender through the suction pipe to
heat the water in the tender, and consequently effect a saving in fuel.
This can generally be done when running slowly or standing at a
station, otherwise the steam would be blown to waste through the
safety valves. Water heaters have been tried with a measure of
success, the feed water being heated by the waste heat in the
smoke box.
The connection between the tender and the suction pipe on the
engine which is universally preferred is a plain flexible hose, which
bends and unbends with the motion of the engine and tender, the
material used in its construction being india rubber and canvas,
with a coiled wire placed inside to prevent the pipe collapsing, and
which springs readily with the motion. A small plug tap is placed
between the delivery valve and the non-return valve on the boiler
for relieving the pipe from any steam that may accumulate, and
which is worked by a rod (having a handle at the end) passing
along to the platform.
THE LOCOMOTIVE TENDER.
THE BRITISH TENDER.
The tender is the vehicle which accompanies the locomotive
engine, and carries the fuel and water, &c., required by the leading
machine, besides in many cases providing the brake power for
controlling the train. The framing of the tender in many examples
is entirely composed of wrought iron, built up in some, or in one
plate with all the parts cut out; while in others the side frame is of
oak, with thin side plates all in one piece, with the guard plates for
the axle boxes cut out in the plates, and in some arrangements
separate from the side plating; the end beams being formed of oak
strengthened with wrought-iron plates. The guide plates are of cast
iron bolted between the thin side plates. The axle boxes are of
LocoMotive ENGINES. 685
the same material, with a top bush of brass and a bottom part
of cast iron, which is held in the axle box with two pins; the
ends of the axle boxes are capped to exclude dust and grit from
the journals. There are generally six wheels placed under the
tender, but some have only four; of course the number of wheels
depends on the size or length of the tender, although we find equal
lengths have in some cases six and in others four. Four wheels
placed closely together will take curves more readily than the six-
wheeled arrangement, but the wear and tear of the four wheels
must be greater, owing to the carrying weight being more on each,
_*------...--- 3.
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- 3 : : : 29, 8.8,...º.g
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Fig. 538B.-Tender for Passenger Engine.
A, Water space, B, Manhole and water pipe. Č, Coal space. D D, Wheels. E, Frame. FF, Springs.
G, Spring buffer. H H, Brake blocks. 1, Lever screw and rod for brake. K, Hand wheel. L., Pipe connec-
tion to the engine.
and certainly we think the brake power not so effective as with the
six wheels. The various parts of the wheels, namely, the boss, arms,
and inside tyre, are forged all in one piece, while in some the
boss, arms, and inside tyre are of cast iron, the outside tyre being
shrunk on in the usual manner. The springs are placed on the top
of the framing, and connected thereto with plain side links, or
harness as it is technically termed; the strap at the centre of the
spring has the usual bearing pin for supporting the load, the
end resting in a recess on the top of the axle box, which pre-
vents the pin shifting. Sometimes the springs are located under-
neath the side oak beams, placed between the thin plates; with
this plan the harness and bearing pin are much shorter than in the
other. $3.
The brake power is a screw and lever arrangement, with rods
connected to arms carried by a top joint fitted to the framing, one
being placed at the front and back of each wheel. These arms



686 MODERN STEAM PRACTICE.
carry wooden blocks, which are forcibly pressed against the tyres
with the screw and lever apparatus. Willow is considered the best
wood for the purpose, as it grips firmly and is noiseless. The best
result attained is when the wheels are barely kept from skidding,
that is, when they are turning round with difficulty, being held by
the friction of the blocks acting on the tyres. The leverage is
usually about 500 to I, that is to say, the blocks move towards the
wheels with a reduced speed of ºr of the speed of the handle or
screw; this, we will allow, is suitable for a weight of tender of 12 tons.
This gives a leverage of, say, 4 I to I per ton of load: thus any
weight of tender multiplied by 4 I will give the power required.
To distribute the strain of the brake, preventing an undue stress on
any particular part of the framing, the motion should be reduced
with the system of levers beyond the screw; the screw should have
a coarse pitch double or triple threaded, and the lever actuated by
it should be long in comparison with the shorter levers which act on
the brake blocks. We will now take examples from practice, and
show what is considered the better arrangement:-
PROPORTIONS.
No. 1. No. 2.
Radius of hand lever or wheel, ........................ I2 in. 7 in.
Pitch of screw, ............................................ % , }%
Length of lever for screw, .............................. I2 , , 39 22
Length of levers linked to brake block,............. 6 , 7 5,
In these arrangements the reduction of speed is effected in the first
instance with the hand lever and screw, and secondly by the un-
equal levers on the transverse shaft which actuated the whole
system of brakes:– -
REDUCTION.
(1st), 75 to 34, or 225 to I by screw.
No. I “” (2d), 12 to 6, or 2 to I by lever.
450 -
(1st), 44 to 34, or 88 to I by screw.
No. 2..........
(2d), 39 to 7, or 5-6 to I by lever.
492.8
It will thus be seen in the first example that the reduction by a
long lever and screw of fine pitch is 225, while in the second ex-
ample it is 88 only; in the latter the motion is reduced beyond the
screw by the system of levers, and even gives a greater reduction
LOCOMOTIVE ENGINES. 687
than the former, the concentration of power in the first example
being severe on the framing, which should be avoided as much as
possible. -
In other examples of brake gear two parallel bars are substituted
instead of the levers and rods, having suitable wrought-iron brackets
bolted thereto for carrying the willow blocks; the bars are guided,
and at the end a rack is formed on each, worked by a pinion, with
spindle forged along with it on the end of which the lever for the
screw is secured. This lever is formed with a jaw for taking the
oscillating nut, through which the screwed rod works, the plain part
of the rod being continued to the top of the tender, passing through
a hole in a bracket, on the top of which the brake handle or wheel
is located. The brake blocks in this arrangement simply move to
and from the wheels in a horizontal line, which tends to wear the
willow blocks more equally; but we must bear in mind that the
concentration of power is very severe on the bracket fitted to the
framing, and provision must be made to meet the requirement.—
For a description of the Continuous Brake, see p. 689.
The coupling between the tender and engine has already been
described in connection with the main framing of the engine. The
back of the tender is fitted with a draw hook and spring, the buffers
being volute springs placed in suitable circular boxes, while in some
the draw spring is extended the whole width between the centres
of buffers, the spring acting as the buffing medium, as in ordi-
nary railway carriages. Two safety chains are likewise provided on
the back beam to connect with the line of carriages, and are fitted
with hooks for attachment to the chains on the first carriage of the
train. sº
The water tank is generally of a horse-shoe form, the space
between being for fuel. The capacity of the tank is about 150 or
I6O cubic feet, containing from 900 to IOOO gallons of water for
ordinary passenger engines, and the capacity for goods engines of
the heaviest description about 240 cubic feet, containing 15OO gal-
lons nearly; but it must be borne in mind that these quantities
vary with the length of the line. Light tank engines, for example,
for short lines have a capacity of about 80 to IOO cubic feet, contain-
ing 500 to 6OO gallons. The tank should be made of the best iron
plates, 34 inch in thickness, and should be well stayed, as its form
is weak, and leakage may occur if it is not strongly stayed. It is
provided with a short hollow cylinder fitted with a cover, which is
683 MODERN STEAM PRACTICE.
placed on the top of the tank at the back end, the principal use
of which is for filling the tank with water, but it is also made of
sufficient size for a man to pass through to inspect the inside of
the tank. %
Two feed pipes are fitted to the front end, and are coupled to the
feed pipes from the engine. They are provided with valves for
regulating the supply.
It is highly necessary that the water used in a locomotive boiler
should be as pure as practicable, and for this purpose all impuri-
ties should be got rid of in the reservoir before the water enters
the tank.
THE AMERICAN TENDER.
The tenders for American locomotive engines are very different
from those of the British type. The tank is of the ordinary form,
and contains from I2OO to 2000 gallons of water, and from I to 3
cords of wood fuel, occupying a space of 128 to 384 cubic feet. The
framing under the tank is constructed of wood, the whole of the
weight being carried on two trucks similar to that of the engine;
in the forward truck the weight is carried on the centre, and at the
back end the load is carried on the sides of the truck; by this means
there are three parts on which the load is supported. The brake
gear is very powerful, each truck carrying its own system of brakes;
the willow blocks are secured to transverse bars of wood, and are
carried up with shackles secured to the truck frames, and which
are actuated by means of a handle and spindle for a chain winding
round, taking a system of levers on the front truck, which draws
the willow blocks forcibly against the wheels, with a similar system
of levers for the back truck, which is connected to the forward
system with a chain; by this means the trucks can swivel without
deranging the mechanism. In some examples the brakes are only
fitted to the back truck of the tender, and are suspended from the
framing. The trucks have each four wheels with axles, having
the necessary axle boxes, the guard plates are of cast iron bolted
to the frame; the springs are placed on the top of the framing, to
which they are secured with suitable harness. A strong chain and
shackle is placed at each top corner of the truck frame, the other
end being carried by the main frame; these are necessary in order
to prevent the trucks swivelling too far.
BRAKES AND REGISTERING APPARATUS.
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Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
Fig. 6.
Dudley Dynamograph.
Westinghouse Compressed Air Brake: Transverse section of Air-Purmp.
Transverse section of the Triple Valve.
3Elevation of the Triple Valve.
Working, or Distributing Valve.
Cylinder with double piston: Section and Elevation.
| Fig. 10. Transverse section of Pitcairn Apparatus.
Fig. 9. Pitcairn Apparatus for ascertaining the Condition of the Road.
Fig. 11. Apparatus for Measuring the speed of Trains (Westinghouse System).
ig. 7. Combination of Conduit : Section and Elevation. t Fig. 12. Longitudinal section of Speed-Registering Apparatus.
ig. 8. Escapement Valve. : IFig. 18. Transverse section of Speed-Registering Apparatus.
Fig. 14. Middle Sidings.
Fig. 15. Signals of the Union Electric Signal Company, for straight course.
Fig. 16. Signals for Crossings,










































LOCOMOTIVE ENGINES. 689
CONTINUOUS BRAKES.
In our notice of the Locomotive Tender we have described the
construction of the ordinary brake gear as fitted to tenders and
brake vans; but the vastly increased traffic on our railways has
rendered necessary some more speedy and certain appliance for
diminishing the speed of trains and stopping them within short
distances. It is now over twenty years since the Board of Trade
first urged upon railway companies the necessity for adopting such
appliances; and in 1878 a bill was passed enforcing upon the Com-
panies periodical returns to the Board respecting their action in the
matter of brakes. With a view still further to protect the travelling
public a bill was introduced into Parliament in 1882, rendering it
compulsory on all railway companies to adopt some form of continuous
brake which will comply with the following requirements:–To be
instantaneous in action, and capable of being applied by driver and
guards; in case of accident, to be self-acting; to be applied to every
vehicle in the train; to be in regular daily working; and the
materials employed to be of durable character, easily maintained
and kept in order. This bill, however, did not become law.
A variety of continuous brakes have been introduced with a
view to meet these requirements; and there can be no doubt that
the use of such brakes has already been of much service in lessening
the risk of accident, as by their means trains which formerly required
about half a mile to pull up can now be brought to a stand in about
300 yards. Among the forms of continuous brake which have been
tried are Barker's Automatic, Eame's, Fay, Newell, and Eame's
Combined, Sanders and Belitho's Automatic Vacuum, the Steel-
MºInnes, Smith's Automatic Vacuum, and the Westinghouse Auto-
matic Brake;—the various arrangements being known as Screw
Brake, Chain Brake, Hydraulic Brake, Vacuum Brake, and Com-
pressed-air Brake. In all these forms the whole or part of the wheels
of the train can be braked by méchanism actuated from the engine.
In the first two methods rigid or flexible bodies are used, in the others
fluids transmit the power required. In the hydraulic brake water
is forced at a high pressure along pipes. In the air brake air is in
a similar manner forced to the point of application, and in the
vacuum brake the air is removed.
For automatic arrangements, whether of air or vacuum, there
43.
690 MODERN STEAM PRACTICE.
are chambers or reservoirs underneath the carriages. These are
fitted with cylinders and pistons, the latter in connection with the
brake blocks; the object
in such arrangements be-
* * *** * *º-> *** * * * * * *= a
§
# ing to keep up a certain
§ 3 condition in the cham-
# bers, whether of pressure
3 * or vacuum, which if de-
. . ; stroyed either intention-
# # ally or accidentally, as by
. . ; the breaking away of the
É ää carriages, the brake blocks
# : â will immediately be ap-
§ 3. # plied to the wheels.
# # § The Westinghouse Au-
#3; tomatic Brake has now
2 : # been extensively adopted
# g; on the more important
s : i railways in Great Britain
ă ă ă as well as those on the
# i; Continent and in the
§ 5 United States of Ame-
i 3 g rica. This brake is con-
## tinuous throughout the
ă ă ă train, and is operated by
§ 3 & compressed air stored in
3 * T a main reservoir on the
i .# engine, and in small re-
&# servoirs, one upon the
... ຠengine, tender, and each
tº ; : carriage, all connected by
... : a pipe running the length
## of the train. There are
# also on each vehicle a triple
gs valve and brake cylinder
< with pistons connected to
the brake levers.
Fig. 538C shows this brake complete fitted to an engine and
tender. The pump on the engine is started by admitting steam to
the cylinder A, air is forced from the cylinder B into the main

LOCOMOTIVE ENGINEs. 691
reservoir, which is connected to the driver's brake valve. When a
train is to be charged—the hose couplings between all the carriages
and engine or tender having been united—the compressed air stored
in the main reservoir is turned into the brake pipe by putting the
handle of the driver's brake valve over to the left. It then fills the
brake pipe and flows by a branch pipe through the triple valve into
the small reservoir on the tender and each vehicle, where it remains
until the brake has to be applied. Uniform air pressure then exists
throughout the train except in the brake cylinders, the brakes being
off, and the pressure per square inch is shown on the gauge con-
nected to the brake pipe on the engine and in the guards' vans.
So long as this pressure is maintained the brakes are kept off, as
the passage from each small reservoir to its cylinder remains
closed; but letting the air suddenly escape from the brake pipe
causes the triple valves to move down and uncover the passages to
the cylinders. The air stored in the small reservoirs then flows into
the cylinders and forces out the pistons and rods, thus applying the
brakes. On the other hand, the brakes are taken off by reopening
the passage from the main reservoir, through the driver's valve,
and thus restoring the pressure in the brake pipe; this liſts the
triple valves, and places the cylinders in communication with the
atmosphere by means of an exhaust cavity in each of the valves,
at the same time recharging the small reservoirs; the air used in
the cylinders is thus allowed to escape, and the brake pistons and
rods are pushed back to their places by springs inside the cylinders.
It follows from the above that any sudden decrease of pressure in
the brake pipe, whether produced by the driver or guard operating
his brake valve, or by the separation of the train, or other acciden-
tal severance of, or damage to, the brake pipe, aftp/ies the brake.
It is therefore called “automatic” or self-acting; and owing to this
principle the brake acts as a “tell-tale” as to its own condition, for
should anything be wrong a warning is unmistakeably given by
stopping the train. Special provision is made to prevent the appli-
cation of the brake from leakage, and a release valve is fitted on
each cylinder for the purpose of releasing the brake direct, if applied
when an engine is not attached.
Fig. 538D shows the Vacuum Automatic Brake which is adopted
on many of our railways. This form of brake is operated as
follows: By means of a small steam ejector placed upon the engine
the air is drawn out of the main train pipe E, from the bottom
692 MODERN STEAM PRACTICE.
side of the piston or diaphragm A through the branch pipe F, and
from the vacuum chamber B and top side of piston or diaphragm
through the valve D, so that a vacuum of 20 to 24 inches (i.e. Io to
12 lbs. per square inch) is maintained throughout the system. To
apply the brake a valve is opened by the driver or guards, which
Fig. 538D.—The Vacuum Automatic Brake.
allows air to flow to the bottom side of the piston or diaphragm, the
top side and vacuum chamber maintaining the vacuum through the
action of the valve D, which closes immediately air is admitted to
the train pipe. To release the brakes when the engine is detached
from the train, the valve D is raised by means of a small lever
placed on either side of the carriage which admits air to the vacuum
chamber and top side of piston or diaphragm, and the brakes fall
off by gravity. The flexible diaphragms, hose pipe connections,
and miniature sacks C are made of the best rubber and coated with
a material which effectually resists oil and grease.
BRAKE RESISTANCES.
From a series of experiments made by Captain Douglas Galton,
C.B., F.R.S., on the effect of brakes upon railway trains, some
curious and interesting results have been obtained, from which it
appears that— ... *
(1) “The retarding effect of a wheel sliding upon a rail was
much less than when braked with such a force as would just allow
it to continue to revolve.” The resistance due to friction of the
wheel on the rail being only one-third of the friction between the
wheel and the brake blocks.

LOCOMOTIVE ENGINES. 693
(2) “The coefficient of friction between the brake blocks and the
wheels varied inversely according to the speed of the train.” Thus
with cast iron brake blocks on steel tyres the coefficient of friction
when just moving was 330—
At Io miles per hour, ... 242 At 40 miles per hour, ... 'IAo
92 2O 5 y $ 2 & gº º * Ig2 9 3 50 32 3.9 gº º º * I 16
2, 30 , , 2 3 dº º Aº 164 ,, 6o , 2 3 gº tº ſº ‘O74
Further, it was found that this coefficient was affected by time,
thus: Starting at 27 miles per hour the coefficient was 17 I; after
5 seconds, "I 3O; after IO seconds, 'I I9; after 15 seconds, OSI; and
after 20 seconds, 'oZ2; and at 47 miles per hour the coefficient at
starting was 132, falling after IO seconds to ozo; and at 60 miles
per hour falling from OZ2 to OS8.
These coefficients are further influenced by material and weather.
It was found that the distance run by a train on the level at 50
miles per hour varied with the percentage of the total weight of train
used for retardation as follows: with 5 per cent, 55.5% yards; IO per
cent, 277% yards; 20 per cent, 139 yards; 30 per cent, 92% yards.
Capt. Galton points out amongst other conditions that a perfect Con-
tinuous brake should be fitted to act upon all the wheels of engine
and carriages, that it should exert upon the blocks of each pair of
wheels within two seconds a force of about twice the load on those
wheels, that the brake-block pressure should be such that the fric-
tion between the block and wheel may not be greater than the
adhesion between the wheel and the rail, and that the action should
be automatic in the event of a separation of the train or failure of
connections.
COMPOUNDING LOCOMOTIVE ENGINES.
The principle of compounding has been recently applied with
good results to the locomotive engine, and thereby enables the
benefit of expansion to be more fully carried out than could be with
the single cylinder. One of the arrangements consists in having a
high and low pressure cylinder, one on each side of the engine, so
that instead of two independent cylinders of the same size, having
steam to each from the boiler, the steam first enters the high-pres–
sure or smaller cylinder and thereafter passes across to the low-
pressure or larger cylinder.
694 MODERN STEAM PRACTICE.
This system was introduced on some of the French lines a few
years ago by M. Anatole Mallet, and appears to have been success-
ful there. In a paper read by that gentleman before the Institution
of Mechanical Engineers he says:–
“The compound system affording a simple and effective means
of expanding, that expansion should be carried to a high degree,
and for this purpose cylinders of a large size must be used. In new
engines this can easily be done. The application of the compound
system to existing locomotives is much more difficult; if some
engines lend themselves readily to the change, this is by no means the
case always. The author is convinced that the system will be further
extended; and its success, he is satisfied, would be speedily assured, if
a thorough practical trial were made on one of the English railways.”
“The usual method of converting an existing engine is generally
to retain one of the original cylinders as the high-pressure cylinder,
Fig. 538E.-Engine with right-hand Cylinder altered.
A, High-pressure cylinder. B, Low-pressure cylinder. C, Steam pipe. D D, Exhaust pipe from the
high-pressure cylinder. E, Blast pipe. F, Safety valve on the starting-valve chest.
and to replace the other by a new one of larger diameter for expand-
ing; the steam and exhaust pipes are suitably rearranged, and a start-
ing valve and reducing valve are added, while the whole of the origi-
nal mechanism is retained for the large cylinder. The first engines
altered in this way were two powerful locomotives, one a passenger

LOCOMOTIVE ENGINES. 695
engine on the Paris and Orleans Railway, and the other a goods
engine on the Northern Railway of Spain. The arrangement of
this altered engine is shown in Fig. 538E. The old cylinders were
17% in. diameter and 2356 in. stroke; of these the right-hand one
has been replaced by a cylinder of 23% in. diameter, which was as
large a size as the engine frames would allow to be got in; the ratio
of the two piston areas is therefore 1.86 to 1. The exhaust pipe
from the small to the large cylinder is made to take a long winding
course, so as to get as large a capacity of receiver as possible,
amounting in this case to I-69 times the capacity of the small
cylinder; by the same means also the pipe has about 20 Square feet
of surface exposed to the heat of the smoke box. As the alterations
were required to be made in the simplest and least expensive
manner possible, the arrangement of the two link motions to work
independently of each other has not at present been carried out in
this engine, which is the more to be regretted as it presented no
special difficulties; but it can be done at any future time. The
reducing valve has been fitted with a spring to prevent any violent
shocks in case of its acting too quickly; and a spring safety valve
has been fixed on the starting valve chest, to avoid excessive com-
pression of the steam when working reversed.”
A trial of this principle has now been made by Mr. Webb of Crewe,
who has recently designed and placed on the London and North-
Western Railway a new compound locomotive which appears to
have given most satisfactory results. We are indebted to that
gentleman for the elevation and plan of this locomotive shown on
the following page.
“The new engine has been constructed at Crewe, and is similar
as regards boiler, wheels, and so on, to the four-coupled express
engines of the London and North-Western Railway. The trailing
drivers are driven by a pair of outside cylinders II 34 inches
diameter and 24 inches stroke, secured to the side frames at a
point just in advance of the leading driving wheels. The piston-
rod heads are guided by two flat bars, one at each side, instead of
four, as usually employed, the crosshead being channelled to slide
on the bars. The slide valves are worked by Joy's patent gear,
and the connecting rods lay hold of pins in the wheel bosses. So
far we have a complete engine with outside cylinders and a
pair of driving wheels behind the fire box, resembling Crampton's
patent engine. In the smoke box, right beneath the funnel, is
696 w MODERN STEAM PRACTICE.
fixed a third cylinder, 26 inches diameter and 24 inches stroke,
the connecting rod of which lays hold of the pin of a single crank
in the middle of the length of the leading driving axle. The
exhaust steam from the two small cylinders passes into a kind of
- - - - - - - - * * * * * * * * * * * * * * = m =
Al Tº TTT —eſ - t
- - Iſo º Q t
li d!— *
sm- * - - - mºs sºme ºne - - * * -- - - - - - - --Rº- - - - - - - - - - *
Figs. 538F, 538G.—Front End Elevation and Ground Plan of Compound Locomotive,
London and North-Western Railway. -
AA, High-pressure cylinders. B, Low-pressure cylinder. cc, Steam pipes. D D, Exhaust pipes from
high-pressure cylinders. E, Blast pipe.
gridiron of pipes between the engine frames, which pipes act as an
intermediate receiver, and from thence it is led into a copper pipe
coiled in the smoke box, in order that it may be reheated and
dried. Thence it goes into the valve chest of the large cylinder.

LOCOMOTIVE ENGINES. 697
We have thus a locomotive with a single pair of driving wheels in
advance of the fire box, driven by a single cylinder. It must be
understood that the double engine and this single-cylinder
engine are quite independent of each other—that is to say, each
may run at any pace it can. There are no coupling rods, nor is
there anything to maintain a fixed relative position between the
cranks of the single and double cylinder engines, save the rails.
The single engine depends for its supply of steam on the double-
cylinder engine, and should the latter slip, more steam is sent into
the receiver than the large cylinder will take, and the back pressure
rises, and so tends to check slipping; while for the same reason
the pressure on the large piston is augmented, and it may slip its
wheels. If, on the contrary, the single engine slips first, it will
take more steam away than the other engines can supply, and its
own pressure will fall off while the effective pressure in the other
cylinders will be augmented. It is found that this controlling
action operates very effectually, each engine doing its own share
of the work fairly. No inconvenience results from the changing
position relations of the crank pin, the size of the intermediate
receiver being sufficient to prevent irregularities in the amount of
back pressure of much moment. With a boiler pressure of 150 lbs.
the pressure in the receiver averages about 50 lbs. This com-
pound locomotive is a handsome engine, and has been run at
very high speeds with perfect steadiness. Mr. Webb states that
the engine works ordinary passenger trains with a little over 23 lbs.
of coal per mile, which represents a saving of perhaps 20 per cent.
in fuel on the ordinary consumption. It is beyond question the
best type of compound locomotive ever constructed, and we shall
be much surprised if a large number of such engines are not soon
put into regular traffic.”
As already stated, the valve gear employed in this compound
engine is Joy's, the ordinary link motion not being considered in
this case satisfactory. This valve gear is described as follows: “In
a kind of box under the running board is fitted a disc, which may
be said to resemble the plug of an ordinary stop cock. In this
plug is a curved slot, having the same radius of curvature as the
length of the link leading from a die in this slot to the end of the
valve rod. This link is coupled to the connecting rod by two bars.
The effect is that as the crank shaft revolves the die is caused to
* The Engineer, Aug. 1879, Feb. Mar. 1882.
698 MODERN STEAM PRACTICE.
travel up and down in the slot in the plug. If the slot is set at
angle with the vertical, the valve stem will obviously be caused to
move backwards and forwards; when, however, the slot is vertical
the valve has no motion imparted to it by the travel of the die.
The plug has a lever arm attached to it answering to the handle
of a tap. This lever is coupled to a reversing lever with quadrant.
By this means the plug can be made to partially rotate, and so
alter the angle of inclination of the slot that the engine will run
forward or backwards.”
DESCRIPTION OF SPECIAL LOCOMOTIVE ENGINES.
FOUR-WHEEL COUPLED BOGIE PASSENGER ENGINE FOR
THE CALEDONIAN RAILWAY. (SEE PLATEs.)
The boiler is of the best Yorkshire iron, plates 34 inch thick in
the barrel, tube plate # inch, firebox casing sides fºr inch, back
% inch, and front 5% inch thick. The longitudinal seams are top-
jointed and double rivetted, and the transverse seams single rivetted
with # inch rivets placed 1% inch between the centres. The
inside firebox is of the best copper 9% inch thick, except the tube
plate, which is 7% inch thick where the tubes are fixed, and 3% inch
below. The casing and firebox are stayed together at the ends
and sides with I inch copper stays, screwed into both plates, and
placed 4 inches apart between the centres. The roof is stayed with
iron through stays I 36 inch diameter screwed through both plates,
rivetted on the outside and secured with nuts inside. The tubes
are of copper 134 inch diameter and swelled to I }# inch at the
smoke box end, 13 W. G. thick at the fire box and 12 W. G. at the
smoke box, fixed in the fire box tube plate with solid drawn steel
ferrules Io W. G. thick.
The frame is of Yorkshire iron I }; inch thick over the driving
and trailing axles and I }% inch thick over the bogie. The bogie
frame is I inch thick. -
The driving and trailing axle-box guides are of steel, of a horse-
shoe form, and securely bolted to the frames; the bogie guides are
of cast iron. Driving and trailing axle boxes are of cast iron with
gun-metal steps and keeps. The bogie axle boxes are of gun metal
with cast-iron keeps. The bearings in all cases are lined with white
A Fire Box.
i i Buffer Beam,
B Tubes. c Stays.
D Smoke Box.
E Smoke Box Door.
F Chimney.
G Fire Bars.
H Ash Pan. I Stays.
K Fire Door.
L L Sludge Plugs.
M. Steam Dome.
N Safety Valves.
oo Steam Whistles & Handles.
P Cylinder.
Q Slide Valve.
R Regulator, Valve.
S Handle for Regulating Valve.
T Blast Pipe.
U Grease Cup.
v Eccentrics & Link Motion.
w Weigh Shaft, with Levers
and Rod connecting with
Starting Handle wa.
Xa x& xc Piston, Rod, Cross-
head. x d Guide Bars.
Y Connecting Rod.
z Driving Axle.
a Trailing Axle.
& & Bogie Axles.
cc Wheels.
d Crank Pin.
e Side Rod.
y Main Frame.
g End Beam.
J. J. Drag and Safety Pins.
-
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SS;
with Spring.
# Buffer.
2 Guard.
mt Axle Box and Guides for
Driving Axle.
rt Axle Box and Guides for
Trailing Axle.
oo Springs.
A Compensating Lever.
g Cab. .
7. Frame for Platform.
s Splasher.
# Injector, with Feed Pipe t'.
ze Check Valve on the body of
Boiler. -
z, Blow-off Tap
zo Steam Pipe for Injector.
+ Socket for Lamp.
y Covering for Steam Dome.
3' Cleading.
z Water Pipe to the Tender.
27 Sand Box and Pipe.
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DIAMETER of CYLINDERs, .. I8
LENGTH of Stroke, ... .. 24 INéHes.
DIAMETER of CoupleD WHEels, 7 FEET 2 INCHES.
DIAMETER of Bogie WHEELs, 3 FEET 4% Inghes.
WHEEL BASE, .. tº tº ... 21 FEET 2% INGHES.
HEATING SURFACE IN Tubes, 905 sq. FEET. '
HEATING SURFACE IN FIREBox, 82 sq. FEET.
AREA of FIREGRATE, 14°6 SQ. FEET.
*
VERTICAL AND HORIZONTAL sections. OF BOGIE PASSENGER ENGINE.
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D. Smoke Box.
E Smoke-box Door.
F Chimney.
PF Cylinders.
Q Slide Valve.
R Cover for Valve Casing.
s End Cover.
T Blast Pipe.
U Stearn Pipe.
v Branch for Steam Pipe.
w Solid Ring.
xx Rivets for securing the Solid
Ring to Barrel of Boiler. N
Y Bottom of the Smoke Box.
z Hand Rail.
a a Studs for Hand Rail.
& & Clothing Plates for Cylinders.
c c Bogie Wheels.
da Hinges and Handle for secur- s '
ing Smoke-box Door.
e Studs and Pin for Hinges.
Jºf Main Framing.
g Platform
h Bogie.
# Swivelling Centre.
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ENGINE. * Frame for carrying Central
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22 Bogie Frame,
m Stays.
n n Springs.
oo Studs for taking Spring
A Bolt. [Shackles,
Q Volute Spring.
,” r Oil Cup.
s Splasher.
Q *t Blow-off Taps on the Cylinders
and Valve Casings,with Levers
and Rods passing along t
Starting Platform. - -
* Tube Plate in the Smoke Box.
zy Tubes.
ww Stays.
+ Mud Plug.
3. Socket for Lamp.
2 Auxiliary Blower Pipe,
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LOCOMOTIVE ENGIN
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A' Crown of Fire Box.
A” Sides of Fire Box.
B Tubes.
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G G Palms for supporting Frame
for Fire Bars, &c.
H H Stays.
II Stays.
K Fire Door.
LL Holes for Plugs.
M Hole for Blow-off Tap.
N Seating for Safety Valves.
o Body of the Boiler.
Jºf Main Framing,
TRANSVERSE SECTIONS OF BOGIE PASSENGER ENGINE.—BUILT FOR THE CALEDONIAN RAILway By MESSRS, NEILSON & Co., GLASGow.
-i:







































































LOCOMOTIVE ENGINES. 699
metal. The axles and tyres throughout are of crucible cast steel.
The crank pins are of Yorkshire iron well case-hardened in the
journals.
The slide bars are of Bessemer steel. The piston rods are of best
Yorkshire iron. The connecting and coupling rods, crossheads,
and the whole of the valve motion, including eccentric straps and
the smaller parts of the pulleys, are made of best Yorkshire iron
and well case-hardened where required. The larger parts of the
eccentric pulleys are of cast iron. The cylinders are of a mixture
of cold blast and Scotch pig iron twice melted and as hard as pos-
sible. The pistons are of the same metal, with two cast-iron rings
in each. -
The wheels are of the best scrap iron, with cranks and balance
weights forged solid in them. The tyres are secured with clip rings
on the sides recessed into the rim of the wheel as well as the tyre,
and are held in place by rivets passing through the clips and the
rim at the end of each spoke. The springs are of the best spring
steel converted from Swedish iron.
The ashpan damper, cylinder cocks, and sand boxes are all work-
able from the footplate.
Two Friedmann's No. 9 Injectors, fitted with check valves and
all other necessary valves and cocks, are used for feeding the boiler.
The boiler was tested after all the fittings were attached with
water pressure to 200 lbs. per square inch, and carries a working
pressure of I 30 lbs. per square inch.
The weight when loaded is as follows:–
Tons cwts, qis.
Bogie, 13 o o (equally divided). Tractive force 90 lbs. for each lb. of
Driving wheels, 14 15 o effective pressure on the piston.
Trailing wheels, 13 12 o -
Total, 4I 7 O -
Tender, 27 8 o Full of water and 3 tons of coal.
The tender is carried on six wheels, and contains 1880 gallons of
water and 4 tons of coal. The frames are of the same quality of
iron as those for the engine, and 7% inch thick. The tank is of
best Scotch iron plates, top and bottom ºr inch and sides 34 inch
thick well stayed. The wheels are of the same description as those
for the engine, and fitted in a similar manner with tyres of Bessemer
steel.
7oo MODERN STEAM PRACTICE.
The axles are of Bessemer steel; the axles boxes and guides of
cast iron fitted with steps of gun metal. A powerful brake worked
by a screw from the footplate acts upon each wheel.
EXPRESS ENGINE FOR GREAT NORTHERN RAILWAY.”
In the next example to which attention is directed, outside cylin-
ders have been used; perhaps as a necessary consequence of the
adoption of a bogie carriage with four wheels, instead of a pair of
leading wheels, to insure greater freedom in passing round curves at
high speeds, for which special object the engine has been designed
by the locomotive engineer of the Great Northern Railway. The
weight on each of the four front wheels is at the same time propor-
Fig. 539.-Express Engine for Great Northern Railway.
A, Fire box. B, Midſeather. C, Fire door and deflecting plate. D, Body of boiler. E, Mud chamber.
F, Smoke box. G, Chimney. H, Stays. I, Injector. K, Cylinder. L., Valve chest. M, Guide bars.
N, Connecting rod. O, Bogie carriage. P, Driving wheel. Q, Trailing wheel. R, Cab. s, Draw
pin. T, Frame. U, Weigh shaft. v., Line of valve spindle.
tionately diminished, and with great advantage. It will be observed
that there is one frame only on each side of the fire box and inside
the wheels, and that this frame receives the cylinders. These frames
are of one solid plate, I 34 inch thick, connected behind the fire box
by a cast-iron cross frame, and elsewhere by wrought-iron cross
brackets and by the buffer beam, receiving the cylinders in front on
each side of the smoke box. This position gives convenient access
to the cylinders, the pistons and rods, the connecting rods, the guide
bars, and the motion blocks, all of which are placed outside the
* Transactions of the Institution of Civil Engineers.

1,OCOMOTIVE ENGINES. 7OI
frames. The slide valves and their gearing are inside the frames,
though somewhat nearer to them than in inside-cylinder engines.
The train is drawn from the cast-iron cross frame, which, together
with the longitudinal frames, is so attached as to allow of the free
expansion of the boiler, to avoid any strain being put upon the latter
by the haulage of the train, and to free it from the contortions for-
merly occurring when rigidly connected with the fraines at several
points. The proper adjustment of the driving axle boxes is secured
by wedge-shaped horn blocks, attached to the frames by a screw
with lock nuts. The boiler is made of Yorkshire plates, 9% inch
thick, and is of the lap-jointed class, having double-rivetted longi-
tudinal and single-rivetted vertical seams. The pressure of steam
employed is 140 lbs. to the square inch.
The fire box is of copper, the tube plate being 34 inch thick, the
back plate 5% inch thick, and the sides and crown 94 inch thick. It
is of the usual square form, and is attached to the external iron shell
by a square iron frame at the bottom; and at the front, sides, and
back by screwed copper bolts, rivetted at both ends. The roof is
stayed to the external shell by wrought-iron radiating stays, 7% inch
in diameter, screwed into the copper plates and into the iron casing.
The fire box contains a sloping midfeather in such a position as to
deflect the heated gases from the fire before they reach the tubes.
The air admitted through the fire door, and directed by the ordinary
deflecting plate, is thus thoroughly mixed up with the heated gases,
thereby securing the best possible combustion. -
The boiler is fed by two injectors, and the water can be supplied
without reference to the motion of the engine. The tubes are of
brass, 217 in number, and each I fºr inch external diameter. This
comparatively small diameter tends to secure the more effectual
abstraction of heat from the gases passing through the tubes.
The cylinders are outside the frames; they are 18 inches in
diameter and 28 inches stroke, and may be considered a large
size for passenger engines. The joint of each steam-chest cover
is in the centre line of the valve spindle, so that when the cover
is removed ready access to the valve facing is obtained. The
valve gearing is of the ordinary shifting-link class. The small
ends of the connecting rods are furnished with solid bushes of
gun metal, which succeed admirably, the connecting rods having
run a distance of more than 50,000 miles without renewal. The
driving wheels are 8 feet. I inch in diameter; and the trailing
702 MODERN STEAM PRACTICE
wheels are 4 feet I inch in diameter. The end of the engine is
carried upon six volute springs, placed in a trough under the foot-
plate, as being more conveniently got in than the ordinary elliptical
springs. There is a cab over the foot plate for the protection of the
driver and the fireman. 3.
The front of the engine is carried upon a four-wheeled bogie
frame, with a cylindrical centre pin, the hole in the bush being
bored taper. It has also sliding bearings in the line of the side
frames under the cylinder steam chests, to give greater stability to
the engine when running at high speeds. This bogie arrangement
imparts flexibility to the engine when passing round curves, and
secures the greatest steadiness of the whole machine, at whatever
speed it runs.
The mode of attaching the inner to the outer fire box, by stays
screwed into each of the plates without the intervention of iron
girder bars, though in use for some time in Belgium, is now in
some cases adopted in this country. By this arrangement the large
amount of deposit generally existing upon girder boxes is prevented,
and the facility for cleansing is much greater. The liability of the
tube holes in the copper plate to become oval, by the pressure of
the ends of the girders upon the edge of the tube plate, is also got
rid of. It is understood that no countervailing disadvantages have
arisen from the adoption of the system.
The heating surface in this engine is:—
In the tubes, tº dº ſº tº ſº º * @ º & ſº e tº º º º ºg e IO43 Sq. feet,
32 fire box, tº gº º tº º º tº gº tº tº º ſº * * º Qº ſº tº I 22 9 3
Total, tº º ºs tº dº tº tº º ſº • * º ... I 165 sq. feet.
The fire-grate area is 17.6 square feet.
The weight upon the wheels, when the engine is in working
order, is:—
On the driving wheels, e tº º tº º º tº tº gº e G & tº e ºp I5 tons.
,, hind wheels, tº gº º tº gº º tº gº tº tº º º te º ºs 8 ,
25 bogie, © tº º tº º e tº gº º tº º º tº º º & & Cº I5 3 y
The distance from the centre of the hind wheels to the centre of
the bogie pin is 19 feet 5 inches.
The engine is capable of drawing a weight of 356 tons on a level
at a speed of 45 miles per hour (the load drawn includes in all
cases the weight of the engine and tender), with a working pressure
of I40 lbs. Its consumption of coal, with trains averaging sixteen
LOCOMOTIVE ENGINES. 7O3
carriages of IO tons weight each, has been 27 lbs. per mile, includ-
ing getting up steam and piloting; the cost of repairs being about
‘52d per mile run. This engine has been designed to fulfil the
requirements of a quick and heavy passenger traffic; and in the
whole arrangement of the parts, as well as in the excellence of the
materials selected for the construction, both durability and economy
of repair have been kept in view.
Smaller engines of this class on the same railway have 7-feet
driving wheels, with cylinders 17 inches in diaméter, with 24 inches
stroke of piston.
PASSENGER ENGINE FOR LONDON & NORTH-WESTERN RAILWAY.
The next example of an engine for passenger traffic is one
designed for the London and North-Western Railway.
Fig. 54o. --London and North-Western Railway Passenger Engine.
a, Fire box. B, Fire door. C, Fire-brick arch. D, Air holes. E, Ash pan. F, Body of boiler.
G, Smoke box. H., Chimney. 1, Steam chest and regulator. K, Safety valves, L, Cylinder.
M, Valve chest. N, Leading wheel, o, Driving wheel. P, Trailing wheel. Q, Frame. R, Weigh
shaft. s, Line of valve spindle. T, Reversing wheel and screw. U, Cab. v. Blast pipe
The cylinders are placed inside between the frames, each of which
is cut out of a piece of solid plate, I inch thick. The frames extend
the whole length of the engine, and are connected by the buffer
beam, by the cylinders, the motion plate, an angled bracket in front
of the fire box, and by a vertical buffing plate and horizontal cross
plates behind the fire box. The train is drawn from these frames,

7O4 MODERN STEAM PRACTICE.
which are free to allow the boiler to slide upon them at every point
behind the smoke box. The boiler is of Lowmoor plates, # inch
thick, and is lap jointed. The steam pressure employed is 120 lbs.
per square inch, and it is controlled by two safety valves. The fire
box is of copper, of the ordinary form, fixed to the external shell
by a square iron frame at the bottom, and by copper Screw stays
placed 4 inches apart, and rivetted over at both ends; the roof
being stayed by longitudinal wrought-iron girders, connected to the
external shell by vertical sling stays. The fire box contains a fire-
brick arch extending backward about half the length of the box.
Under this arch are two circular holes, 7 inches in diameter, covered
by doors which can be worked from the foot plate, so that the
amount of air admitted is well within the control of the driver.
The fire doors are of the double lever sliding kind, and invariably
secure the admission of air in the middle of the firing hole.
The boiler is fed by two injectors, to the arrangement of which
particular attention is directed. They are placed vertically behind
the fire box, so as to be easily manipulated by the driver. A ver-
tical screw with a wheel handle regulates the admission of the water
to the injector, which ascends and passes through a clack box (that
can be closed at pleasure) into the boiler along an internal pipe,
carried forward two-thirds of the length of the barrel of the boiler.
By this arrangement all external pipes running forward outside the
boiler are done away with, and greater simplicity and freedom from
accidents are secured.
The boiler tubes are of brass, 192 in number, and each 176 inch
external diameter. The cylinders are in the smoke box; they have
a diameter of 17 inches and a stroke of 24 inches, the slide valves
being placed vertically between them. Each piston is guided by
one upper and one lower steel guide bar after the fashion of an
outside-cylinder engine. The valve motion is of the ordinary shift-
ing-link class, the valve rods being square at the back part, and
working in cast-iron guides. The reversing motion is effected by a .
screw and fly wheel, to obviate the danger of the lever flying back,
as in the ordinary arrangement, and to lessen the effect on the
motion of the train when diminishing the admission of steam.
There are four driving wheels, each 6 feet 7% inches diameter,
coupled together by outside rods. The leading wheels are 3 feet
7% inches diameter. The connecting rods are forked, so as to gain
a greater length in proportion to the length of the stroke. The
LOCOMOTIVE ENGINES. 705
cross-head step bushes are of wrought iron case-hardened. The
coupling rods are furnished with circular step bushes of white metal.
All the rods are of steel. The end of the engine is carried upon
six volute steel springs, three on each side, placed below the axle
boxes, all of which are of solid brass, those for the coupled wheels
working in steel guides. The total heating surface is I IO2 Square
feet. The fire-grate area is 15 square feet.
Distribution of weight, when in working order, on the leading
axle 9 tons 9 cwts, on driving axle II tons, on trailing axle 8 tons
I5 cwts.; total, 29 tons 4 cwts. Total wheel base I 5 feet 8 inches.
FOUR-COUPLED BOGIE PASSENGER TANK ENGINE ON NORTH
BRITISH RAILWAY.
In Fig. 541 we give sectional and horizontal views of a new
type of engine designed by Mr. D. Drummond, locomotive super-
intendent of North British Railway. Originally intended to work
the company's coast traffic, the engine has been found most useful
for branch work generally.
The cylinders are 17 in. diameter, stroke 26 in. There are four
coupled wheels, 6 ft. diameter; diameter of bogie wheels 3 ſt. 6 in.;
total wheel base 2 I ft. I in.
The boiler barrel is telescopic, Io ft. I in. long, and 4 ft. 4 in. diameter
outside of the front plate. It is composed of two rings of plates,
each being in one plate. The longitudinal seams are butt-jointed,
and secured outside and inside with butt straps, strongest in their
transverse section, 7% in. wide and 5% in. thick, double rivetted.
The circular laps are 2% in. wide and single rivetted. The boiler
barrel is secured to the smoke-box tube plate by a solid rolled angle-
iron ring, 5% in. by 3% in. by I in. thick, double rivetted to the
boiler barrel and single rivetted to tube plate. The outside fire-box
shell is 5 ft. 5 in. long outside, and 4 ft. 6% in. at centre line, and
4 ft. 1 in. at bottom. The depth of the back end below the centre
line of the boiler is 4 ft. 4 in. to bottom of foundation ring, sloping
to 5 ft. 6 in. at the front end. The corners of the fire-box are made
to a radius of 6 in. outside. The sides and top of the fire box shell
are made in one plate, flanged, double rivetted at the longitudinal
portion only, and single rivetted to the outside shell of the fire-box.
The fire door is I ft. I in. by I ft. 4 in., and is fitted with a solid
wrought-iron ring I 34 in. thick by 2% broad, rivetted with a single
- 45
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Fig. 541.-Longitudinal Section and Half Plan of Four-coupled Bogie Passenger Tank Engine, North British Railway.
handle.
M, Crosshead, motion bars, &c.
R, Regulator handle.
x, Springs. Y, Tool box, &c.
z, Coal space, &c.
N, Connecting rod.
S, Main framing.
A, Fire box.
B, Fire-brick arch.
K, Stays. L, Cylinder.
link. Q, Weigh shaft.
c, Fire bars.
D, Tubes.
E, Smoke box.
F, Funnel.
G, Steam dome and safety valves.
N', Side rod. O, Cranked shaft.
H, Whistle. 1, Ashpan.
P, Double eccentrics and
T, Bogie and wheels. U, Driving wheel. v., Trailing wheel. w, Brake






LOCOMOTIVE ENGINES. - 707
% in.; tube plate, 34 in. The inside fire box has a circular top and
is of copper, 4 ft. 5% in. long by 3 ft. 2% in. wide at top, and 4 ft.
Ioj6 in. long by 3 ft. 65% in. wide at bottom. The inside of the
top of the fire box is II in. above the centre line of the boiler.
There is water space of 2 in. all round at the bottom of the box,
which is increased at the top of the back plate to 5 in. The tube
plate is flanged at the top to 2 in. radius outside, and is 4% in. broad,
and 33% in. radius outside and 5+3 in. broad at the bottom. The
tube plate is 3 ft. 8% in. wide at the top. Back plate flanged at
the top to 2 in. radius outside and is 4% in. broad and 3% in.
radius outside, and 5+. in. broad at bottom. It is dished at fire
hole. . The crown and sides are in one plate. The sides next to
tube plate are made with a pocket equal to the extra width of tube
plate at this part, and joined to the plain part of the box with I 2 in.
radius. Thickness of copper plates: tube plate, 76 in. and ºr in...;
back plate, fºr in.; covering plate, #3 in. The fire box is single
rivetted, except at the foundation ring, which is double rivetted. Lap
of copper plates, 2% in.; diam. of iron rivets, # in., 176 in. pitch.
The stays are of copper 76 in. diameter, twelve threads per inch;
each bar was tested to stand being bent round close, cold, without
fracture. The pitch of stays 4 in. The crown of the box is stayed
with I; in. in copper, and Iºs in. diameter stays in the iron plates,
twelve threads per inch, with round collars and square ends screwed
in from inside, having nuts on the inside screwed on the top of the
copper plate. The ends are rivetted over on outside shell. The
copper tube plate is secured to the boiler barrel by eight palm stays.
The foundation ring is made from scrap iron of two bars welded
in the centre 3% in. deep by 2 in. broad, corners 536 in. radius out-
side and 33% in. inside. The bars have projections at each of the
corners to allow for the radius outside, so that no V's were required.
The boiler contains 22O brass tubes, IO ft. 8 in. long by 134 in, ex-
ternal diameter, Nos. Io and II B. W. G., 34 in. water space; ex-
panded at both ends with Dudgeon's patent tube expander; steel
ferruled and carefully caulked in the fire box, and projecting j4 in.
through the smoke-box tube plate. No ferrules in that end.
The dome is of cast iron 34 in. thick at the top and I in thick
at bottom, flattened to 1334 in. diameter on top for receiving the
safety-valve seatings. Safety valves and seatings are Ramsbottom's,
of the best gun metal. The joints were scraped up perfectly steam-
tight and made with boiled oil only.
703 - MODERN STEAM PRACTICE.
The chimney is 13 ft. from rails to top, 16 in. diameter at bottom
and I7 in. diameter at top inside, made of one plate 94 in. thick. The
base plate is best Yorkshire iron 8 in. high, solid welded, and
flanged; secured to the smoke-box by ten 5% in. rivets. Plate tube
butt-jointed with a 3% in strap, ºr in thick on the inside. All the
rivets are countersunk and filed flush. The chimney is fitted with
a cast-iron top, as illustrated.
The main frames are of Yorkshire iron in one plate from the
back buffer beam to the front end of the cylinders, where they are
welded. The front part is forged and solidly welded to the frame.
They are placed 4 ft. I }% in. apart from the back end to the front
of the cylinders, where they are 3 ft. I 194 in. apart. Their total
length is 30 ft 6 in.; from the inside of the front buffer beam to
the centre of the bogie, 5 ft. 4 in.; from the centre of bogie to centre
of driving axle, 9 ft. IO in.; from centre of driving to centre of trail-
ing axle, 8 ft.; from centre of trailing axle to end of frame, 7 ft. 4 in.
The height from the rails to the top of the frame is 4 ft.; and the
depth of the frame over axle boxes, 18 in. The front buffer beam
is I 334 in. deep and I }4 in. thick by 7 ft. 2% in. long. It is stif-
fened with two 2% in. by 2% in. by 3% in. angle irons as shown.
The back buffer beam is 15 in. by I }4 in. thick by 7 ft. 25% in,
with a slot cut for draw bar.
The horn blocks are of the best tough cast iron free from defects,
the sliding surfaces, which are to be 5% in. wide, are continued
across the top, and the flange with which the same is fixed to the
frame is continued round in a similar manner.
The driving and trailing axle boxes are crucible cast steel, 2 in.
thick at the crown, 15% in. and I }% in. thick at sides, 7% in. wide,
a flange # in. thick by I ft. running down the sides. The bushes
also recessed at the top for white metal. A gun-metal keep is
placed below the axle
The driving springs are volutes, 7 in diameter by 834 in. long.
The trailing springs are composed of one plate 5 in. broad by
% in. thick, and seventeen plates 5 in. broad by 36 in. thick, and
one wrought-iron packing piece 5 in. broad by Vá in thick, 3 ft.
6 in. span and 3% in. Camber when loaded.
The driving, trailing, and bogie axles are of the best Yorkshire
iron, double faggotted. The wheels are solid forged, the coupled
wheels having forged balance weights and crank bases. The tyres
are solid rolled crucible cast steel, 3 in. thick on tread by 5% in.
LOCOMOTIVE ENGINES. 709
wide, and secured on the inside by Drummond's patent clip ring
tyre fastening. The cylinders are 17 in. diameter and 26 in. Stroke,
2 ft. 3 in. centres; the back ends are cast solid. They are lagged
with wood and covered with sheet iron. The thickness of metal in
the cylinder barrel is I in.; in the steam chest, % in.; the steam
ports are 13% in. by 14% in.; the exhaust port 234 in. by 14% in.;
bridges, 1% in.; width over faces, 10% in. The cylinders have an
inclination I in 34. The slide valves are made of gun metal; they
have an outside lap of I in, a travel of 4% in., and a lead of Vá in.
The buckle is of wrought iron, solid with spindle. The pistons are
of gun metal 4 in. deep, with two cast-iron rings 34 in. wide by
† in thick. The piston rods and crossheads are forged solid of
selected Yorkshire iron. The slide blocks are of cast iron of the
same quality as the cylinders, 12 in. long by 3% in. wide, forced
on the gudgeon pins with a pressure of 4 tons, and accurately fitted
to the slide bars. The connecting rods are forged in one piece,
without weld, from the best selected scrap iron; section at large
end, 5 in. by 2 in.; at small end, 3% in. by 2 in.; and 6 ft. 6 in.
centre to centre. The outside rods are made of the very best
selected scrap iron forged in one piece without weld, and fitted
with gun-metal bushes. Bushes are pressed into the rod ends,
secured in their places with taper pins and set screws. The inter-
mediate valve spindles are made of the best selected Yorkshire
scrap iron 3% in. diameter. The bushes are gun metal.
The reversing gear is of the screw type with cast-iron column
and wheel, worked by a bell crank and rod. The eccentric rods
are made from the best selected scrap iron, having a foot forged on
for bolting to the straps. The straps are of cast iron and fitted
together without liners. The two eccentrics of each side are cast
together in halves, the outside eccentrics are bored, recessed, and
tapped to receive the screw, securing it together. The inside has a
round flange which abuts against a similar flange on the opposite
eccentrics; both flanges are tightly embraced with a wrought-iron
hoop, bolted together with two I in. diameter bolts. A projecting
lug is cast on the outside eccentric, and carefully fitted to the web
of the crank for driving the eccentrics. The throw of the eccentrics
is 6% in.; they are 25% in. wide.
The boiler is fed by two injectors, No. 8, with movable cones. A
tank is provided on each side of the engine to carry 950 gallons of
water. The iron plates are is in., excepting the flanged plates for
7Io - MODERN STEAM PRACTICE.
the splasher's sides, which are of Yorkshire iron 4 in thick. The
angle irons are 134 in. by 134 in. by Hºs in.; rivets 94 in. diameter
and I }% in. pitch in bottom. A cast-iron dry sand box is placed
on each side of Smoke box. The injector pipes are of copper solid
drawn. Delivery pipe, I }% in, external diameter, by No. 1 o B. W. G.;
feed pipes, I 34 in. external diameter, by No. IO B. W. G.; steam
pipe, I 34 in, external diameter, by No. IO B. W. G. All flanges
have been Scraped up to a true surface so as to make a perfectly
steam-tight joint, with boiled oil only.
The engine is fitted with the Westinghouse automatic air brake
On the driving and trailing wheels.
The bogie frames are Yorkshire iron, I in. thick by 8 ft. 9% in.
long. A cast-iron frame is fitted between the frames, with a mov-
ing frame supported by two volute springs at the ends. The bogie
centre is rivetted on to a 1% in. thick transverse plate, which is
rivetted to the main frames with 4 in. by 4 in. by 34 in. angle irons.
The centre pin is 2% in. diameter, fitted with a wrought-iron washer
and cotter underneath. The centre on the moving frame is ar-
ranged for and fitted with oil cups for lubricating the moving sur-
faces. The cast-iron frame is rivetted to the plate frame as shown;
frames 2 ft. 8% in. apart, and wheel centres, 6 ft 6 in.
The springs are composed of twelve steel plates, 5 in. broad by
% in. thick, and one wrought-iron packing piece, 3% in. thick, 4 ft.,
eentres, 2% in. Camber loaded.
The boiler was tested previous to being put in the frames by hot
water to a pressure of 200 lbs. per square inch, by the hydraulic
pump; and with steam to 150 lbs. per Square inch. º
PASSENGER ENGINES FOR GREAT SOUTHERN AND WESTERN
RAILWAY OF IRELAND.
The frames are inside, of solid plate, I inch thick. They are
attached at one end to the cylinders, and at the other end to a cast-
iron foot plate, and are stayed by the motion plate and by a plate
in front of the fire box. The boiler is of 34-inch Lowmoor plate,
4 feet inside diameter. Each ring of the boiler is formed of a single
plate; and the two sides and top of the outside fire-box casing are
also formed of a single plate. The fire box is of 36-inch copper, the
tube plate being 34 inch thick, and the two sides and crown are
formed of a single plate. There are 185 tubes of brass. The cylinders
LOCOMOTIVE ENGINES. 711
are inside, and 17 inches in diameter, the length of stroke being
22 inches. The driving wheels are 6 feet 6 inches in diameter,
and are coupled to the trailing wheels. The valve motion is of the
ordinary kind, a screw being used for reversing. The coupling rods
have cast-iron bushes, lined with white metal. The axle boxes are
of cast iron, and have the brasses cast into them. The horn blocks
of cast steel are attached to the frame all round the opening for the
axle box; they have adjustable wedges for taking up the wear of
the axle boxes. The slide blocks are of cast iron, and the little end
steps are of wrought iron, case-hardened. The boiler is attached
to the frames at the smoke-box end, is free to expand at the fire-
box end, and does not touch the motion plate. The heating surface
consists of: tubes, 835 superficial feet; fire box 96, and fire grate
17% superficial feet. The wheel base is from the driving to the
leading wheels 7 feet, and from the driving to the trailing wheels
7 feet 9 inches. The weight on the leading wheels is IO tons, on
the driving wheels it is 108 tons, and on the trailing wheels it is
9:5 tons, the total weight being thus 3O3 tons.
The performance of these engines is shown in the following
table:— -
º

Average Con-
Length Average Load Maximum Load Maximum - *
of jºi. of Six-wheel for Average Load for part ..". º
Journey. pe, & Carriages. of whole Journey. of Journey. Pºiº
Miles. Miles. Carriages. - Carriages. Carriages. lbs.
165% . 3: - §: II ‘54 I4
3 y 3 7-64 IO'54 I3 tº
3 3 3O e 8-56 I4-67 . . . . 2 I 25-64
2 3 3O 8-59 I4'47 I6
AVERAGE WEIGHT OF CARRIAGES.
Tons. cwts. Tons. cwts.
First class, * @ ge ... IO 3 Composite, tº e tº ... 8 Io
Second class, ... ... 9 8 Post-office vans, ... ... IO O
Third class, , ... ... 9 Io Guards' vans, ... ... 9. I2
The coal was from South Wales, of good quality, though much
of it was small, being broken in shipment.
These engines have run an average distance of 48,748 miles in
each interval between general repairs. The cost for repairs, exclu-
sive of shop expenses and tools, has been a trifle under Id. per
mile.
The light passenger engines are of similar construction; the chief
dimensions are:–Diameter of cylinders, 16 inches; length of stroke,
712 MODERN STEAM PRACTICE.
20 inches; diameter of the driving wheels, 5 feet 8 inches; the wheel
base is, from the driving to the leading wheels 6 feet, and from the
driving to the trailing wheels 7 feet II inches. The weight on the
leading wheels is 92 tons, on the driving wheels it is 92 tons, and
on the trailing wheels it is 8:8 tons, the total weight being thus 27.2
tons. The heating surface consists of: tubes, 774 superficial feet;
fire box 88%, and fire grate 16 superficial feet. There are 175 tubes.
The performance of these engines is shown in the following
table:–

or ** yº tºº or •; .* Average Con-
†" | jº. ºf "ºº" |ºl;
Journey. ge Carriages. of whole Journey. of Journey. 644,412 Miles. y
Miles. Miles. Carriages. Carriages. Carriages. lbs.
I65% 32 . 6:17 9-64 IO Y
3 5 3O}% 6'82 II '42 I3 |
3 * : {}: 7-64 º
- 2 e I2 “OO
. % ; II '55 18 } 23'36
3 3 28% 7.68 I6'66 25
3 y 28% 7:17 15°oo I 5 |
5 y 28 7:18 I4°58 I5 J
These engines have run an average distance of 54,635 miles in
each interval between general repair. The cost of repairs, exclu-
sive of shop expenses and tools, has averaged four-fifths of 1d. per
mile.
GOODS ENGINE FOR GREAT SOUTHERN AND WESTERN
RAILWAY OF IRELANL).
In Fig. 542 is shown an example of a locomotive specially adapted
for goods traffic. . It is a six-wheeled coupled goods engine made
for the Great Southern and Western Railway of Ireland, and is
believed to be one of the most powerful goods engines in use upon
an Irish railway. -
There are no frames outside the wheels. The two inside frames
extend the whole length of the engine, and are of solid plate, I inch
thick, connected in front by the buffer beam and cylinders, under
the boiler barrel by the motion bracket in front of the fire box, by
a strong 76-inch angled plate, and by a heavy cast-iron block fixed
firmly between the frames, forming the base for the foot plate.
The train is drawn from this cast-iron block, and the boiler is free
to expand along the frames. The horn blocks are of cast steel, and
extend on both sides of, and over, the top of the openings for the
LOCOMOTIVE ENGINES. 7I 3
axle boxes. The axle boxes are of cast iron with brass bearings,
and they are adjustable by wedge pieces recessed into the horn
blocks so as to take up the wear; these are held up by Screws
inserted from the back. The boiler is of Yorkshire plates, 3% inch
thick as a rule, but 3% inch where the tubes are fixed. The fire box
is of copper, of the ordinary square form, 9% inch thick, swelled to
34 inch where the tubes are fixed, and connected to the outside shell
in the ordinary way. -
+ º-sºº sm ºr * * * * - - - ITI
HiFºſ-Diſ
Fig. 542. —Great Southern and Western Railway of Ireland Goods Engine.
A, Fire box. B, Fire door. C, Body of boiler. D, Smoke box. E, Chimney. F, Steam chest.
G, Safety valve. H, Injector. 1, Cylinder. K, Valve chest. L, Leading wheel. M., Drivi g
wheel. N, Trailing wheel. O, Frame. PP, Wedges for axle boxes. Q, Outside connecting rods.
R, Weigh shaft. s, Line of valve spindle. T, Reversing wheel and screw. U, Cab. v., Steam pipe
for counter-pressure brake system, w, Spark trap. x, Blast pipe.
The boiler is fed by two injectors, placed horizontally on each
side of the fire box. Some boilers now being made have ver-
tical injectors feeding through the back of the fire box into the
front, thus avoiding all outside pipes, as described in the London
and North-Western Railway passenger engine. The tubes are
of brass, 16O in number, and each 2 inches external diameter.
The safety valves are arranged to prevent weighting by the driver.
A spark arrester of wire, of the inverted truncated form, is placed
in the chimney. The cylinders are 17 inches diameter, with a stroke
of 24 inches; the slide valves working vertically between them.
The valve motion is of the usual form, the link being shifted by a

714 MODERN STEAM PRACTICE.
screw motion, so as to insure absolute control by the driver. All
the wheels are coupled, and have a diameter of 5 feet 1% inch.
The tyres and the axles are of cast steel. The coupling-rod ends
are furnished with cast-iron bushes, lined with white metal. The
small ends of the connecting rods have wrought-iron steps, case-
hardened. The sand boxes are fixed in the smoke box to insure
the dryness of the sand. The counter-pressure steam brake is
applied, in order to obtain a greater degree of safety in descending
inclines, and to enable the driver to assist in stopping the train.
The heating surface of this engine is:–
In the tubes, " ... tº $ tº tº $ tº tº a tº ... • ... 846 sq. feet.
, fire box, ... © tº º tº º º e s tº © e is tº e is 93 , ,
Total, e tº tº tº tº º ê º º e ſº º ... 939 sq. feet.
The fire-grate area is about 17.5 square feet
The weight upon the wheels, when the engine is in working
order, is:—
Tons. cwts. Qrs.
On the leading wheels, ... tº gº º • * * tº º ºs e g tº Io 12 I
,, driving wheels, ... tº º º tº gº º tº º º tº $ tº I I 6. 3
, trailing wheels, ... tº tº 9 * * * ‘e gº º * * * 8 . 15 2
Total, tº e tº & 9 º' * * * tº te tº tº ºn tº 3O I4. 2
tº-Rºmº .
The total wheel base is 15 feet 6 inches. *
The engine will draw a weight of 607 tons on a level at a speed
of 25 miles an hour, with a working pressure of 140 lbs. Its average
consumption of coal is 35 lbs. per mile with a load of fifty-five
Waggons.
The performance of these engines is shown in the following
table:—

Average Average Con-
Length Time occupied Time occupied Speed Load for Maximum sumption of Coal
of in Running. at Stations. per Hour. whole Load. per Engine Mile,
Journey. U. g Journey. 1,028,826 Miles.
Miles. Hours. mins. Hours. mins. Miles. Waggons. Waggons. lbs.
165% 9 22 3 26 I7% 3I '5 50 ||Y
IO7 5 50 2 16 18% 32 3 5O
IoW 5 4O 3 46 I9 24'8 5 I
96% 5 25 3 52 17% 29'9 49 37:6
165% 8 37 3 8 I9% 27.7 52
Io'ſ 5 4O 4 56 I9 30.8 54. |
IoW 5 36 I 45 I9 3o'7 52
96% 5 29 3 : 30 I7% 27°5 52 |J
The waggons, which are nearly all covered, weigh from 4% to
LG)COMOTIVE ENGINES. 715
5% tons, and carry 6 tons. The probable average load is from
3 to 4 tons.
These engines have run an average distance of 44,232 miles in
each interval between general repair. The cost for repairs, exclusive
of shop expenses and tools, has been o'9a, per mile.
GOODS ENGINE–BOMBAY, BARODA, & CENTRAL INDIA RAILWAY.
This engine has been specially designed for the working of heavy
traffic in India, where the gauge, 5 feet 6 inches, has given great
PC - -
Fig. 543.-Bombay, Baroda, and Central India Railway Goods Engine. &
A, Fire box. B, Fire door. C, Body of boiler. D, Smoke box. E, Chimney F, Steam chest. G, Man-
hole door. H, Injector. 1, Cylinder. K, Steam chest. L, Leading wheel. M., Driving wheel.
N, Trailing wheel. O, Frame. P, Weigh shaft. Q, Line of valve spindle. R, Reversing lever,
s, Cab. T, Blast pipe. U, Spark trap.
facility for the construction of a powerful engine on a reasonable
length of wheel base. It will be found that several appliances exist
for suiting this engine to the requirements of a colonial railway, and
in this respect it differs from ordinary goods engines in this country.
The frames consist of a pair of longitudinal plates, I }6 inch thick,
placed inside the wheels, connected at various intervals by the buffer
beam, the cylinders, the motion plate, a strong cross bracket in
front of the fire box, a similar one behind it, and by strong plates
and angle irons at the foot-plate end. The train is drawn by a pin
inserted through these plates, and, as the boiler has no positive
attachment to the frames behind the smoke-box tube plate, it is free
from all strain arising from the haulage of the train.


716 MODERN STEAM PRACTICE.
The boiler is of the ordinary form, 4 feet 4 inches diameter, and
IO feet 9 inches long, of Yorkshire plates, 9% inch thick. The fire-
box shell is of the same material and thickness, deep in front, but
sloping backwards, with a long inclined fire grate suitable for burn-
ing the small and inferior coal usually procurable in India. The
fire box proper is of copper, of the same tapering form as the exter-
nal shell, all the plates being 3% inch thick, but the tube plate is
swelled to 7% inch where bored to receive the tubes. The wrought-
iron roof girders in this engine run transversely, so as to obviate the
necessity for their being so deep as would have been requisite had
they been placed longitudinally. A spark arrester of wire is fixed
on the top of the blast pipe, and extends into the chimney.
The water is supplied to the boiler by two injectors, either of
which is capable of delivering the amount of water usually evaporated.
The tubes are of brass, 222 in number, and each 2 inches external
diameter. The cylinders are 18 inches diameter, with a stroke
of 24 inches; the slide valves being placed vertically between
them. The valve motion is of the straight-link double-lever
form. All the wheels are coupled, and are 5 feet diameter on the
tread. There is a cab with a double roof of wood and of iron over
the foot plate to shelter the driver from the rain and the great
heat. A cow catcher is fixed in front of the buffer beam to fit the
engine for use on the unfenced railways of India.
The escape of smoke, when the engine is standing still, is pre-
vented by the introduction of air above the surface of the fire by
means of jets of steam through hollow stay tubes at the front and
back of the fire box.
The heating surface of this engine is:—
In the tubes, ... & © tº tº º tº & e <> tº sº tº ... I278°o sq. feet.
,, fire box, ... tº º (º tº gº tº tº gº tº tº e º ge º 'º 99"3 , ,
Total, ... tº º ſº tº gº º tº º º ... I3773 sq. feet.
fººmººn
The fire-grate area is about 25.5 square feet.
The engine will draw a weight of 694 tons on a level at a speed
of 25 miles per hour, with a working pressure of I40 lbs. Its con-
sumption of coal is 59:25 lbs. per mile for an average load of 490
tons. The cost of repairs has been 2:15 annas, or, say, 322d, per
mile.
A peculiar feature of this engine is the position of the hind axle
under the fire box, permitted by the long sloping fire grate, and by
LOCOMOTIVE ENGINES. 717
the shallowness of the end of the fire box. This arrangement
answers the double purpose of allowing a comparatively short wheel
base and an equable distribution of the weight of the engine upon
the wheels, 11 tons, 11 tons 16 cwts, and II tons I6 cwts, being
carried on the leading, the driving, and the trailing wheels respec-
tively. As there is less weight on the leading wheels than on either
of the other pairs, it might be supposed that there would be danger
of the engine running off the line under certain circumstances; but
this is not the case, as the weight actually upon the springs of the
leading wheels is greater than on those of the driving wheels.
FURNESS RAILWAY TANK ENGINE.
This locomotive was constructed for the conveyance of mineral
or heavy goods traffic over a portion of the Furness railways, having
Fig. 544.—Furness Railway Tank Engine. .
A, Fire box. B, Fire door. C, Body of boiler. D, Smoke box. E, Chimney. F, Steam chest. G, M n-
hole door. H, Injector. 1, Cylinder, K, Valve casing, L, Leading wheel, M., Driving wheel.
N, Trailing wheel. O, Frame. P, Weigh shaft. Q, Line of valve spindle. R R, Water tank.
s, Coal box. TT, Sand boxes, u, Brake gear. V V, Brake blocks.
gradients of I in IOO, and I in 80, &c., for II miles. It was desired
to get as powerful an engine as possible on six wheels, with inside
cylinders, and to carry fuel and water sufficient for a considerable
distance, in case it was found necessary to take the train forward on
the main line. The cylinders are between the two frames, which
extend the whole length of the engine, and are I }4 inch thick.

718 MODERN STEAM PRACTICE.
Besides being connected by the cylinders, the frames are tied by two
cross brackets under the boiler, by the buffer plank in front of the
cylinders, and by four cross ties behind the fire box; the frames are
further strengthened externally by heavy angle irons arranged for
carrying the water tanks. The train is drawn from the foot plate,
and as the boiler is free to slide in the frames, all haulage strain is
removed from it, as well as that arising from a too unyielding con-
nection with the frames. The horn blocks are of cast iron. Those
of the driving and the front axles are carried round the top of the
horn plate to strengthen the frames. The boiler is of Yorkshire
plates, 3% inch thick as a rule, but 34 inch thick where the tubes are
fixed. The fire box is of copper, ſº inch thick, of the ordinary square
form, connected with the outside shell by a square wrought-iron
frame at the bottom, and by copper screw stays at the sides, front
and back. The roof is stayed by longitudinal wrought-iron girders,
Connected by means of sling stays, with T irons rivetted to the roof
of the external casing. The proper combustion of the fuel is effected
by the admission of air through the fire door, deflected on to the
surface of the fire by the ordinary scoop, aided by a fire-brick arch,
placed across the fire box under the tubes, which serves also to pre-
vent the emission of sparks through the tubes and chimney. The
fire bars are simple flat pieces of iron, with two corners cut off, and
are supported by two cross bars, with pins to keep the distances
equal. The boiler is fed by two injectors, and the engine can there-
fore stand any required time, when waiting as a pilot, without being
set in motion to obtain water for the boiler. The tubes are of brass,
186 in number, and each 2 inches external diameter. The cylinders
are 18 inches diameter, with a stroke of 24 inches, and the valves
work vertically between them. The valve gearing is of the ordinary
shifting-link class, and is reversed by the common lever handle.
All the wheels are coupled, and have a diameter of 4 feet 6% inches.
The end of the engine is carried by a transverse elliptical spring.
A coal bunker and cab are conveniently placed on the foot plate.
The arms of the crank axle, which is of Bessemer steel, are hooped,
to prevent accident in case of fracture. -
As the engine is intended to work in either direction, the cab is
arranged as a screen both forward and backward.
Tanks to contain IOOO gallons of water are placed along each side
of the smoke box, the boiler, and the fire box above the level of the
frame. The coal is carried behind the engineman's platform in
LOCOMOTIVE ENGINES. 7I9
bunkers, which hold 2 tons. A powerful screw break is attached to
the engine, actuating six blocks in front of each of the six wheels.
Sand boxes supply sand in front of, or behind each wheel, as
required, and are so contrived as to be opened or closed by one set
of levers for each direction of the engine.
The heating surface in this engine is:—
In the tubes, ... e g e * = & • 6 tº e - © ... IO478 sq. feet.
,, fire box, ... * * * tº s º * * * * - © ... , 962 ,
Total, ... & s gº e - º tº gº tº ... I I44°o sq. feet.
The fire-grate area is nearly 15 square feet. -
The weight upon the wheels, when the engine is in working order
and the tanks full, is:—
Tons. cwts.
On the leading wheels, ... tº e is e = 9 e - © tº e tº ... I3 I6
,, driving wheels, ... * - - * - tº - - - 4- - - ... I4 II
,, trailing wheels, ... tº º º * * * * - tº & e & ... I 3 8
Total, ... * - e. e - e. • * * tº tº º ... 4 I I5
The total wheel base is 15 feet.
The engine will draw a weight of 872 tons on a level at a speed
of 20 miles per hour, and a weight of 367 tons up an incline of I in
80 at a speed of I 134 miles per hour, with a working pressure of
145 lbs. to the square inch. Its consumption of fuel with this latter
load has been 40: 16 lbs. per mile, taking the whole trip, which
includes the descent as well as the ascent of the gradients before
alluded to. The cost of repairs has not been taken into account,
as the distance run does not usually exceed 76 miles per day.
This engine was designed to obtain as much power as was pos-
sible upon six wheels. The frames have been put inside the wheels,
to allow convenient access to the motive parts; the cylinders being
placed inside, to secure great structural stability. The tanks are
arranged alongside the boiler to distribute equal weights upon the
wheels, whether the tanks are full or empty. The distribution of
the weight, when they are empty, is:—
Tons. cwts. Qrs.
On the leading wheels, ... © - - º e & tº e º ... II 7 2
,, driving wheels, & e º & © tº tº e <> tº gº tº ... I I I6 2
,, trailing wheels, © & 8 * - e. * c & tº e ſº ... Io 8 2
It is believed that the engine has in all respects answered the
purpose for which it was built.
For engines with rigid frames, a simple and convenient arrange-
tº
72) MODERN STEAM PRACTICE.
ment has been applied, in the shape of a sliding top to the leading,
and sometimes to the trailing axle boxes. This cap has a double
incline in the transverse direction of the engine. The axle box has
also similar corresponding inclines, so that when passing round a
curve the leading wheels are free to move sideways, without at once
carrying the engine with them. As the axle box incline must at
the same time lift the engine when so sliding, the gravity of the
engine tends to make it assume its normal position on the axle
boxes as soon as the road permits this to be done.
NARROW-GAUGE ENGINES FOR STEEP INCLINES.
To enable engines to draw heavy loads up excessively steep
inclines a system invented by Mr. Fell has been adopted, in which
a set of horizontal wheels are pressed against a central rail, giving
in this manner additional traction hold. A railway on this system
was worked successfully over Mont Cenis during the construction
of the tunnel through that mountain.
The Festiniog Railway in North Wales is the smallest gauge line
in Great Britain used for passenger traffic. The gauge is only 2 feet,
with correspondingly small and light rails and roadway generally.
Some of the curves are as low as 2 chains radius. The steepest
gradients are I in 60 and I in 80.
The carriages are peculiarly constructed, to suit so narrow a
gauge. They are IO feet in length, and fully 6 feet in breadth and
height, with four wheels 18 in. diameter. The seats are arranged
so that the passengers are seated along the central part of the car-
riage, back to back. The engines weigh about 7% tons, with four
coupled wheels each 2 feet diameter, the cylinders being 8 inch dia-
meter with a 12-inch stroke. -
The small railway line on the Righi Mountain in Switzerland has
a gauge of I metre, and as the gradients are excessively steep, in
some cases as much as I in 4, it is necessary to provide for greater
grip of the locomotive than can be obtained by weight on smooth
wheels only. This is accomplished by placing a central toothed
rail or “rack” between the bearing rails, and by means of
suitable gearing sufficient “bite” is obtained. The engine, which
has a vertical boiler, draws only one carriage. The radii of the
curves are 180 metres.
The Vesuvius Railway leads from the foot of the cone to the
NARRow-GAUGE LocoMOTIVEs.
; :
º
J
s
- ... '
-- -- .#
Fig. 1. Elevation of Danforth Locomotive Tender. Fig. 5. Longitudinal section of a Cylinder.
|
Fig. 2. Transverse Sections of Iºanforth Locomotive Tender. Fig. 6. Truck of a Passenger Locomotive on the Louisville and Nashville R. R. Front view and transverse sections
Fig. 3. Elevation of Locomotive Tender with Mason double truck. Fig. 7. Longitudinal section and side view of Truck of Passenger Locomotive, Louisville and Nashville R, R,
i
Fig. 4. Half Plan of Locomotive with double truck. Fig. 8, Half Plan of the preceding,

LOCOMOTIVE ENGINES. 721
summit, and has a double line of rails with fixed engines which
wind the carriages up and down by means of steel wire ropes. The
inclination is very steep, sometimes about 40°, and the carriages are
so arranged that the seats are kept horizontal, and the wheels are
arranged to grip the rails in such a manner as to prevent their
leaving the rails, and powerful automatic brakes are fitted to prevent
accident in the case of a rope breaking. .'
A light system of railroad has been introduced into Canada, the
gauge being 3 feet 6 inches. The gradients are steep and the
curves sharp. The permanent way has timber sleepers, and the
rails are flat-bottomed, weighing 56 lbs. per yard, being fastened to
the sleepers with dog spikes. The engines are coupled in eight
wheels, and weigh 30 tons, taking a load of 360 tons up a gradient
of I in 60. Curves are used in some places of 500 feet radius on
gradients of I in 60 and I in 70. In one case a gradient of I in 50
extends for four miles.
ENGINES FOR NARROW-GAUGE MINERAL LINES HAVING STEEP
GRADIENTS.
The lines leading from the numerous mines and works in our
mineral and manufacturing districts to the main lines of railway
were formerly merely tramways worked by horses, but the need for
more ready and cheaper communication soon led to the introduc-
tion of a special class of locomotive engine fitted for such work.
The following are the details of tank engines employed on one
of these branch lines about 2 miles in length, connecting the lime
quarries with the main line of railway. The quarries are situated
at a height of nearly IOOO feet above the sea; the country is very
bleak, and much exposed to Snow and rain storms in winter. Start-
ing from the lowest level the line runs 1400 yards I in 80, 360 yards
I in I2, 450 yards I in 15, 630 yards I in 18, 680 yards I in 15. The
gauge of the rails is 32 inches; the rails, 28 lbs. per yard. This
single line was originally indifferently constructed, and crosses a
deep ravine on a narrow embankment about 150 yards in length,
before commencing the steep ascent of I in 12, with curves of one
and a half chains in some but not dangerous parts of the line. The
first experimental engine on this line was designed and constructed
by Messrs. Hawthorn & Co. of Leith, the usual formula being
adopted, and which has been found to be quite correct in practice.
46
722 MODERN STEAM PRACTICE.
The cylinders were 8 inches in diameter, with a piston stroke of 15
inches. Steam pressure, I2O lbs. in the boiler. There were four
wheels coupled, 27 inches diameter, with a wheel base of 4% feet.
The engine in working trim weighed 7 tons 5 cwts. This locomo-
tive, when put to work, was found to take up the gradient of 1 in
12 about its own weight, besides itself, at 4 to 6 miles per hour in
any state of the rails, sand being used when necessary, and it could
be started or stopped with the load on the incline, the brake power
having ample control over the motion of the train. Taking the
foregoing result by calculation from the formula &#, with four-
fifths of the boiler pressure for average pressure in cylinders, or
96 lbs. against I2O lbs., the engine should take about 7% tons gross
load, besides its own weight, allowing 22.4 lbs. per ton friction for
load, and limiting the possible adhesive force to one-fifth of engine
weight on incline. The average cost of maintenance for this engine
amounted to I2s. per day.
Another engine constructed for this narrow-gauge line had cylin-
ders IO inches diameter, stroke of piston I5 inches, with 150 lbs.
steam-boiler pressure; wheels 27 inches in diameter, coupled 5 feet
apart, or wheel base. The weight in working trim being II tons
11% cwts, it was found on trial to take over the I in 12 gradient a
load of 18 tons, composed of empty trucks, with I 25 lbs. per square
inch in boiler, and holding this pressure well at the summit of the
incline. With 150 lbs. steam pressure in the boiler it is calculated
to take a load of 20 tons, with a margin of one-fifth more, as a pos-
sible result in favourable circumstances.
A line of railway in Portugal, which had been formerly worked
with about seventy mules, with drivers, &c., at a considerable cost,
may be taken as a favourable example of what we may term nar-
row-gauge lines with small-wheeled mountain locomotive engines.
The railway runs a distance of 1 I miles over a very rugged country,
crossing many ravines and torrents, and with many curves, some as
sharp as I 3/4 to 2 chains radius. The gradients, starting from the
sea level to the mines which supply copper ore, are as follows:—
(I) Rising I in 23 to I in IOOO, 3% miles; (2) falling I in 24 to I in
6o, 2 miles; (3) rising I in 30 to I in 190, 2 miles; (4) falling I in 50
to I in 19, I }% mile; (5) rising I in 15OO to I in 43, 3 miles. The
gauge is 3% feet; rails, 35 lbs. per yard. -
The first engine employed had 9-inch cylinders, with a piston
LOCOMOTIVE ENGINES. 723
stroke of 15 inches; steam pressure in boiler, 130 lbs.; the wheels
being 27 inches diameter. This engine hauled 20 tons, waggon
and ore, up the incline of 1 in 19, and could have done a great
deal more (waggons, say 22 cwts, each, carrying 2 tons of ore);
also thirty waggons and forty men over the I in 3O=36 tons, in
splendid style; engine in trim weighing IO-5 tons. The calcula-
tion, as before, meets this load on the I in 19 gradient exactly,
namely, 20 tons, and on I in 30 gives 38 tons. It was found from
experiments made with such engines that this limit may be
practically increased one-fifth, thus leaving a large margin for
effect.
Small engines coupled together.—Whilst the experiments were
going on in Derbyshire for the proposed Mont Cenis Railway, the
question was discussed whether the central-rail system possessed
any advantage over ordinary locomotives and railway lines, likely
to recommend its adoption unless in very exceptional circumstances.
One point raised was, whether two engines coupled together could
not be used with as much or more advantage than a single engine
of twice the weight. -
An experiment was therefore made with two of these small
engines; the front engine having an 8-inch cylinder, I 5-inch
stroke of piston, 27-inch wheels, and I2O lbs. Steam; and the second
one, 9-inch cylinder, 15-inch stroke of piston, 27-inch wheels, and
150 lbs. steam. These coupled together took over an incline of I in
12 twenty empty trucks=24 tons weight, at 4 to 6 miles per hour;
and the latter by itself, with 125 lbs. steam pressure in the boiler,
took 14 tons 12 cwts. over the same gradient, the weight of engine
in working trim being IO tons. Calculating as before on one-fifth
weight of engine on gradient for adhesion, one-fifth less average
pressure in cylinder than that in boiler, and making extra allow-
ance for friction of load, owing to number and inferior construction
of trucks and railway, the load to be taken would be about 20 tons.
Engines coupled together are often used when the train of car-
riages is heavy. It does not appear that any loss accrues from
using the engines together, but rather the reverse; probably any
disadvantage from want of simultaneous action of wheel trod on
the rails is counterbalanced by the points of adhesion gained.
There can therefore be little doubt of the comparative advantage of
small engines coupled together when required on such railways as
have been under consideration, as arrangements can always be made
724 MODERN STEAM PRACTICE.
to utilize them, when not in use for through haulage, for shunting,
and other purposes.
In these engines the frame plates are connected together by one
or more water tanks, of which they form the sides, the whole being
framed on angle iron, with all joints rivetted and caulked in the
same manner as the boiler. By this arrangement, the tanks being
an integral part of the framing, great rigidity is secured to the
latter, while the weight of water, &c., is carried at the lowest pos-
sible level, insuring steadiness to the engine in running. The work.
ing gear, being entirely outside of the frames, can be examined or
repaired with facility, and without the necessity of using a pit to
get access to any part. The principle is applicable to locomo-
tives variously constructed as regards number and position of
wheels, &c.
DIMENSIONs of SMALL TANK NARROW-GAUGE ENGINES.

ºr." | Stoke. Pº." | "Wºº' sº." |weight inton.
8 inches. I5 inches. 27 inches. 4% feet. 120 lbs. 7 tons 5 cwts.
9 , , 15 , , 27 , , 4% " I 50 , , IO , , O , ,
IO 33 I5 3, 2 27 3 y 5 92 I 25 32 I I 2 3 I I % y 9
9 J 3 I5 92 27 3 y 5 3 y I3O } % IO y 3 IO y 9
IO 2 3 I5 3 y 27 3 y 5 ?? - * * *
. I 2 x , 18 5 7 3O , , 5 y 9 6 in.
In Figs. 545 and 546 we give examples and details of a four-
wheeled and a six-wheeled tank engine, both having the tank placed
underneath the boiler. The dimensions of the first engine are as
follows:–Diameter of cylinders, II inches; length of piston stroke,
18 inches; diameter of driving wheels, 3 feet; distance between
centres of wheels, 6 feet; diameter of body of boiler, 3 feet; length
of body, 8 feet 3 inches; 81 brass tubes, 2 inches diameter
outside; heating surface in fire box, 38 square feet; tube surface,
352 square feet. The dimensions of the second engine are:—
Diameter of cylinders, 15 inches; length of piston stroke, 21 inches;
diameter of wheels, 3 feet 6 inches; 5 feet 9 inches, centres; I I feet
6 inches, wheel base; diameter of body of boiler, 3 feet 9 inches;
length of body, 9 feet; IOO brass tubes, 2% inches diameter outside;
heating surface in fire box, 67 Square feet; tube surface, 545 square
feet; contents of tanks, 800 gallons; for 4 feet 8% inches gauge of .
rails; weight of engine in working trim, 28 tons. -
-r--
** *-
*- *
- **
Fig. 545. —Tank Engine with Four Whecle coupled. _*
A, Boiler. B, Smoke box. c, Chimney. D, Blow-off tap. E, Steam dome. F, Safety valve. G, Steam whistle. H, Cylinder. I, Valve
casing. k, Regulator handle. L, Eccentrics and link motion. M, Weigh shaft. N, Starting handle, o, Crosshead. P, Piston rod.
oo, Guide bars. R, Connecting rod. S, Crank pin. Tº Tº, Driving and leading whecls. U, Side rod, v, Spring, w, Framing and tank.
x, Check valve, y, Brake gear. z, Platform. z' z*z”zº, Buffers and end beams, safety chains, rail guards, awning zº, Coal box.
Š

§
i
* *
Fig. 546.—Tank Engine with Six Wheels coupled.
A, Boiler." B, Smoke box. c, Chimney. D, Blow-off tap. E. Steam dome. F, Safety valve. G, Steam whistle. H. Cylinder. 1, Valve casing.
k, Regulator handle. L, Eccentrics and link motion. M, Weigh shaft. N, Crosshead, o, Piston rod. P, Guide bars. Q, Steadinent for valve
motion. R, Connecting rod, s, Crank pin. Tº tº Tº, Leading, driving, and trailing wheels. U, Side rod. v.v, Springs, w, Framing and tank,
x, Check valve. z, Platform, end beams, and buffers. 2, Rail guards, 2%, Coal box. *

LOCOMOTIVE ENGINES. 727
EXPRESS ENGINE FOR THE PENNYSYLVANIA RAILROAD
The following description of an express locomotive for the Penn-
sylvania Railroad is given by the Engineer, Feb. 10, 1882, as an
excellent example of American practice. The boiler is of the wagon-
top form, and is of steel; the grate is large, for burning anthracite
coal, and therefore water tubes are used instead of fire bars.
Aoiler:— Alimensions.
2 in.
º e
Diameter, e Լ e a - e.
Length of grate, Io ſt.;
Mean height of fire-box crown above grate,
º - © - tº º º 4 ft.
Width of grate, 3 ft. 5% in.
3 ft. I}% in.
Thickness of boiler plates, & ge • * * tº º & % in.
5 3 internal fire box, & is & tº º º e e ſº % in.
3 y tube plates, º, e - tº & ge º, º & tº tº º % in.
No. of wrought-iron tubes, 201; Inside diameter of tubes, 1% in.
Length of tubes, * * * * - tº ... Io ft. Io94 in.
Grate surface, .. tº tº tº e tº º º ... 35 sq. ft.
Total heating surface, ... e - e. sº e © ee ... I2O5 sq. ft.
Engine:– º
Diameter of driving wheels, ... 6 ft. 6 in.
5 5 bogie 3 y © tº º .2 ft. 9 in.
Wheel base of coupled wheels 7 ft. 9 in.
Total wheel base, a s tº e tº e e e - e. 22 ft. 7% in.
Diameter of axle boxes, 8 in...; Length of axle boxes, IO% in.
Diameter of cylinders, 1 ft. 6 in.
Stroke, .. .* - - - & Cº º 2 ft.
Centre to centre of cylinder, ... 6 ft. 5 in.
Lap of valves, ... tº º - e e & * * * e - - • * * I}4 in.
Width of ports, I ft. 434 in. ; Length of ports, I}% in.
Length of exhaust ports • 3% in.
Weight full:—
On drivers, e - tº • * * e e e tº e e I5 tons.
On trailers, 14 tons 3 cwt.
On bogie, I2 tons 4 cwt.
In all, tº º º • * * ... 4 I tons 7 cwt.
The tractive force is 100 lbs. per lb. of cylinder pressure.
HAULAGE POWER OF LOCOMOTIVES.
The following tabulated statement of the relative haulage power
of locomotives is given by the Railroad Gazette. It is the result of
experiments by an American railway commission, and includes three
types of engine, viz. A. American locomotive with four driving wheels
and 12,000 lbs. on each,wheel, total weight of engine 36 tons. B. Ten-
wheeled locomotive with six driving wheels and I2,OOO lbs. on each
wheel, total weight of engine about 42 tons. C. Eight driving wheels
and 12,000 lbs. on each wheel, total weight of engine about 54 tons.
728 MODERN STEAM PRACTICE.
WEIGHTS of TRAIN WHICH LOCOMOTIVES CAN HAUL AT A SPEED OF 20 MILES AN
HOUR UNDER ORDINARY CONDITIONS, IN TONS OF 2000 LBS. (NOT INCLUDING
THE WEIGHT OF ENGINE AND TENDER).
TYPE OF LOCOMOTIVE.
On straight track— A. B C
Level,............................... Io96 1664 2226
Grade, 20 ft. per mile,.......... 547 840% II 28
, 4O 9 3 • * * * * * * * * 35O 545 734
,, 60 9 3 ... . . . . . . 249 390% 522
,, 8o , , , . . . . . . . . . I88 3O2 4IO
,, IOO 5 * * * * * * * * * * 148 242 33O
On 5 deg. curves— -
Level,............................... 92 I I4O1% 1876
Grade, 20 ft. per mile,.......... 464 716 962
2, 4O 2 y - - - - - - - - - 3IO 485 654
,, 60 3 3 - - - - - - - - - 227 360% 488
,, 8o 35 - - - - - - - - - I73 27.9% 38o
, , IOO 2 y - - - - - - - - - I37 225% , 308
On 10 deg. curves—
Level,............................... 662 IoI3 1358
Grade, 20 ft. per mile,.......... 4O1 62.1% 836
2, 4O 3 y • * * * * * * * * 278 477 590
, 6o y? • * * * * * * * * 2O7 330% 448
,, 8o 93 - - - - - - - - - 16o 26o 354
,, IOO 32 - - - - - - - - - 128 2 [2 290
SPECIFICATION FOR LOCOMOTIVE ENGINE
AND TENDER.
As a good example of what such a document should be, we give
the subjoined Specification for a bogie passenger engine and tender
designed by Mr. W. Kirtley, locomotive superintendent of the
London, Chatham, and Dover Railway. This class of engine
differs in some respects from those previously in use on the line,
and has frequently to work heavy trains at express speed.
The engines described in the following specification are known as class
M. The following are their leading dimensions:—Diameter of cylinders,
I foot 5% inches: stroke of cylinders, 2 feet 2 inches; diameter of bogie
wheels, 3 feet 6 inches; diameter of coupled wheels, 6 feet 6 inches; total
wheel base of engine, 20 feet 1 13% inches; total wheel base of tender,
12 feet; heating surface of tubes, 945.6 square feet; firebox, Io'ſ square feet;
total heating surface, IoS2 square feet; grate surface, 16.5 square feet;
capacity of tank, 25.5o gallons. -
Quality of Materials.—Where “brass” is specified it must be good tough
metal. Gun metal must be composed of five parts of copper to one part
of tin. White Metal.—This must be composed of—Tin, sixteen parts;
LOCOMOTIVE ENGINES. 729
antimony, two parts; copper, one part and a half. Other materials to be
obtained of the manufacture to be hereinafter specified, unless the consent
of the Company's locomotive superintendent in writing be first obtained to
an alteration.
Boiler.—Barrel, dome, fire-box casing, and smoke-box tube plate, and all
angle irons, rivets, and stays to be made of Lowmoor, Bowling, Taylor's,
or Cooper's (best Yorkshire) iron. Barrel to be telescopic, and made in
two plates, the circumferential seams to be single rivetted, and the longi-
tudinal seams to be butt-jointed, with inside and outside strips, double
rivetted. Tube plate to be attached to barrel by a ring of angle iron,
bored, faced, turned on edges, and shrunk on, and zigzag rivetted to both.
The dome to be in one plate welded at the seam, and flanged at the bottom
to fit barrel, to which it is to be double rivetted; a strengthening liner plate
to be placed inside the barrel round the opening for the dome. The top
to have an angle-iron ring rivetted to it, and to be fitted with a strong
wrought-iron cover. The cover and angle iron must be accurately faced
so as to make a perfectly steam-tight joint. Fire-box shell to be made as
shown, the sides and top in one plate, the front or throat plate flanged for-
ward and single rivetted to the barrel, and the back plate to the sides and
top as shown. Angle irons for carrying the sling stays to be rivetted to the
top in the position shown. The manhole to be of wrought iron, flanged
top and bottom, and single rivetted to the casing, the top flange to be
accurately faced to receive the safety valves. The boiler to be stayed by
six longitudinal stays screwed into the back plate of the casing, and passing
through the smoke-box tube plate, with nut and washer on either side, the
back plate to be strengthened where the stays pass through by a liner plate
rivetted to it on the inside. The longitudinal stays to be supported in the
middle of their length in the manner shown. The fire-hole to be circular,
the ring of the section shown to be Yorkshire iron, rivetted to the casing
and fire-box plates, flush outside casing. The foundation ring to be York-
shire iron, the corners of the form shown, carefully rivetted, so as to
be thoroughly tight. Twenty-one brass taper mud plugs for washing out
to be placed in the positions shown on the drawings."
Alimensions.
ft. in.
Length of barrel tº º gº tº gº tº tº º te . IO 2
Diameter ,, outside at fire-box end ... tº g tº e tº e ... 4 3
Thickness of barrel ... * @ a tº is tº tº tº gº & º º # * * ... O OP's
5 y tube plate dº tº e e g tº tº º e © tº & tº $ & ... O O%
* These specifications are only supplied to selected firms of engine builders, who are
invited to tender (upon the specification), and the drawings can be seen at the chief office
of the Locomotive Engineer of the Railway Company. After a tender has been accepted,
a complete set of detail drawings are supplied by the Company, and these have to be
carefully worked to. +
73O MODERN STEAM PRACTICE.
Thickness of dome plate ; &
Length of fire-box shell tº g & tº e gº e º 'º tº º e ... 5 9
Breadth * > at bottom, outside ... e e º © tº ºf ... 3 II
Depth 3 9 from centre line of boiler ... 5 2
Thickness 9 y plates tº gº tº e e : tº tº º * & © ... o ox3,
Section of ſoundation ring ... º tº º ... 3 in. × 2% in. * *
9 3 fire-hole ring § tº º tº º ſº ... 2 in. × 2% in. ... — —
Diameter of rivets in boiler ... e tº º e tº º & © tº tº e e ... O Oż
9 3 foundation ring tº e & * * * * e º ... O O’;
Height of centre line of boiler from rail ... tº º tº tº º ve ... 7 2
Fire Box. —The fire-box plates to be of copper of the very best quality,
obtained from Messrs. Everitt & Sons, Grenfell & Sons, Vivian & Sons,
or other approved makers. The stays and rivets to be made from the very
best soft rolled copper bars, by the same maker as the plates. The plates
to be annealed both before and after flanging, and strips cut off must be
tested by being doubled cold, without showing any sign of fracture, and also
to be analyzed, and must not contain more than 5 per cent. of impurities.
The sides and crown to be in one plate, the Crown curved as shown, and
stayed with eight Yorkshire iron roof bars of the section shown, each secured
by thirteen studs I inch diameter, screwed through the crown plate into the
bar, with nut on the underside of the plate. Six of the roof bars to be con-
nected to the angle irons on the casing plate by twelve sling stays of York-
shire iron. Great care must be taken to bed the ends of the roof bars accur-
ately on the fire-box plates, and that the sling stays are of the correct length,
bearing on the pins top and bottom. The tube plate to be stayed to the barrel
by six 1-inch copper stays, screwed through the plate into palm stays rivetted
to the barrel. The copper stays to be screwed tightly into the fire box and
casing plates, and neatly rivetted over at the ends, the thread being turned
off the portion between the plates. A brass plug with fusible centre to be
inserted in the crown of the fire box. A brick arch to be built in the fire
box, supported on studs in the manner shown. Fire-box back plate to be
dished at fire hole to meet the ring, and the fire hole fitted with air deflector
scoop, and sliding doors, in the manner shown on the drawings. Fire grate
to consist of nineteen wrought-iron fire bars and two cast-iron fire bars of
the sections shown, supported on two cast-iron comb bar bearers by four
wrought-iron brackets, studded to foundation ring. Fire box to be rivetted
with best Yorkshire iron rivets.
JDimensions.
ft. in.
Length at top, outside tº tº º tº º º tº a tº tº ſº º * tº gº 5 O}%
JLength at bottom, , , 5 2
Breadth > * 3 y • * * 3 4
Depth, inside ... tº º tº tº $ tº 6 o
Water space at bottom, all round O 3
Thickness of plates ... tº e e tº e e tº e i º 4- ºr ºt o oj4
LOCOMOTIVE ENGINES. 731
ft. in.
o of #
º | and
o o'4
Diameter of fire hole ... tº º º © & wº e e c & © & & Cº º ... I 4%
2, rivets ... ... ... ... ... ... ... o of:
| “..."
Thickness of tube plate * * * ſº e 6 is e tº
and
99 copper stays * * * tº º tº * * * ſº tº gº © o º
* I
Workmanship.–All the plates are to be planed or turned on the edges
before being put together. The holes must be drilled or punched slightly
Countersunk, and rhymed out perfectly fair with each other in all plates and
angle irons; drifting will under no circumstances be allowed. Care must be
taken that the smaller diameters of the holes come together, that all burrs are
carefully filed off, and that the plates are brought well together before any
rivet is put in. All rivets must completely fill the holes, and the heads must
be perfectly true and central. Any caulking that may be required must be
done with a broad-faced tool, so that the plates may sustain no injury. Before
being lagged the boiler is to be tested in the presence of the Company's
locomotive engineer, or his inspector, to a pressure of 200 lbs. per square
inch with water, and afterwards to 160 lbs. per square inch with steam, and
it must be perfectly tight under these pressures. *
Tubes.—To be of copper, solid drawn, of either Everitt's, Broughton
Copper Company's, or other approved make, 9 B. W. G. at the fire-box end
tapering to 12 B. W. G. at the smoke-box end. To be secured by a roller
tube expander—great care being taken that the tubes are not cracked—and
fixed with ferrules at the fire-box end. Ferrules to be of ferrule steel, and
to go into the tubes a tight driving fit. The tubes are to project through
the Smoke-box tube plate # inch.
Pimensions.
ft. in.
No., 199 - - - * * * e - - º - -
Length between tube plates ... tº - - e - e. - © - • * * ... IO 6
Diameter, outside • Q • & e e is e - - - e e ºr ... o 134
7 5 9 3 ... at smoke-box end for a length of 6 in.... o 1%
Thickness at fire-box end º tº º * * * ... No. 9, B. W. G.... — —
r 5 y smoke box end ... * * * ... No. 12, B. W. G.... — —
Distance apart of centres, about * e * - tº * * * ... o 2%
Smoke Box and Spark Arrester.—Plates for smoke box and door to be of
BB Staffordshire iron, having a perfectly smooth surface. The rivets are to
be countersunk outside and filed smooth. Wrought-iron liners are to be
placed against the tube plate, and the sides and front of the smoke box. The
door to be dished as shown on drawings, and fitted with baffle plates and
suitable dart, handles, and hinges, the latter to be finished bright.
A wrought-iron grate for arresting sparks to be supported in the smoke box
732 MODERN STEAM PRACTICE.
in a horizontal position just below top of blast pipe. Care must be taken
that this grate fits accurately round the steam and blast pipes.
JJimensions.
ft. in.
Length of smoke box, inside ... e tº e tº º e e tº o ... . ... 2 8%
Width on centre line of boiler, inside tº e G e - e. • * * . . . 4 II
Thickness of plates tº $ tº - - - tº º e * * * • * * ... o ojº
Section of angle iron ... * * * 2% in. by 2% in. by }% in.... — —
9 3 ring round door hole * * * ... 3 in. by % in.... — — .
Diameter of rivets ... sº e se - - - º ºg o ość
Pitch of rivets, about ... *** : * ~ * ' < * * * * * - * * ... O 3
Chimney.—To be of BB Staffordshire iron; joint to be made with a butt
strip, and the rivets to be countersunk, and filed smooth on the outside.
The bottom, of best Yorkshire iron, to be quite free from hammer marks,
and to be carefully fitted to smoke box. The top, of cast iron, to be made
to drawing. -
Pimensions.
- & 4. ſt. in.
Height of top of chimney from rail ... * e sº tº º º • * * ... I3 3%
Diameter inside at top... tº sº º tº º - tº e e º “º & º, º º ... I 6
3 * 53 bottom ... • 3 º' º “t & tº nº ſº tº º ſº ... I 5
Thickness of plates ... © & e - - - © & e e º 'º * a tº ... o oſí
Ash Pan.—To be made to hold water; to be fitted with a damper, front
and back, each to be worked separately from the footplate; the damper rods
to be on the right-hand side of footplate.
' '
Dimensions.
ft. in.
Thickness of plates of ash-pan - - - tº e e e e Q ... " ... O OFs
Depth of ash-pan © - e. tº gº º • *e - • ‘g e tº tº - • ‘º º ... I 2
Width ... & sº º ºr sº º * @ & - tº sº tº © ºn tº tº gº & ... 3 4
Safety Valves.—To be of the kind known as “Ramsbottom's duplex”
safety valves, to be fixed on the fire-box casing. The columns to be of
brass turned bright, fixed on a cast-iron manhole cover. The springs (of
approved manufacture) and gear to be made accurately to drawing, and set
so as to blow off at 140 lbs. per square inch. The seating to be of wrought
iron, carefully fitted to the fire-box casing. All the joints must be accur-
ately faced, so as to be perfectly steam-tight.
Aimensions.
ft. in.
Diameter of valves ſº tº tº º º • * * e sº e • * * `-- * tº * tº § ;
Distance apart of columns & g O IOHº:
Height of brass columns . I O24
Diameter of spring steel O OH}
5 3 manhole cover I '6
Thickness of seat o 1%
Regulator and Steam Pipes.—Regulator to be of cast iron, the head to be
fitted with double valves. The steam pipes to be of copper sheets hard
LOCOMOTIVE ENGINES. * 733
soldered together on the inside. Flanges and cone to be brass. Steam
pipe in boiler to be fixed to tube plate by a turned ferrule of best steel and
to regulator by means of three claw bolts. Elbow pipe in smoke box to be
of cast iron.
Alimensions.
ft. in.
o 4%
Diameter of steam pipes, inside * Gº º & º & - - - & sº tº * - 4-
3 y < * * gº º º • *-º ... No. 7, B. W. G. ... — —
Thickness
Blast Pipe.—The blast pipe to be of cast iron, the top to be bored and
turned to the form shown.
Pimensions.
- ft. in.
' Diameter of blast orifice tº s e º 'º - e. & © tº • * * tº º º ... o 4%
Height of blast pipe above top row of tubes --- ... ... O 2
Frames, Inside.—Inside frames and front buffer plate to be Bessemer
steel of Cammell & Co.'s, John Brown & Co.'s, Bolton Iron and Steel Co.'s
manufacture, or other approved makers, solid rolled, and each plate must
have the brand of the manufacturer legibly stamped on its outer side. The
plates are to be planed all over on the inner side, and the outer side must
be finished with a good smooth surface. All holes to be marked from one
template, and drilled and rhymed out to the exact size given. The frames
to be set in and thoroughly well stayed together by the buffer plate, and
with plates and angle irons at the leading end in the manner shown on
drawings, the front footplate to be thinned at the edges as shown. A plate
is to be placed horizontally under the cylinders to carry the bogie pin, and
must be firmly bolted to angle irons on the frames. A transverse stay ar-
ranged to carry the back ends of the motion bars and the intermediate spindle
guides, and a vertical stay in front of the fire-box casing, must be placed
in the positions shown. Over the trailing axle a horizontal flanged stay is
to be securely bolted to the frames, and at the hind end of the frames a cast
iron footplate arranged for the tender couplings, is to be placed. All these
stay plates and angle irons to be of BB Staffordshire iron. The casting and
the transverse stays must be securely fastened to the frames by turned bolts.
The rubbing pieces for tender buffers to be well case-hardened. When
finished the frames must be perfectly true and square in all directions.
The footplate to be of steel, of the same make as the frames, and the rivets
to be countersunk on the top. Guard bars of the form shown are to be
securely bolted to the frames and buffer plates.
Jimensions.
ft. in.
Thickness of frames, finished * * * - - - O I
Depth over leading bogie wheels ... I 3
,, between cylinders and driving horns I 5%
,, between driving and trailing wheels, open I 9%
Greatest depth of plates ... C & © º, e - ſº e <> tº º º 2
I 134
*
734 MODERN STEAM PRACTICE.
Distance from centre of bogie to front end of frame ... e tº a . -
3, 2 9 3 9 y to centre of driving axle ... 9
2 3 * > driving axle to centre of trailing axle 4.
99 9 3 trailing axle to hind end of frame O
Extreme length of plates ... we 27 I
Distance from centre of driving axle to front of fire-box casing
Distance between frames at leading end ... • * * « g ſº
59 $ 3 from cylinders to trailing end...
Height of top of frame from rail ... *
Depth of buffer plate
Length 35
Thickness 92
Thickness of footplate
Extreme width of footplate
I3%
IO
9
Outside.—To be of Yorkshire angle iron — the step plates to be
welded on—and to be stayed to the inside frames as shown on the drawings.
All the rivets to be countersunk outside. Section of angle iron for frames
4 inches by 2% inches by 34 inch. r
Buffers and ZXraw Gear.—Buffers to have wrought iron cases and
plungers, with “Timmis” unequal section steel springs, and to be in all
respects similar to drawings supplied. Draw bar to be of best chain-cable
iron, and to be fitted with. a screw coupling, and to have an india-rubber
spring (No. 6A), to drawing, of George Spencer & Co.'s make.
AXimensions.
i
:
Height of centre line of buffers from rail ... * & & tº ſº º
Distance of centres of buffers apart
Diameter of draw bar
:
Cylinders.--To be made of the best close-grained, hard, and strong cold-
blast cast iron, twice cast, as hard as can be worked, and perfectly free
from honeycomb or other defects. They must be bored out perfectly true,
the ends being bell-mouthed. The cylinders are to be made with loose
covers at each end, the back cover having provision for carrying the front
ends of the slide bars. All joints and faces to be machined and scraped to
a true surface, so that a perfect joint can be obtained. When the cylinders
are bolted together, they must be tested by hydraulic pressure to 250 lbs.
per square inch. The cylinders to be horizontal, and to be attached to
the frames by flanges—the holes in which and in the frames are to be rose-
bitted—and secured by turned bolts a driving fit. The front flanges and
covers are to project through the frames as shown on drawings. To be
provided with waste-water cocks and gear worked from the left-hand side
of footplate. The top of cylinders to be covered with thin fire-brick or
cement; the bottom flanges to be planed perfectly true, so that the bogie
pin-plate may bear truly against them.
LOCOMOTIVE ENGINES. 735
Pimensions. ſt in.
Diameter ... tº e e & © a tº e - & & Cº. ... --- gº tº e I 5%
Stroke e tº e 2 2
Distance of centres ... & 6 º' tº a tº 2 4
3 y valve spindle centres ... o 3%
Thickness of metal ... e g tº • & & tº e º tº ſº º O O%
Length of ports s & e ... " ... ºr e > - - - gº tº º I 2
Width of steam ports © O 1 %
,, exhaust ports ... ... ... ... ... o 3%
Thickness of bridges * - e. e - e. º, º ºs • * * & sº tº e p & O I
Length of working face ... * * * e g = is e - & e e º tº 3 O II
Distance from centre of driving axle to centre of exhaust port ... 9 9
Pistons.—To be of tough cast iron, made from cylinder metal, and to be
sound and free from all defects. To be accurately fitted to cones on ends
of piston rods, and fixed with nuts as shown on drawings. Piston heads to
be turned sº inch smaller than bore of cylinder. Packing rings to be of
cast iron, turned only on the outside and on edges, and made 34 inch
larger in diameter than the cylinder bore, and then cut and sprung into their
places. When finished the whole must be an easy but accurate fit in the
cylinder, so that the piston and rod can be moved backwards and forwards
by hand.
APimensions. ft. in.
Width of piston e e e * - ſº º, º – dº º & e ‘e tº o 3%
,, rings, two in each piston tº º º - - - ... ... o ox!
Thickness of rings ... tº º º As º o * * * tº & & tº º & tº s º o oj4
Piston Rod and Crosshead—To be of the best mild cast steel, manufac
tured by Taylor Brothers, Vickers, Sons, & Co., Cammell & Co., or other
approved makers, with cone and nut for fixing to piston; the crosshead to
be solid with the rod. -
Alimensions. ft. i
t. 1n.
Diameter of rod ... e sº e - - - is e gº • * * o 2%
I.ength between cone and shoulder of crosshead 3 oyá
Taper of cone in piston ... - - - e tº º ... I in 3 - *-*
No. of threads per inch piston end * 6 tº - - - 6 ... — —
Gudgeon Pins.—To be of best Yorkshire iron, keyed in the crossheads
and well case-hardened. -
Slide Bars and Slide Blocks.—Slide bars to be of cast steel from the
same makers as piston rods, and to be provided with brass oil siphons to
drawings. The slide blocks to be of cylinder metal, sound and free from
all defects.
Dimensions.
ft. in.
Width of slide bars ... tº º º * * * tº tº º & © tº e - © O
Thickness 3 y • * * o 2%
length 3 y & g tº * - © * - © e e Q & © º 3 9
,, of slide blocl * * * • * - © º ºs tº º º 1 o
Distance between slide bars vertically ... & º e tº º º e is e o 3%
92 ” P horizontally ... © tº º vº º º ... o 6%
736 MODERN STEAM PRACTICE.
Connecting Rods.--To be of best Yorkshire iron, forged solid in one
length. The brasses to be of gun metal, those for the big ends to be
lined with white metal. The cotters to be of steel, and the bolts of the
best Lowmoor iron forged from the solid, the heads must on no account
be welded on.
AXimensions.
* ft. in.
Distance of centres ... tº º * @ e ſº tº º tº º e tº gº º & ºn tº 6 I
Diameter of big-end bearings tº tº tº & e e * * * tº º e * * * o 7%
3 y small-end bearings ... © tº e * tº a *** * * > *... tº ſº. O 3
Slide Valves and Valve Spindles.—The valves to be of phosphor bronze.
The spindle frames and intermediate spindles to be of best Yorkshire iron,
of the form shown on drawings, the latter to be well case-hardened.
The intermediate spindle guides to be of cast iron, bushed from either
end with gun-metal bushes, and to have oil boxes cast on as shown.
Dimensions.
ft. in.
Lap of valve & & © tº e ºs. & & & & ſº º * * * tº º ſº tº tº º O I
Lead, in full gear ... ... ... & sº * * * * tº-e ſº O Oſſºr
Centre line of valve above centre line of cylinder O I
Diameter of valve spindle ... * o 17%
9 3 intermediate spindle ... tº º ſº. o 3%
Length of 3 y 9 3 guides ... I O
Valve Motion.—The valve motion to be made from the best scrap iron,
and the working and rubbing surfaces to be thoroughly case-hardened, and
provided with oil siphons and grooves, and finished in the best manner.
Expansion link to be supported at the top from the forward eccentric rod
pin, the reversing shaft being below the motion and behind the link. The
motion pins to be of best iron, thoroughly case-hardened and accurately
fitted. Eccentric sheaves to be in two pieces, the smaller piece being of
best scrap iron, and the larger piece of cylinder metal. Eccentric straps to
be of wrought iron, Solid with the rod, and to be fitted with white-metal
liners.
AXimensions.
ft. in.
Length of expansion link between centres tº º tº tº e ºs tº º e I 4%
92 eccentrie rods ... e tº º * * g. 4 7
5 * liſting links we dº ſº * * * I Io;;
Diameter of motion pins e, ſº tº o 1%
, , eccentric sheaves tº ºpe e. tº gº tº I 4%
Throw y 5 93. o 3%
Reversing Gear.—Reversing to be performed by means of a screw
arrangement, firmly supported on the right-hand side of footplate.
Coupling Rods.--To be of Bessemer steel of approved make, with solid
ends and siphons, and to be fitted with phosphor-bronze bushes. Each
rod to be forged solid in one length, and finished bright.
LOCOMOTIVE ENGINES. 737
AE)imensions.
ft. in.
Distance of centres ... & sº gº gº tº tº g º & gº º s tº gº tº $ tº 4. 8 4
Section of rod • - - - - - º tº ſt ... 4% in by 1% in. — —
Coupling Rod Pins.—To be of wrought iron case-hardened, accurately
turned to gauge, and to be exact duplicates; to be turned to a taper of 1 in
50 and forced into the wheels by hydraulic pressure, the inner end to be
afterwards rivetted over; the outside end of pin to be fitted with a screwed
washer and taper pin, as shown on drawings.
{ . - Pimensions. ft. in.
Diameter of pin * * * e e e tº gº tº tº ſº º e & e te º 'º tº gº tº O 4.
• &
Length of bearing ... & dº gº tº gº e * * * • ſº e º & 4. jº º ſº O 4
Bogie.—To have four wheels, and to be in all respects of the form and
dimensions shown on drawings. The frames to be of steel by the same
makers as the engine frames (the brand to be on the outer side), raised as
shown over the axles, the inner sides to be planed all over, and the outer
sides where any attachment is made. The carrying girders to be of best
Yorkshire angle iron bent round and securely rivetted to the frames, and
machined on the outer sides, clearances being made where shown; steel
bearing plates planed and scraped to a good working surface are to be
rivetted to the angle irons. The ends of the frames are to be stayed by
flanged plates of BB Staffordshire iron placed vertically, and bolted to the
frames by the horn block bolts. When finished the frames must be perfectly
true and square. The sliding block is to bear on the steel plates and work
between the angle irons before mentioned, the side play being controlled
by “Timmis” unequal section steel springs, arranged as shown on drawings.
The bogie pin of wrought iron to have a projection on it fitting into a corres-
ponding hole in the horizontal plate under the cylinders before mentioned,
to which it is to be securely rivetted, and to have the end screwed with a
washer nut secured by a taper pin through it. The sliding block to be of
tough cylinder metal perfectly free from honeycomb or other defect; to be
machined on all working and bearing parts, and to be scraped to a good
working surface on the sliding portions, and to have lubricators fixed and oil
grooves cut where shown. The spring cradles are to be made of best
Yorkshire iron, with wrought-iron saddle pieces at each end, shaped to bear
on the axle-boxes, and fitted with oil siphons as shown. The spring shaft
to be of best Yorkshire iron passing through cast-iron bushes in the frames,
with washer nuts and taper pins outside the spring buckles.
Dimensions.
ft. in.
, Bogie wheel base ... tº º º e tº dº © tº e gº tº º tº º tº º º
Thickness of frames, finished tº gº tº tº $ tº tº gº tº tº e º * tº º o o?%
Depth at centre ... ... ... ... ... ... ... o. Io .
• horns & tº tº e º 'º tº “. ... ... * - ſº I 7%
47
738 * MODERN STEAM PRACTICE.
* t ft. in. .
Length of frames ... tº e tº * & © © tº º * * * * * * * * * 7 6%
Distance between frames tº º ſº tº tº . . . . . . ... 2 7%
Section of angle iron for carrying girders, 7 in. by 5% in. by I in. — —
} y. steel bearing plates ... , 6 in. by 3 in. by 34 in. — —
Length 9 3 5 y • * * * * * * ... ... . ... 2 5%
Thickness of end stays tº º tº º ve e & tº ... ... . o oſ.
Depth $ 2 tº º º tº a tº tº e º * - ſº tº e e * * * o 8
Total side play of bogie ... tº º e tº ſº º e tº º e º º tº e e o I}%
Diameter of bogie pin, tº º q © º º tº a tº • . . . . . . o 6%
Section of iron for spring cradles ... tº º is ... 5 in. by I in. — —
Diameter of spring shaft ... ſº º º © tº * tº e & & a tº tº gº & o 2%
2 3 check springs unloaded tº $ tº & g e * * * tº gº º O 3+;
Length $ 9 3 2 * * * * & gº tº ...e. ... O IO
Springs and Connections.—The springs to be of the very best spring steel,
manufactured by Messrs. Turton & Sons, or other approved makers. Before
being put in position each spring is to be fully tested until the camber is
taken out, and the spring must afterwards resume its original form. The
bogie springs are to be inverted, the buckles being connected direct to the
shaft before mentioned, through the bogie frames; the ends of springs
are to be connected to the spring cradles by hooks. The driving springs
are to be under-hung, and the buckles are to be connected to the axle-boxes
by T-links. The ends of the driving springs are to be connected to wrought-
iron liners on the frames by adjustable links; the trailing springs to be
“Timmis” unequal section steel springs, two under each axle box, arranged
in the manner shown on the drawings. All the brackets, links, hooks,
buckles, and pins connected with the springs must be of best Yorkshire
iron, and the working surfaces must be thoroughly case-hardened.
JJimensions.
BOGIE. ft. in.
Length loaded 4. O
Camber , , O 3
Breadth of plates tº e tº tº ſº tº & © º * @ e tº º tº sº tº º O 5
No. of 5 § tº º tº * * * * e tº º tº dº º tº º º tº e º I4 — —
Thickness of ,, o oy/4
DRIVING.
Length loaded 3 4. .
Camber , Q 3
Breadth of plates • * * * * * * tº tº * * * tº $ tº º º º o 4%
No. of 3 y tº e º * @ 9 tº º ſº * @ e * & º? tº º ... I3 — —
Thickness of , , o OX4
Axle Boxes.—The axle boxes to be of the very best gun metal, lined with
white metal, and fitted with cast-iron keeps and spring lubricating pads,
and suitable covers. Every axle box must be made accurately to dimensions,
so as to be interchangeable in any of the engines.
Born Blocks and Horn Stays-The horn blocks to be of crucible cast
IOCOMOTIVE ENGINES. 739
steel of Vickers', Cammell's, Taylor's, or other approved make; the bogie
horn blocks to be fitted with cast-iron distance blocks and securing bolts as
shown. The driving and trailing horn blocks to be solid, and provided
with adjustable wedges and securing bolts. The horn blocks must be
accurately bedded to the frames, and secured by turned bolts a driving fit.
The horn stays to be of wrought iron; care must be taken that they fit the
horn blocks accurately. -
Axles.—To be of crucible cast steel of Vickers, Sons, & Co.'s extra make;
the webs of crank axle to be hoopéd; all corresponding parts to be of an
exact size and made to template, so that they may be interchangeable, and
each axle must be clearly stamped with the maker's name, and the brand
extra. The journals are on no account to be swaged down, but in all cases
turned from the solid. The wheel seats must be accurately turned to a taper
of I in Ioo.
AXimensions.
- BOGIE AXLES. ft. in.
Diameter in middle ... § º º * * * § & © tº ſº wº & ſº º tº º º o 5%
,, on wheel seats o 7%
, of journals * * > tº º º # tº tº tº e ºf o 6
Length 9 y tº e & & ſº º tº º ºs e is º – O 9
Distance apart of centres of journals s = e e s • tº ſº º 3 7
CRANK Axle.
Diameter in middle ... o 7
,, on wheel seats O 9
,, of journals tº tº º tº e ºs & ſº wº o 7%
Length 3 9 © º º o 7%
Diameter of crank-pin journals ſº o 7%
Distance apart of centres of cranks © tº º gº tº º tº gº e * º º 2 4
4.
Do., journals e tº º tº g ſe * * * tº º tº
I2 in. by 4% in. }
ross sections of crank arm & g
C ** { and 12 in. by 4% in.
Throw of cranks o I3
TRAILING AXLE.
Diameter in middle ... o 7
,, on wheel seats ... tº & * * { } * * * tº º ºs O 9
,, of journals gº º tº e tº º * * * tº º ſº * - G o 7%
Length 2 3 * * e & e ſº o 7%
Distance apart of centres of journals 4. O
Wheels.—To be of wrought iron, of the best materials and workmanship,
with solid rims, spokes, bosses, and balance weights. The spokes must be
forged with solid T ends, and welded in the centre. The surfaces of rims
and spokes to be shaped so that the wheels are exactly balanced. Each
wheel is to be bored taper and put on the axle, before the tyres are shrunk
on, by hydraulic pressure of not less than 60 tons, and then properly keyed
on. Great care must be taken that the keys fit accurately.
74O . MODERN STEAM PRACTICE.
Dimensions. ,
BOGIE. ft. in.
Diameter on rim ... tº º ºr Ú º º © º is tº º º sº º º 3 O
Width of rim tº º º tº gº º tº º º tº gº tº tº º º tº gº tº O 4
Thickness of rim ... tº gº is tº gº tº * * * e ºf gº tº e ſº ty is o 15%
No. of spokes * * * tº its tº tº tº ſº tº gº º we gº tº tº gº tº ... IO – —
Section of spokes at boss ... * * * e 4 in. by 1% in. — —
3 5. » rim ... gº tº gº ... 3% in. by 1% in. — —
Diameter of boss ... & ſº tº --- tº tº e * & $ tº gº tº . I 4.
Width of boss tº tº º • * * ºr ºr º * g tº tº tº º o 7
Diameter of hole in boss ... . ... tº ſº wº w & tº tº ºr ºf to gº tº o 7%
DRIVING AND TRAILING...
Diameter on rim ... & & & gº º tº º º * * * tº ºp º * @ e- 6 o
Width of rim ... ... ... ... ... ... o 4%.
Thickness of rim ºr is a tº º ſº tº q > g o 1%
No. of spokes it is tº • * * * * * * tºp º e * * * tº tº º ... 2C – –
Section of spokes at boss ... • * * ... 4% in. by 1% in. — —
9 3 5 y rim ... gº gº º ... 3% in. by 1% in. — —
Diameter of boss ... tº e & * † tº tº e a & ſº tº g gº tº tº º & 1 7
Width of boss an e ºs * * ~ tº ſº tº * * * gº tº e tº º º tº gº e o 7%
Diameter of hole in boss ... tº º ſº ty º º • * * tº tº º tº tº º O 9
Centre of wheel to centre of coupling pin * * * * tº gº tº *º º º I Q.
WHEEL CENTRES.
Trailing to driving ... e gº tº tº gº is * * * & © º tº º º tº gº e 8 4
Driving to centre of bogie ... º, º is tº e & gº tº e 9 9
Bogie wheel base .. * * tº tº º & • e. e. tº ºr e • * > 5 9
Total wheel base of engine ‘... tº gº tº tº gº & * * * ... 20 II)4
Zyres.—To be of crucible cast steel, of Vickers, Sons, & Co.'s extra
manufacture, and to be of the section shown on drawing; to be shrunk on,
and to be fixed to the wheel by lips on the outside, and by a wrought iron
lip ring on the inside, of the section shown. Each tyre must be clearly
stamped with the maker's name and the brand “Extra.” t
Pimensions. . .
BOG.I.E. ft. in.
Diameter on tread ... gº tº º & © & tº º ve & © º tº * * tº º is 3 6
Width & © & tº tº gº * * * * & e. tº gº tº * º o 5%
Thickness, finished ... O 3
Distance between tyres tº º tº º ſº tº is º 4 5%
DRIVING AND TRAILING.
Diameter on tread ... tº tº tº & sº tº • * * * * * * is ºn tº 6 6
Width ... ... … … ... ... ... o 5%
Thickness, finished ... . O 3
Distance between tyres 4 5%
Cab and Splashers.-The cab and splashers to be made of best Staf. .
fordshire plate # inch—full–thick, the former to be fitted with two plate- .
glass windows in brass frames, to be made to open. All rivets to be
countersunk and filed smooth. A brass number plate, to pattern, is to be
placed on each side of the cab.
i.
LOCOMOTIVE ENGINES. 741
. Dimensions. ft. in.
Width of cab tº dº º * * * & © º tº gº º dº ſº º º ºg & tº º º r 6 - 6.
Height at centre ... • * * * * * * & & gº tº º tº & 4. & ſº 7 o
Sand Boxes.—To be of cast iron, four in number, and fitted with valves
and substantial gear for working from footplate. The leading boxes to be
fixed on to the splashers of the driving wheels, and the valves are to be
coupled together so as to work simultaneously. -
Zagging.—The boiler and fire-box shell to be lagged with well-seasoned
pine, and covered with smooth iron sheets—14 B. W. G.-supported on a
light wrought-iron frame, and secured by belts in the usual manner.
Brake.—The engine to be fitted with the Westinghouse Automatic Brake,
consisting of air pump, steam cock, 3 inch triple valve, release cock, 9% inch
cock, driver's brake valve, air gauge, Io inch by 24 inch reservoir and nipple,
hose coupling and union, the whole of which are to be obtained of the
Westinghouse Brake Co. The brake cylinder to be the L. C. D. R. stan-
dard pattern, Io inches diameter. The brake shaft, hangers, brackets, rods,
pins, crossbars and adjusting screws to be of the best scrap iron, the pins
and working surfaces to be thoroughly case hardened. Brake blocks to be of
cast-iron, one to each wheel, and the whole arranged as shown on drawings.
Pome and Man-hole Casings, &c.—To be of the form shown on drawings,
of charcoal iron 14 B. W. G. thick, thoroughly well finished. Brass moulding
pieces are to be arranged round the back of smoke-box and fire-box casing.
Band Rail and Zamp Irons.—A neat hand rail to be provided round the
boiler, supported by polished wrought-iron standards. Lamp irons to be
fixed on the smoke-box, footplate, and fire-box casing, in the positions shown.
Injectors.—Two injectors, Gresham & Craven's (brass), No. 8, to pattern,
to be fixed on the ashpan sides in the position shown.
Boiler Mountings, &c.—A brass seating to be fitted to the fire-box casing,
to carry two whistles and pressure-gauge cock. Two injector steam valves,
screwed into brass seatings, to be fixed on the fire-box casing in the positions
shown, with spindles through the weatherplate, and brass hand wheels
inside of the cab. Pressure gauge to be Bourdon's manufacture (Paris), with
solid drawn tube (to sample to be supplied), to indicate from 1 lb. to
200 lbs. per square inch. A blower to be fixed on right-hand side of
smoke box, and worked from the footplate. Two glass water gauges, with
asbestos packed cocks, two ball Clack boxes, a Furness lubricator to each
cylinder, a displacement lubricator, oil boxes for axle boxes and glands,
lubricators for bogie sliding block, an ash-pan water cock, and a coal
watering cock to be fixed in the positions shown on the drawings, the whole
to be made of brass, in accordance with drawings, and of first-class finish.
g * & wº Diameter Thickness
pimensions, &c., of Pipes. inside. B. W. G.
Matn steam pipes in boiler and smoke box $ 4t º tº dº º 4% in. 7
Injector suction and delivery pipes & ſº & & sº º & & is 1% in. IO
"742 MODERN STEAM PRACTICE.
Diameter Thickness
. B. W. G.
- inside.
Injector steam pipes • * ~ tº e ºf • * * | * * * © & © I}4 in. IO
Blower pipe in smoke box, copper solid drawn... . ... 56 in. I2
Furness lubricator pipes in smoke box, copper solid drawn % in. II \
Oil pipes • * tº º, a - * c º • * * º *r in. I5
Pressure-gauge pipe, copper solid drawn • * @ ... Y's in. I5.
Bolts and AVuts.--To be made to drawings and gauges, and all threads
to be Whitworth's standard, except where otherwise specified or shown on
drawings. Every nut of the same description, to be exactly the same size.
Gland nuts to be case-hardened. All nuts in the smoke box to be of hard
brass, and made with a cap. All union nuts to be made exactly to drawings.
Mo. of Threads per Inch.
Brass work of 3% in. diameter and upwards © º º & © tº © tº º ... I2
Mud plugs ... tº - º - e º tº e e © e º • . . • * * tº e º ... I 2
Copper fire-box stays tº º º & © e • * - tº us e • * * tº e e ... II
Piston rods, piston ends ... tº e e tº e - e e Q e e - tº e e ... 6
TENDER.
Zank.--Tank to hold about 25.5o gallons, to be of the horse-shoe form
with a well, with angle irons, stays, man-hole, and coping as shown on draw-
ings, to be constructed entirely independent of the frames and footplate.
The whole of the plates, angle irons, and stays to be of BB Staffordshire
iron. All the joints to be made with butt strips, and the rivets to be
countersunk on the outside and filed smooth; care must be taken that the
holes are perfectly fair with each other in all plates and angle irons, and
that the rivets completely fill the holes. The man-hole to be fitted with
a lid and strainer. Two water-tight tool boxes of wrought iron, lined with
wood, are to be fixed on the tank. The mouths of feed pipes to be pro-
tected by copper rose boxes. The feed cocks of hard brass are to be pro-
vided with suitable sectors and handles worked from the footplate. The
tank is to be fixed to the framing in the manner shown on drawings.
JDimensions.
- ft. in.
Length of tank, outside ... & © e • * * * & © tº a B. ... 18 2
Width 5 y $ 2 a s a --> 7 I
Height , 5 y - * * tº º e 3 6
Between arms of horse-shoe tº tº º 3 6
Length of , , 3. 7 o
2 3 well outside tº ºn tº II 6
Width y 3 35 tº - © 3 6%
Depth 33 33 • * @ I 6
Height of coping above tanl • * * * * * O IO
Thickness of side, back, and coping plates ſº tº º, * * * o ox{
, , , inside of horse-shoe and top and bottom plate O OP's
Section of angle iron for tank 2% in. by 2% in, by % in. —
–
93 25 . , 52 stays 2% in. by 2% in. by 9% in.
LOCOMOTIVE ENGINES. 743
y s 111,
Section of stays ... tº º ºs e º tº iº & dº 6 in. by 3% in. ſt *-
Diameter of rivets ... tº º º • * * ſº º te tº e - © e is - o oj4
Pitch 33 . . . . . . . . . . o 1%
Diameter of man-hole, inside * * º tº ſº º * * * º e ſº * c & I 6
Height 32 , above tank . ... es e º e º 'º tº e - O 9
Frames.—Outside frames and buffer plates to be of steel, by the same
makers as the engine frames; finished with a good smooth surface, angle
irons of the section shown to be securely rivetted to the frames. Inside
frames, vertical and horizontal transverse stays of BB Staffordshire iron,
draw pin washers, and foot-steps, are to be placed as shown on drawings.
All holes are to be marked from one template, and drilled and rhymed out
to the exact size. -
- Alimensions. ft. in.
Thickness of outside frame ... * e - tº e º a tº ºr • * - tº e - o OZ
Depth. 33 , , Open ... tº º º e º sº 2 II
Distance from front end of frame to leading axle O
33 leading axle to middle axle O
93 middle axle to trailing axle O
92 trailing axle to hind end of frame... 4.
Extreme length
Distance apart & º ºs * - ſº • * * tº º o & e is
Height of top of ſrame from rail ... ſº º e * * *
Thickness of inside frame ...
4.
Depth 3 y - y 9 • . . . . . . tº e e ... I ft. 6 in. and I
Length , , 3 2. tº º º * * * ... 17 6%
Distance apart e tº e * * * © º & tº e c tº º is • 2 º' 3 8
Thickness of vertical and horizontal transverse stays ... ... o oſ.
Section of angle iron for stays, 2% in. by 2% in. by 34 in. — —
Length of buffer plates * @ e * * * - - - & © tº tº tº e 7 6
Depth 2 3 $ 2 • * * * * * I 4
Thickness , 2 3 leading end o off/
3 y 2 3 $ 5 trailing end O I
Thickness of footplate O Oiºs
Extreme width of footplate... e - © e is e & G = tº e e ge e - 7 Io
Buffers and Draw Gear.—Buffers on trailing end of tender to be in all
respects similar to those on the engine; buffer spindles at leading end to
be of wrought iron case-hardened, and to be guided in cast-iron sockets.
The draw bars, safety links, and coupling chains to be of best chain-cable
iron. Trailing draw bar to have an india-rubber spring, No. 6, of George
Spencer & Co.'s make, and to be fitted with a screw coupling.
& e ->
AXimensions.
.. ft. in.
Distances of centres of buffer spindles apart * * * tº º & * * * 3 3
$ 3 3 y buffers apart tº gº tº tº s e * * * * * * 5 8
Height of centre line of buffers from rail .. tº º e & e º * * * 3 5
Hand Rail, Pillars, Zamá Irons, &c.—A hand rail and pillar to be
placed on each side of the footplate as shown, and fixed to the tank and foot-
744 MODERN STEAM PRACTICE.
plate. Three lamp irons, one gong iron, pulleys for communication cord, and
a brass number plate, to be fixed on the tank in position shown on drawings.
Springs.—Bearing springs to be of the very best spring steel, by the same
makers as engine springs, and to be similarly tested. They are to be con-
nected by links to brackets rivetted to the frames by turned cold rivets of
Lowmoor iron. Brackets, links, buckles, and pins to be of best Yorkshire
iron, and the working surfaces must be well case-hardened. A laminated
buffing spring of similar quality to the bearing springs is to be arranged at
the leading end of the tender, as shown on drawings.
Dimensions.
BEARING SPRINGS: .. ft. in.
Length, loaded ... tº º º e tº e tº º ºs tº ſº º * * * tº º º 3 6
Camber , , is tº e ... tº º º * - e. tº º º © tº º * e º o 3%
Breadth of plates ... § º º e tº º tº tº tº tº $ & tº e g e tº a O 4
Thickness , , * g e is * * is º º tº tº e © & © tº º º e e º o oj4
No. of plates in leading and middle springs • * * © e tº II — —
3 5 3 y trailing springs ... --- tº C tº gº tº ſº I2 – —
BUFFING SPRING:
Length screwed up ... tº º º • * > e G & tº e ºs tº ſº tº tº gº ºn 3 3
Camber 9 y © tº º tº $ tº tº º is gº º º * gº tº tº gº tº tº º º o 3%
Breadth of plates tº ſº tº e & & tº tº º tº º º tº gº tº ... o 4%
Thickness , , & © tº ... I plate % in. and 17 plates 3% in. — —
Axle Boxes.—Axle boxes to be of good tough cast iron, and to be care-
fully fitted with gun-metal bearings lined with white metal, wrought-iron
covers, and keeps of cast iron arranged for spring lubricating pads.
Born Blocks.-Horn blocks to be of cylinder metal as hard as can be
worked, secured to the frames by turned bolts a driving fit: they are to have
cast-iron distance blocks and securing bolts, as shown on drawings.
Axles.—To be of crucible cast steel of Vickers', Cammell's, Taylor's, or
other approved manufacture, all corresponding parts to be of the same size
and made to a template, so that they may be interchangeable, and each axle
must be clearly stamped with the brand and the maker's name. The journals
must on no account be swaged down, but turned from the solid metal.
AXimensions.
ft. in
Diameter in middle ... O 6
2 3 on wheel seat º tº w & tº e e tº º ºs o 6%
> y of journal ... & is wº * * * * † tº tº º º tº e e * † tº O 5%
Length of journal tº J & O 9%
Distance apart of centre of journals 6 4.
Wheels.--To be of wrought iron, of the best materials and workmanship,
with solid rims, spokes, and bosses. The spokes to be made in a similar
manner to the engine-wheel spokes. The wheels to be put on the axles—
before the tyres are shrunk on—by hydraulic pressure of not less than
60 tons, and then properly keyed. - w
LOCOMOTIVE ENGINES. 745
Alimensions. ft. in.
Diameter on rim ... tº º is tº º is tº gº tº & p & tº º º a 4 ºf 3 3
Width of rim... tº ſº º * * * tº gº º tº dº e ...' tº g & tº gº º o 4%
Thickness of rim ... tº tº G tº ſº tº gº tº º tº $ tº & & tº & e o 1%
. Number of spokes ... & ſº º tº dº ſº tº º ſº. & & s tº s º II - —
Section of spokes at boss ... tº º ſº tº º is 4 in. by 1% in. — —
3 9 9 y rim ... sº a tº ... 3% in. by I}4 in. — —
Diameter of boss tº º ºs tº gº º * E & ë e º a º º e tº º I 2
width of boss tº º Aº © º 'º tº º 'º tº e is © tº tº tº gº º tº dº tº o 7
Diameter of hole in boss ... & © tº tº dº ſº tº & ºw tº tº º * o 6%
Tyres.—To be of crucible cast steel of Vickers’, Cammell's, Taylor's,
Monkbridge, or Bowling Iron Company's manufacture, of same section as
driving and trailing tyres, and to be fixed to the wheels in a similar manner.
AXimensions.
ft. in.
I)iameter on tread ... 3 9
Width © tº t e º ſº o 5%
Thickness (finished)... , O 3
Distance between tyres 4 5%
Brake.—The tender to be fitted with the Westinghouse Automatic Brake,
consisting of Io-inch brake cylinder, 12 inch by 26 inch reservoir, 3-inch
triple valve, release valve, 3% inch cock, brake pipe cock, drip cup, release
spring and hose coupling, which are to be obtained of the Westinghouse
Brake Co. The brake to be arranged so as to be worked independently
by hand. The brake screw and handle to be placed on the left-hand side
of the tender. The brake shaft, hangers, brackets, pins, rods, levers and
adjusting screws to be of the best scrap iron. A cast-iron block to be
applied to each wheel, and the whole arranged as shown on the drawings.
Bolts and Muts.--To be similar in all respects to those used on engine.
Aainting.—Each engine and tender is to be painted in the following
manner.—The boiler, before being lagged, to receive one coat of boiled oil
and one coat of thick red lead; the inside of tender tank to have two coats
of thick red lead. The lagging plates, cab, Splashers, outside frames, tank
plates, and wheels to have one coat of lead colour; then to be thoroughly
stopped and filled up and rubbed down, one coat of vegetable black, two
coats of drop black, then to be panelled in slate colour and lined to
pattern in vermilion, and afterwards to have four coats of best engine copal
varnish, to be properly rubbed down between each coat. The buffers and
buffer plates to be similarly prepared and painted vermilion, with the num-
ber of the engine in gold shaded black on the latter; inside of frames and
axles to be finished with one coat of vermilion and two coats of varnish.
The company's monogram L. C. D. R. to pattern to be painted on each side
of the tender tank in shaded gold letters. The frames, smoke box,
chimney, fire-box casing, ash pan, coal space, footplate, bottom of tank,
brake work, &c., to have three coats of japan black. - -
746 " ' ' ' ' MODERN STEAM PRACTICE.
RULES FOR THE LOCOMOTIVE ENGINE.
Effective pressure of the steam in the cylinder—The effective pres-
sure of the steam in the cylinder, cutting off at various grades, is as
follows, assuming IOO lbs., per square inch as the pressure in the
boiler:— - . .
bffective mean pressure.
Steam cut off at 34 of the stroke of the piston, .............. ..... 90
9 9 3 p % $ 2 3 y * * * * * * * * g º e º e º e º e º & 8o
2 y 2 3 % y 2 :* D tº e º º sº º º ºs e º 'º e º ºs e s a s s 69
} 0. 9 p. % 5 3. y 9 tº e e s e e º e s e s is e º s = e w 50
92 y 9 % 33 29 v < * * * * * * * * * * * * * * * * 4O
Tractive power of locomotive engines—The tractive power of
locomotive engines is found by squaring the cylinder diameter in
inches, multiplying by the mean pressure of the steam in lbs. per
square inch, and again by the length of the stroke in inches, and
dividing the result by the diameter of the wheel also in inches.
Hence the following formula:- *
D”. P. L. tº
W
Where T represents the tractive power; P, mean pressure in lbs. per
square inch; D, the diameter of the cylinder; L, the length of the
stroke in inches; and W, the diameter of the driving wheel in inches.
Resistance of trains due to gravity on any incline.—The resistance
of trains due to gravity alone, on inclines, which may be I in 25,
I in 50, or I in 100, as the case may be, is found in lbs. per ton of
train by dividing the constant 2240 by the gradient, which gives the
resistance in lbs. per ton of train; hence with the preceding gradients
we have— t
T =
* = 89-6 lbs. per ton of train.
2249 –
5O 92 93.
224O g
— = 22
IOO 4. 9 y 9 y
and so on according to the gradient or inclination of the rails.
Resistance of trains at different speeds.—To find the resistance of
trains at different speeds, on a level line of railway, in lbs. per ton
of load, square the velocity, and divide the result by the constant
171, adding 8 to the quotient. This will give the resistance in lbs.
per ton of load on a level. Hence the formula— *
R= ; +8 = lbs, per ton of load.
LOCOMOTIVE ENGINES. 747
To find the load which an engine will take up a given incline—To
find the load which an engine of a given tractive power will take
up an incline at a given velocity. Divide the tractive power of the
engine in lbs. by the force of the resistance due to gravity and speed
in lbs. per ton, and the quotient will be the load in tons, deducting
the weight of the engine and tender. Hence the formula—
T
L– G+ RT W = the load of the carriages in tons.
To show what must be considered in designing locomotive
engines for steep gradients, we will take an example from actual
practice. A line of tramways was worked by a contractor's loco-
motive of the ordinary description on various gradients, the heaviest
being I in II for about 800 yards. The cylinders of the engine
were II inches in diameter; the stroke of the piston, 18 inches; the
four wheels were coupled, 2 feet 6 inches in diameter, and placed
4 feet 6 inches apart from centre to centre. The weight of the
engine in working order was IO tons, and it drew behind it a load
of 13 tons up the gradient of I in II. The pressure of the steam
was from 90 lbs. to IOO lbs. per square inch. On an incline of 1 in I I
the resistance due to gravity would be 203:64 lbs. per ton, and taking
the engine friction at 18 lbs. per ton, and the waggon friction at Io lbs.
per ton, we have the following total resistances to be overcome by
the engine in ascending the gradient:- -
lbs.
Resistance due to gravity, 23 tons at 203-63 lbs., .... = 4683-5
Engine friction, Io tons at 18 lbs. per ton, ...... ...... = 18O
Waggon friction, 13 tons at Io lbs. per ton, ............ = 130
Total,............--------- 4993'5
or, say 5000 lbs. The weight available for adhesion was IO tons or
22,400 lbs., which would be diminished by one-eleventh on an incline
of I in II. The actual adhesive weight available in the incline
would therefore be—
22,4OO
22,400--H-
=2O36°3 lbs.;
and the adhesion must therefore have amounted to very nearly one-
fourth of the load on the wheels. An engine of the above dimen-
sion would develop a tractive force of
II*x I'5 – 121 x 1°5 – ca.
2.5 TT 2:5 = 72'6 lbs.
&
748 MODERN STEAM PRACTICE.
for each pound of effective pressure on the inch of the pistons; and
to overcome the tractive resistance of 5000 lbs. the effective pressure
must then have been
5000 68-6 lbs, on the inch.
72-6
This pressure on the pistons could be readily maintained by a boiler
pressure of IOO lbs. per square inch.
In another example of small-wheeled coupled engines on a short
line, the heaviest gradient on which was I in 12 for a length of
360 yards, the engine, weighing 7% tons, took up a train loaded,
of equal weight as the engine, at a rate of from 4 to 6 miles
per hour. The cylinders of the engine were 8 inches diameter;
the stroke of the piston, 15 inches; there were four wheels,
coupled, 27 inches in diameter, with a wheel base of 4% feet.
Steam pressure in the boiler I2O lbs. per square inch. So we
have— -
RESISTANCES.
lbs.
Resistance due to gravity, 15 tons at 1866, .............. = 2.799
Resistance due to speed, 15 tons at 8:21, .................. = I23
Engine friction, 7'5 at 18 lbs. per ton, ..................... = 135
Waggon fiction, 7.5 at 10 lbs. per ton, ................... - 75
Total,............. 3I32
8° x 15 — 35 lbs.
Tractive force per lb. on the inch of the piston,
Steam pressure per lb. on the inch, * = 92 lbs.
This pressure could be easily maintained, considering the steam
pressure in the boiler is I2O lbs. per square inch. -
Adhesive power of locomotives.—The adhesive force of locomotive
engines is due to the load on the driving wheels, when they are not
coupled; but for goods engines, and ordinary coupled passenger
engines, the adhesive force is due to the weight on all the wheels
that are coupled. The adhesive force per ton of load on the wheels
varies from 600 lbs. per ton when the rails are in a good condition,
to 300 lbs. per ton when they are in a moist and greasy condition.
The adhesive force must be greater than the tractive power of the
wheels on the rails, otherwise the wheels will slip; consequently,
we consider that the weight upon the wheels should be so arranged
as to give the full tractive power when the rails are in a moist or
slippery state; in ordinary English weather this may be taken at
450 lbs. per ton of load on the wheels. -
LOCOMOTIVE ENGINES. 749
Distribution of the load.—The average distribution of the load on
a six-wheeled engine may be found by multiplying the total weight
of the engine by the following, assuming the total weight of engine
to be I—
PASSENGER ENGINEs witH THE DRIVING AND TRAILING WHEELS COUPLED.
Load on the leading wheels, multiply the total weight by....... "3o
Load on the driving wheels, ?? y 9 ‘46
Load on the trailing wheels, , , 5 p. "24.
I •
GOODS ENGINES WITH THE WHEELS ALL COUPLED.
Load on the leading wheels, multiply the total weight by... 346
Load on the driving wheels, ,, 3 2 '36
Load on the trailing wheels, , 92 ‘294
I •
To find the centre of gravity horizontally when the load on the aarles
and distance apart are given.
Four-wheeled engine.—For engines with four wheels, multiply the
load on the driving axle in tons by the length of the wheel base in
feet, and divide by the total weight in tons; the quotient gives the
horizontal distance in feet of the centre of gravity from the other
axle. Note—When the loads on the axles are equal the centre of
gravity lies half way between them.
Six-wheeled engines.—For engines with six wheels, multiply the
loads on the fore and hind axles in tons, by their respective dis-
tances from the middle axle in feet, find the difference of the pro-
ducts found, and divide this distance by the total weight in tons;
the quotient is the distance in feet of the centre of gravity from the
middle axle, measured towards the axle, for which the greatest
product was found. Moſe.—When the products are equal the centre
of gravity lies exactly over the middle axle.
To find the loads on the axles, when the total weight, the distance
of the axles, and the position of the centre of gravity horizontally, are
given. - -
Four-wheeled engines.—For engines with four wheels, multiply
the total weight in tons by the distance of the centre of gravity from
the driving axle, and divide by the length of wheel base. The
quotient is the load on the other axle in tons; and the difference of
this and the total weight is the load on the driving axle in tons.
Note—When the centre of gravity is half way between the axles
the loads on the axles are equal. -
75O MODERN STEAM TRACTICE.
i
For engines with six wheels.--When the load on the middle axle
is given, multiply the total weight in tons by the distance of the
centre of gravity from the hind axle in feet. Multiply also the load
on the middle axle by its distance from the hind axle; find the
difference of these two products, and divide it by the wheel. The
quotient is the load in tons upon the front axle; whence the load
on the hind axle may also be found. -
When the load on one of the axles is given, multiply the total
weight by the distance of the centre of gravity from the other end
axle, on which the load is unknown. Multiply also the given load
by the wheel base; find the difference of these products, and divide
it by the distance of the middle axle from the aforesaid end axle.
The quotient is the load in tons upon the middle axle; whence the
remaining load may be found.
Mem.—The conditions which chiefly control the arrangement of
the axles are that there shall be a sufficiency of weight on the lead-
ing wheels for safely guiding the machine, and on the driving wheels
for the purpose of traction. To illustrate this, we will take two
engines of the passenger type, with and without coupled wheels,
of which the following are the necessary data:- -
Six-Wheeled Passenger Engine, Single Driving Wheel Six-wheeled Engine, Driving and Trail-
in the middle or front of Fire Box. ing Wheels Coupled.
Wheel base, .......................... . . I2 ft. o in. .... 12 ſt. 8 in.
Front to middle wheel, ............ , 5 , , 6, , e º 'º 5 ; ; 4 »,
Middle to hind wheel, ............. 6 , , 6, 7 * 4 »
Centre of gravity with respect * -
to middle axle,................. 6 in. before tº º º 4 in. behind
Total weight,......................... I9 tons. tº p & I9 tons IO cwts.
Load on front axle,................. 5 , , I5 cwts. ... 5 × 15 s,
Load on middle axle, ............... 9 , , 15 , , ... 9 3, O 9,
Load on hind axle,.................. 3 , , IO 2, ... 4 × 15 , ,
Tables showing the diameter of cylinders, stroke of the piston, diameter
of wheels, and wheel base. -

ENGINES WITH ALL THE WHEELS COUPLED.
Diameter of cylinders, .......... 16 in. 16 in. I6 in. 18 in.
Stroke of the piston, ............ 24e5, 24 , , 24 , , 24 »,
Diameter of the wheels, ........ 54 , , 6o , 6o , 57 2,
Distance between driving and 2
leading wheels,.............
Distance between driving and
hind wheels, ................ 7 , , 7 , , 5 , , 3 , , 7, 9 , | 8, 1% ,
Wheel base, ....................... 15 , , 3 , , I2 ſt. 15 , 6 , , | 15 × 3 ×,
x
7 ſt. 8 in. 6 ft. 9 in. 7 ft. 9 in. 7 ſt. 13% in.
* Engine marked thus, the wheels are all placed in front of the fire box.
LOCOMOTIVE ENGINES. 75 I
ENGINEs witH THE DRIVING AND HIND WHEELS COUPLED.

Diameter of cylinders,.......... I4 in. 15 in. I5 in. 18 in.
Stroke of piston, ................. 2O , , 22 , , . 2O , , 24 , ,
Diameter of coupled wheels,.. | 66, 63 ,, . . . 66 , , 73 , ,
Diameter of leading wheels,... 44 y, 36 , . 42 5, 43 y,
Distance between driving and & º
leading wheels, ............. 6 ft. 6 in. 7 ft. 6 in. 6 ft. o in. 6 ft. 1 in.
Distance between driving and -
hind wheels,........ tº e º gº tº ſº. 4 - 0 6, 6, 6, 6 × 8, 6, 9 ; ; O >>
Wheel base,....................... I3 - 2 I4 2, - I4 53 6 35 I5 2, 1 » |
zº:
* Engine marked thus is a tank engine, with a bogie truck in front, the distance between
the driving and leading wheels is taken to the centre of the truck, the truck wheels being
4 ft. 6 in. apart from centre to centre.
ENGINEs witH THE DRIVING AND LEADING WHEELS COUPLED.

Diameter of the cylinder, ...... I5 in. 16 in. 16 in. 16 in.
Stroke of the piston, .......... ... • 24 , , 20 , , 2O >> 22 , ,
Diameter of coupled wheels, 57 2, 55 , , 55% , 6o ,
Diameter of hind wheels, ...... 42 y, 43% , 42%, 42 25
Distance between driving and -
leading wheels,............. 6 ft. 9 in. 6 ft. O in. 6 ſt. 2 in. 7 ft. 3 in.
Distance between driving and
hind wheels, ................ 6 , 6, 7 , , C , , 7 : , I 2, 7 2, 3 , ,
Wheel base, ---...---------------- | 13 2, 3 , , I3 ; ; O >> 13 2, 3 ; ; ; 14 2, 6 3 3
{k
* This is a tank-engine.
ENGINES HAVING NONE OF THE WHEELS CoupleD.

Diameter of the cylinder, ............ I4 in. I5 in. 16 in. I6 in.
Stroke of the piston, ................. 22 , , 2O >, 2O >, 22 , ,
Diameter of driving wheels, ......... 72 , 69 , , 78 , , 78 ,,
Diameteroffront lead- ) Both placed
ing wheels, ...... ... ( in front of 42 y, 42 22 42 25 48 ,
Diameter of back lead- (the driving
ing wheels, .......... wheels, 42 22 42 s, 42 3, 48 ,
Distance between driving and lead- -
ing wheels, ........................... 5 ft. and 7 ft. 4 in. 5 ft. Io in. 7 ſt. 3 in. 7 ft. 9 in.
Distance between driving and hind
wheels, ................................ In One. 7, 4% in. 7 ft. 3, 7, 3 ,
Wheel base, ............................ I2 ft. 4 in. 13 ft. 2% ,, . I4 ſt. 6, 15 , o,
Tables of weight of six-wheeled engines taken from practice.
ALL THE WHEELS COUPLED.

Length of outside fire box, ........................ 4 ft. 4 in. 4 ft. II in. 5 ft. 2 in.
Length of body of boiler, .......................... I4 , o ,, . Io , 6, 1o , 6 ,,
Piameter of wheels,................................. 5 , o , || 5 , o, 5 , o ,
Distance between driving and leading wheels, 6, 11 , || 7 ,, 4 ,, 7 ,, 9 ,
Distance between driving and hind wheels, ... 5 , , 3 ,, 7 , , 11 , || 7 ,, 3 3
Centre of gravity in front of driving wheel centre, o ,, 7%, o , 4%, o ,, , 9%,
Weight on leading wheels, ........................ 8% tons. Io tons. royº tons.
Weight on driving wheels, ........................ 9 9 º' 9% , II.3% ,
Weight on hind wheels,............................ 8%. ,, 8 , 7% ,
Total weight, .......................... 26% , 27% 29% ,
§:
* Engine marked thus has all the wheels in front of the fire box.
75
MODERN STEAM PRACTICE.
ENGINES WITH DRIVING AND HIND WHEELs CoupleD.

Length of body of boiler,
IDiameter of coupled wheels,
Distance between driving and
wheels,
wheels,
Weight on leading wheels,
Weight on hind wheels,
Total weight,
Length of outside fire box, ..............
* @ e º e º e º e º e º e º e º º
e e e º e º 'º e º e º 'º &
Diameter of leading wheels, ........
leadin
Distance between driving and hind
Weight on driving wheels,................
Or
35
3 ft. 7% in. 7 ft. o in.
9 } % 4% 5 5 8 2 3 6 5 §
5 , , O , , 5, 6 ×,
3 3 3 6 } 3 3 9 3 6 3 y
5 3 3 4. 3 y 6 5 y 6 y 3
7 9 3 4. 5 3 6 2 3 6 9 3
5% tons. | 6 tons IO cwts.
9 2 3 9 , , 15 , , -
4% , 7 2, 5 , ,
19% , , , |23. , 5 ,
x
3 ft.
II , ,
5 5 y
3 3 y
6,
in.
y
3 y
y
:
3 y
O 2 3
6 y 9
8 cwts.
II , ,
IO , ,
25 9 , ,
* This engine has an inclined fire box, with hind axle placed underneath the box.
ENGINES HAVING NONE OF THE WHEELS COUPLED.

Length of outside fire box, ...
Length of body of boiler, ....
Diameter of driving wheels,
Diameter of leading and hind
wheels, .......................
Distance between driving and
leading wheels,.............
Distance between driving and
hind wheels, ................
Centre of gravity in front of
driving wheel centre, ......
Weight on leading wheels, ...
Weight on driving wheels,...
Weight on hind wheels, ......
Total weight,....................
3 ft.
IO , ,
5 , ,
I
9%
2%
I8
7% in.
O
6
6
9
O
9% ,
toll.S.
3 5
3 2
y 3
9 3
$ 2
3 y
y?
25
3 ft. 7% in.
9 , ,
6 ,
9
y 5
3 2,
5 , ,
6 ,
3 x
.
O % 93
5% tons.
9% ,
3% ,
I9 y 9
5 ft. 7 in. 4 ft. IO in.
IO y 5 8 2 3 IO 5 5 6 3 2
7 2 3 O 3 y 2 3 O 3 y
4 3 y O 9 3 4. 5 y O 33
7 2 3 I 2 3 7 9 3 3 3 *
7 53 7 2 3 7 35 3 9 7
I 33 4. 9 3 O 5 § 6%,
II tonS. 8% tons.
IO% 3 3 12% y 5
5% 25 6% 9 y
27 9 y 27% ,
Diameter of the cylinder–To find the diameter of cylinder for a
given tractive power, the mean pressure of steam in the cylinder,
length of stroke, diameter of driving wheels being given.
We
certainly consider that locomotive engines, should be bought and
sold by the amount of tractive power they develop, suitable to the
requirements. Supposing a tractive power of, say,9216 lbs. is wanted,
the mean pressure being 90 lbs. per inch, the length of the stroke of
the piston 24 inches, and the diameter of the driving wheel, say,
6o inches.
To find the cylinder's diameter, multiply the tractive force by the
diameter of the wheel, dividing the product by the mean pressure,
multiplied by the length of the stroke of the piston, and the square
root of the quotient will be the diameter of the cylinder, thus—
92.16 × 60-552960
T90 x 24 = 2160 T
256=16 inches diameter.
LOCOMOTIVE ENGINES. 75.3
CYLINDER PROPORTIONS.
Area of each steam port, divide the cylinder area in square inches by Io
Area of exhaust port, 2 3 2 3 6
Area of each steam pipe, 93. 92 9
Area of main steam pipe, 93 2 º' 6
Area of each blast pipe at bottom, , , y 9 9
Area of blast orifice, 5 y 2 3 I3
Length of steam and exhaust ports and opening by valve.—To find
the length of the ports, divide the diameter of the cylinder by I-2.
The opening by valve is found by multiplying the area of the
cylinder by the speed of the piston in feet per minute, dividing the
product by the constant IO,OOO, this will give the area of the open-
ing by valve in square inches.
Thickness of the cylinder—To find the thickness of the metal in
the cylinder, multiply the diameter by the steam pressure, as in the
boiler, and divide the product by I2O, this will give the thickness in
sixteenths of an inch nearly.
Area of piston rod and depth of piston.—Multiply the area of the
cylinder in sq. inches by the steam pressure per Sq. inch, and divide the
product by 4480, and the quotient is the area of the rod in sq. inches.
Por the depth of piston multiply the diameter of the cylinder by 28.
Area of slide-valve rod and pins for valve motion.—To find the
area of the slide-valve rod, divide the area of the valve face by IOO.
The pin for carrying the sliding block in link equals the diameter
of the rod nearly, being a trifle more, the pin on eccentric rod end
being of the same diameter; the rods are a third more in width than
the diameter of the pin at the small end tapering to the eccentric end.
Marimum speed of piston.—For a speed of 40 miles per hour and
upwards allow 15 feet of piston speed per minute for each mile per
hour; thus at 40 miles per hour 15 × 40 = 600 feet per minute; at
the same time, so long as an engine runs steadily, the speed of piston
may be more.
Ratio of the diameter of cylinder to the stroke of piston.—The
ratio of the diameter to the stroke of piston varies to suit the
requirements; the usual proportion is as 3 to 4; thus for 15 inches
diameter the stroke is 20 inches; while in some small engines
suited for heavy gradients the diameter of the cylinder may be
8, 9, or IO inches, the respective strokes being 15 inches.
Ratio of the stroke of piston to the diameter of driving zwheels.
The ratio varies to suit the requirements; from 1 to 3% to I to 4
work well for high speed on the rails. For lower maximum speed
43
754. MODERN STEAM PRACTICE.
the ratio may be as I to 2; while for small engines suited for heavy
gradients the stroke in some cases is 15 inches, the diameter of the
wheels being 27 inches.
Mumber of cubic feet of water required to be evaporated for a given
speed of engine per hour.—We will suppose a speed of 25 miles per
hour is desirable with, say, 16-inch cylinders, stroke 2 I inches, and
5 feet 6 inches the diameter of wheels. :
To find the number of revolutions, multiply the number of feet
in a mile by the speed in miles per hour, dividing the product by the
circumference of the driving wheels, and the quotient gives the
number of revolutions, thus—
5280 x 25
I 7'3
Now we will suppose the steam pressure is 90 lbs. per square inch,
and that it requires 6 cubic inches of water to raise a cubic foot of
steam at that pressure.
To find the number of cubic feet of water required.—Multiply the
number of revolutions per hour by the cubic contents of both cylinders
in feet for an entire revolution, and then by the number of cubic
inches to raise a cubic foot of steam at 90 lbs. per square inch,
dividing the product by 1728, gives the number of cubic feet of
water required, thus—
7630 x 9’7 x 6
1728
The boiler: proportions of fire-grate and heating surfaces:—
Area of fire grate—Multiply the period of admission in hundreds
of the stroke by O275, and add 1.75 to the product; multiply the
sum by the tractive force due to the given dimensions of engine,
and by the speed in miles per hour. Divide the product by 48,187.
The quotient is the area of the fire grate in square feet.
=763o revolutions per hour.
=256 cubic feet of water required.
Table giving the dimensions of fire grate, tubes, and diameter of
cylinder, and length of stroke of the piston.
ENGINES WITH ALL THE WHEELS COUPLED.

Diameter of cylinder, I6 in. I6 in. I6 in. I6 in. 18 in.
Stroke of the piston, 24 , , 24 , , 24 , , 24 , , 24 , ,
Length of fire grate, 4 ft. O in. 4 ft. O in. 4 ft. 6 in. 4 ft. 3 in. 4ft. 10% in.
Breadth of fire grate, 3 , , 5 , , 3 , , 5 , , || 3 , , 5 , , 3 : 6 , , 4 , , 3 *
Area of fire grate,.... 13-6 sq. ft. 13-6 sq. ft. I5'5 sq. ft. 14.8 sq. ft. 27°5 sq. ft.
Number of tubes, ... I49 I33 158 I9 I 256
Diameter of tubes
outside, .......... oft. 2 in. oft. 2% in. Oft. 2 in. oft. 2 in. oft. 2 in.
Length of tubes, ..... II , , 4 », 13, Io , , . Io , 4, II , , 6 ,, . Io , 9 ,
LOCOMOTIVE ENGINES. 755
Heating surface. — To find the heating surface, multiply the
number of cubic feet of water evaporated per hour by the area of
the fire grate in square feet; find the square root of the product,
which, multiplied by 2 I-2, gives the total heating surface in square
feet.
Six-wheeLED ENGINEs, witH Four WHEELs CoupleD.
Diameter of cylinder, I3 in. 14 in. I5 in. I5 in. 16 in.
Length of stroke,..... 2O , , 2O , , 2O , , 22 , , 2C , ,
Length of fire grate, 3 ft. 6% in. 6 ft. 6 in. 3 ft. O in. 3 ft. 5% in..] 3 ſt. 6 in.
Breadth of fire grate, 3 , , 5% 35 I , , 7% 5 * 3 , , 6 3 * 3 : , O% 2 3 3 , , 2 22
Area of fire grate, .... II '9 sq. ft. 19°25 sq. ft. Io'5 sq. ft. Io'52 sq. ft. II sq. ft.
Number of tubes,..... 158 2 IO I5O I45 2 I 2
Diameters of tubes, ... oft. I 7% in. Oft. 134 in. O ſt. I 7% in. Oft. I 7% in. Oft. I 7% in.
Length of tubes, ...... Io, 3 2, 9, 1%. , | 11 , 4%. , | Io, 4 », Io, 7 s.
Fire-box heating sur-
face, .... ........... 64 sq. ft. IO7 sq. ft. 58 sq. ft. 65 sq. ft. 65 sq. ft.
Tube heating surface, 712.6 755 750 662 984
Total heating surface, 776-6 862 8O8 727 IO94
To find the cubic contents in feet and area in square feet of the
body of the boiler approximately: dividing the cubic contents of both
the cylinders in inches by 80 will give the cubic contents of the
body of the boiler, which, being divided by the length of the body,
will give the area in square feet approximately. -
Strength of boiler.
TABLE OF THE WORKING STRENGTH of Joints.
Best Yorkshire. Best Staffordshire.
lbs. º lbs.
Scarph welded,............................ I, OOO 9000
Double rivetted, double welt, .......... 9, OOO 7Ooo §
Double rivetted lap,...................... 8,OOO 6500
Lap welded, ............................... 7,400 6OOO
Double rivetted, single welt,........... 7,300 6OOO !
Single rivetted lap, ....................... 6,700 54OO
Body and round parts of boiler—To find the working steam pres-
sure due to a given diameter, thickness of plates in decimal parts
of an inch, and particular kind of joint; multiply the thickness of
plates in decimal parts of an inch by 2 — and by the working
strength of the longitudinal joint in pounds per square inch as above;
and divide by the diameter of the body in inches; the quotient is
the working pressure of the steam in the boiler in pounds per square
inch.
756 MODERN STEAM PRACTICE.
To find the thickness of plates in decimal parts of an inch due to
a given diameter, particular kind of joint, and working pressure;
multiply the working pressure of steam in pounds per square inch
by the diameter in inches, and divide the product by the working
strength of the longitudinal joint in pounds, and then again by 2;
the quotient is the required thickness in decimal parts of an inch.
Flat parts of boilers.-The strength of the flat parts of boilers
depends entirely on the strength of the stays, which are arranged
at regular intervals, dividing the surface into segments, which may
be reckoned as one segment to each stay. The fire-box stays are
arranged in squares, pitched equally.
To find the working steam-pressure due to a given diameter of
the rod, and area of segment stayed, the working tensile strength
of best iron rods being as follows:–
% inch diameter, a e º 'º e s s e s e e s a e º e º ºr e º e º 'º e º e º s a e s a e º tº s º e º º 'º - º 8,000 lbs.
I inch diameter, ........................................... 10,000 , ,
I }% inch diameter, ........................................... 13, OOO 53
If the section of the rod is reduced by screwing, Io per cent. is deducted ©
from the working strength.
Divide the working strength of the tie rods in pounds by the area
of the segment in Square inches; the quotient is the working steam
pressure in pounds per square inch.
To find the area of segment due to a given diameter of tie rod
and working pressure, divide the working strength of the tie rod
in pounds by the steam pressure in pounds per Square inch; the
quotient is the area of the segment in square inches.
Screwed stays.-Screwed bolts are generally pitched in squares
or right angles. -
To find the working pressure due to a given pitch, screwed and
rivetted into the plates, the solid diameter of the stays being 34 inch,
the working strength being as follows:—
Copper stay bolt in copper plates, ............................ 3200 lbs.
Iron stay bolt in copper plates, ........ ....................... 4Soo ,
Iron stay bolt in iron plates,.................................... 5600 , ,
Divide the working strength of the stay in pounds by the product
of the pitches, multiplied together horizontally and vertically; the
quotient is the working pressure in pounds per square inch.
To find the pitch of the stays due to a given pressure, divide
the working strength of the stay bolts in pounds by the working
LOCOMOTIVE ENGINES. 757
pressure in pounds per square inch, and find the square root of the
quotient, the result is the pitch in inches. Note—The working
strength cannot be materially affected by the thickness of the
plates. -
Pitch of the stays in the fire bor—The pitch of the stays varies
from 4 inches horizontally and 5 inches vertically to 4% inches each
way for iron stays. For copper stays from 4 inches each way to
4% inches each way, and some have been pitched 3% one way and
4 the other way.
Roof stays of the fire bor—To find the pressure carried by the
roof stays of the fire box, multiply the span of the roof in inches
by the pitch of the stays in inches, and by the pressure in pounds
per square inch, and divide by 2240; the quotient is the pressure
uniformly distributed, borne by each roof stay in tons.
To find the working strength of a roof stay of given dimensions,
fixed in its place, multiply the thickness of the stay at the centre in
inches by the square of its depth at the centre in inches, and by 30,
and divide the product by the length of span in inches; the quotient
is the working load, equally distributed in tons, when the stay is
fixed in its place.
Note—The side plates of the fire box sustain part of the pressure
on the roof, and consequently the whole pressure, as calculated for
the roof stays, errs on the safe side.
WEIGHT AND StowAGE of FUELs, &c.

Equivalent fuel to
& - Weight per Stowage weight|Space to stow Weight of water evaporate the same
Kind of Fuel. foot. per cubic foot. I toll. evº per §: of water.
& & Coal being I'o.
lbs. łbs. cubic feet. lbs. ratio.
Coal, ................ 8o 5 I 44. 9 I "O
Coke,................ 63 28 8o 9 I "O
Pine,................. 2 I IO/ 2% 3:6
Area for safety valves.—To find the diameter of each valve, two
being fitted, multiply the number of square feet of heating surface
in the fire box by 144, dividing the product by 450, and one half of
the quotient is the area for each valve in square inches; thus, for
68 square feet of heating surface in the fire box—
68 x 144
45O
The spring balance represents a weight of IOO lbs. more or less
according to the pressure required, and the length of the lever is
=2 I '7-3-2 = Io:8 =say, 3H diameter.
/
758 MODERN STEAM PRACTICE.
calculated in the first instance to the greatest amount of total pres-
sure upon the valve. Thus, with an area IO-8 and IOO lbs. Steam
pressure, the distance of the centre of valve from the short end of
the lever being 35 inches, we have— -
Io-8 x 100 x 3.5–378o-i-Ioo-37-8,
The total length of the lever from the stud to the spring balance.
Diameter of the feed pump.–Find the cubic contents of the steam
cylinder in feet for an entire revolution, multiply the result by the
number of cubic inches of water required to raise a cubic foot of steam
at the required pressure, divide the product by the stroke of the pump
in inches, then multiply the quotient by 1.5; this will give the area
of the pump. Then, by a table of areas, you can find the diameter.
This is when the stroke of the pump equals that of the steam
cylinder, two pumps always being fitted. We will take an example.
The diameter of the cylinder being 16 inches; stroke of piston,
24 inches; Steam pressure, IOO lbs. per square inch, requiring
6.6 cubic inches of water to raise a cubic foot of steam at that pres-
Sure, thus—
I 396 × 4 × 6.6
24 = 1 -53 × I'5 = 2:29, say 134 inch diameter.
The Giffard injector.—When Q represents the quantity of water
injected in gallons per hour; P, pressure of steam in atmospheres;
D, diameter of throat in inches—
D = or 58 v/3,
WP
O = (63.4 D)” VP

t Delivery in gallons per hour with a pressure
Diameter of throat in per square inch as under:—
decimal of an inch.
3o Ibs. 60 lbs. 90 lbs. 120 lbs. | 150 lbs.
*I 56 8O 98 II 3 127
‘I 5 127 18O 22 I 255 285
*2 226 32 I 393 455 508
‘25 354. 502 615 7 II 793
"3 505 722 884 I O2 I II4O
Arca of airles and bores.—To find the area of cranked axle: mul-
tiplying the total weight on the axle by 3-5, will give the area at
the pin, and for plain axles by 2-9, will give the respective areas in
square inches. The cranked axle at centre may be 3% inch less in
LOCOMOTIVE ENGINES. 7.59
diameter, as likewise the diameter of the inside journals. The out-
side journals may be I inch less than the pin in diameter; for the
length of the outside journals multiply the diameter by I'36; in Some
plain axles the length of the journal is the same as the diameter.
The distance between the jaw of the cranks is bare ſº inch less
than the connecting rod brasses, the thickness of the jaws in direc-
tion of the length of axle is three-fourths the diameter of the pin.
The raised part for taking the wheels may be I inch larger in
diameter than the inside journals, the length being equal to the
diameter. The bearing surface or top brass in the axle boxes
should have a surface of not less than 18 square inches for every
ton on total load on the axle. For ordinary sides of, say, 5% dia-
meter of axles the brasses are 34 inch thick at top and 3% inch at
side, and the axle box I 34 inch thick at top and I inch at side.
Dimensions of wheels.—For ordinary 5-feet wheels, all of wrought
iron, the eye of the wheel is 7 inches, the length of the boss
634 inches, the greatest thickness of boss is struck with a radius
equal to the diameter of the eye from the centre line. The spokes
are flat, 3 inches broad at point and 3% inches at the boss, and
from 196 to I }4 thick at point, and from 13% to I }% inch at boss.
The pitch of the spokes at the inside tyre or trod is II inches
on the average. The inside tyre, 5% inches broad, by 136 at middle
and 7% inch at edge. The outside tyre, 2+, inches in thickness at
middle. The flanges about 76 inch deep and 5% inch broad for
driving wheels, and I }4 inch deep and I 34 broad for leading and
driving wheels.
For 3-feet wheels all of wrought iron: eye 6 inches diameter;
length of boss, 6% inches; diameter of boss, IO)4 inches; spokes, I to
1% thick at point and I }4 to 13% inch thick at boss. The inside
tyre 5% by I}6 inches, and the outside tyre 5% by 1% inches, the
number of spokes being ten.
Dimensions of springs and harness.-Ordinary springs, when
loaded, are 2 feet 8 inches from centre to centre, and when unloaded
2 feet 7% inches, having a set of 5% inches from centre of scroll to
top of plates, the breadth of the plates being usually 4 inches. To
find the depth of the spring, multiply the constant 8-5 by the total
load on the axle in cwts, then by the length of the spring in inches
when loaded, dividing the product by the breadth of the spring in
eighth parts of an inch, and the square root of the quotient is the
depth in eighth parts of an inch. Top plates, # inch thick at middle,
7óo MODERN STEAM PRACTICE.
and 3% inch at ends; all the other plates, ſº inch in thickness; sus-
pension pins, I inch in diameter; eye, 2% inches diameter.
To find the area at the bottom of the thread for tension rods of
spring harness, divide the total weight on the axle by 4, and then
by 2, and the quotient will be the area at the bottom of the thread,
adding the thread gives the total diameter. The compressive pin
in steel equals the total diameter of the tension rods. When fitted
with side links, the suspension pins being, say, I inch in diameter,
the side links may be 1% inch broad and 5% inch in thickness.
Dimensions of framing.—The minimum dimension of framing for
a goods engine with six wheels, all coupled, 5 feet in diameter, is
9 inches broad by 76 inch in thickness for inside frame, and 9 inches
broad by I inch in thickness for outside frame, the horn plates
being 94 inch in thickness, rivetted to the outside beams, forming
the framing, the inside and outside beams being strongly bracketted
together, and the horns stayed together, and diagonally to the end
beams with flat stays, 234 × I inch in thickness. For ordinary pas-
senger engines the minimum dimension of the inside frame is
about 12 inches in depth, and for the outside frame, 9 inches in
depth for plain bars, the horns being forged on. Of course
there are a variety of frames made much deeper and cut out to
lighten them. The front and end beams of oak may be from 5%
to 6 inches thick and I2 inches in depth, strengthened with corner
plates, angle iron, &c.
Area of crosshead, motion bars, &c.—To find the area of the gud-
geon of crosshead, divide the area of the cylinder by 28, this will
give the area in square inches. To find the area of the slide-block
pin in square inches, divide the area of the cylinder by 80. The
thickness of the brass blocks is about 3% inch, this, supposing the
pin to be 134 inch, will give 2% inches to the depth of the sliding
or guide blocks; for the length of the sliding blocks multiply the
diameter of the pin by 5-8. For the breadth of the motion bar take
Tº less than the diameter of the gudgeon for crosshead, when double
motion bars are used, thickness of the motion bars one-half of the
diameter of crosshead. -
Or treating the motion bars as a beam and allowing one-third of
the pressure on the piston as the thrust, multiply this thrust by the
distance between the points of support in feet, dividing the result
by the constant I.338 (for iron) multiplied by the total breadth; then
the square root of the quotient will be the depth of the bars. For
LOCOMOTIVE ENGINES. 761
bolts one-third of the total pressure on the piston by 40OO gives the
total area of the bolts at the bottom of the thread.
Area of connecting rod—To find the area of the small end, mul-
tiply the area of the piston by the steam pressure in pounds per
square inch, and divide by 40OO for the area at the small end, the
breadth being equal to the diameter of the gudgeon of the crosshead.
For the breadth at the crank end, multiply the breadth at the small
end by I-5 for connecting rods of about 6 to I of the crank. The
breadth of the large butt is regulated by the diameter of the crank
pin; for the thickness of the butt multiply the thickness of connect-
ing rod by 1:42. The breadth of the jibs and keys at the large end
equals the breadth of the rod at that end; for the thickness of the
keys divide the thickness of the butt by 3-3. The breadth of the
jibs and keys at the small end equals the breadth of the rod at that
end, and the thickness is the same as for the large end; the area of
the butt across the key way being equal, at least, to the area of the
piston rod; the same holding good as regards the smallest area
of the straps at the key ways.
Outside cranks and side rods—The diameter of the crank pin
equals the diameter of the gudgeon for crosshead, the length of the
crank pin being 3% inch or so longer than the diameter. The dia-
meter of the large eye may be 94 inch smaller than the main crank
pin as for cranked axles; for the thickness at eye multiply the
diameter of the eye by 3; for the breadth of the eye multiply the
thickness by 2; for the breadth of the web divide the breadth of the
eye by I'4; the sides of the web are straight lines drawn from the
extreme diameters at each end. There is one large steel key let
into the web, I 34 by # inch, and two other keys, I 34 by fºr inch;
for eyes, say, 6% inches in diameter.
The breadth of the body of the outside rods equals the diameter
of the crank pin, tapering to the centre of body; the thickness
should be regulated to give an area equal to nearly that of the
piston rod; the thickness of the butts should not be less than the
rods at the key ways, and their breadth I inch less than the length
of the crank pin. The diameter of the steel coupling pin for the
rods, when six wheels are coupled, may be one-third less than the
breadth of the rod at end ; the diameter of the eye being twice
the diameter of the pin, and the thickness one-half of the diameter
of the pin. The thickness of the brasses is 76 inch or so at ends,
and 36 inch at sides. The keys are about 12 inches long, tapering
762 MODERN STEAM PRACTICE.
from 1% to 134, and 5% inch in thickness, for crank pins 3 inches
in diameter.
All the minor details in the locomotive engine, such as handles,
rods, pins, &c., should have ample strength, more so than what is
usually allowed in any other class of engine, so that the parts may
not vibrate or bend with the hand power applied. In the fore-
going rules we have given the leading formulas required, and which
are in general practice; the numerous engravings throughout this
section clearly show the details of handles, pins, and other minol
parts without further investigation.
ROAD LOCOMOTIVE OR TRACTION ENGINE.
Road Locomotives or Traction Engines have been used now for
some time with good results. In large towns they are most useful
for the haulage of heavy loads, which formerly could only be accom-
plished by a large number of horses; for agricultural purposes they
have been used for some time, and extensively in India for the
haulage of trains along the roads there both with goods and passen-
gers. One of the essential features of a road steamer is the tyres of
the wheels and the method whereby the engine is connected with
the driving wheels. One great advance was made by the introduc-
tion of india-rubber tyres by Mr. Thomson of Edinburgh, whose
road steamers with india-rubber tyres proved very successful,
some of his engines being purchased by the Indian Government,
and a regular service of trains was started in the Punjab as far back
as 1873. These india-rubber tyres lessened the objectionable vibra-
tion of the engine and gave a high percentage of adhesion. The
tyres are protected by iron shoes. -
The engine is connected with the driving wheels by means of
spur gearing working on a counter shaft, by means of which fast or
slow speeds can be obtained by throwing suitable pinions in or out
of gear. These pinions are either made of malleable cast iron or of
crucible steel. - ;
The boilers are sometimes of the vertical Field arrangement, the
engines being also placed vertically. In others the boiler is hori-
zontal, the machine not differing much in appearance from a railway
LOCOMOTIVE ENGINES. 763
locomotive. The wheels number either three or four, there being
two large as drivers and one or two for guides; these latter wheels
are steered by the driver or attendant by suitable gearing.
The speeds obtained by such engines necessarily vary with the
load, but in some cases speeds of Io, 16, and even as high as 22 miles
per hour are obtained, and with a train of carriages about 5 miles
per hour over fairly steep gradients. The working expenses are
necessarily varied, being from 194 d. to 3d per ton per mile.
Mr. R. E. B. Crompton, in a paper read before the Institution of
Mechanical Engineers on this subject, says, “It cannot be denied
that the question of improved and cheapened haulage on our tram-
ways and streets is one of great importance for engineers and to the
public. Now when we consider the inconvenience to ordinary
wheeled vehicles of the present system of tramways when laid down
in crowded thoroughfares, the high frictional resistance of the cars
on the unmechanical tram rail, the liability to derangement of all
street traffic by the derailment of the cars or the accidental break-
down of any other vehicle on their line; and when we contrast with
this the traction engine, with its extreme handiness in turning and
steering, its high adhesion, its minimum of harm done to the road
surface, &c.; does it not point to the use of real railways of light
Construction carried as far towards the crowded centres as traffic
will permit, and from thence onwards the hauling of the cars by
such engines as have been here described, but of lighter construc-
tion and capable of being readily steered and worked in with the
regular traffic?”—The following are the dimensions of engines as
used by Mr. Crompton:—
ft. in.
“Length of engine and tender, tº e ſº tº º º tº tº gº tº ſº º * Gº tº 3I IO
3 9 engine only, & & ( , tº º' º ſº tº •e tº º • * > ... • * * I6 o
Extreme width of engine, ... * * * & ſº tº * 8 8
3 y height to top of spark-catcher, ... tº tº ge * * * I3 4.
Outside diameter of driving wheels (original), ... tº º º tº sº ºn 6 2
3 * y 3 3 y , , (altered), ... iº º ºs tº º tº 6 6
9 3 ,, . steering wheels, * * * * † tº $ & © tº dº ſº 3 IO
Width of driving wheels, outside armour, tº de gº tº tº ſº. e tº e 1 7
Diameter of cylinders, tº ºr ſº dº º º & © tº ge e > tº gº º tº ſº tº O 8
Stroke of 9 3 & e º is ſº tº tº sº º * G - tº it tº tº ſº º O IO
Diameter of crank shafts, ... © & $º is º e tº º tº º ſº * † tº O 4
3 y counter shafts, tº º ºs © e e tº º º tº e = tº q = o 3%
Average pressure of steam—lbs. per sq. in., ... ... I6O *
Ratio of gearing, fast speed, tº us tº tº gº tº tº º º ... 375 to 1 –
93 9 3 slow speed, e º º tº º º tº e º ... 12 , I –
99 22 39 (altered), & e & tº c > tº sº. 8 23 I
764 MODERN STEAM PRACTICE.
It appears that the wear of the india-rubber tyres is on the inner
surface, which appears to be so far prevented by black-leading the
rubbing surface, but better still by preventing the slipping of the
tyre by making depressions on the wheel.
The traction engine has been used instead of horses for tramway
purposes; in some cases, however, the tramcar has the engine placed
at one end, so that one vehicle only is used.
PORTABLE ENGINES.
(See PLATE.)
Portable Engines are now much used for agricultural and other
purposes. They consist essentially of locomotive boilers, having an
engine placed on the top, and connected with a fly-wheel, which serves
for transmitting the power to any machine by means of belting; the
whole is set on wheels with broad tyres, by means of which it may
be readily shifted from place to place. Single-cylinder engines of
this class work up to about IO horse-power; the double-cylinder
arrangement being made up to 20 horse-power. The total weight
of course varies with the power, a five-horse power engine being
about 3 tons, and a ten-horse power 5 tons.
The great point to be aimed at with such engines is economy and
durability, ample boiler power, and a steady base for the boiler
and engine to rest on.
Our Plate shows vertical and transverse sections of an eight-
horse power Portable Engine of approved construction. The boiler
is made of best plates (36 in. thick) and strongly stayed, with an
ample allowance of heating surface; and each boiler is tested to a
pressure of I2O lbs. per sq. inch before it is used. The fire box is
of best Yorkshire plates (% in. and 5% in. thick), with a large grate
surface. The cylinder is 9% inches in diameter, with a stroke of
12 inches, and is furnished with a steam jacket. The piston and
valve rods are both of steel. There is no steam joint between the
cylinder and the boiler; the governor, which is both powerful and
sensitive, acts direct upon the throttle valve. The feed pump is
placed vertically, and is constantly at work whilst the engine is
running, either circulating the water through the heater or forcing
it into the boiler. The feed-water heater heats the water to nearly
POFTAELE ENG IN E.
A Fire Box. F Cylinder and Valve Casing, &c. L I. Brackets ſor carrying the Cranked
B Tubes. G Motion Bars, Crosshead, &c. Shaſt.
c Smoke Box. H Connecting Rod. * Mi Feed. Pump driven by an Eccentric.
D Funnel. I Cranked Shaſt. N Blast Pipe.
rt Ash Pan. k Fly Wheel. o Regulator Handle.
p Saſety Valve.
Q Governor.
*-
R Front Wheels with Swivelling Axle
S Back Wheels with Fixed Axle,
T Stay Rod. w
. VERTICAL AND TRANSVERSE SECTIONS OF EIGHT IIORSE-POWER PORTABLE ENGINE.
CONSTRUCTED BY THE READING IRON WORKS, LlMITED,

LOCOMOTIVE ENGINES. 765
'boiling point. The travelling wheels and fore carriage are of
wrought iron; the hind axle is cranked under the fire box, the
weight being taken on the bottom, which prevents the fire box from
being strained and joints rendered leaky. The main bearing
brackets have a large area of base, so that the strain is well dis-
tributed; and the bearings, eccentric straps, pump plunger, valve,
and seats are made of best gun metal.
STEAM ROAD ROLLER.
Steam Road Rollers are of much service in road making or repair-
ing, and effect a considerable saving on the road repairs, as the
road metal is thoroughly and effectually pressed into the roadway,
giving a hard and smooth surface for the traffic. A layer of metal
is laid down and the roller passes over it two or three times. Sand
well watered is then sprinkled over the surface and again rolled.
The mechanism is somewhat similar to the road locomotive, the
rollers taking the place of the wheels. Where four rollers are used
these are of equal widths, and are sometimes arranged so that the
two hind rollers act as drivers and the two in front as steering
rollers, the latter rolling on the space left uncovered by the driving
rollers. The weights of the rollers vary with width covered, such as
from 8 to 15 tons. -4
The Road Roller manufactured by Aveling and Porter of Ro-
chester weighs 15 tons, and has four broad wheels or rollers. The
front pair, 5 feet in diameter, act as driving wheels; the hind pair,
4 feet 9 inches in diameter, form as it were one broad roller, and
slightly overlap the tracks of the front pair. The rollers cover a total
width of 6 feet. The mounting of the hind rollers is so arranged
as to leave the fore wheels free to adjust themselves to the turns or
inequalities of a road. The arrangement of the cylinder and gearing
is the same as that of the firm's ordinary traction engine. Two men
attend the machine: one acting as steersman, the other, the driver,
stands on the opposite side of the engine, and feeds the fuel by a
side door in the fire box.
THE MACHINERY OF THE INMAN LINER “CITY
OF NEW YORK.”
ON our large folding plate we give a view of one set of the triple-
expansion engines of the twin-screw steamer City of New York,
built and engined by Messrs. James & George Thomson, Clyde-
bank, to the order of the Inman and International Steamship Com-
pany. The many novel features of the hull are accompanied by
almost as many novelties in the machinery. The adoption of the
principle of twin-screws has been almost compulsory in this case, as
it would be very difficult and probably very imprudent to construct
single-screw engines having the enormous power that these com-
bined twin-screw engines are intended to exert. The great ad-
vantage of the duplication of all parts is too obvious to be dwelt
upon here, excepting to state that with only one of the engines run-
ning sufficient power would be developed to propel the vessel at
about fifteen knots per hour. To indicate how the dimensions and
power of the engines of the City of New York compare with those
of the principal merchant single-screw steamers afloat, we give on
page 77O a table compiled partly from a paper read by Mr. W. John,
at the Liverpool meeting of the Institute of Naval Architects last
year, and partly from the records of the trials of the steamers.
It will readily be seen that the power to be developed in the City
of New York (2O,OOO indicated horse-power) is considerably in ex-
cess of that in the other steamers, and to have fitted a single set of
engines, even supposing it had been advisable from every other
standpoint, would have been a very questionable step to take. The
view we give is of the port engine. The two engines are separated
by a longitudinal bulkhead reaching up to the main deck, commu-
nication being established by a sliding door, worked by a rack and
pinion from above in case of need.
Many of the features which are common to war-ship machinery
have been introduced into the design of these engines in order
partly to save weight and in consideration of the high piston speed.
The engines are built upon a very Solid structure in the ship, but
(766) .*
THE “ CITY OF NEW YORK.” 767
have, in addition, a cast-steel bedplate. This bedplate is formed in
three parts, each part weighing about sixteen tons. The columns
are also of cast steel and are of the “split type.” The condensers,
which usually form part of the main engine structure, are made, as
in war-ships, of brass, and are quite independent. The cylinders and
their covers are cast iron, but the pistons are of cast steel of the
dished type. The crankshafts are built of steel; the thrust, tunnel,
and propeller shafts are also of steel. The crankshaft is 20% inches
in diameter at the journal, and 21 inches at the pin ; the tunnel
shafting is 19% inches, and the propeller shafting 20% inches.
The piston-rods and all the principal moving parts are of ingot
steel. The piston-rods have tail-rods, and are attached to the
pistons by flanged connections.
The high, intermediate, and low-pressure cylinders are 45 inches,
71 inches, and 113 inches in diameter respectively, the stroke being
6O inches. All the valves are piston valves, being one on the high,
two on the intermediate, and four on the low-pressure cylinders.
The adoption of the four sets of piston valves for the low-pressure
cylinder is unique, and is necessitated by the large port area in this
cylinder, and to avoid the strains due to the great overhang which
would be caused by the adoption of two sets only. The valve gear
is of the ordinary eccentric type, the eccentric straps being of cast
steel lined with white metal. The equilibrium valve, which controls
the inlet of steam, is worked by an independent engine which can
be connected to the Dunlop governor. The adoption of this engine
renders the handling of the main engine very much easier.
The turning engine is of a new type, being simply a hydraulic
ram working by a pawl on a ratchet wheel. This ram is vertical,
and takes up very little space; but is at the same time very power-
ful.
In addition to the usual draining from the jackets and casings,
which is collected in the hot-well, there is a continuous flow through
the casings from the high-pressure to the intermediate pressure
casings, and from the intermediate pressure to the low-pressure
casing. In the latter casing the drainage passes into the low-pres-
sure cylinder in the form of vapor, there doing work, and finally
passing into the condenser. By this means any accumulation of
water is prevented in the casings when the engines are running, and
the glands are always dry.
768 THE “ CITY OF NEW YORK.”
The air pumps are the only auxiliaries driven from the main
engine. There are two of them to each engine, of the ordinary
vertical type, and they are worked by levers off the high-pressure
and low-pressure crossheads. A small oil pump is also driven off
the main engines. It is for keeping the crank-pits clear of oil,
which is forced into the stern tubes.
The boilers are fed by Worthington vertical pumps, four in num-
ber, associated with Gilmor's feed heater. These during the trial
proved satisfactory, and in this connection it may not be uninterest-
ing to indicate briefly their system. Each pump has two 12-inch
steam cylinders, and 28%-inch double-acting water plungers, with
a 10-inch stroke. There are two pumps in each engine-room. Of
these one supplies the feed heater with water at the temperature of
the hot well. This water has its temperature raised in the feed
heater by live steam from the boiler to nearly the boiler temperature,
and the second pump delivers this heated feed water at a slightly
increased pressure to the boiler. There is no advantage on the
score of economy; but in so far as the feed water is introduced at
boiler temperature there is complete absence of any possibility of
strain due to irregular cooling of the boiler plates. The heater can
be thrown out at any time and only one pump used, and as the
capacity of each pump is sufficient of itself for boiler feeding, the
other may be looked upon as an alternative in case of breakdown.
In the ordinary arrangement, the first pump, which delivers from
the hot-well into the feed heater, is controlled by a float in the tank,
so that it will be impossible either to have overflow or an insufficient
quantity in the hot-well. As all the water passing through the feed
heater is at a high pressure, all impurities in the water are deposited
in the latter, from which they are occasionally discharged by means
of a blow-off, and since the heater itself is in no way cramped or
confined by large tubes its cleaning becomes a very easy matter.
Indeed it is completely done by blowing off at regular intervals.
There are two fire and bilge pumps in each engine-room for gen-
eral ship purposes. These are also so arranged that they can be
used as feed pumps in the event of the main getting out of order,
and they are connected to the double-bottom system of piping, and
are available for pumping the compartments between the bottoms
should the circulating pumps be in use for other purposes. The
water is circulated through each of the main condensers by two sets
- Fºº -º- M \, ºſº
A º, º || ||
5. ºf TTTTTTTTT
| ſ= |-- ºr tº sº. -
| = º
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Nº.
º
º,
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TRIPLE-EXPANSION ENGINES OF THE INMAN STEAMER “CITY OF NEW YORK,” SEE PAGE 766.
CONSTRUCTED BY MESSRS. J.
& G. THOMSON, ENGINEERS AND SHIPIRUILDERS, GLASGOW.

{{ 33 • * :
THE “ CITY OF NEW YORK. 769
of 15 inch-centrifugal pumps, either of which is more than capable
of doing all the work required. There are fresh-water condensers
in each engine-room, which have their own feeding and circulating
pumps automatically worked. All these pumps are of the Worth-
ington type.
The hydraulic installation of the ship, which is the most exten-
sive fitted on shipboard, has its pumping engines—two in number—in
the engine-room. These engines are of the compound surface-con-
densing type of Messrs. Brown, now so well known in connection with
hydraulic ship plant. These engines work seven hoists, nine der-
ricks, two warping ends, a windlass, and two warping capstans aft
on the promenade deck.
The steel boilers which supply the steam are nine in number,
and are equally divided in three water-tight compartments. They
are built of steel, the shell plates being 13, inches in thickness.
The diameter of each boiler is 15 feet 6 inches, the length 19 feet
and the working pressure is 150 pounds to the square inch. The
boilers are double-ended, and have each six furnaces, the mean
diameter being 3 feet II inches. The tubes are 7 feet 6 inches
long, 2% inches in diameter, and in each boiler there are 1,056
tubes, or 9,504 in the nine boilers. The total heating surface 50,-
O40 square feet. The furnaces on each end have a common com-
bustion chamber. Each boiler weighs 74 tons.
The boilers are worked on what is known as the closed stokehold
system. This is the first ship for the Atlantic passenger trade that
has been worked on this system, and it necessarily introduces many
novelties. There are no air hatches excepting those through which
the fans draw down the air supply. The fans for supplying air to
the furnaces are twelve in number, and are each 66 inches in diam-
eter. They are the result of very exhaustive experiments. The
application of forced draught has become so general that the design
of the engines has become equal in importance with the engine for
propelling the ship. The experience which the Messrs. Thomson
have gained during the past few years in constructing high-speed
war-ships fitted with forced draught has enabled them to design
a fan and engine that will work with great efficiency and com-
paratively no attention.
It may be added that during the construction of the machinery,
Mr. J. i Doran, Superintending Engineer of the Inman Company,
77o THE “CITY OF NEW YORK.”
acted as inspector, discharging duties, ordinarily difficult and trying,
in such a way as to merit and secure the confidence of the Inman
Company, and the acquiescence by the Messrs. Thomson in all his
proposals.
HULLS AND ENGINES OF OCEAN STEAMERS.

45 in. 71 in 173 in.
Vessel's Dimension. Engines Engine Cylinders. Boilers,
NAME. a | # #. Tº #; *ś # .#
# | 3 | ##| || 3 #3 Diameters. $ §§ | < * | ##
# # | 3: #8. 8 || $3 | #3 || 3:
H & sº 5 5 I. £g | > a.
ſt. in Iſt, in,'ft. in. 3 3 ſt in, in sq. ft. in sq.ft. (b.
e w g R tº º º a tº a R - —— --- - *
S. S. City of Rome 542 6152 o |21 5%| 11,890 46 in. 86 in. 6 o 29,286 1398 || 9o
& Cº. Nemandie * - G - e º tº ºt 459 449 II 19 9: 6,959 sº in Riº 5 7 || 21,404 756 || 85
“ Arizona..............]45o ol45 14 18 9 6,300 an º 5 6 || --------- | ...... - 90
g I 2 ,
& & Orient.......... tº e º 'º º ve 445 O 46 O #2 I 4% 5,433 6o in 85 in. 5 O. e sº tº e º g tº º * * * es e 75.
* Stirling Castle..... 420 oſso o 22 3 8,396 an. zi 5 6 2x,161 || 787 || roo.
** The 42O of 44 9 20 O 5,665 º † 5 o
“ Umbria & Etruria. Soo oſs? o |22 6 || 14,321 Fº rºm 6 o 38,817 | 1606 || Iro
“ Aurania.............. 47o of 57 o 20 o 8,500 wº º 6 o 23,284 || Ioor || 90
“ America............. 432 of 51 o 26 o 7,354 º sº 5 6 22,750 || 882 95
-> Y 2 r
“. Servia................ 515 o'S2 o |23 3}| Io,3oo 72°in Ioo in 6 6 27,483 || IoI4 |. 9o
“ Alaska............... 5OO of 5o O |2x o Io,500 wº rºm 6 o --------. ...... IOO
- I 2 -
** Erns 43o o46 ro 20 7# 7,251 62 in." 36 in 5 o | 19,700 | 78o 1oo-
& & * I 1 r - *
Aller..................! 438 o'48 o 21 o 7,974 44 in. 7o in. Ioo in. 6 o 22,630 || 799 so
I I I
“ Ormuz........ tº e º 'º e º º 4. * - w
Ormuz 465 6|52 1% 9° 46 in. 7s in Irain. 6 o 26,ooo 85o 1so
“ Lahn.................. 448 5149 o |......... 9,500 —#– =#— =#– 6 o dº 15o
y 324 in. 68 in. 85 in. “ º º a sm s a “s .
“ City of New wº o63 3 ||25 o 20,000 *— — — — . 5 o 50,265 | 1293 || 15o

EVAPORATOR FOR TRIPLE COMPOUND ENGINES.
WE illustrate an arrangement of evaporator and auxiliary
feed boiler for triple compound engines made by Messrs. G. and J.
Weir, of Holm Foundry, Cathcart, Glasgow. Steam is taken from
the intermediate receiver, and passes to the tubes shown. Sea water
is admitted to the interior of the cylindrical shell, and is there evap-
orated by the steam in the tubes. The resultant steam from the
evaporation of the salt water is taken to the low-pressure receiver
of the engine, and follows the usual course.
It is claimed that by the adoption of this apparatus the cost of
production is one-third of the cost that would ensue were the ordi-
£4.2,
TÉ
EvaPORATOR FOR TRIPLE-EXPANSION ENGINEs of THE “city of
NEw York” AND “CITY OF PARIs,” CONSTRUCTED BY MESSRS. G.
& J. WEIR, ENGINEERS, GLASGOW.
nary practice followed. In order to prevent priming the steam space
is ample in proportion to the heating surface, and in order that the
whole of the latter may be equally efficient the outlet ends of the
tubes are contracted, and the condensed water is drawn off by a
tube, returning through the evaporator. In practice the tubes may
be kept clean by blowing the brine out entirely and admitting cold
water, which breaks off the scale, or the tubes may be scaled occa-
sionally in the usual way, a man-hole door being provided as shown.
If very dirty the tubes can be removed, both ends being exposed in
the plate, as shown; they all come out together, the operation taking
but a few minutes, as the tube-plate joints are faced.

(771)
ENGINE-DRIVERS.
THEIR RESPONSIBLE DUTYES AND THEIR TRAINING FOR THEM.
ENGINE-DRIVERs, says our London editor (September, 1888), are
very little known as a class, though the duties they discharge
are public and very responsible. The fact is that the engine-
driver, who must not only be skilled in the technicalities of his
business, but must possess intellectual and moral qualities of a high
order, has never risen above the rank of the artisan; nor does he
pretend to rise above it; and yet he must be almost as capable and
as dutiful as the captain of a ship or the commander of a regiment.
This workman, whose cool judgment and unceasing watchfulness
are more serviceable than any mere manual skill he may possess, is
worth attention. -
Engine-drivers are neither born nor made: they grow. You
cannot apprentice a boy to engine-driving. Engine-driving, how-
ever, is the goal of the ambition of most boys who begin their
working life in a locomotive shed. From being a kind of “devil.”
to everybody, the boy gradually becomes a “cleaner.” Supplied
with a bundle of cotton-waste, he rubs over the working parts of
the engine, and thus acquires a knowledge of its construction. At
this work he may be kept four or five years. If he is fit for nothing
better, he remains at it all his life. But if he is steady, quick and
handy, he is sure to attract the notice of the foreman; and the fore-
man occasionally calls on him to fire an engine, or haply to run one
out of or into the shed. It is a proud day for him when he first
steps on the foot-plate of an engine, charged to drive it a few yards—
out into a siding, perhaps, or up to the train to which it is to be
attached. From this point everything depends on himself. By-
and-by he obtains an appointment as fireman, most likely on an
engine which is never engaged in hazardous work. Perhaps it is a
pug-engine doing yard or station duty, and never permitted on the
main line or principal sidings. Here the growing engine-driver
learns something of the weight of trains, of the regular supply of
steam, of the relation between the steam-pressure and the work to
(772) - .
ENGINE-IDRIVERS. 773
be done, of economizing coal, and generally of the management and
working of an engine. Then..a vacancy occurs among the firemen
on the regular goods traffic, and “the most steady and promising
young hand in the shed ” is promoted. He now obtains a knowl-
edge of “the road,” learns to read the signals as well as the other
multitudinous signs by which the experienced engine-driver feels his
way along, and, of course, becomes proficient in the art of keeping
up the motive power to the point needed by the driver. He may
even now be working merely on a branch or on a slow goods train;
but he is decidedly getting on. He fathoms the mysteries of shunt-
ing. Billiard players will understand what we mean when we say
that in shunting “strength '' is everything. The engine, like a cue,
propels the trucks with just sufficient force, and no more, to land
them at the desired spot, the engine itself pulling up as soon as the
momentum has been applied. Marvellous stories are told of great
shunters—men of genius in their way. There was Joe , on the
Caledonian, who could shove his train up to and past a set of points,
check his engine to give time for the points to be changed, then run
on without having stopped, put on speed so as to overtake and get
ahead of the still running trucks; and finally, passing over another
set of points, bring up his engine just in time for it to receive a
gentle tap on the other end from the trucks, which are now coupled
on behind it instead of before. Our young fireman may never ven-
ture to attempt this feat; but at a very early period it is set before
him as the sort of thing that can be done, though he may never
hope to do it.
From goods fireman he is promoted to goods driver: an impor-
tant move. He already knows the road, can read the signals, and
gauge the weight of a train; but he has yet to learn how to keep
time on a journey, how to regulate the brake so as not to waste
power, how to utilize “straights” and descents, how to climb hills
and go safely round curves. Goods trains not being greatly pressed
for time, he has a margin to work upon, and after a few journeys
his difficulties disappear. Not only can he work his train in perfect
accordance with the system laid down, not only does he learn by
heart the signals, points, gradients, and other features of the road,
but he is able to detect weak spots in the permanent way. In such
cases he scribbles a line on a piece of paper, and throws it out to
the first platelayer he passes. That generally suffices; but if not, he
774 ENGINE-DRIVERS.
makes a report to the chief engineer. He does not know what it
is—ballast shifted, sleeper broken, chair defective, or rail given way;
but he feels there is something wrong, and until it is put right he
passes over the spot with such caution as to neutralize the danger.
His phase as goods driver is one of the most important in his pro-
gress. But he has not yet done with stoking. His next step is as
passenger fireman. His finer qualities, if he possesses them, are
now coming into play. It is true he has simply to maintain the
motive power for the service of the driver, but he is something
better than the boy who blows the organ bellows. He is the
driver's companion and helpmate; he is probably as competent as
the driver himself; and he necessarily exercises a moral influence
which, if strong, proves invaluable to both of them in cases of emer-
gency. One might almost compare them to companion lighthouse-
keepers. Should an accident occur, it is the fireman's duty to run
forward with a danger flag, just as it is the rear guard's duty to run
back and “protect” a following train. Then from passenger fire-
man he becomes passenger driver. But there is a great difference
in passenger drivers. The one whose development we have traced
is one of the best. Passing over his stages of employment on
branch-lines, slow main-line trains, specials, and so on, we come to
his final phase, as the driver of the great express—the Flying
Dutchman, Scotchman, or Zulu, or the Wild Irishman, as the reader
may choose to suppose. --"
What is his position now? Well, he is a man whose efficiency
and character will, from any point of view, stand the severest tests.
He is an expert, whose training has been of the most gradual,
minute, and thorough description, who has climbed step by step to
the top of the ladder, where his foothold is now as firm as if he
were standing on the solid ground. His wages are (say) fifteen
shillings a day; his working hours are fifty-six or fifty-seven a week;
he is exposed to all sorts of weather—very peculiar weather it is,
too, on the footplate of a locomotive, with your feet scorched by
the heat while the bitter east wind freezes the moisture on your
beard; and he is charged with the duty of taking (say) three hundred
passengers from London to Exeter, or Glasgow, or Edinburgh, or
Holyhead, within a certain time, at an average speed of fifty miles an
hour. From the moment he starts to the moment he arrives he is
under a constant strain. Not only are the peculiarities of the road,
ENGINE-DRIVERS. 775
which he knows from experience, to be noticed, but every mile or
two there is some official sign put up for him to read. Level cross-
ings, points, tunnels, bridges, viaducts, stations, platelayers, gradi-
ents, curves—all these he must look out for. Consider the operation
of climbing and descending a “summit,” or descending and then
climbing a “valley.” At these times the driver's hand is never off
the lever. In the course of a few miles he will perhaps make fifty
imperceptible changes in the speed of the train—accelerating it or
diminishing it so steadily that not a passenger notices what is being
done. That is the perfection of engine-driving. That is the climax
of the driver's skill, and he attains it coincidently with the full
development of those qualities which he has unconsciously trained
within himself, and which are all governed by an overmastering
sense of duty.
RAILWAY VERSUS ROAD.

CONTENTS.
THE BOILER AND STEAM.
in Working—Position and Form of the Shaft—Dangerous Gases—Ventilation
and Lighting of Mines—The Guibal and other Fans—Methods of working
776
- - Pa
COAL AND COAL-M.INING. The Coal-beds of Britain–Boring for Coal—“Troubles”
3O
Coal—Machines for Cutting–Utilization of Coal, gº tº º * * g. • . . . . . .
BOILERS FOR STATIONARY ENGINES : -
Distinctive Forms of Boilers—Common Cylindrical–Cornish–Tubular—Self-
contained Flue—Vertical—Pot Boiler—With Suspended Annular Tubes—
Annular—Water-tube Boilers—Perkins System, * e º * * * tº g a ... IO
Shape and Rivetting of Boilers—Strength of Plates and Joints—Professor Ran-
kine's Rule—Prof. W. R. Johnson on the Strength of Cylindrical Boilers—Illus-
trations of their Bursting Pressure—Internal Flues—Table of Working and
Bursting Pressures—Strength of Rectangular Forms or Flat Surfaces—Factors
of Safety, tº ºn tº is tº e tº e ºs © tº º tº $ tº $ tº s $ tº e tº tº e ... I9
Strength of Round Boilers with different Qualitiés of Plates—Use of Steel—
Tables of Strength and Weight of Plates, Angle Irons, Bars, and Tubes, “...
Proportions for Parts of Land Boilers—Relative Value of Heating Surface, 34.
Boiler Foundations—Form and Position of Boiler House—Construction of Flues, 36
Area and Dimensions of Chimney, . . . 4 I
Arrangements for Smoke Prevention, ... 42
Systems of Tubing, * * * tº is wº tº e ºs * * * tº tº tº tº a g º º ºf © 2 & ... .45
Dry Steam—Use of the Separator–Plans for taking Low-pressure Steam from .
High-pressure Boiler, is & e * e # & e ſº tº º º tº º q tº $ tº tº ſº tº ... 46
Deterioration of Land Boilers—Experiments on, by testing them to destruction, 48
BOILERS FOR MARINE PURPOSES: , *
Flue and Tubular Boilers for Dredgers—Multitubular and Double Boilers—Over-
head Flues—Boilers for Royal Navy—Arrangement of Furnaces—High-pres-,
sure Boilers—Boiler for Torpedo Boats—The Haystack Boiler, ... 51
Proportions for Marine Boilers—Fire Grate and Heating Surface for indicated
Horse-power--Staying—Fire Bars—Tube Area—Furnaces, &c.—Thickness
of Plates—Strength zersus Weight of Boiler—Funnel, Damper, &c.—Recent
Improvements—Boilers of the Steam Ship Parisian–Plates for Coal Boxes, 62
Prevention of Priming, ... 78
TREATMENT OF STEAM FROM THE BOILER TO THE CYLINDER. Forms of Super-
heater—Covering of Steam Pipes, 79
MANUFACTURE OF BoII.ERs. Preparation and Fitting of the Plates—Punching
and Drilling Machines—Plate and Tube Stays—Report of the National Boiler
Insurance Co.—Safety Valves and Pressure Gauges—Setting of Boilers—
Cleaning—Use of Steel Plates, 85
CONTENTS. 777,
Page
REGULATION OF STEAM BY THE SLIDE WALVE, as applied to Land, Locomotive,
and Marine Engines:
Form of older Valve without Lap—Valve with Lap—Proportioning the Slide
Valve—Lead—Back Pressure—Position of the Valve—Means of imparting
Reciprocating Motion—The Eccentric and Cam Arrangements—Link Motion
applied to the Land and to the Locomotive Engine–Slide Valves for various
forms of Engine—Starting Gear—Expansion Valve and Gear, - * * tº gº &
Geometry of the Steam Engine—Connecting Rod and Crank—Crank and Eccen-
tric Paths—Crank and Eccentric Paths delineated as regards the Cover, Lead,
and Cut-off—Double Eccentrics and Link Motion—Lap of the Valve varies
as the Cut-off and Length of Connecting Rod—Opening of Port by Valve
—Setting out the Valve Faces, ... tº e g * G - * - e. e ºf 4- - - - tº ºr e
Relieving the Cylinder from Internal Pressure—Relieving the Slide Valve from
Back Pressure, & d - s' s g º 4 tº * - e. º ºg s * c º tº gº tº & © - ... 126
THE INDICATOR DIAGRAM. M'Naught's Indicator—Diagram from Eccentric
Valve Motion—Diagram from Corliss’ Valve Gear—Examples of Compound
Engine Diagrams—Theoretical Diagram—Mechanism for actuating the Roller
of Indicator, * * * tº º º © tº e tº e e º º ºs º e e º tº dº - - - ... I3O
THE EXPANSION OF STEAM:
Tables of Hyperbolic Logarithms, ... tº º tº tº º tº & sº tº tº gº tº - - - * * *
Properties of Steam and other Gases—Constituent Heat of Saturated Steam—
Relations of Pressure, Volume, Temperature, and Weight—Motion of Steam—
Velocities of Saturated Steam—Differences of Pressure in the Boiler and
Cylinder—Friction of a Fluid through a Pipe, .. - - - * * * - * > ... I43
Table of Properties of Saturated Steam at different Pressures, ... • * * ... I47
94
117
I4 I
STATIONARY ENGINES.
PUMPING ENGINES FOR MINES:
Details of the Cornish Engine—Details of the Pumping Gear—Valve Gear—The
Cataract—Condenser and Air Pump-The Ejector Condenser, - - - ... I 50
Horizontal, Overhead-beam, Side-lever, and Direct-acting Pumping Engine, ... 180
Pumping Gear for Direct-acting Engine—Examples of Pit Work, • e e ... I 92
Direct-action Compound Pumping Engine, ... * * * º º & * * * & a e ... 198
PUMPING ENGINES FOR WATER WORKS:
Single-acting Engine with Stand-pipe Tower—Engines at Wolverhampton Water
Works—Valve Regulator a substitute for Stand Pipe—Arrangement of the
Pump Valves—Gutta-percha Ball Valves on Metal Seatings—Berwick-on-
Tweed Water Works—Arrangement of Tanks, Engine and Boiler Houses—
Cost of raising Water, ... - - - * a º * - - tº º º g & Cº. - - - ... 202
Stand Pipes and Towers—Air Vessels—Stop, Relief, and Pressure Valves, ... 221
PUMPING ENGINES FOR DRAINAGE WORKS AND GENERAL PURPOSES :
The London Drainage System—Pumping Engines at Abbey Mills, Deptford,
and Crossness—Arrangement of the Pumps—Discharge of the Sewage into
Reservoir—Construction of the Pumping Station at Crossness, © 4 + ... 226
High-pressure Geared Pumping Engines for emptying Docks, &c., • * * ... 235
The Centrifugal Pump-Gwynne & Co.'s Machinery—The Pulsometer, ... 236
WINDING ENGINES. Details of Construction, tº º q * * * • & e • * * ... 239
Biowing ENGINEs :
Overhead-beam Blowing Engine—Details of Construction—Examples of Blowing
Engines erected at Dowlais Iron Works, & Q - & © º • * * • * * ... 250
778 CONTENTS.
Page
Side-lever Combined Blowing Engines, ... © tº e • * * © e ºl * c tº ... 274
Vertical Blowing Engines—Vertical Table Engine, • * * tº g e * - G ... 277
Horizontal High-pressure Blowing Engines, tº a tº • e s * * * • * * ... 280
ROLLING-MILL ENGINEs. Examples at Dowlais Iron Works—Arrangement of
Rolls for working in two directions, tº e tº a s e tº tº e e - e. ... 285
COMPOUND REVERSING RAIL-MILL ENGINEs. Examples at Hallside Steel Works,
near Glasgow, tº a º • * * tº e º * * * tº e ºs * * * * * * tº º º ... 291
THE CORLISs ENGINE. Characteristic Features of this Engine—Diagrams from
Beam Condensing Corliss Engine, tº - tº tº a s a tº a e is tº tº tº º ... 295
HIGH AND Low PRESSURE COMBINED BEAM ENGINE, ... • q tº e - e. ... 299
RULES FOR PUMPING ENGINEs. Horse-power—Pumping of Water out of Docks—
Area of Cylinder—Valves—Duty of an Engine—To overcome Friction of
Water through Pipes—Delivery of Water in Pipes—Thickness of Pipes for
conveying Water—Standard Pipes for Water Supply—Weight of Cast-iron
Pipes–Pipes for Pit Pumps—Horse-power of an Engine—Diameter of
Cylinder and Length of Stroke—Speed of Piston—Opening of Port by Valve, 301
RULES FOR THE BEAM ENGINE. The Beam—Wrought-iron Tubular Beams—
Air Pump and Condenser—Cold-water Pump and Injection Water—Feed
Pump—Piston and Connecting Rods—Cranks and Crank Shaft—Fly Wheel
—Governor—Formulae for Safety-valve Levers, * - tº e ... 3 IO
WATER-PRESSURE ENGINEs. Early Hydraulic Cranes—Hastie's Variable Water-
power Engine, 3I4
The Accumulator, e sº º - - - tº e e * * * tº e tº 3I5
Pumping Engine for charging the Accumulator, ... • * * tº º º e º º 316
Water Wheels: Undershot, Overshot, and Breast—The Turbine, * @ & ... 317
The Hydraulic Crane—General Arrangement of Machinery—Details of Valves, 318
Water-pressure Cylinder for opening and closing Dock Gates, ... tº e e ... 322
Water-pressure Engines for working Dock Gates, Swing Bridges, &c., ... ... 325
Water Power from Natural Falls—Engines at Lead Mines in Northumberland
and at Portland Harbour, ..., 327
Hydraulic Machinery for Warehousing Grain at the Liverpool Docks—Plan of
Warehouse—Throwing-off Apparatus—Distributing Fan—Hoisting Gear, ... 329
HYDRAULIC MACHINE Tools—for Rivetting, Punching, Flanging, Bending or
Straightening—Hydraulic Machines at Arsenal, Toulon, ... tº º º ... 345
MARINE ENGINES.
THE OSCILLATING ENGINE :
Details of Construction, - - - tº º º © º º * tº tº ſº tº ºr º ºg - 347
Details of Slide-valve Gear—Starting Gear, tº we tº • * * * tº º • e º ... 365
The Link Motion, • * * * * * • * * * * * * * * * - - tº e tº ... , 374
Specific Examples of Marine Engines–Steamers with Oscillating Engines—The
Steeple Engine—Side-lever Engine—Penn's Trunk Engine—Diagonal Direct-
acting Engine—Details of the Engine and Hull of the Comet, * @ & ... 377
The Paddle Wheel—Constructive Details—Disconnecting the Paddle Wheel—
Experiments with Ruthven's Hydraulic Propeller–Professor Rankine's Rule
for the Thrust of a Propeller, ... * * * * - - tº e º & © e * * * ... 378
HORIZONTAL DIRECT-ACTING AND RETURN CONNECTING-ROD ENGINES :
Details of Construction—Cylinder—Valves—Link Motion, &c.,.... tº ºn tº ... 385
CONTENTS, 779
Page
Piston for Horizontal Marine Engines—Mr. Howden on Packing and Friction—
Mr. Rowan's form of Piston—Piston Rod—Crosshead and Guides—Con-
necting Rod–Cranked Shaft—Built Crank Shaft—Main Framing—Condenser
and Air Pumps, ... ſº tº 4. 4 tº º tº sº tº © & & * < * tº e & * * * 399
Arrangements for Direct-acting Single Piston-rod and Double Trunk Engines, ... 423
Surface System of Condensation—Construction and Arrangement of Surface Con-
densers—Making and Fitting of the Tubes—Arrangement of the Refrigerating
Surface—Pumps—Valves, º * * * tº gº º tº gº & * * * tº gº º ... 424
Hand Gear—Lubricators—Turning Gear, ... & ſº tº ſº ſº º * Hºº & * * * ... 450
Boiler Fittings—Valves–Steam Pipes—Separator—Lagging—Gauge Glass—
Scum Taps—Steam Whistles, ... * * * e s is $ tº tº tº us & tº g ºn tº sº tº
Safety-valve Openings—Experiments and Formulae—Loading of Safety Valves
by Direct Springs—Conclusions of Investigation Committee on Safety Valves, 462
THE SCREW PROPELLER:
Shafting for the Propeller—Repairing Couplings—Pillow Blocks—Stern Tube—
454
Hollow Propeller Steel Shafts, ... tº it tº tº º º tº º G * @ e ... 47 I
Construction and Forms of the Propeller—Number and Configuration of the
Blades—Plan for lowering the Propeller below the Keel, ... tº ſº . ... 477
Raising the Screw Propeller and Shaft, ... * * * * * † e & ſº e gº tº ſº ... 488
THE COMPOUND ENGINE :
General Adoption of the Compound Arrangement—Professor Rankine's Defin-
ition of a Compound Engine, ... * & wº * † e º º & tº º º & a ſº ... 49 I
Arrangement of Cylinders, ... g º º * * * tº € $ tº tº & * * * tº $ tº . . . 494
Engines of the Parisian, &c., ... & © tº tº º ſº tº º is e e º * & & e tº º ... 496
Engines of the Screw Steamer ſtata,... te tº gº º * * * tº gº ºf 498
Details of the Machinery of the Servia, Itata, and Sir Bevis, ... & ... 5OO
Engines of the Arizona, tº tº gº s sº a e tº $. ſº ºf we $ 8 tº & © tº 505
Governors for Marine Engines—Dunlop's Pneumatic Governor, ... * * g. ... 505
Three-cylinder Compound Steeple Engine for the Paddle Wheel, tº tº º ... 506
Table of Average Consumption of Coal, per indicated Horse-power per hour, by
Compound Engines on long Sea Voyages, * tº * * & © & e º * * * ... 508
RULES FOR THE HORIZONTAL DIRECT-ACTION MARINE ENGINE, &c. Nominal
Horse-power—Proportion of Power to Tonnage—Rule for Tonnage—Per-
formance of Screw Vessels—Diameter of Cylinder—Stroke of Piston—Valves
—Eccentrics and Link Motion—Connecting Rod—Main Cranked Shaft—
Crosshead and Guides—Main Frame—Piston—Air Pump and Condenser—
Surface Condensation—Feed Pump-Screw Propeller—Proportions of Grif.
fith's Screw Propeller—Screw Aperture and Shafting—Hand and Turning
Gear—Safety Valve and Waste-steam Pipe—Copper Steam Pipes—Number
and Diameter of Kingston Valves and Blow-off and Injection Cocks—Flanges
for Copper Pipes, ... e tº º * * * ... * * * * * g * * * * * * ... SIO
LOCOMOTIVE ENGINES.
CoMBUSTION IN THE LOCOMOTIVE. The Steam Blast—Its Mechanical Action—
Steam Jets–Arrangement of the Fire Box—Utilization of Smoke and Gases, 531
THE BRITISH LOCOMOTIVE:
Construction of the Boiler and Boiler Mountings—Fire Box—Stays–Dampers, 547
Shell of the Boiler–Steam Chest and Dome—Tubes—Smoke Box—Chimney—
Ash Pan—Fire Bars—Steam Pipes—Blast Pipe, tº 8 tº tº ſº e * * * ... 554
78o CONTENTS. *
Safety Valves—Gauges—Whistles—Taps—Hand Rail—Stud for Lamp, - * * º;
Construction of the Engine—Cylinders—Valves—Link Motion, - * * ... 578
Piston—Piston Rod, Crosshead, and Motion Bars—Connecting and Coupling
Rods—Cranked Axle—Axles and Wheels—Outside Cranks, * * * ... 596
Framing and Axle Boxes—Springs and Harness—Compensating Levers, ... 626
Bogie Carriage—Buffers, Couplings, Rail Guards, Sand Boxes—Foot Plates and
Steps—Splashers, ... º r * * * • * * * * . 644
Feed Pumps and Feed-water Apparatus—Connection Pipe between Engine and
Tender—Auxiliary Feed Pump—Injector, * ~ * - * * • ‘w e . * *e e ... 651
THE AMERICAN LocoMotive:
Constructive Details of Boiler, Fire Box, Tubes, Smoke Box, Chimney, Steam
Pipe, Safety Valves, Gauges, Whistle, Bell, Sand Box, ... © -e ºs ... 663
Cylinder and Slide Valve—Valve Motion, ... - - - • * * •º e e --- ... 67 I
Piston—Piston Rod, Crosshead, and Motion Bars—Connecting and Coupling
Rods—Wheels and Axles and Crank Pins, ... • * * * * * • * * ... 675
Framing and Axle Boxes—Bogie Frame—Cowcatcher—Cab–Springs, ... 679
Feed Pumps—Hose between Engine and Tender, ... • * * * * * • * * ... 683
THE LOCOMOTIVE TENDER:
Construction of the British Tender—Brake Gear—Couplings with Engine—Water
Tanks and Feed Pipes, ... . ... - - - & a 9 tº tº e • *e “e * * * ... 684
Construction of the American Tender • * > - - - tº º e • * -º * * * ... 688
CONTINUGUS BRAKES :
Requirements of the Board of Trade—Varieties of Continuous Brake—Westing-
house Automatic Brake—Vacuum Automatic Brake, ... ... • * * ... 689
Brake Resistances, ... - - - * * * • * * - - - • * * - © tº ... 692
CoMPound LocoMotive ENGINEs. M. Malet's System—Mr. Webb's new Com-
pound Locomotive, * * * • * * - -- e. - - - • - e. © º º º, º e ... 693
DESCRIPTION OF SPECIAL LOCOMOTIVE ENGINES:
Four-wheel Coupled Bogie Passenger Engine for the Caledonian Railway, ... 698
Express Engine for Great Northern Railway, * ~ * © tº º º e g 7oo
Passenger Engine for London and North-Western Railway, • ‘º º • * * ... 7O3
Four-coupled Bogie Passenger Tank Engine on North British Railway, ... 705
Passenger Engines for Great Southern and Western Railway of Ireland, ... 7 IO
Goods Engine for Great Southern and Western Railway of Ireland, ... ... 712
Goods Engine on Bombay, Baroda, and Central India Railway, * * * ... 715
Furness Railway Tank Engine, tº e - * - - 717
Narrow-gauge Engines for Steep Inclines—Festiniog Railway–Righi Railway
in Switzerland–Vesuvius Railway—Railroad in Canada,
... ... 72O
Engines for Narrow-gauge Mineral Lines having Steep Gradients—Small Engines
coupled together—Details of small Tank Engines, ... © e e • * * ... 721
Express Engine for the Pennsylvania Railroad, ... - - - • * * • e º ... 727
Haulage Power of Locomotives, tº º tº - - - & - tº * * * * * * e tº º ... 727
SPECIFICATION FOR LOCOMOTIVE ENGINE AND TENDER for London, Chatham,
and Dover Railway: - -
Leading Dimensions—Quality of Materials—Boiler—Fire Box—Workmanship—
Tubes—Smoke Box—Chimney—Safety Valves, &c., ... • * * - * * ... 728
Frames—Buffers and Draw Gear—Cylinders–Pistons—Piston Rod and Cross-
head—Connecting and Coupling Rods—Valve Motion, 733
Bogie—Springs and Connections—Axles and Axle Boxes—Wheels—Tyres—Cab
and Splashers—Brake—Injectors—Boiler Mountings—Bolts and Nuts, ..., 737
CONTENTS. 781
Page
Tender for Engine—Tank—Frames—Buffers and Draw Gear—Springs—Axles
and Axle Boxes—Wheels and Tyres—Brake—Painting Engine and Tender, 742
RULES FOR THE LOCOMOTIVE ENGINE:
Effective Pressure of Steam in Cylinder—Tractive Power of Engines—Resistance
of Trains due to Gravity on an Incline—Resistance of Trains at different
Speeds—Load of Engine on a given Incline—Adhesive Power of Locomotives
—Distribution of Load—To find Centre of Gravity horizontally—Loads on
the Axles, ... . . . . . tº sº 4 & © & ſº tº º s & gº *º ºr º * * * ... 746
Tables of the Diameter of Cylinders, Stroke of Piston, Diameter of Wheels, and
Wheel Base—Tables of Weight of six-wheeled Engines, tº gº º s 750
Diameter of Cylinder—Length of Steam and Exhaust Ports—Thickness of
Cylinder—Area of Piston Rod and Depth of Piston—Area of Slide-valve Rod
—Maximum Speed of Piston—-Ratio of Diameter of Cylinder to Stroke of
Piston–Ratio of Stroke of Piston to Diameter of Driving Wheels—Water
and Steam required for a given Speed per hour, & º º & & & © & s º ºg 4°
The Boiler—Area of Fire Grate—Heating Surface—Strength of Boiler—Working
Steam Pressure—Screwed Stays—Pitch of Stays in Fire Box—Pressure on
Roof Stays—Weight and Stowage of Fuel—Area for Safety Valves—Diameter
of Feed Pump-Giffard Injector, g & ſº tº º º * * * tº º tº gº º is ... 754
Area of Axles and Boxes—Dimensions of Wheels—Dimensions of Springs and
Harness—Dimensions of Framing—Area of Crosshead, Motion Bars, &c.—
Area of Connecting Rod—Outside Cranks and Side Rods, ... ſº º e ... 758
752
Road. LocoMotive or TRACTION ENGINE. Thomson's India-rubber Tyres—
Mr. Crompton on improved Road Haulage—Dimensions of his Engines, ... 762
PortABLE ENGINEs. Description of Engine by the Reading Ironworks Co., ... 764
STEAM ROAD ROLLER. Description of Road Roller by Aveling and Porter, ... 765
THE CITY OF NEW YORK AND HER TRIPLE ExPANSION ENGINEs, ... ... 766
HÚLLS AND ENGINES OF THE LATEST GREAT OCEAN STEAMERs, gº gº tº ... 770
EvapoRATOR FOR TRIPLE CoMPOUND ENGINES, gº tº ſº tº e is tº ſº º © ºn tº ... 77;
ENGINE DRIVERs; Their Responsible Duties and their Training for Them, ... 772
LIST OF PLATES.
WINDING MACHINERY.—WINDING ENGINES, witH Double
ECCENTRICS, LINK MOTION, AND TAPPET VALVE GEAR.
Erected in 1881 by Messrs. Gibb and Hogg, Airdrie, for the
Benhar Coal Company e e e º
ROLLING MILL MACHINERY.—COMPOUND REVERSING ROLL-
ING MILL ENGINES, Steel Company of Scotland's Works at
Hallside, near Glasgow. Constructed by Messrs. Miller &
Co., Coatbridge . © º * º ©
HYDRAULIC MACHINE TOOLS.—HYDRAULIC MACHINES FOR
RIVETTING AND FLANGING PLATES, RIVETTING KEELS, AND
ANGLE IRON OR BEAM STRAITENER OR BENDER. Designed by
Mr. R. H. Tweddell, London e * tº e º
MARINE ENGINE.—THREE-CYLINDER COMPOUND INVERTED EN-
GINES OF STEAMSHIP “PARISIAN.” Constructed by Messrs.
Robert Napier and Sons, Glasgow
MARINE ENGINE.—THREE-CYLINDER COMPOUND DIRECT-ACTING
ENGINES OF STEAMSHIPS “ UMBRIA ’’ AND “ETRURIA.” Con-
structed by Messrs. James and George Thomson, Glasgow
AMERICAN PASSENGER FAST LOCOMOTIVE.-SIDE ELE-
VATION AND SECTION (1882) te ë &
AMERICAN PASSENGER FAST LOCOMOTIVE.—HALF ELE-
VATION AND SECTION (1882) * ſº e e cº º
PASSENGER LOCOMOTIVE.—SIDE ELEVATION AND SECTION.
Built by the Baldwin Locomotive Works, 1888 *
PASSENGER LOCOMOTIVE.—HALF ELEVATION AND SECTION.
Built by the Baldwin Locomotive Works, 1888 -
AMERICAN LOCOMOTIVES e e
BRAKES AND REGISTERING APPARATUS
LOCOMOTIVE ENGINE. –VERTICAL AND HORIZONTAL SECTIONS
OF BOGIE PASSENGER ENGINE. Built for the Caledonia Rail-
way by Messrs. Neilson and Co., Glasgow . º º
LOCOMOTIVE ENGINE.—TRANSVERSE SECTIONS OF BOGIE PAS-
SENGER ENGINE. Built for the Caledonia Railway by Messrs.
Neilson and Co., Glasgow . e & ſº e e e
NARROW GAUGE LOCOMOTIVES * tº * >
IPORTABLE ENGINE. –VERTICAL AND TRANSVERSE SECTIONS OF
EIGHT HORSE-Power PortABLE ENGINE. Constructed by the
Reading Iron Works, Limited & e e
TRIPLE EXPANSION MARINE ENGINE OF STEAMSHIP “CITY
of New York.” Constructed by Messrs. James and G. Thom-
son, Glasgow se *
(782)
. 68o
PAGE
25o
291
345
496
5oo
664
664
673
673
689
698
698
764
768
- LIST OF THE PRINCIPAL TABLES
IN THIS VVORK.
PAGE
BoILERs, Working and Bursting Pressures of º o © . 28
& & Proportionate Strength of Cylindrical . ſº o . 25
COAL, Average Consumption of, per indicated Horse-power per hour 508
COPPER PIPEs, Flanges for • º to s º º • 529
DISPLACEMENT of a River Steamer ſº e º º º . 853
GRIFFITH's SCREw PROPELLER, Proportions of . * © . 526
HoRSE Power AND DIMENSIONs of the different Modern Ocean
Steamships e * to o º • e e . 779
HYPERBOLIC LogARITHMS . * º tº º • I 4 I
IRON, Weight of a Lineal Foot of Square and Round Bar . • 34
LOCOMOTIVE ENGINEs, Diameter of Cylinder, Stroke of Piston, etc. 750
& & é & Dimensions of Small Tank Narrow-gauge . 724
4 & “ Haulage Power of, at speed of 20 miles an
hour * > • se & e . 728
6 & & & Heating Surface in . e te e . 755
& & & & Performances of te e • 7II, 7I 2, 7 I4
& & & & Weight of, of various classes . º . 75 I
& 4 SPRINGs, Deflections of, under given Loads * . 637
PIPES FOR WATER SUPPLY, Proportions of Socket for Standard • 307
PLATEs, Mean Strength of, in direction of and across fibre . • 32
4 & Tensile Strength of Single and Double Rivetted º • 33
& 4 Weight of a Square Foot of Wrought Iron, from sº to 1
inch thick . © ve O & º e • 33
RiveTTED Joints, Strongest Form and Proportion of . tº • 3 I
SATURATED STEAM, Properties of, at different Pressures e . I 47
TUBEs, Surface and Weight of Iron, Brass and Copper 34
683)
I N D E X
FOR PRACTICAL WORKERS ON BOILERS AND STATIONARY, MARINE
AND LOCOMOTIVE ENGINES.
Abbey Mills Pumping Station, 226, 98o.
Accumulator, the, 202, 315, 329.
— pumping engine for charging the, 316.
Adhesive power of locomotives, 748.
Adit in mines, 193.
After-damp in mines, 4.
Air cylinder of blowing engines, 256, 273, 279, 282.
Air pump of Cornish engine, 173.
— — of oscillating engine, 35o.
— — for condensers, 435.
— — rod crosshead, 360.
— — and condenser, rules for, 3ro.
— — of marine engine, rules for, 523.
— — bucket head and foot valves, 351.
Air vessel for water works, 211, 225.
Alaska, details of the, 415,494, 497, 770.
Allenheads, water engines at, 327.
Arzerica, details of, 770.
Aller, details of, 770.
American locomotive, the, 663. .
Angle iron, weight of, 33.
Angle irons, hydraulic machine for bending, 346.
Annular safety valve for locomotive, 568.
— water spaces in boilers, 15.
Aperture for screw propeller, rule for, 526.
Arbors in pumping engines, 163.
Area of locomotive piston rod, to find the, 753.
— — slide-valve rod, to find the, 753.
— of the water lines, to find the, 856.
Arizofa, details of the, 415, 505, 779.
Ash pan for locomotive fire box, 553, 559.
— — specification for locomotive, 732.
— — of American locomotive, 668.
Ash pits in marine boilers, 75.
Atmospheric line, 132.
Aurania, details of, 770.
Auxiliary fire box for locomotive, 537.
Available heat in coal, 64.
Axle of locomotive, 62o, 678.
—- – specification for, 739, 744.
— — rules for, 758. -
— of American locomotive, 678.
Axle box of locomotive, 626.
— — — specification for, 738, 744.
— — — rules for, 758.
— — of American locomotive, 679.
(784)
B
Back pressure, relieving the slide valve from, 127.
Balance bobs on pump rods, 198.
Ball safety valve for locomotive, 569.
– valves on metal seatings, 214.
Bar iron, weight of, 34.
Bars in locomotive fire box, 533, 539, 549.
Beam of engine, rules for the, 310. * .
Beam engine, single-acting, 151, 162.
— — high and low pressure combined, 299.
Bed plate of winding engine, 246.
— — for trunnion blocks, 354.
Bell cranks for pumping engines, 200.
Pells for American locomotive, 670, 682,
Bilge injection valve, 444.
“Black damp ’’ in mines, 4.
Blades for the screw propeller, 48o.
Blast orifice, form of the, 532,566.
— pipe of lècomotive, 532.
— — — construction of the, 566.
— — — specification for the, 733.
— nozzle in American locomotive, 668.
Blowing mills at Dowlais Iron Works, 288.
Blowing engines, 25o.
— — horizontal high-pressure, 28o.
— — self-contained, 279.
— — side-lever combined, 274.
— — vertical, 277.
— — vertical table, 279.
Blow-off plug tap for locomotive, 577.
— — valves for American locomotive, 671.
— valves for water mains, 203.
Blow-through condenser, 183.
— valve for oscillating engine, 361.
––for horizontal marine engine, 395.
Bogie carriage for locomotive, 644.
— — specification for, 737.
— — for American locomotive, 681.
Boiler Insurance Co., report of, 89.
— of the locomotive, 547.
— — specification for, 729.
— — — for mountings of, 741.
— — rules for strength of, 755.
Boiler plates, riveting of, 19.
— — strength of, 19, 30.
INDEX.
785.
Boilers, distinctive forms of, 1o.
– economy in weight of, 72.
Boilers, manufacture of, 85.
— strength of cylindrical, 20.
— for blowing engine, 274.
- for marine purposes, 51.
— for river boats, 61.
— for stationary engines, Io.
— for torpedo boats, 62, 72.
— for war ships, 56.
Bollard heads, 819.
Bolts for locomotive engine, 742.
Boring for coal, 2. - t
— keelson, 798.
Brackets for locomotive boiler, 562.
Brake gear for locomotive tender, 685.
* resistances, experiments on, 692.
- specification for locomotive, 741, 745.
Brakes, continuous, 689.
— for winding engines, 248.
Branch steam pipe, 457.
Arandon, compound engines of the, 491.
Breast wheel, 317.
British locomotive, the, 547.
Bronze for propeller blades, 486.
Bucket for pumping engine, 16o.
Buffers, locomotive, 646.
— — and drawgear, specification for, 734, 743.
Buildings for pumping engines, 228.
Bulkheads, construction of, 812, 876, 971.
“Bull's-head” in pumping machinery, I97.
Bursting pressure of boilers, 28.
Butterly boiler, the, 43.
C
Cab, specification for locomotive, 740.
— of American locomotive, 682.
Casings of locomotive engine, 741.
Cataract of pumping engine, 170.
Catch for eccentric on shaft, 369.
Centrifugal pumps, 236.
Charlotte Duma'as, the first steamer, 378.
Check valves for marine boilers, 459.
Chests for cylinder of blowing engine, 257.
Chimney, area and dimensions of, 41.
Chimney of locomotive, 558.
Chimney of locomotive, specification for, 732.
— of American locomotive, 667.
Choke damp in mines, 4. -
Circular regulator for locomotive steam pipe, 563.
Circulating pumps for condensers, 432.
City of New Pork, details of, 766.
City of Rome, details of 73, 345, 415, 432,497,770.
Clack valve with leather hinge, 159.
Cleaning of boilers, 93.
Clothing steam pipes, 458.
Clyde river steamers, engines of, 378.
Coal and coal mining, 1.
— consumption and cost of, 220.
A
Coal, machines for cutting, 8.
— machines for raising, 8.
Coal-burning fire box of locomotive, 534, 537.
— American locomotive, 663.
Coal boxes, thickness of plates for, 78. *
Coals used in American engines, 666.
Cocks for marine engines, table of, 528.
Coefficient for steam ships, 513.
— of steam ship Cadiz, 512.
Coke, uses of, 1. -
Cold-water pump, 181.
— — rules for, 311.
— — of blowing engine, 267.
Columéa, engines of the Clyde steamer, 377.
Combustion chamber in locomotive fire box, 534.
Coulet, details of the steamer, 378.
Compartments for water ballast, 831.
Compensating levers for locomotive springs, 642. '
Compound engine, the, 491.
— — diagrams, 134.
— beam engines, 492.
Compounding locomotive engines, 693.
Condensation, surface system of, 424.
Condenser of Cornish engine, 173.
— for a pair of oupled engines, 180.
— with self-adjusting jet of steam, 179.
— for horizontal marine engines, 419.
— for oscillating engine, 349.
— of marine engines, rule for, 524.
Connecting rod and crank, 117.
— — of blowing engines, 263,273.
— — of winding engine, 245.
-— for horizontal marine engines, 4xo.
— — rules for, 311. -
— — of marine engines, rule for, 521.
Connecting rods of locomotive, 608.
— — — for outside cylinders, 614.
— — — rules for the, 761.
— — — specification for the, 736.
— — of American locomotive, 676.
Connections between engine and tender, 646, 659,
68o, 684, 687.
Conning tower in war ships, 912.
Constance, compound engines of the, 492.
Constant pressure, 143.
— temperature, 143.
— volume or density, 144.
Consumption of coal, table of, 508.
Copper steam pipes for marine engines, 528.
Corliss engine, the, 295.
— — diagrams from beam condensing, 298.
Cornish boiler with single furnace, Io.
– and multitubular boiler, 11.
— engine for mines, 150.
– valve gear, 164.
Corrosion in boilers, 71.
Coupled locomotive engines of small size, 723.
Coupling rods of locomotive, 616.
— — — specification for, 736.
— — of American locomotive, 677.
Coupling between engine and tender, 646, 687.
50'
786
INDEX.
Couplings of screw shafts, repairing, 472.
Covering for boilers at Tettenhall, 204.
— of marine boilers, 458. *,
— of locomotive boiler, 562.
Cowcatcher in American locomotive, 681.
Cradle hoists, hydraulic, 344.
Crane, hydraulic, 318.
Cranked shaft for air pump, 353.
— — for horizontal marine engines, 413.
Crank and eccentric paths, 118.
Crank pin, rules for, 312. "
Crank shaft and crank of blowing engines, 262,272.
Crank shaft, rules for, 312.
Crank shafts, built, 414.
Cranked axle for locomotives, 618. ,
Cranks and side rods of locomotive, rules for, 761.
Crank pins of American locomotive, 679.
Creuzot Iron Works, blowing engine at, 277.
Crompton's traction engine, details of, 763.
Crosshead of Cornish engine, 151.
— for rod of winding engine, 245.
— — of oscillating engine, 359.
— for single piston rod, 409.
— and guides of marine, engine, rules for, 522.
Crossheads for blowing engine, 265.
Crosshead for piston rod of locomotive, 603.
— — — — rules for the, 760.
— — — — specification for the, 735.
— of American locomotive, 675.
Crossness Reservoir and Pumping Station, 23o.
Currents in locom. fire box, steam-inducted, 544.
Curtain plate for locomotive fire box, 535.
Cut-off of steam, 117
Cylinder of Cornish engine, 151, 492.
— of horizontal marine engine, 385.
— of oscillating engine, 347.
— of winding engine, 241.
— area of, and length of stroke, 304,309.
— of marine engine, rules, for, 516, 527.
— cover for blowing engine, 256.
— — of horizontal marine engine, 387.
Cylinders of hydraulic crane, 318.
— arrangement of high and low pressure, 494.
Cylinder of locom. engine, construction of, 578.
— — — — to find dimensions of the, 752, 753.
— — — specifications for the, 734.
— oS American locomotive,.671.
Cylindrical boiler, different kinds of the, 1o.
— — strength of, zo. -
r D .
Deptford Pumping Station, 229. . .
Depth of locomotive piston, to find the, 753.
Despatch boats, boiler for, tº.
Diagrams in steam cylinder, 130.
— of compound engines, 134.
— from engines of the Parisian, 497. .
Diaphragm in locomotive fire box, 539, 542.
Direct-acting horizontal engine for winding, 240.
— pumping engine, 189.
Discharge valve for condenser, 441.
Disconnecting paddle-wheel shaft, 383.
Distance pipe for air chests, 257.
Distributing fan for grain, 338.
, Distribution of load on locomotive, 749.
Dock gates, opening and closing of, 322.
Docks, hydraulic machinery at, 329.
Dome for locomotive, 573.
Dome vertical boiler, 13.
Double-acting pumping-engine, 198.
Double-beat valve, 158, 203, 213.
— — regulator for locomotive steam-pipe, 564.
Double eccentrics and link motion, 121.
— furnace boiler, 11.
— marine boilers, 53, 59.
Dowlais Iron Works, blowing engines at, 269.
— — — rolling mill engines at, 285. .
Drainage works, pumping engines for, 226. x
Draining of mines, 3.
Draughts, economy of forced, 73.
Dredger, boilers for a, 51.
Drilling and punching of plates, 71.
Drum for winding engines, 239, 248.
Dry steam, 46. -
D slide valves for marine engines, Ioë.
Dunlop’s prleumatic marine governor, 506.
A
Duty of an engine, to find the, 305.
Dyke in mining, 2.
E-
Engine drivers, their duties and training for them,
772. -
Eccentric for slide valve, 98.
— and rod for blowing engine, 255.
— of horizontal marine engine, 393.
— of oscillating engine, 367.
— gear of marine engine, rules for, 519.
Eccentrics of locomotive, 587.
Efficiency of paddle vessels, calculation of, 515.
Ejector, condenser for pumping engine, 176.
Elba, details of, 770.
Electric lighting, 41.
Elevator for raising grain, 342.
Elliptical fire box for locomotive, 542.
Jºmts, details of, 770.
Engine, duty of an, 305.
Engines for water works, 204.
Entablature of blowing engine, 260.
Equilibrium valve for reducing pressure, 47.
— — for pumping engine, 162.
Escape valve for horizontal marine engine, 396.
Etruria, details of, 770.
Evaporator for triple compound engines, 771.
Exhaust pipe of horizontal marine engine, 389.
Expansion in boilers, 70.
— of gases, 143.
— of steam, 141–149.
— valve for oscillating engine, 364. .
Explosion of boilers, 27.
index. 787
-
Express engine for Great Northern Railway, 7oo.
— — for Pennsylvania Railroad, 727.
F
Factors of safety, 69.
Fairy Queen, engine of the, 377.
Fan for spreading grain in warehouses, 337.
Fans, variety of ventilating, 6.
“Fault” in mining, 2.
Feathering paddle wheel, 378.
— propellers, 481.
Feed pump of overhead-beam blowing engine, 268.
— — of Cornish engine, 182.
— — of winding engine, 247.
— — rules for the, 311.
— — for marine engine, 445.
— — — — rules for the, 525.
Feed and bilge pumps, 353.
Yeed-water heaters, 76,249.
— — for locomotives, 662.
Feed pumps of locomotive, 651.
— — — rules for the, 758.
— — of American locomotive, 683.
Fell’s system for steep railway inclines, 720.
Festiniog Railway, Wales, details of, 720.
Fire bars of marine boilers, 67.
— — of locomotive, 560.
— —of American locomotive, 668.
Fire box, flat, 88.
— — of locomotive, 533, 547.
— — — specification for the, 73o.
— — of American locomotive, 663.
— — stays in locomotive, 548.
— — — — rules for the, 757.
Fire-brick arch in locomotive fire box, 54r.
Fire damp in mines, 4.
— grate for marine boiler, 63.
— — of locomotive, to find area of, 754.
Firing, necessity for careful, 545.
Fittings of boilers, report on, 91.
— for marine boilers, 454.
Flanges for copper pipes, table of, 529.
Flanging plates, hydraulic machine for, 346.
— surfaces in boilers, 28.
Flexibility of locomotive springs, table of, 637.
Flue boiler, self-contained, 12.
Flues in boilers, 25.
Fluid, friction of a, 146.
Fly wheel of blowing engines, 263, 272.
— — rules for the, 312.
Foot plates for locomotives, 650.
Foot and head valves for air pump, 437.
Forcing set of pumps, 154.
Foundations for boilers, 36.
Framing of locomotive, 626.
— — rules for the, 760.
— — specification for the, 733. 743.
— of American locomotive, 679.
Friction of a fluid through a pipe, 146.
— of water through pipes, 305.
Fuel, economy of, 182.
Funnel, construction and dimensions of, 73, 74.
Furnaces in marine boilers, 68, 75. -
G
Galton, Capt. D., on brake resistances, 692.
Gas in coal workings, 4. -
Gases, expansion of, 143.
Gauge glass for marine boilers, 460.
Geared engine for pumping, 201.
Giffard injector for locomotive, 758.
Gland for piston rod of oscillating engine, 349.
Goods engine for East Indian Railway, 715.
— — for Furness Railway, 717. • .
— — for Great South. & West. Ry. of Ireland, 712.
Governor, rules for the, 313.
Governors to prevent “racing,” 5os.
Grain, machinery for warehousing, 329.
Grease cups for locomotive cylinder, 584.
Great Eastern, details of the, 347, 377, 778.
Great Western, voyage of the, 377.
Gridiron expansion valve, 114.
— — — for horizontal marine engine, 394.
— injection valves, 443.
— regulator for locomotive steam pipe, 563.
Griffith's screw propeller, proportions of, 526.
Guard’s whistle for locomotive, 576.
Gudgeon for rod of winding engine, 245.
— pins, specification for locomotive, 735
Guibal fan for mines, 6.
Guides and crosshead for double piston rod, 407.
Gutta percha ball valves, 214.
Gwynne's centrifugal pump, 236.
H
Haarlem Lake, draining of the, 239.
Hallside Works, rail-mill engines at, 291, and
flate.
Hand gear for horizontal marine engines, 451.
— — for marine engines, rule for, 527.
— pump for horizontal marine engines, 448.
— rail for locomotive, 578, 741, 743.
— — for American locomotive, 671.
Harness for locomotive springs, 639, 759.
Hastie's variable water-power engine, 315.
Hatchways, framing of ships’, 815.
Haulage power of locomotives, 727.
Hawksley's formula for water pipes, 306.
Haystack boiler for river boats, 62.
Head light for American locomotive, 670.
– stock for crank shaft, 356.
Heat, expenditure of, 63.
Heating surface, relative value of, 36.
— — for marine boiler, 63.
— — in locomotive, to find the, 755.
— plug valves for locomotive, 577.
High boilers for royal navy, 56.
High-pressure beam engine, 251.
— — geared pumping engines, 235.
788.
INDEX.
High-pressure marine boilers, 58.
Hoists at landing stations, 327.
Hoisting gear for grain warehouse, 339.
Hopper for receiving grain, 338.
— barge, 93o. -
Horizontal high-pressure pumping engine, 200.
-- marine engines, 385.
Horn blocks, specification for locomotive, 738,744.
— plates for locomotives, 629.
Horse-power of land engines, to find the, 3or, 309.
— — of marine engines, to find the, 510.
Hydraulic crane, 318.
– machinery for warehousing grain, 329.
– machine tools, 345, and plate.-
Hyperbolic logarithms, table of, 141.
I --
Indicator diagram, the, 13o.
— — from Corliss valve gear, 133.
— — from eccentric valve motion, 132.
Injection pipes of marine engines, rules for, 524.
— valve for oscillating engine, 360.
— — for condenser, 443.
Injector for locomotives, 660, 741.
Internal pressure on cylinder, 126.
Itata, details of the screw steamer, 498, 5oo.
J
Jib of hydraulic cranes, 320. -
Jiggers for loading and unloading, 344.
Joy's valve gear for compound locomotive, 697.
K
Kingston valve, 361, 450, 528
L
Lagging for cylinder, 85, 161.
— for locomotive boiler, 562, 669, 741.
— for marine boiler, 458.
Lahn, details of, 770. "
Lamp iron for locomotive, 741, 743.
Land engines, 150-346.
— boilers, deterioration of, 48.
— — proportions for plain, 34.
Lap of the valve, 122.
Lead of the valve, 96.
Leven, engine of the, 378.
Lifting set of pumps, 153, 192.
Lighthouses, construction of, ro58.
Link motion, roo.
— — for horizontal marine engine, 393.
— — for oscillating engine, 374.
— — for locomotive, ro2, 587.
Links for parallel motion of blowing engine, 265.
Lizyadia, details of the, 73.
Liverpool Docks, hydraulic machinery at, 329.
Load of locomotive, to find the, 747.
Loading safety valves by direct springs, 467.
Loam covering for boilers, 204.
Locomotive Engines, 530–765.
— — description of special, 698.
Logarithms, tale of hyperbolic, 141.
London drainage system, 226.
“Long-wall ” in coal mining, 7. -
Lord of the Isles, details of the steamer, 377.
Low boilers arranged for royal navy, 57.
Lowering of the propeller, plan for, 487.
Lubricating cups for horizontal marine engine, 398.
— — for oscillating engine, 365.
— plug tap for locomotive, 578.
Lubrication of horizontal marine engine, 45x.
M
Main beam of blowing engines, 258, 273.
— cranks of oscillating engine, 357.
——of winding engine, 246.
— cranked shaft of marine engines, rule for, 521.
— frame of marine engines, rules for, 522.
– framing for horizontal marine engines, 415.
— pillow blocks of winding engine, 246.
— shaft of winding engine, 246.
— slide valve of locomotive, 584.
Mallet's compound locomotive engine, 694.
Manhole in marine boilers, 75, -
Marine Engines, 347–529.
– boilers, prºportions for, 62.
Mechanical stºkers, 76.
Mineral engine for Furness Railway, 717.
— lines, narrow-gauge engines for, 721.
Mining, coal, 1.
McNaught's Indicator, 131.
Motion of steam, 144.
t
— bars of winding engine, 24s.
— — of locomotive, 6c6.
— — of American locomotive, 675.
Multitubular boiler for ocean steamers, 52.
N -.
Narrow-gauge engines for steep inclines, 720.
Nautilus, experiments with the, 384.
Nominal horse-power, 51.o.
Mormandie, details of, 770.
Nozzle chest of blowing engine, 253.
— valve chests, 163.
Nuts and bolts for locomotive engine, 742.
O.
Opening of port by valve, 124.
Ormuz, details of, 770.
Oscillating engine, 347.
Outside cranks for locomotive, 625.
Overhead beam blowing engine, 250.
— — pumping engine, 183.
— flue boilers, arrangements of, 54.
Overshot water wheel, 317. -
INDEX.
P
Packing ring for condensing tubes, 426.
— — for locomotive piston, 596.
Paddle wheel, the, 378.
Parallel motion of blowing engine, 265.
Parisian, details of the, 76, 496, and plate.
Passenger engine for Caledonian Railway, 698,
and plates.
-— for London and North-Western Railway,703.
— — for North British Railway, 705.
— — for Great Southern and Western Railway of
Ireland, 710. - -
Performance of locomotive, tables of, 711, 712,714.
Perkins system of boiler, 19.
Pillar safety valves for locomotive, 570.
Pillars for ship’s beams, 8or.
Pillow block for paddle wheel, 381.
— blocks for blowing engine, 258, 261.
— — for screw shafting, 473.
Pipes for delivery of water, 306.
— for pit pumps, 308.
— of marine engines, rules for the, 517, 528.
Piston of Cornish engine, 152.
— of blowing engine, 252.
— — cylinder, 258.
— of horizontal marine engine, 399.
— of oscillating engine, 357.
— of marine engines, rules for the, 516, 523.
— of winding engine, 244.
— speed of, 3C9.
— of locomotive, 596.
— — specification for the, 735.
— of American locomotive, 675.
Piston rod of beam engine, rules for the, 3rx.
—— of horizontal marine engine, 405.
— — of oscillating engine, 358.
— — of marine engines, rules for the, 518.
— — of locomotives, 603.
— — — specification for the, 735.
— — of American locomotive, 675.
Pit shafts, form of 3.
— work, examples of, 192.
Plate stays, forms of, 87.
Plates, tables of strength of, 32.
— tables of weight of, 33.
Plug tap for locomotive cylinder, 583.
Plunger and bucket pump combined, 156.
— of pumps, 154.
Polyphemus, constructive details of the, 928.
Port, opening of steam, 124, 309.
— of locomotive, to find the length of the, 753.
Portable engines, 764, and #iate.
Portland Harbor, water power at, 328.
Post Boy, condenser of the Clyde steamer, 377.
Pot boiler, 14. - *
Power versus speed of a vessel, 511.
— — tonnage of a vessel, 511.
Pressure, working and bursting, 28.
— cylinder of hydraulic crane, 318.
— difference of, in boiler and cylinder, r.
Pressure, loss of, raó.
- on piston, 141.
— valve on water pipe, 226.
— in locomotive cylinder, rule for the, 746.
— gauge for locomotive, 575.
— — for American locomotive, 670.
Prevention of smoke, 544.
Priming, 78.
Propeller, construction and forms of the, 471, 477.
Proportion of water to Steam, 311.
Pulsometer pump, the, 239.
Pump bucket for water-works engine, 219.
– rods of Cornish engine, 152.
– valves for pumping engines, 213.
Pumping engine for drainage works, etc., 226.
— — for mines, 4, 150.
— — for water works, 202.
— — rules for the, 3or.
Pumps for floating docks, 973.
Punching of plates, 71.
R
Rail guards for locomotive, 648.
Rail mill at Dowlais Iron Works, 288.
–– engines, compound reversing, 291.
Raising the screw propeller and shaft, 483.
“Rance” in coal mining, 7.
Rankine on the compound steam engine, 493.
Ratchet bolt for valve rings, 129.
Ratio of diameter of cylinder to stroke of piston
in locomotive, 753.
– of stroke of piston to diameter of driving
wheels, 753.
Refrigerating surface in condenser, 428.
Regulators for locomotive steam pipe, 563, 732.
Relative volume of steam, to find the, 144.
Relief valve on delivery pipe, 225.
— — for horizontal marine engine, 396.
— — for oscillating engine, 363.
Reservoirs at water works, 211.
Resistance of trains, to find the, 746.
Return tubular boiler, 12.
Reversing gear of locomotive, 594, 736.
Revolving screws for discharging grain, 331.
Ring pump valves for water works engines, 209.
Rivetted joints, form and proportion of, 31.
Rivetter, portable hydraulic, 345, and plate.
– for ships' keels, 345, and plate.
Rivetting of locomotive boiler, 554.
Road locomotives or traction engines, 762.
— rollers, steam, 765.
Rolling bars in two directions, 289.
— mill engines, 285.
Ropes for winding engines, 259.
Round boilers, strength of, 30.
— — thickness of plates for, 69.
Rowan's form of piston, 403.
Rules for beam engine, 3ro.
— for marine engines, 510.
— for pumping engines, 310.
790
INDEX.
Rules for the locomotive engine, 746.
Ruthven's hydraulic propeller, trial of, 384.
S
Safety valve, construction of the, 454.
— — openings, 462.
— — — experiments with, 465.
— — for marine engine, rule for the, 528.
— — of locomotive, 567.
— — — rules for the, 757.
— — — specification for the, 732,
— — in American locomotive, 669.
Sand box for locomotive, 649.
— — — specification for the, 741.
— — of American locomotive, 671.
Saturated steam, heat of, 143.
— — rules for, 145.
— — table of properties of, 147.
Scale on steel plates, 72. ~.
Scotia, engines of the Cunard steamer, 377.
Screw propeller, construction of the, 471, 477.
— — rules for the, 525.
— shafting, thrust collars, etc., rules for, 526.
— vessels, performance of, 512.
Scum taps for marine boilers, 461.
Self-contained flue and tubular boilers, 12, 13.
Separator, the, 46.
— for marine engine, 458.
Serzia, details of the, 345, 415, 497, 5oo, 770.
Setting out the valve faces, 125.
Shafting for screw propeller, 471.
Shell of locomotive boiler, 554.
Side-lever engine for paddle steamer, 377.
— links of parallel motion for Cornish engine, 151.
— pumping engine, 187.
Silent blow-off nozzle, 47.o.
Sir Bezis, details of the, 5oz.
Sirius, description of the, 377.
Slide bars, specification for locomotive, 735.
— blocks, specification for locomotive, 735.
Slide valve, the, 94, 126. -
— — for horizontal marine engine, 390.
— — gear for oscillating engine, 365.
— — of marine engines, power to move, 520.
— — rod of marine engines, rule for the, 519.
— — for locomotive, Io2, 584.
— — — specification for the, 736.
— — of American locomotive, 671.
Slip of the paddle, 383.
— of the screw, 478.
Smoke box of locomotive, 558.
— — — specification for the, 731.
— — of American locomotive, 667,
— doors in marine boilers, 75.
— prevention, 43, 544.
Snifting valve for condenser, 445.
—— for oscillating engine, 362.
Sockets for standard water pipes, 307.
Spark arrester, specification for locomotive, 73r.
Specification for locomotive engine and tender, 728.
Speed of locomotive piston, to find the maximum,
753. j
Splashers for locomotive, 650, 740.
Spring beam of blowing engine, 259.
Spring-loaded safety valve for locomotive, 569.
Springs for locomotive, 636.
— — rules for the, 759.
— — specifications for the, 738, 744.
— for American locomotive, 682.
“Stall and pillar” in mining, 7.
Stand pipes, 202, 211, 221.
Starting gear for marine engines, Ixo.
— — for oscillating engine, 372.
— handle of winding engine, 243.
Stationary engines, 150–346.
Stays for boilers, 29.
Stay tubes in locomotive fire box, 541.
Staying of marine boilers, 65.
Steam, admission of 94.
— expansion of 141–49.
— properties of, 143.
— treatment oſ, 79.
— to find the motion of, 144.
— to find the relative volume of, 144.
— to find the temperature of, 144.
— to find the total pressure of, 144.
— to find the weight of, 144.
— blast, mechanical action of the, 531.
— cylinder of blowing engines, 251, 269,279, 282.
— engine, the early, 9.
— jacket for cylinder, 85. #
— reducing valve, 47. ,'
— regulating valve of blowing engine, 268.
— stop valve, 456.
– tightness in a piston, 403.
– valve of oscillating engine, 349.
— — of winding engine, 242.
— chest of locomotive, 555.
— pipe in locomotive boiler, 563.
— pipes, specification for locomotive, 73a.
— pump for locomotive, 660.
—jet in American locomotive, 668.
— pipe in American locomotive, 669. '
– road roller, details of the, 765.
— ship efficiency, Mr. Mansel on, 513.
Steel boilers, 32.
Steeple engines for river boats, 377.
“Step” in mining, 2.
Step grate for locomotive, 535.
Stern posts of screw vessels, 789.
– tube for the screw propeller, 475.
Stirling Castle, details of the, 770.
Stoup for valve motion of blowing engine, 254.
Straight link motion for locomotive, 591.
Straightening, hydraulic machine for, 346.
Stud for locomotive, lamp, 578.
Stuffing box of horizontal marine engine, 388. .
— — of oscillating engine, 349.
— — of marine engine, rule for the, 518.
“Stythe ” in mines, 4.
“Sump” in mines, 157.
INDEX. 7.9 L
Superheaters, use of, 54.
— forms of, 8o. -
Surface condensation in marine engines, rules for,
524.
Surfaces, relations of, 65.
Swing bridges, working of, 325.
t
Tank for water works, 217.
- in locomotive tender, 687, 742.
- locomotives, 705, 717, 721.
— narrow-gauge locomotives, dimensions of, 724.
Tappets for shutting valves, 164.
Temperature.of steam, to find the, 144.
Tender for locomotive, 684.
— — specification for, 742.
— for American locomotive, 688.
Testing old boilers to destruction, 48.
Three-cylinder compound engines, 497.
— — compound steeple engine, 507.
Throttle valve for horizontal marine engine, 395.
— — for oscillating engine, 364.
Throw of eccentric, 367.
Throwing off apparatus in discharging grain, 334.
Thrust of a propeller, Rankine’s rule for, 384.
Thrust block for screw shaft, 473.
Tonnage of a vessel, rule for, 512.
Total pressure of steam, to find the, 144.
Toulon Arsenal, hydraulic power at, 346.
Traction or road engines, 762,
Tractive power of locomotive, to find the, 746.
Travelling bands for carrying grain, 333, 341.
Triple compound engines, 766, 771.
“Troubles" in coal mining, 2.
Trunk engines, 378, 492.
Trunnion blocks, 354.
— pipes for steam and exhaust, 348.
Trunnions of oscillating engine, 347.
Tube area in marine boilers, 67.
—- stays, conical water, 88.
Tubes, surface and weight of, 34.
— for surface condensers, 426.
— — — arrangement of the, 430.
— for locomotive boiler, 557.
— — — specification for the, 731.
— in American locomotive, 666.
Tubing, triangular and square systems of, 45.
Tubular boilers, forms of, 12, 13.
Turbine, the, 317.
Turning gear for horizontal marine engines, 453.
— — for marine engine, rule for the, 528.
Tweddle's hydraulic tools, 345, and Élate.
Twin screw propellers, 481.
Tyres, specification for locomotive, 740, 745.
— for traction-engines, 762.
D
Unbria, details of (illustrated), 770.
Undershot water wheel, 317.
Uptakes for marine boilers, 58,60.
V
Vacuum automatic brake, details of the, 691.
— valve for marine boilers, 461.
Valve, the slide, 94, 126.
— without lap, 95.
— with lap, 96.
— casing for horizontal marine engines, 392.
— faces, setting out the, 125.
— gear, Corliss liberating, 295.
— — Cornish, 164.
— — of horizontal marine engine, 393.
— — of oscillating engine, 1oz., 371.
— regulator for water works, 212.
— spindle of blowing engine, 254.
— motion of locomotive, 587.
— — — specification for the, 736.
— — of American locomotive, 673.
Valves for blowing engine, 253.
— for direct-acting horizontal marine engine, rog.
— for high and low pressure combined engines, ro2.
— for hydraulic cranes, 318.
— for marine engines, rules for, 517, 528.
— for water pipes, 203.
Velocity of saturated steam, to find the, 145.
Ventilation of mines, 6.
Vertical boilers, various forms of, 13.
— compound engine, 495.
Vibrating engine, 347.
W
Waste-steam funnel for locomotive, 572.
Water, power required to pump out, 303.
— weight and measurement of, 307.
— pipes, thickness of, 307.
— power from natural falls, 327.
— pressure engines, 314.
— — — for dock gates, 325.
— tube boilers, 16.
— wheels, 317.
— works at Berwick-upon-Tweed, 217.
— — at Bromhills, Walsall, 221.
— — at Goldthorn Hill, Wolverhampton, 209.
— — at Tettenhall, Wolverhampton, 204.
— gauge for locomotive, 573.
— gauge in American locomotive, 669.
— space in locomotive fire box, 534, 540.
— tank in locomotive tender, 687.
— required for given speed of locomotive, 754.
Waterwitch, experiments with the, 384.
Webb's compound locomotive engine, 695.
Weigh bar of locomotive, 594.
Weight of cast-iron pipes, 307.
— of wrought-iron plates, 33.
— of steam, to find the, 144.
Westinghouse automatic brake, 690.
792
INDEX.
*
Wheels for locomotive, 622.
— — rules for the, 759.
— — specifications for the, 739, 744.
— for American locomotive, 678.
Whistle for steam vessels, 461.
— for locomotive, 576.
— for American locomotive, 670.
Winding engine, the, 239.
— — for a pit at Niddrie, 250, and plate. "
Wiper shaft of blowing engine, 254.
Wood-burning American locomotive, 664.
Working pressure of boilers, 28,
Workmanship of locomotive boiler, 731.
Y
“Yokes” in pumping machinery, 197.
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