ﬁULLE TIN OF THE

Agricultural and Mechanical College of Texas

(In co-operation with the United States Department of Agriculture.)

APRIL, 1919. EXTENSION SERVICE i 3-39

   

  GROUND
SILO

Convenient hoist erected between four underground silos 200 tons each and carrier track and silage
box for conveying silage to the barn. Cost $250 each.

Address
T. 0. WALTQN, _Acting Director
College Station, Texas

THE UNDERGROUND SILO.

By M. T. Payne

State Agent, Extension Service and U. S. Department of Agriculture,
A. and M. College of Texas.

mrnooucrion.

The demand for information on the construction of the underground silo is
steadily increasing. Every day some one makes inquiry of the county agent, or the
Extension Service of the A. and M. College, for information on this subject.

It is not the purpose of this bulletin to discuss, at length, the value of a silo,
the feeding of silage or discourage the construction of any other type of silo, but to
give in detail the steps to take in the construction of the underground silo-—for they

have come to stay-—and to point out the mistakes that may easily be made by those A

without experience, who want to build a silo of this type at a minimum cost. Many
farmers would build a silo if it were not so expensive. By using the pit silo this ob-
jection is overcome.

With few directions any farmer, with ordinary hired labor, can construct a
100 ton underground silo at a cost, ranging from $75 to $150, in the ordinary type
of soil. In some cases it may be constructed for a $60 cash outlay, or less, if a man
does his own work and uses home-made hoisting apparatus. It has been demonstrated
thoroughly by the farmers that silage keeps perfectly in a properly constructed silo
of this type, and that they are entirely practical and permanent. A large per cent. of
the silos in the Southwest are of the underground type. ‘

Carrying Feed in Reserve.

The forage crops are the most easily produced and the most satisfactory way
to dispose of them is to feed them to live stock, but with the ordinary methods of
curing them dry, 50% or more of the crop is lost in shattered and bleached leaves,
waste in feeding, etc. If made into silage the total loss of the crop should not ex-
ceed 10 per cent.

The silo in the semi-arid climates will be found very desirable, as a means of
storing green feed to be reserved for use in drouthy seasons. - Silage does not appear
to deteriorate with age, hence the crops of heavy seasons can be carried over in-
deﬁnitely. Thus, the farmer is more independent of the seasons, and is enabled
to carry a larger herd upon the same amount of land. The crop is preserved in the
most; nutritious and palatable condition, and is the best supplement for short pas-
tures during drouthy seasons.

The Two Types.

There are two types of the underground silos in use in Texas: First, the
most common type is the one, in which a concrete collar is placed, extending from
the ﬁrm subsoil, two to four feet below the surface, to two or three feet above the
ground. The surface of the silo is then plastered from the bottom of the concrete
collar to the bottom of the silo. Second, the type in which a concrete wall is con-
structed from the bottom of the silo to two or three feet above the surface of
the ground. l

Location of the Silo.

_ Convenience should be considered in locating the place to build the silo. It
1s usually best in a mild climate, not to locate the silo in the barn, as it will ob-
3

struct the free circulation of the air; also, it is more difficult to ﬁll a silo in a barn
than one on the outside.

The silo should be convenient to the place where the silage is to be fed, and
should be situated especially with reference to future improvement about the prem-
ises. If the silo is constructed near the feed lot or barn the silage can be handled
very conveniently and economically with a carrier, similiar to the hay carrier equip-
ment, which is illustrated elsewhere in this bulletin. The water table should be

below the bottom of the silo.
Size and Capacity of the Silo.

It is not advisable to construct underground silos of large size. Two small
ones, having the total capacity desired, will give better results.

The expenses of digging and removing the silage increase as the depth in-
creases. The smaller the silo in diameter the less surface exposure of silage whiie
feeding. The silo, ordinarily, should not be more than thirty feet deep. The depth

‘should be about twice the width.

The silage should be removed from the entire surface of the soil, while feed-
ing, at a rate of not less than two inches per day in the winter and three inches
per day in the summer. The diameter of the silo should not be larger than is neces-
sary to accomodate the herd. The average weight of silage in a 30 foot silo is
about 4O pounds per cubic foot. By knowing approximately the amount of silage
to be fed daily it is possible to estimate the diameter of the silo needed to suit the
herd, or if one has a silo and not a sufficient number of cattle to consume theneces-
sary amount of silage per day, a very accurate estimate can be made, by using the
following tables, of the number required to consume the necessary amount to pre-
vent spoiling, both for winter and summer feeding.

“(Relation of size of herd to diameter of silo for winter feeding, on a bisis
of 40 pounds of silage per cubic foot.)”

 

Inside Qll_allllity_ Number of Animals that May be Fed Allowing
Diameter of silage 1n
of Silo. de-pthh of 2 40 pounds 30 pounds 20 pounds 15 pounds
me es‘ per head. l per head. l per head. l____per head;
Feet Pounds I ' '
1o 524 13 17 l 26 l 35
11 634 16 21 31 42
12 754 19 25 37 50
13 885 I 22 29 44 59
14 1026 25 34 51 68
15 1178 29 39 59 78
16 1340 33 44 67 89
17 1513 38 50 75 101
18 1696 42 56 85 113
20 2094 52 70 104 139

“A 900-pound cow will ordinarily consume 30 pounds of silage a day; a 1200»-
pound cow about 40 pounds; yearlings will eat about one-half as much as mature
animals; fattening cattle, 25 to 35'pounds for each 1000 pounds of live weight; a
sheep will take about one-eighth as much as a cow; horses should be limited to
15 or 20 pounds daily.”

Great care should be exercised to see that no spoiled and moldy silage is
fed to horses and mules, for even a small amount may cause ‘serious sickness and
often death. Begin by feeding a small amount and increase gradually to the amount
suggested. .

The practice of using silage to supplement pastures during the summer
droughts and in the early fall should be encouraged. For such feeding the daily

4

 

ration may be as low as 10 pounds per cow, depending upon the amount and quality
of pasture and other succulent feeds available. For the same herd, for summer
feeding the silo should be of smaller diameter than the one used for winter feeding,
since 3 inches instead of 2 are to be removed daily. In order to provide for this
summer feeding an additional silo of smaller diameter should be constructed where
the conditions demand it. 4

The following table shows the relation between the size of the herd and the
diameter of the silo when 3 inches of silage are removed daily:

(Relation of size of herd to diameter of silo for summer feeding, on basis
of 40 pounds of silage per cubic foot). A

pwide “Qggggiéﬁyin Number of Animals that May be Fed Allowing
 delggclhg: 3 40 pounds l 30 pounds 20 pounds 15 pounds
‘ ' per head. per head. per head. per head.
Feet I Pounds I
10 l 785 I 19 26 39 52
11 950 23 31 47 63
12 1131 | 2s 37 56 75
13 1327 33 44 66 88
14_ 1539 38 51 77 102
15 1767 44 59 88 118
16 2011 I 5O 67 100 134

Capacity of Silo.

Depth of silage (after settling) for a given capacity of silo with a given diameter.

Depth of Capacity of silo Having Inside Diameter of—
silage yfler 10 11 12 13 14 15 16 17 1s 20
Settlmg Feet Feet Feet Feet“ Feet Feet Feet Feet eet _ e et

Feet Tons Tons Tons Tons Tons Tons Tons Tons Tons Tons

 

The above ﬁgures were taken from U. S. Farmers’ Bulletin No. 589."
Construction.

The ﬁrst type mentioned in Figure No. 2, consisting of a concrete collar and
plastered wall, is used most extensively in sections of the state where the water table
is below the bottom of the silo.

After deciding upon the location and size of the silo to be built, the ground
should be made perfectly level, as this will help in making the walls perpendicular
in digging. If they are rough and outiof plumb, space will be left between the wall
and the silage, as the latter settles, allowing air to get down around the silage,
which will cause it to spoil about the edge, for a foot or so. With irregular walls
the silage will not settle evenly.

Marking Cut Trench’,

Drive a stake in the ground where the center of the silo is to be. To this
stake nail one end of a board 1”x4” about 7 feet long for a marker. Assuming
5

and as smooth as possible, especially the inside Wall, which will form the inside

"thantwo or three feet. In most such cases it is found more convenient not to use

that t h e
silo is to be
12 feet in
d i a m eter,
d r i v e a

large ' spike
through the
board“ at a
point 6 ft.
from the
nail in the
stake. Six
inches out
from this
spike, then
another _4
nail is driv- .1} l" ~-
en throng-h  '
the board.
W o o d e n
pegs, shar-
pened and
nailed t o
the board, c

may b e ,___,_._l_=r.
u s e d i n - » _ _‘ '
stead o f .  ' <
the spikes ,_"_*._-";-' . 1;; _ t t" ' a - - _ _

or large  Y- _._-- ~._ .;1,_ ,.
nails. B y ‘Efif  _ _ "' '  " F 
revolviog “Kﬁf: ' " ~- .- ._.. , -. \
the board T}.  _ - _ ‘YE _ i g_ “ll ,, "'
around the ' - ~ i - T" if" -

center stake
two circlesFigure 2.——(a) Shows the method of laying off the trench for the collar of the under-

ground silo. (b) The middle shows the trench dug. (c) The lower section shows
Will b e the forms in place made of horizontal strips ﬁlled with concrete.

made on the ground giving the Width of the collar and the diameter of the silo, as
shown in ﬁgure (2). Where the soil is ﬁrm and not subject to cracking, the wall ~
of the collar may be made four inches thick. 1

The space between these circles is dug out to the ﬁrm subsoil, which is usu- i
ally from 18 to 24 inches deep. The walls of the trench should be perpendicular

_ ' V- ‘ \- ' ,..
m; n -__--

Wall of the silo when ﬁlled with concrete. A sharp spade and spirit level should be
used in trimming and plumbing the trench.

When the trench is ﬁnished it will be six inches Wide and 18 to 24 inches
deep. If‘ the soil is light, the trench should be made wider at the bottom, so as to
afford a better foundation. To do this the earth should be sloped back on the out-
side of the trench, as shown in ﬁgure 7.

Forms for Collar.

The bottom of the trench should be level and smooth. Some are made deeper

6

W W

the trench. Mark the outside circle, remove all of the dirt from the inside of the
silo to the desired depth of three or four feet. Then build a Wooden form made of
horizontal strips, nailed to upright pieces of 2”x4”; or make wooden hoops and line
them with 6-inch boards, standing vertically well braced; or use metal forms for the
‘inside wall and the dirt wall for the outside form, in which to mold the concrete

Figure 3.——An inexpensive method of building forms for concrete collar which does not
extend far above the surface of the ground.

collar. In cases where only the trench is used as forms, the extension of the collar
above the surface of the ground may be made of concrete or of brick and plastered
on both sides. One farmer used a strand of hog wire around the brick, plastering
over this, making it very durable. A stone wall may be used or concrete plaster
on metal lath of about three inches thicknesswill be suﬂicient for this part_of the
collar. When lath is used the ﬁrst round should be bedded in the concrete foun-
dation in the trench, thus binding the parts of the collar together ﬁrmly.

In the construction of forms for the concrete collar to be built above the
ground, where either sheet metal or wooden forms are to be used, the following
suggestions, given by A. D. Melvin, in U. S. Farmers’ Bulletin No. 589, have been
found to be very helpful:

“For each form it is necessary to build two supporting circles (See Figure
5 c) to which the sheet iron or wood, as the case may be, is nailed. These circles
are built out of 1 by G-inch material, rough or dressed, of a length depending upon
the diameter of the silo so that 16 pieces will exactly’ make the circumference. It
is not an easy matter to compute these lengths of chords for the various diameters,
so they are give nbelow. In Figure 4 ‘the chord is the distance from A to B.

TABLE OF CHORDS _

Diameter Chord j Diameter i Chord
of silo. Measurement i of silo. ‘ Measurement

1| Ft. In. l | Ft. In.
1O feet 1 1-% 15 feet 2 1
11 feet 2 15% S 16 feet i 3 1-%
12 feet 2 4 17 feet 3 35%.
13 feet 2 6-3/8 l 18 feet i 3 6-%
14 feet 2 8-374, g \

7

Laying Out the Templets for Sheet-Iron Forms.

Figure 4 shows how to proceed to lay out the pieces to be used as temp-
lets, or patterns, by which to cut the pieces which, when laid end to end, are to
form the supporting circles
for inside and outside forms
when sheet iron is used. For
this part of the work use the
barn ﬂoor or any clear space
available. If there is no con-
venient place available, it will
be advisable to build the con-
crete mixing board described
later, and use this.

Select a straight piece of
1 by 3-inch board about a
foot longer than half the di-
ameter of the proposed silo,
and with a ten-penny nail
tack one end to the ﬂoor so
that the slat will be free to
swing about. From this nail
as the center of the silo, meas-
ure off on the slat one-half
the length of the inside diam-
eter. Here drive a nail, and
6 inches beyond drive another
nail until the points extend
through far enough to scratch
clear marks on the ﬂoor as
the slat is swung around on
the center 0, as shown in fig-
ure 4. These circles repre-
sent the inside and outside

.1

6 " P15 qss

FIG. QL-Method of laying out tem plets.
faces of the wall. An are equal to 1-4 of the circumference will be suﬁicient. From any
point which has been determined to be A on the inside arc, measure off the length of
the chord in Fig. 4 as given in the table of chords for the diameter of the proposed silo,
and ﬁnd point B. With a straight edge laid through the points A and O_ and also
through B and O, draw short lines on the floor from D to E and from C to F, re-

spectively. On these lines measure inward 4 inches from points A and B, and locate
points C and D. Similarly measure outward from points H and G 6 inches to find
the exact location of points E and F.

Next take two pieces of the 1 by 6-inch board and lay one of them on the
arc with the inside edge flush with points C and D, as shown in Figure 4. Lay the
other on the outside arc with the outside edge ﬂush with points E and F. Tack
them to the ﬂoor with several small nails. Next lay off the arcs again on these pieces,
and with the straight edge remark lines DE and CF. The pieces are now ready
to be taken up and sawed. The resulting patterns, or templets, will serve to mark
out the 64 pieces necessary to build the two inside circles and the 64 pieces to build
the two outside circles.

The curved pieces can be sawed by hand, but if there is a mill or shop con-
venient that is equipped with a band saw, it will hasten and generally cheapen the
job to have it done there.

8

“May-um . 
,. _: .

Laying Out the Templets for Wooden Forms.

If the sheet iron for metal forms can not be obtained, or if for any other

reason it becomes necessary to build wooden forms, then 1-inch ﬂooring 3 inches 4

Wide and 3 feet long nailed on these supporting circles may take the place of the
sheet iron. In working out the templets for wooden forms the nail used for mark-
ing oﬁ‘ the inside circumference is driven one inche nearer the center to allow for
the thickness of the ﬂooring which is nailed on the circles instead of the sheet iron.
In other words, the inner circle is described one inch nearer the center and the outer
circle one inch farther away from the center in order to allow for the thickness of
the flooring. As shown in Figure 5c the circles are raised one above the other, 26
inches apart, and the ﬂooring is nailed on vertically with 8-penny nails. Before
the ﬂooring is nailed on it should be thoroughly soaked in water to prevent buckling
later. Lugs are used similar to those used for sheet-iron forms. (See Figure 5c).
Instead of riveting these lugs on the side, they are fastened on top of the circles
with screws.

As shown in Figure 5c, each of the supporting circles is built two-ply, that
is, the pieces are lapped so as to break joints. After cutting four or ﬁve pices, lay
them out on the circles, so as to make sure they fit the curve. Before starting to
nail the pieces together, mark out the whole circumference on the ﬂoor or on a level
piece of ground with the slat as shown in Figure 4, and build the circles accurately
by laying the pieces ﬂush with the mark. It is important that the circles be well
nailed with 8-penny nails driven through and clinched. While the circles are be-
ing built, approximate points of division intoquarter circles can be marked, and
those pieces nailed sparingly until after the circle is completed. It is generally
safer to build the circles complete and then divide into quarter sections rather than
to build each quarter separately. This division into parts is for the purpose of
loosening and resetting the forms.

Dividing the Circle into Quarter Sections.

Remove the nails in one-half of every fourth piece in the top layer of each
circle. This will divide each circle into four equal parts, with lapped joints.

Building the Inside Form,

A hole one inch wide and three inches long should now be cut through both
layers in the center of each joint. (See Figure 5b). These holes are provided for
wedges which are used in ﬁtting or releasing the forms from the wall. The ends of
the quarter sections should then be cut oﬁ‘ at the outer edges of the Wedge holes.
This will allow the sections to slide together when they are to "be removed from
the wall. _

When all the wedge holes have been cut and the work of dividing into
quarter sections is complete, temporarily nail the quarter sections together at points
of division and brace the top circle directly over 32 inches above the lower one.
See that both circles are perfectly level and that the joints in the upper circle are
directly above the joints in the lower circle, and then proceed to nail it securely,
between the top and bottom circles, using 1 by 3-inch studding, 32 inches long care-
fully plumbing the studs and placing them from 12 to 18 inches apart as shown’ in
Figure 5a to keep the iron from bulging.

In nailing on the sheet iron use 6-penny nails, and nail securely. Before
starting to nail on the iron, however, see that it is cut to the proper length. The
sheet for each quarter section should be just three inches longer than one-quarter
of the circumference. If several sheets are required to make a single quarter
section, they should be carefully riveted together with a double row of ﬁat-headed
rivets. Since the quarter sections lap 3 inches, and in removing need to slide together

severa1_inches farther, it is necessary to leave one end of the sheets loose 8 to 10
inches from the end, while at the other end it should be nailed all the way.

    

Loos: BL0¢K

 

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‘ . 4 ‘ ‘\- ‘ '2 V  ~' l|  E
.‘ ll  ' \ P ,4 l. " ' . ‘ .v~ '
lllll \ ' "'-- \-'"~-_ 7/) , I l Q.' u, _ __r
\  l‘ l  "I, 12"‘;   /' “ A“ "l": ‘~~ A.“ ‘in H. "l L‘ Z/(ég. ‘will A’ 
. .Y t} ‘ . I ‘I  l ll I y  ‘L:  "I;  |l ~ ‘ ,/Z> ’ - . \ ‘ I  l. I I  . ‘L
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. i‘  \ _-_~_:._-— _  ' I ‘ II l‘ Yliv/
\ p l I  I l y ' l \ I '. — | ' 
\'~ rl- a 1' " h 1'1 ' 
\~._ lawn] ‘I: 11- Iv‘ . ,.-_/k
\\\‘-: . ¢g | a’ I I ‘ ' ~ 1/  '/
.\<*§\> \ , , , I /,-
~<‘ ‘\\ ‘

Figure 5.—_—Meta1 and wooden form for a concrete silo. They may be used for con;
structlng concrete collar above or inside form may be used in putting; in con-
> crete wall from botton of pit silo» to the. top, '

10

 

Wedges for Inside Form.-—The wedges should be of hardwood, 8 to 1O inches
long, 2 inches wide at the narrow end and 4 to 5 inches at the other. In order to
make the wedges drive true and hold, it is necessary to put in loose blocks, as shown
in Figures 5a and 5b.

Building the Outside Form.

The outside circles are built up and divided into quarter sections just as are
the inside circles, but no provision is made for wedges. The sheet iron is made up
in to quarter sections, three inches longer than one-quarter of the outside circum-

i ference, to provide for the lap.

Lugs and Bolts for Outside F orm.-—The quarter sections are joined and drawn
together by means of bolts and lugs, the latter made from %-inch tire steel and
rivited on the forms as shown in Figure 5c.‘ Note that on one end of the section the
lugs are riveted on ﬂush with the edge of the iron, while at the other end they are
set in 5 inches from the edge to permit the lap. If preferred,‘ the lugs may be put
on the top of the supporting circles instead of on the sheet iron. The lugs should
be made about 24 inches long to provide for several rivets. For drawing the sec-
tions together use ‘Vs-inch bolts, ﬁve inches long, with hexagonal heads and nuts
and extra long thread. (See Figure 5c). The forms are now ready for use.

The experienced silo builder may leave off the supporting circles from the
outside form. For the inexperienced man it is generally safer to provide these’
supporting circles,‘ as they prevent the sheet iron from drawing at the top when the
concrete is being placed.”

As a rule such forms as described above should be made by the farmer who
has several silos to build, or by a group of farmers in a community who centemplate
building underground silos. Such forms are very substantial, and can be easily
moved from place to place.

Where a farmer has only one or two small silos to build and no one to co-
operate with him in building forms, he may use a little less expensive method of,
building the forms, such as are shown in Figures 2 and 3.

Proportion Material for Collar.

If the soil is very dry the walls of the trench should be wet; if the soil is of
such nature that it will not crumble too badly, after ﬁlling the trench entirely full
of water, this should be done. When the water has been taken up by the soil the
trench is then ready to be ﬁlled with concrete. If the walls are not wet they may
absorb too much moisture from the concrete and cause it to dry too quickly.

If hard ﬁinty rocks or clean gravel is available a 1:2 :2 mixture (one part
cement, two parts sand and four parts crushed rock or gravel) should be used in
making the collar. If no rock or gravel can be had a 1:4 mixture (one part cement
and four parts sand) should be used; Where the sand is coarse, containing consider-
able gravel, a 1:5 mixture (one part cement and ﬁve parts sand) may be used. The
mixture should be made wet enough to pour, but not sloppy. With ﬁne sand, more
cement is required and in that case a 1:3 mixture may be used, but avoid using ex-
ceedingly ﬁne sand. The concrete should be well mixed and carefully spaded, being
careful not to mar the inner wall. i

Reinforcing Concrete Collar.

Where the subsoil is ﬁrm and the surface soil not subject to cracking very
little if any reinforcement will be necessary. If reinforcement is necessary, the
farmer can usually ﬁnd old scrap iron, and old wire about the place which can be
used for this purpose. Hog wire makes a good reinforcing material. Allow the

11

concrete in the collar to set for 24 hours, before commencing the excavation of the
silo. The farmer should also, make his elevator for elevating the silage, and use it
in removing the dirt while digging. A device for removing the earth may be made
of a half barrel, ﬁxed up in the form of a bucket; or a trip bottom box, which is
suspended from the hay carrier track or derrick.

The collar should extend two or three feet above the suface of the ground,

  

Q’ to shed the

9 QP surface wa-

Vqg» ter. If It

~}.~ 1 s b u 1 l t

f higher than

dig ;__\_'\ two f e e t

._ . ix} above the

T” . -_ . ‘ > \'*;>- surface of
' " ~55?" \-§.'f;the ground,

‘i;  __ \o r higher

\ " ‘than t h e
- g fgéuﬁend of the
. I, T ""' ~-- /'\ silage cut-

” STE/i "-~. f! f _
'._ -, '_ . Q ter, dirt
' ~ ' , ~ i‘ ' " _.'- --  should b e
‘T5 PREVEWT banked up
CRACK/NI} around the

BELOWOQ-LLAR walls, so as

to elevate
the silage cutter, per-
mittinﬁ the silage to
drop from the cutter
into the silo, doing
away with an elevator

. _ \ or blower. The dirt

‘ USE PLUMB BOB '7 -__ _ TQE’ bank will serve also in
L9cllTlN5-cFllrFnl: §$ shedding surface mois-
‘STAKE FOR PIPE‘; ture and prevent it

from seeping in and
' softening the plaster
UN DER QROU/VD S/LO on the wall below the

Figure 6. Showing one method of shaving walls in making_an under- 3011313
ground silo and other interesting points 1n construction.

Plumbing the Wall.

The inside diameter of the collar must be the same as the inside diameter of
the silo,‘ which should be uniform from top to bottom. It, is very necessary that the
walls of the silo be kept perpendicular. To do this one should use a plumb line,
straight edge, or a piece of 2x4 and spirit level. Another simple method is to fasten
a gas pipe in the center of the silo in a perpendicular position, after ﬁve or six feet
of dirt have been removed. Saw off a 2”x4”, so it will revole in the silo, bore
a hole through one end of the board and ﬁt over the gas pipe. Bolt a heavy blade
or cutting tool to the outer end of the 2" x 4”. Beginning at the top revolve the
2”x4”, causing the cutting tool to shave the wall smooth and plumb. This instru-
ment will serve best where there is little or no rock encountered. The trimming

should be kept well up with the digging. See Figure 6.

Plastering Below Collar,

After five or six feet of dirt have been removed below the bottom of the
12

~04» waves?‘ g1 ‘.,—-— -----.—--_-»-_~_.._.__._.,...._..-_, . _. ..

concrete collar and the walls have been trimmed smooth, moisten the dirt wall,
but do not make it soft and sticky. Plaster within one and one-half feet, of the
bottom with a 1:2 mixture, (one part cement and two parts clean, sharp sand)
before digging deeper. Make the walls from one to one and one-half inch in
thickness, depending upon the kind of soil in the silo and the diameter; as the
diameter increases, the thickness of the plaster on the walls should increase. Ap-
ply the cement in three or more coats. Two coats will be suﬂicient in heavy clay
soil, but if the soil is light more will be required. The thicker the wall the more
permanent it will be. In order to prevent the cement from cracking immediately
below the edge of the collar, remove the earth for two inches under the inner
edge of the collar, allowing the trench to slope down two or three inches back to
the edge of the wall; (See Figure 6) when applying the ﬁrst coat of plaster ﬁll
the trench. If the collar is made of concrete, the plaster should come out even
with the inner wall of the curb when finished, but if it is made of brick the
plaster should extend to the top of the curb. The first coat of plaster should

be left rough. As soon as the wall will stand brushing, use an old stiff broom
to scarify it, and before the ﬁrst coat has time to set, apply the next coat and
repeat the brushing, as in the ﬁrst, and so on until you have a suﬂicient thick-
ness. After the last coat has been -applied trowel down smooth and follow it
with a cement wash made of cement and water of about the consistency of thick
lime whitewash, and apply with a whitewash brush in the ordinary way. If the

walls have had time to dry before applying the wash, wet the walls.
When the first course has been finished dig another five or six feet and

plaster as before and so on. By doing this the silo may be finished without _

using a scaffold. If the walls are not plastered, they will eventually cave, also
the soil will take up too much of the moisture causing the silage to spoil around
the edge of the wallfor a foot or so.

The cement plaster should he dampened twice a day for a week, as
cement, that dries slowly is tough, while if it is dried quickly it may crack or
crumble. It is well to keep the silo covered during this period.

Unless the farmer has had some experience in handling cement, it is advisable
that-he employ an experienced man for a few days to show him how to do the
cement work. - I

Painting Walls.

After the coat of cement has ben applied and has dried, the Walls may be
painted with coal tar, thinned with gasoline. The silage will keep without apply-
ing the coal tar, but it makes the wall more impervious, also protects it from the
action of acids which develop in the silage. If necessary the wash may be re-
newed from year to year.

The following formula has been used in some cases for putting a glazed
ﬁnish on the inside walls of the silos, making them considerably impervious and
has been reported as giving good results.

Cement . . . . . . . . . . . . . .. 100 lbs. »Water . . . . . . . . . . . . . . . .. 1s gal.
Hydrated lime . . . . . . . .. 10 lbs. Concentrated lye . . . . . . .. 1 lb.
Mix thoroughly. Powdered alum . . . . . . . . . 2 lbs.

Thoroughly dissolve the lye and the alum in the water, then use same in

mixing cement to about the consistency of thick cream.
13

Wetsilo "and wash off dirt, then “apply cement mixture, rubbing thoroughly,
ﬁlling all cracks and jointsand rub smooth.

The Texas ExperimentStation has had good results for the pest three years
from painting the inside Walls of concrete silos with gas-tar. The gas-tar is heated
to aboiling point. While hot a small quantity of gas will form. on top of the gas-
tar. Touch a match to the gas and allow it to burn for a minute or so, then fan

out the ﬁre with an old~ sack or something similar. Then apply the. gas-tar to the
silo ‘wallswhile hot. with a stiﬂ’ brush or broom.
Director Youngblood reports that the walls of a large reinforced concrete silo

on the feeding and breeding’
farm at College Station,
treated in this manner more
than three years ago, is now
in as good condition as when
ﬁrst treated.

Some prefer to use rosin
with the gas tar, as it makes
a better glazed“ surface. To
do this mix thoroughly, 1
part well pulverized rosin,
to 10 or 12 parts hot gas
tar. Mix the rosin before
heating the gas tar. Best
results are obtained by heat-
ing the rosin before mixing,
and then cooking the tar
and rosin to a boiling point
before applying.

Removing Soft Strata

of‘ Soil.

Should you come in con-
tact with a strata of soar)
stone, lignite coal, loose sand
or any substance to which
cement would not adhere
readily, remove this strata
of soil just far enough to
give room to lay a layer of
brick t0 make it ﬁrm. When
soft spongy spots are found
‘in digging, hollow them out
and ﬁll with cement.

If this sort of soil is not
removed in this way, the ce-
ment will be apt to crack
at each such strata.

VIf the soil should be

Figure '7.——Convenient hoist for removing dirt while digging, Of SllCll IIEItHTG that tllé p188-

also may be used 1n removing silage. ter could not be‘ applied di_

rectly to the wall, use metal lath or close mesh rabbit wire, fastening it securely to

the wall, and plastering as directed above. The bottom of the silos are usually not
plastered, as the soil absorbs the excess moisture more readily. - A ~ 

~ 14

3*

 

“ Solid Concrete wall.

_ Where the soil is very sandy or joint clay is encountered, it sometimes becomes
necessary to use a three-inch Wall of concrete from the bottom to top of the silo, if
thewalls will stand until excavation is completed. Ir! that case the silo is dug and a
sheet metal or wooden form, about four feet high, is used for the inner form and the
earth wall for the outer form. The wall is built in sections from the bottom upward,
the form being raised after each section has been completed or the Walls may be lined
with one thickness of bricks laid in cement mortar.

The concrete should be made of 1:2 :4 mixture (one part-cement and two
parts sand, four parts crushed rock or clean gravel, or 1:4 (one part cement and
four parts clean sharp sand.)

Concrete Collar on Black Wax Land.

g The soil on black wax land, such as is found in sections of the gulf coast;
country and central Texas, cracks badly in dry seasons, and for this reason it is.
best to make the’ concrete collar thicker than usual. Probobly eight inches thick
will be sufficient, with an extra amount of reinforcement of heavy hog wire and old:
rods.

In many sections of the gulf coast country the water table is of sufficient.
depth to permit the construction of the underground silo, without danger of water
seeping in the silo. A method that has been. used and proved satisfactory so far
in the wax land to prevent the cracking of the ground from cracking the silo collar,
is to’ use plow and scraper in beginning the pit silo, taking oﬁ the top surface for
two or ‘three feet in and around the silo. Upon reaching the desired depth mark-

-out the circles as previously described and dig a trench as much deeper as neces-

sary, preferably allowing it to rest on clay subsoil, then, build forms and extend
them about two or three feet above the surface of the ground. By doing this you,
remove all the black wax soil from the concrete collar for several feet.

When digging use the clay from the bottom of the silo to ﬁll in the exca-.
vation around the collar wall. This will prevent the soil from cracking so badly
around the silo and eliminate, to a great extent, the danger of the cracking of‘
the wall.

Quantity of Material Required.

The farmer is often at a loss to know how much material to arrange for
before beginning the construction of his silo. The following suggestions are for the
purpose of giving a general idea of the amount rejuired. For further information
concerning the use of concrete on the farm, make request of the U. S. Department
of Agriculture, Washington, D. C., for Farmers’ Bulletins No. 461 and 481.

A silo 28-feet deep, 14 feet in diameter, having a four foot collar, six inches
thick, and 24 feet of plastered wall below the collar of one inch thickness, will under-
ordinary conditions, require approximately 20.2 sacks of cement, 1.48 cu. yds. sand,
3 cu. yds. gravel for the collar, and 41.34 sacks of cement, and 3.1 cu. yds. of sand
for the plastering, making a total of 61.54 sacks of cement, 4.58 cu. yds. of sand
and 3 cu. yds. of gravel or crushed rock for the entire silo.

The following table applies to ordinary materials and covers the usual range-
of proportions.

By this table may be determined the quantities of materials required for
the above silo,which contains 3.374 cu. yds. of concrete in the collar made of a
1.2:4 mixture, and 3.277 cu. yds. in the plaster wall below the collar made of a,
1:2 mixture.’

We ﬁnd by the table that for each cubic yard of concrete (1:2 :4 mixture).

' 15

there will be required six sacks of cement, .44 cu. yds. of sand and .89 cu. yds.

of gravel. Then for 3,374  yds. of concrete ‘the quantities required will be
3.374x6—20.2 sacks of cement, 3.374x.44-—1.48 cu. yds. sand and 3.374.89 3'
cu. yds. of gravel. _

We ﬁnd by the table that for each cubic yard of plaster (1:2 mixture) there
will be required 12.8 sacks of cement and .95 cu. yds. of sand.

Then for 3.277 cu. yds. of plaster the quantities required will be 3.277x12.8-—
41.34 sacks cement and 3.277x.95—3.1 cu. yds. of sand.

Quantities of Material Required for Various Mixtures of Mortar and Cement.

 

 

 

_ _ Resulting l Quantities of Cement, ‘Sand and Pebbles or
Mlxture Materlals for Volume in l Stone Required for one cubic Yard of
one Bag Batch Cu. Ft.  Compacted Mortar or Concrete.
l O g g2 gm“ g 9 9 Sand  Stone or Pebbles
m _ _ ﬁr»
$5 5"‘?-  é; E g2? .
l;“3 9* l3 55 " l i? i?’ Cu. Ft. Cu. Yd. Cu. Ft. Cu. Yd.
I 5' I I 8 I E 5'
_1=11/2 l 1 | 1.5 1.751 15.5 23.2» .85 I l
1:2 l 1 l 2.0 2.1 l 12.8 _ 25.6 .95 l
l” 1 i l 3'3 l i‘? l 158 55'? l3‘? l
1:3 . . . . .
112:3 l 1 l 2.0 l 3.0 l 3.9 7.0 14.0 .52 I 21.0 l .78
1:2:4 l 1 l 2.0 4.0 l l 4.5 6.0 12.0 .44 l 24.0 l .89
1;2%=4 l 1 1 2.5 | 4.0 _ 4.8 5.6 14.0 .52 22.4 l .83
1:2%:5 | 1 l 2.5 l 5.0 5.4 5.0 12.5 .46 l 25.0 l .92
1:316 l 1 3.0 6.0 6.4 4.2 12.6 .47 25. l .94

(Based on tables in “Concrete, Plain and Reinforced,” by Taylor & Thompson).

Selecting Materials.

Cement.——~Cem6I1t absorbs moisture from the atmosphere very readily, and
if kept in a damp place it soon becomes caked or hardened, and should not be used
in concrete work. Lumps, caused sometimes by heavy pressure in the storehouse,
are not injurious, as they may be crushed readily between one’s ﬁngerswith light
pressure. Select a dry tight shed with ﬂoor raised from the ground, in which to
store cementtill used. In storing cement, wooden blocks should be placed on the
ﬂoor and covered with boards; after piling the cement on boards cover with canvas,
rooﬁng paper, or other such material, and do not pile it against the outside wall.
Much cement has been ruined by failure to observe these precautions. If it should
contain lumps that are not very easily crushed they should be screened out and re-
jected. It is always wise to order a few extra sacks of cement if the dealer is at
considerable distance, as by doing so one may avoid trouble caused by shortage.
The left over cement, if any, may be used in repair work about the farm.

Sand.—Sand from the bank or creek should usually be screened before using
in the concrete or plaster work. It should be clean, coarse and free from vegetable
matter. Exceedingly ﬁne sand should not be used. If it is of such ﬁneness that
over 50 per cent. of the bulk of sand will pass through a 40 mesh screen, when set
at an angle of 45 degrees, it is generally unﬁt for concrete Work. A 40 mesh screen
means one with 40 holes to the lineal inch surface. Particles that will pass through
a one-quarter inch screen are considered sand; coarser particles being considered
gravel. If there is a large quantity of ﬁne sand, get coarse sand and mix the two
sands together in equal parts. If the sand is very ﬁne increase the cement 10 per
cent. The sand should not contain more than 10 per cent. of clay. To determine
this the following test should be used:

16

 

A common method of testing sand for vegetable 10am is to take a handful
of the moist sand from the bank and rub between the hands. If the palm and
ﬁngers are covered with a ﬁlm of pasty slime, the sand contains vegetable matter
and should be washed before using. -

The coarseness of the sand can be felt, or can be determined by a screen and
the vegetable matter can be seen, but the amount of clay or loam can not be de-
cided in either of these ways. Four inches of sand should be put in apint preserving
jar and when the jar has been ﬁlled with clear water to within an inch of the top,
the lid should be fastened on and the jar shaken vigorously for ten minutes. The
jar should then be rested up-right and the contents allowed to settle. The sand

‘will settle in the bottom, leaving the clay and the loam on the top and the water

above them. If more than one-half inch of clay or loam shows, the sand should be
rejected or washed. The difference in color and ﬁneness shows clearly the line of
division between the clay or loam and the sand. ‘

“If the sand must be washed, the simplest way is to build a loose board plat-

form, from 10 to 15 feet long, with one end 12 inches higher than the other. On

the lower end and on the sides and edges a piece two inches by six inches should
be nailed to hold the sand. The sand should be spread over the platform in a layer
three or four inches thick and washed with a three-fourth inch garden hose. The
washing should be started at the high end and the water allowed to run through the
sand and over the two-inch by six-inch piece at the bottom. A small quantity of
clay or loam does not injure the sand, but any amount, over 10 per cent. should be
Washed out.

Gravel.-—The gravel should be cleaned, free from clay, loam and vegetable
matter. The size for best results should range from one-fourth inch to one and
one-half inch in diameter. In handling creek or bank material, ﬁrst a one-fourth
inch screen should be used to keep out the gravel and then the material which has
passed through this screen should be screened again over a 40 mesh screen for the
sand; all the material which passes_ through the 40 mesh screen should be rejected.”

Dirty gravel should be washed in the same way as dirty sand. The dirt
can usually be observed without making test. ~

Mixing Materials.

Mixing‘ Boarcl.-—A water tight mixing board for two men should be about
9x10 feet made, preferably of 1x6 tongued and grooved plank to prevent the water
from washing away the cement; two sides and one end of the mixing platform
should have a strip nailed along the edge, projecting about two inches above the top
of the platform to prevent materials from being washed off of the platform while
mixing. The boards are so laid as to enable the shoveling to be with, and not against
the cracks between the boards. The boards must be nailed close to prevent the ce-
ment grout from running through while mixing. Place the board level and locate
it as close as possible to the forms in which the concrete is to be deposited.

Measuring Box.—-A measuring box should be used whether or not, the mixing
is done by hand or machinery. A bottomless box can be made of one or four cubic
feet capacity. If a four cubic foot box is made, marks on the inside of the box
should be made to indicate capacities of 1, 2 and 3 cubic feet. In using the measur-
ing box set it on the mixing platform, ﬁll with the required amount of sand, then,
raise the box and spread the sand out level over the board in a layer three or four
inches thick; next add the cement, which need not be measured, as one sack (weight
94 lbs.) may be considered one cubic foot. Spread over the sand in an even layer,
after which mix with square point shovel, turning the cement and sand two or three
times or more, until the mixture is of a uniform color. When ﬁnally ﬁnished every

17

particle of sand and gravel should be coated with cement. In hand mixing do not

Imake up a larger batch than can be placed in thirty minutes.

Wet the gravel thoroughly, then measure out and spread in a layer over the
sand and cement, and mix all the material by turning with shovels, then add Water

while the mixture is being turned, until the desired consistency is obtained.

After water has been applied to cement it begins to harden or “set” in abozii;
thirty minutes. To disturb the concrete after this initial set has started or is well
under way, means a loss of strength, or possible destruction of the concrete.

Water Required in -Mixing.-When sand is moderately damp, a quaky jelly
like mixture may be produced by using water in the proportion of one gallon to
one cubic foot of concrete in place, or about ﬁve gallons of water to one sack of
cement. The amount given is approximate. If the sand is dry or the gravel a
little porous, more water will be required. The water should be measured carefully
for the ﬁrst batch. If the material contains a large amount of moisture, less water
should be required. Do not use so much water as to make the mixture sloppy. The
water used for concrete should be clean and free from strong acids and alkalies.

Placing Conerete.—-Concrete should be deposited in a layer or layers of uni-
form depth, all around the trench or form, not deeper than the length of the blade
of the spading tool being used. In placing the concrete in a trench where forms
are not used, boards or planks should be laid around and across the trench for the
workers to stand upon when dumping and spading the concrete, so as to prevent
knocking down earth from the sides of the trench in to the freshly placed concrete.

Care of Fresh Concrete and Plaster.-—After concrete has been placed, it
should not be exposed to the hot; sun for four or ﬁve days, especially during the hot
summer months. During this period the concrete should be Wet down by sprinkling
Waterion the Walls, both night and morning, or the Walls may be covered with old
burlap, canvas or other such material, placed so as to hang an inch or so away from
the face of the concrete when wet. This will serve very well as a protection. It
is also best not to allow a green cement mixture to freeze. If it should freeze
after placing, and is not subjected to any load until it has thawed and allowed to
“set” in the usual way, the binding qualities do not seem to be affected.

Stopping for the Day,

It often occurs that the work of placing the concrete is stopped before the
forms are ﬁlled. In this case the concrete may suffer suﬂiciently so that the fresh
concrete will not bond to it readily. This may take place, even in an hour or so,
in warm weather. The concrete last placed should be roughened by scratching with
a stick to prepare for a good bond with fresh concrete when the work is resumei.
Immediately before resuming concreting, the surface of the old concrete should be
washed off and painted with a mixture of cement and water to a consistency of thick
cream, and applied just in advance of placing the fresh concrete.

Filling the Silo.

Packing Silage.-——A silage conveyor connected to the cutter, is preferred by
some. It may be made of galvanized iron in sections or of canvas. It is necessary
to have two or more men in the silo, whether a conveyor is used or not; if not a
hopper should be arranged to allow the silage to drop in the center of the silo, and
the men with forks can distribute the silage and tramp it evenly both around the
edge and the center of the silo. By ‘tramping the center, as well as the edge the
silage will settle evenly and toward the wall and not away from it. No silage has
been lost by packing, but many have lost silage from lack of packing. After the
silo is ﬁlled a few days it will settle ﬁve to six feet in a 30-foot silo, after which
several more tons may be put in. When the silo is ﬁlled it is well to run a few

18

 

loads of straw, old hay or some less valuable feed on top of the silage for covering.
Wet it well and pack thoroughly, or six or eight inches will decompose 0n the top
of the silo.

Silage Cutter.-—A six or eight horse power engine will furnish abundant
power for a 12-inch cutter without a blower elevator which is not required with the
pit silo. This is perhaps the most practical outﬁt for the average farmer. Where
the elevator blower is required with the average above-ground silo it will take a
twelve H. P. engine to pull a 12-inch cutter.

Watering Silage.-—It may be necessary to run water in with the silage when
cutting, if the crop has stood too long and become somewhat dry. A small stream
turned on the silage as it leaves the cutter will wet each particle thoroughly as it
goes into the silo, causing it to pack well, thus excluding considerable air, and pre-
vent spoiling. The amount of water to use will depend upon the condition of the
crop. There is not much danger of using too much water on a dry crop. Enough
should be used to replaceithe water lost by the crop through drying. When the
grain becomes a little glazed and the bottom leaves a little brown, the crop is in
good stage for the silo. If perfectly green, the addition of water is usually not re-
quired. It is better to have the crop too ripe than immature. As the plant ripens
the total weight of dry matter increases very rapidly, hence harvesting before time
is wasteful and mature crops make a better grade of silage.

To avoid loss of space at the top of the silo caused by the settling of the
silage, while ﬁlling, place a temporary picket fence, or such material, on the top of
the collar ﬂush with the inside edge of the wall. Fill this with silage and pack
well. When the silage has settled, very little space will be wasted below the top
edge of the curb. Then remove the temporary fence wall. _

Precaution.

While ﬁlling the silo and for the ﬁrst few days, after silage is put into the
silo, carbonic acid gas is generated very rapidly. If the air is very still a suﬁicient
amount may accumulate over the silage to make it impossible for a man to live in
it. If the work is stopped for several hours or a day or two while the silo is being
filled, or if it should stand empty or partly so far some time without being entered,
care should be taken not to enter it upon resuming work until, the silo has been
tested for gas. If gas is present the machinery should be‘ started. The falling
silage will stir the air up suﬁiciently to render it pure enough to work in, but it
should be tested again before entering. One may throw in a few bundles of hay
or loose sacks; this will create a current sufficient to displace any gas that may be
present.

One can easily detect the presence of gas by lowering a lighted lantern or
a chicken t'nto the silo. If the light goes out, or the chicken dies, gas is present;
but if undisturbed, there is no gas. By observing this precaution at the time of
ﬁlling, by continual use after the silo is opened for feeding, and by having top
ventilation, the trouble is eliminated.

The writer has made diligent inquiry for the past few years, but has failed
1o ﬁnd any instance where gas has been found in an underground silo, but it must
rot be understood from this statement that gas may not occur. Since it may be
present, the silo should be tested, as it takes only a minute.

With reference to gas forming in pit silos, C. I. Brady and D. L. Foster (De-
partment of Animal Husbandry) in an Oklahoma Bulletin (Silos in Oklahoma)
makes the following statement:

“Suifocation from carbonic acid in pit silos, while possible has perhaps been
over-emphasized. The formation of gas in quantities large enough to be danger-
ous ceases in about ten days after ﬁlling the silo.”

19

Plenty of time should be given the cement. to cure before ﬁlling the silo-
possibly 10 or 15 days. One instance is known where a silo was ﬁlled four days
after completion-—the result was that_the plaster cracked to the extent that the
silo had. to be replastered after removing the ﬁrst silage.

Feeding Livestock.

For information on the subject of feeding livestock write to the Extension
Service of the A. and M. College, College Station, Texas.

Removing the Silage.

The removal of the silage from the underground silo is often urged as an
objection; however, the writer has never heard of a man having an underground
silo who offered this as an objection. It is usually those who have not tried the
underground silo. It should be remembered that the underground silo is very
cheap. A blower is not required with the cutter and only one-half the engine power
is needed to operate the cutter which is necessary when silage is elevated into a
silo above ground. The saving of expense in the size of the engine, and the elimi-
nation of the blower, will pay for an underground silo in many cases.

Hoist and Derrick.——In hoisting the silage a number of devices may be used——
the common hand Windlass with system of double pulleys, proving very satisfactory.

Figure 8.—-—A one H. P. gasoline engine placed on a revolving derrick, between a group
of four underground silos,iused for hoisting silage. It was also used
in removing the dirt while digging the silos. g

A swinging derrick, in connection with the windlass and pulley, or a block
and tackle, may be used in raising silage by horse-power. Where a large silo and
an extra large swinging derrick is used, an ordinary truck bed 1O"x31/2” can be
used in removing the silage. Build the crane high enough to allow the bed "-0
swing the truck wheels when lifting to and from the silo.

The common hay carrier and track may be used with, or without shed very
conveniently. A hoisting frame may be made consisting of a tripod made of poles
set up on one side of the silo and a scissor frame, made of similar material, on the
other. The latter may be-extended beyond the silo a sufﬁcient distance to allow

20

a wagon to pass be-
tween it and the silo.A
2x12 may be fastened
between these supports
and an ordinary hay-
fork-carrier-car attach-
ed to this will elevate
and carry the dirt oi:
silage. This track may
be extended, as far as
necessary, t0 the barn
or feed pens.

In this way a trip
bottom box, holding
several hundred lbs.
of silage may b e
handled with very lit-
tle trouble, as it can
be emptied from the
hoisting box directly
into the feed trough.
The box may be con-
veniently pulled up by
horse power or gaso-
line engine.

11) is patented by W.
J. Knorpp, Broom, Tex-
as, and may be bought,
or the farmer may rig
up a home-made hoist
that is probably not 4S
efficient, but will ans-
wer the purpose. ‘
The hoist is built
over the silo and sup-
ported by a frame, or
trestle made of 4x4’s.
The hoist works on the
principle of a hand
freight elevator.

Figure 9.——Shows the same engine as ﬁgure No. 8 in addition in re- The holst conslst?
{fﬁlgllglftﬁﬁeliflck is pdlaced betﬁiveenzamggroup olf foununderground silos. of one large pulley

as raise as muc as poun , th 1 1 ' - _
pounds. Total cost of the four silos, derriclsi and leﬁiglneogg8lis legal‘. Wheel’ about 24 Inches
silo 15x25; encountered rock while digging, collar 4 1-2 inch’es by in diameter 011 a ShOTC

20 ' h d 1 t d .
2 ‘inches an p as ere walls . 3X16 t0 WhlCh lS keyed
a Ziinc cog wheel. This small cog meshes with a large cog wheel about 2O inches
 dametel‘,_which is bolted or keyed to a long axle, or drum, on which the rope
w? s tflliat lifts the feed box. An endless rope or chain runs over the large pulley
goiee thrsizf nilentioned and extends into the silo. By.this arrangement the man
ng e ee ing rides on the box going down, controlling the speed of the descent
by the endless rope. The box is ﬁlled with silage and the man rides the bux up
lifting both his own weight and that of ztlhe silage by pulling on the endless rope.

The hoist (Figure

With the approximate back gear mentioned. above, ‘a man should be able to lift his
o'wn weight and at least 1500 pounds of silage, without great effort.

Roof for the Silo.

It is best not to build a roof over the silo, as it prevents free circulation of
air and it is also in the way, both while ﬁlling the silo and in removing the silage.
Some provisions should be mJade for a fence to keep- stock or small children from
falling in the silo if the curb is very low.

Points to Keep in Mind.

While constructing an underground silo the following points must be kept
in mind, in order that it may give the best satisfaction:

1. The silo must be located where the water table is below the bottom of
the silo. .-
2. The silo as a rule should not be more than 30 feet deep——depth about
twice the diameter.

Figure 10.—A home-made track for carrying the silage box to feed pen.

3. The silo must have a collar extending about two feet, both above and
below the surface of the ground, made of concrete 1:2 :4 mixture.

4. The walls should be plastered with cement from one to one and one--
half inch thick, with cement and sand (1:2 mixture). If dirt wall is dry dampen
Before applying cement.

5. Wash the walls with cement and water reduced to a consistency of thick
cream; then paint with coal tar, thinned with gasoline, or with gas-tar as described.

6. Walls must be perpendicular and smooth.

7. Bank dirt up around the concrete collar, so as to shed surface water.

8. Wet cement collar and walls twice each day for a week after completion,
keeping them covered during this time.

9. Remove soft strata and spongy spots, if any, in wall. Fill in with brick
of cement.

10. Select clean, coarse sand and gravel for concrete and plaster work.

11. Do not allow dirt to fall in fresh concrete while placing.

22

 

Advahtages of the Underground Silo.

The following are some of the advantages of the underground silo, brieﬂy
stated:

1. The expense of constructing an underground silo is very small, labor
being the chief item.

2. The average farmer can construct one with the ordinary hired labor,
as it requires little skill or outside help. i

3. It will keep silage indeﬁnitely, when well packed. Feed may be carried
in reserve for droughty seasons. .

4. The ﬁlling can be done with little cost; the cutter does not require a
blower, hence only half the engine power is necessary to operate the cutter as re--
quired where a blower is used. -

5. It is a permanent improvement; will not blow down ,burn up, and re-
quires practically no repair.

6. Does not require expensive forms in construction.

7. Since they cost but little they are in reach of the farmer with limited
means. He may have two-keeping a small one for summer feeding.

Figure 11.—-The frame work and hoist above the silo as described above and carrier
track extending over a continuous feed trough.