S3 PRACTICAL WIRE ROPE INFORMATION And Useful Information on the Drag-Line Cabieway Excavators H. B. SAUERMAN Price 20 cents PRACTICAL WIRE ROPE INFORMATION And Useful Information on the Drag-Line Cableway Excavators H. B. SAUERMAN Price 20 cents <^^ Copyright 1910 BY H. B. Sauerman r ! (0 )CI.A4;U7!i3 im -1 1916 CONTENTS Page t^ The Conslructioii and tlic Properties of Wire Rope ~ Table of Comparative Strenofh of Wire Ropes S The Al)tisc and L'se of Wire I'iojie 13 Careless Handling 13 How to Uneoil A\"irc Rope 14 Poor Installations 15 Abrasion i() Excessive and Short liending 17 Careless ()])eration 17 Poor Lubrication 18 Main Points to P>e Considered ig Wire Rope Fittings 21 Thimble and Clips 22 Socketing Wire Rope 23 The Long Splice 25 Wire Rope Connections 27 Tackle Pdocks 27 A Home-Made Rope Lul)ricant 29 The Dragline Cableway I{xca\'ator 30 Masts and Towers 3 Guy Cables 33 Anchors t,^ Track Cal)le 33 llridle Cable 35 Bridle Frame 35 Shifting- the Bridle Frame 35 The Load and Tension Cables 36 Tension and (kiide Blocks 36 Cable Fastenings 36 Bucket, Carrier and Dumping Device 36 Hoists 38 Adaptability 38 Uses 40 — 3— :> FOREWORD H'hc universal use of wire rope for hoisting, conveying and also carrying material over large spans proves conclusively that wire rope renders a very important service in the engineering field. The economic use and service of wire rope depends largely upon the construction, the material composing the rope, the in- stallation and the care it receives both before and after it has been put into service. Many wire ropes have been ruined before they were ever installed, and this was due entirely to the lack of knowl- edge of the properties of wire rope. If selected, installed and used with reasonable care, wire rope becomes one of the most economic servants in the engineering field. This book has been prepared to assist the user of wire rope in getting the best results and the most economic service with the use of wire rope and wire rope appliances. In preparing this book the aim has been to set forth the practical knowledge and ex- perience obtained in the field and on the work. Technical calcula- tions have been omitted. The information on the Dragline Cableway Excavator is in- tended for all who are interested in the economical handling of material. HENRY B. SAUERMAN, Member American Society of Civil Engineers, Member Western Society of Engineers. Copyright 1916 by H. B. SAUERMAN THE CONSTRUCTION AND THE PROPERTIES OF WIRE ROPE. Wire Rope is made of wires, either twisted together or laid parallel to each other. The first mentioned is in general use for lioisting, conveying and power-transmission; the other is used only on the large suspension bridges. Ropes differ in respect to their construction as follows: (i) their cross-section being flat or round; (2) the number and shape of the strands; (3) the number, size and shape of the wires in the strand; (4) the lay of the wires with respect to the lay of the strand. Flat wire ropes consist of a number of wire strands which have been laid side by side and sewed together with annealed wire. Round wire ropes are made up of a number of wire strands twisted around a core of hemp or around a wire strand. The standard wire rope is made of six wire strands laid up around a hemp core. The wire strands are laid around the core either to the right or to the left and the rope is thereby designated as right lay or left lay. The twist or lay of strand may be long or short. The shorter twist forms the more flexible rope ; the longer twist the more rigid rope. When the strands and wires composing same are twisted or laid up in the same direction, the rope is known as "Lang" lay. The Tiller Rope is made up of wire ropes which in turn are made up of wire strands. These wire ropes are laid around a hemp core, resulting in a very flexible rope. The wire strands are made of wire twisted together. The number of wires commonly used are four, seven, twelve, nineteen and thirty-seven, all depending upon the nature and condition of the work for which it is intended. The wires are made from the following materials: (i) Iron; (2) Crucible Cast Steel; (3) Extra Strong Crucible Cast Steel; (4) Plow Steel; (5) Improved Plow Steel. The ultimate strength of these dififerent wires is as follows: Iron, 75,000 to 100,000 lbs. per sq. in. Crucible Cast Steel, 1 50,000 to 200,000 lbs. per sq. in. Extra Strong Crucible Cast Steel, 180,000 to 220,000 lbs. per sq. in. Plow Steel, 200,000 to 260,000 lbs. per sq. in. Improved Plow Steel, 220,000 to 280,000 lbs. per sq. in. The twisting of tlffe wire and strands in laying up the wire ropes reduces the strength of the individual wires from lo to 15 per cent. The elastic limit of iron wires is about 75 to 80 per cent of the ultimate strength of the wire. The elastic limit of steel wires is about 65 to 70 ])er cent of the ultimate strength of the wire. Crucible Cast Steel Rope has about twice the strength of iron rope. Extra Strong Crucible Cast Steel Rope is about 15 per cent stronger than the Crucible Cast Steel Rope. Plow Steel Rope is about 25 per cent stronger than the Cruci- ble Steel Rope. Improved Plow Steel Rope is about to per cent stronger than the ordinary Plow Steel Rope. Table of Comparative Strength of Steel Wire Rope. Ultimate Strength in Tons (2000 Lbs.) of Wire Rope DIAMETER DESCRIPTION V 4' r r ;- •• la U' IS' ir 11' n- .!«' 2' 2J' 2i' 23- 6/7 Cast Steel 4 6 7 7 13 IS 6 ?4 31 37 46 53 63 6/7 X Strong C. Steel.... 5 25 8.85 14,5 21.0 28 35 43 54 63 73 6/7 Plow Steel S 9 in n 16 n 23 n 31 38 47 60 72 82 6/7 Improved Plow Steel. 6.5 11.0 17.5 25.0 33 42 52 67 79 90 6/19 Cast Steel 4.8 8.4 12,5 17.5 23 30 38 47 56 64 72 85 96 106 133 170 211 6/19 X Strong Cast Steel. 5.3 9,2 14,0 20.2 26 34 43 53 64 73 83 99 112 123 160 200 243 6/19 Plow Steel 5.75 10.0 15.5 23,0 29 38 47 58 72 82 94 112 127 140 186 229 275 6/19 Improved Plow Steel 6.75 12.1 19.0 26,3 35 45 56 69 84 98 110 133 150 166 210 263 315 The hemp center or core of a wire rope performs the follow- ing service: First : The hemp core forms a soft cushion for the strands of the rope to bed themselves into and work upon. Second: The hemp being a much softer material than the metal of which the strands are composed, it protects the wires of the diiferent strands against internal wear. Third: The hemp core being elastic and also compressible, it acts as a cushion to absorb more or less of the strain when a load is suddenly applied. Fourth: The hemp core is lubricated and therefore preserves itself as well as the wires of the rope internally from corrosion, and further affords lubrication for the rope. If the wire strand is used for core it will increase the strength of the rope from 7 to 10 per cent. l)Ut it will wear frcnn the friction between it and the other strands and this wear will l)e as rapid as the wear on the outside of rope. This does not appl}- to ropes that are used for guys or other stationary work. The different constructions of ropes are usually specified as follows : 6 strands 7 wires each. si)ecifled as "haulage rope." 6 strands 19 wires each, specified as "hoisting rope" (scale type). 6 strands 19 wires each, s])eciried as "hoisting rope." 6 strands Ti,"/ wires each, specified as "special flexible rope." 8 strands 19 wires each, specified as "extra flexible rope." 6 strands 12 wires each, specified as ''running rope." 6 ropes, 6 strands 7 wires each, specified as "tiller or hand rope." In specifying a rope construction the practice is to specify the number of strands first and the number of wires in each strand last: thus, 6 strands 19 wires is usually specified as 6x19. The 6x7 haulage rope is used for haulage, power transmission, oil well lines, and for work where surface wear is the main consider- ation. It is also used for guys and ship rigging. The 6x19 hoisting rope is used for general hoisting work, such as elevator work, derrick work, mine hoists, inclined planes and haulage lines where the abrasion is not severe and where flexibility is the main consideration. The 6x19 hoisting rope scale type, in which the 19 wires are placed 9 around i) around i and in which the middle coils of strand wires are of smaller diameter than the others is used for all work where a rope is required of intermediate flexibility or adaptability to withstand abrasion, between the standard ropes of 7 wire and 19 wire strands. The 6x37 special flexible rope composed of 6 strands of t,"/ wares each (18 around 12 around 6 around i wire) is used where great strength is desired in combination with a high degree of fiex- ibilit}^ It is used in logging operations and also for hawsers, in which case the wires are galvanized. The 8x19 extra flexible rope composed of 8 strands of 19 wires each (12 around 6 around i) is produced to meet the recjuire- ments wdiere greater flexibility is needed than is possessed by the standard 6x19 rope. As the hemp core of this rope is larger than the core of a 6 strand rope, this rope is not as strong as the 6x19 standard hoisting rope or the '^x37 special flexible rope. Due to the large core, it will also flatten out under heavy pressure. Its sur- face, however, is more closely a cylindrical shape, resulting in a better distribution of wear. It is used for derrick work and where —9— rope has to run aroufld small sheaves with comparatively light loads. It is also used almost exclusively for bull wheels on derricks and steam shovels. The 6x12 running rope, also called hawser or flexible running rope, consists of 6 strands of 12 galvanized wires each encircling a fibre cord. It is used mostly for hawsers and for running ropes in the rigging of ships. These ropes are also made with 6 strands of 24 galvanized wires each; such ropes are nearly as pliable as manila ropes of equal strength. The tiller rope consists of 6 small 7 wire ropes laid around a hemp core. It is used extensively for operating tillers, as hand ropes for operating elevators and for work where extreme flexibil- ity is necessary. The non-spinning hoisting rope, consisting of 18 strands of 7 wires each, 12 of which are laid in the reverse direction around 6, receives its name from the fact that it has little or no tendency to twist or turn in operation. The size of wires is the same as for the standard hoisting rope for a given diameter. It has 126 wires where the standard hoisting rope has only 114. This rope cannot be spliced. Lang-lay ropes are used to good advantage for all kinds of haulage work, especially in the endless rope systems where grips are used. They are also used in mine shafts or hoists where the cages run in guides. The principal objection to Lang-lay rope is its tendencv to untwist, and it should, therefore, not be used where loads are lifted in free suspension. It is very hard to splice to rope of the ordinary lay. The principal advantages of the Lang-lay rope are the in- creased distribution of surface wear and greater pliability. The flattened-strand wire ropes have been produced for work where a larger and smoother wearing surface is necessary than can be obtained with the round strand ropes. In these ropes the strands have an elliptical or triangular cross section. This cross-section is produced by an elliptical or triangular metal center in each strand. The rope has either a hemp core or a wire core. The advantage claimecl for these ropes, in addition to the increased wearing sur- face, is flexibility with a decreased tendency to spin or kink. Armored or steel clad hoisting rope is sometimes used where the ordinary hoisting ropes wear out quickly. This type of rope has each strand served with flat steel strips. This flat covering gives considerable additional wearing surface. The steel covering does not add anything to the strength of the rope. Flat ropes are usually made up of a number of loosely twisted four-strand ropes without hemp cores placed side by side. The strands are sewed together with annealed wire. There are several advantages in using flat ropes, namely, there is no tendency to —10— 6 Strands, 7 Wires (1 Hemp Core) TRANSMISSION HAULAGE OR STANDING ROPE 6 Strands, 19 Wires (1 Hemp Core) STANDARD HOISTING ROPE 6 Strands, 37 Wires (1 Hemp Core) SPECIAL FLEXIBLE HOISTING ROPE 8 Strands, 19 Wires (1 Hemp Core) EXTRA FLEXIBLE HOISTING ROPE 6 Strands, 12 Wires (7 Hemp Cores) RUNNING ROPE 6 Strands, 42 Wires Each (7 Hemp Cores) TILLER OR HAND HOPE PLATE No. 1 — n— 18 Strands, 7 Wires (1 Hemp Core) NON-SPINNING ROPE Type A 5 Strands, 28 Wires to the Strand (1 Hemp Core) Type B 6 Strands, 25 Wires to the Strand (1 Hemp Core) STEEL CLAD HOISTING ROPE SMOOTH COIL TRACK CABLE LOCKED WIRE TRACK CABLE PLATE No. lA —12— twist; as the rv])v winds on drum llu- conical drum ettect can thus he in-oduced: and in Ik listing the rope is always in the same vertical plane. Locked-wire ropes have a smooth cylindrical surface, the outer wires of which are made of such shape that each wire interlocks witli the other and the inner wires are disposed in concentric layers around a wire core. Owing to its large and smooth wearing sur- face it is used extensively for track cahles in aerial tramway work and for cableways where a stationary track cable is used. Plate No. I and Plate No. i-A illustrate the different construc- tions of ropes. It is very apparent from these illustrations and from the foregoing description that not one type of rope is suited to give good results and service in all kinds of work The rope should be carefully selected which experience has found to be the best suited rope for the work under consideration. In other words, "Get the Right Rope for Your Work," and this applies both to the construction and the material composing the rope. This is the first step towards a successful and economic rope installation. The lowest priced rope does not always prove to be the cheapest, nor does the highest priced rope under all circum- stances give the greatest service per dollar of cost. Requisitions for wire rope should be accompanied by full information as to the conditions and requirements of the work for which the rope is intended to be used. Information as to the weight of loads, in- clination of slopes, diameters of sheaves and drums, angles of bends, etc.; is very essential in determining the kind and grade of wire rope best suited for the work. THE ABUSE AND USE OF WIRE ROPE. We mention "abuse" before "use" in our heading because wire rope is ofttimes abused before it is used. Wire rope can easily be abused. The following are some of the most common abuses to which wire ropes are subjected: 1. Careless handling. 2. Poor installation. 3. Abrasion. 4. Excessive or short bending. 5. Careless operation. 6. Poor lubrication. Careless Handling. One of the most common abuses of wire rope is Careless Handling. Large wire rope reels are sometimes dropped from cars, regardless of the obstructions which may lie in the way of the —13— reel. Many a wire ropi has thus been mined by dropping same on a rock with sharp edges or other forms of obstruction. The proper way to unload a reel or heavy coil of rope is to bring several heavy planks or timbers on an incline up to the side of the car and then lower the reel or coil to the ground by slowly rolling or sliding same down the inclined timbers. Wire rope is sometimes ruined by dropping the reel or coil into water containing acid or other destructive agencies. Rope exposed to the elements for any considerable length of time before being put into service will have a tendency to rust. If exposed to the sun for a long time the core will have a tendency to dry out, thus reducing the wearing cjuality of the rope. Placing rope under shelter before putting" same into service cannot be too strongly recommended. HOW T-O UNCOIU NA/IRE. ROPt FiO. I Fi«3. 2 Fi<3.3 FIQ.-4- flGUKES I, 2 Also 3 SHOW THC. KJOHT WAV Or UNCOII.INS \^/IRC: ROT»C FIGURED- SMO\*/6 TME. VVRONQ \A/AY. -THIS IS SURE. TO BRINQ KINKS ir* ROF»c Kinking the wire rope by careless uncoiling is another very common abuse. Figure i shows the proper method of unreeling wire rope from a reel with the axis of reel in a horizontal position. Figure 2 shows the proper method of imreeling wire rope with the axis of reel in a vertical position. Figure 3 shows the proper method of uncoiling a wire rope from a coil. The coil should always be held in a vertical position as shown in cut and rolled along ground. —14 — Figure 4 shows the improper method nf uncuiHng wire rope. If tliis inclhixl is followed il is sure to produce kinks. Figure 5 shows tlie start of a kink. This is simply produced by a loop in the rope. These loops should be carefully guarded against and should be thrown out before any pull is brought on rope. Figure (> shows the loop pulled tighter, but even at this point the damage can be avoided by throwing out the loop. Figure 7 shows the "damage" done. This shows the strands twisted out of place with some of the wires partly twisted. Figure 8 shows the kink pulled tight with the wires badly twisted. Figure 9 shows the rope after an attempt was made to straight it out, with the result of breaking wires and leaving the strands twisted out of place. Fie s "HE START OF" KITSK Fie ->-ED TISHT Kinking of wire rope can easily be avoided by following the proper methods as outlined in Figures i, 2 and 3. Kinks can never be straightened by pulling on the rope. Wire rope is also ofttimes abused by improper hitches, drag- ging same over sharp obstructions or by making sharp bends when putting the rope in place. A little judgment and care will avoid these abuses and will be amply repaid by the extra service obtained from the rope. Poor Installations. The improper selection of wire rope applied to both the con- struction and material composing same is the first step toward a poor installation. The author has seen an installation where a five- eighths-inch rope made up of six strands and thirty-seven wires to each strand was used. This rope was used on a dragline cableway —15— excavator where abrasion of sand and gravel was the chief consid- eration. The reader can readily imagine how long the fine wires in the rope lasted and what better service could have been obtained with the standard 6xio hoisting rope wdiich has the coarser wires. Other installations have been made where the grade of steel of the wire rope was entirely unsnited for the work and the conditions. The author desires to impress on the reader's mind that the cheapest rope for his work is the rope that gives him the greatest service per dollar of cost, and that this can only be obtained by getting the right constructed rope, made of the proper grade of steel for the work under consideration. To get the right rope it is well to consult a competent wire rope engineer. Installations where sheaves are poorly aligned so as to cause chafing and abrasion, where sheaves are used of very small diam- eter, where the wire rope is made to take numerous or reverse bends, where loads are suddenly applied, where the rope is allowed to sag and where rope is allowed to whip, the results that can be obtained with the wire rope imder such conditions is very question- able. All these faults can usually be avoided by the designer of the installation, if he has had sufficient experience in wire rope engi- neering. Abrasion. Abrasion is one of the worst enemies of good wire rope service. Many wire ropes have been condemned as "rotten" when the fault was entirely due to abrasion. Some work, such as dragline cable- way excavator work, requires that the cables must come in contact with the material, such as sand and gravel. The operator who operates such equipment can, however, avoid considerable abrasion by using some care in bringing" the ropes clear of the material whenever the conditions allow. Wire Rope Showing Effect of Abrasion Abrasion is further caused by poor alignment of sheaves and hoist drums, by sheaves with broken flanges, b}'^ sheaves with eccen- tric holes or bearings, by sheaves which refuse to turn or by ob- structions in the path of the rope. There is one way to avoid abrasion and that is careful inspection and prompt removal of the cause of the abrasion after the same has been located. —10— Excessive and Short Bending. Excessive and undue bending causes the ruin uf many wire ropes. The destructive effect of this abuse has not been sufficiently understood, and owing to this fact bending has not received the proper attention. In practice it is ofttimes found that large diam- eter sheaves are entirely out of the question. The question of Wire Rope Showing Wires Broken from Undue Bending flexibility will then become one of the most important features in the selection of the proper rope for the work in question. Theoretically the curvature should be such that the bending stress resulting therefrom added to the load stress will not produce a tension in the wires exceeding" the elastic limit. Wire Rope Showing Good Wear Short bends are also very destructive to wire rope. One of the most common places to find short bends is at the point of attach- ment. The use of thimbles is strongly recommended. The thimble, if properly used, does away with considerable of the short bending, MOTE. aXRETCH l»* l.OOF>. MOT Al-U OT. THC STRANOSQtT TMCIR SHARE. 0»v. U.OAD. n<5 lO NOTK. aE.NO >N l_0«(> WMtNTHE oAo >s orr AVOIDS BOTH STUCTCH 8f BE. NO. F-|«. U rici.»2 -17— it also helps to distribute the load in the ditTerent strands. Figure 10 and II show the bending etTect where the thimble is omitted. Figure 12 shows a thimble in place and how this eliminates the bending effect. Careless Operation. Wire rope manufacturers sometimes find after furnishing a certain kind and grade of rope which gave excellent service for years, that this same kind and grade of rope does not come up to its past good record. Investigation shows that the installation has not been changed in the least, but further investigation reveals the fact that a new operator is now operating the plant. He is careless, he throws his levers regardless of the vibration and shock caused b)^ throwing his drums in operation. Constant shock and vibration is bound to ruin the best rope. Wire rope does not rec^uire "nvirsing," but it does require the usual care that is generally given the equip- ment operated in connection with wire rope. The author has oft- times observed plants where the hoist, sheaves and bearings re- ceived excellent care and where the wire rope was allowed to drag over logs and through mud and water. A few guide rollers would have increased the rope service manifold. In operating the dragline cablewaiy excavator, some operators, by careless operation, produce a whip' in the track cable. This whip produces the eft'ect shown in dotted lines in Figure 13. This careless operation, if continued, is bound to crystallize and break the wire. BV WHIPPING OR DROPPING CA^UC SUOOtlMUY IT \A/IL.l_ -PAKE THtPOSITION SHo^^/^4 iin dotted uiMta.ir this is C.ONTINUAI-L'V DOME.BV CARtUtaS OF>E.RAT«ON -rHC. WIRC.a» N^lUU CRVSTAUIZE AND BREI^K. ^ >^PA ^jif mM^^^ vvmt^^^^-^fW^^ * I > .»jp ^ M ," I jj > ' j 9 jmj ^ H.B.S- Poor Lubrication. Poor lubrication or entire lack of lubrication has in many cases been responsible for poor rope service. A proper lubricant will not only lubricate the wire and strands, but will also protect the rope —18— against corrosion. Some lubricants will lubricate the outside wires but will not penetrate to the inside wires. Such lubricants should be avoided, as they are worse than worthless. Main Points to Be Considered. Briefly stated, the main points that should receive careful con- sideration in the use of wire rope are as follows : 1. Select the right grade and the right construction of wire rope for your particular work. If in doubt consult a wire rope expert. 2. Use care and judgment when unloading heavy coils and reels so as not to injure the rope. 3. Do not let wire rope coils or reels lie in water. 4. Do not expose wire rope to the direct rays of the sun for a long time before using. 5. Do not expose wire rope to the elements for any length of time before using. 6. Place wire rope coils or reels under shelter. 7. In uncoiling wire rope avoid kinks. Kinks are bound to occur and ruin a rope if an attempt is made to pull out the loop by exerting tension on rope. 8. Avoid abrasion. This can only be avoided by careful and frequent inspection. 9. Use as large diameter drums and sheaves as the conditions will permit. This will avoid excessive bending. 10. Avoid reverse and short bends wherever possible. 11. Use thimbles in connection with attachments wherever possible. 12. Do not run wire rope over sheaves having broken flanges. 13. Do not run wire rope over sheaves having eccentric bear- ings or where the bore of sheave has been worn eccentric. Con- stant vibration due to eccentricity of bore or bearing is bound to crystallize the rope. 14. Align the sheaves properly so as to avoid unnecessary chafing and abrasion. 15. Align the hoist drums with lead sheaves so that the rope will wind properly on drum. 16. Avoid careless operation. 17. Avoid unnecessary whipping and dropping of the rope. 18. Thoroughly lubricate the wire rope with a lubricant which will not only penetrate to the hemp center, but will also thor- oughly cover the inside wires of the strands. —19— Ho\^ to Gauge Wire Rope. Figure 14 shows the correct diameter of a rope. It is that of an enclosing circle, as shown in dotted lines touching the strands. Figure 15 shows the correct gauge of a rope, and Figure 16 RlG. I4-. THE CORRtCT 0»AMi;"rEI? OF A WIREROPC IS THAT OF ACllKCl_C. WHICH CHCUOSES ANO OUST TOuCME.a Tnt OUT Side or strawsss '^'^^wv«' Fl<3. 15 Via [••»•-• ^^_ • ••>•• •'•' a'*! 8 •• 1 ■ 1 a Ravi, Fie. ifc HOW TO GAUG&WlREl F^0F»E: shows the wrong or small gauge of rope. Care should be taken in gauging the correct diameter of rope, not only when ordering a new rope but also when ordering new sheaves. Plate No. 2 shows the ditTerent wire rope fittings usually em- ployed in making attachments. The type of attachment is usually determined by the specific requirements and conditions. The Clip Attachment. On plate No. '3 the pr()])er method of making an attachment with clips and thimble is shown. The first step is to place the thimble from 30 inches to 40 inches from the end of rope and then wire the thimble to the rope. The rope is then brought around the thimble by bringing the short end of rope against body and draw- ing same together at the thimble with a vice or clamp. The clips are then attached as shown in Figure 3 with the first clip at thimble placed with the jaw on the long part or standing part of rope. The second clip is placed as shown with the jaw on the short or lapping end of rope, and the third clip is placed the same as the first. By staggering the clips as shown, tests and actual practice have shown that the greatest holding power is obtained. By tap- ping the clip lightly with a hammer after it has been drawn tight, it will ofttimes be fovmd that several turns can be taken on the nuts. —20— TURN-BUCKUE. Cl_OSE.D OR l_OOP SOCKET OREIN SOCKEZ-T S-rtF" SOCKCT- ^ ^^S '^ l_OOF> SXIRRUP SOCKET <)PCrH ST\RRUF> SOCKET ^ THirvlBUC. AND HOOV OF A \a/ire: rope, and A-r-r/\CH\r^G ci-»PS »s dome BV F=l_ACirMG -THE -THIMBUt ABOUT 30ns»CHtS p-ROM ElfMCS or" ROF'e: aisd wiring t-himbue: to f?oF»E:.. -THE.ROF'EIS BROUGHT AKOUrSD THIMBUC BVBRIMeiMS THE END OrROPt AGAiriST BODV ANDORANVING SAMC TOOtT-HER With A Cl_/SMR F-»e.3 THE F>ROPE.R ARRANCEMEMT Ol^-THE CI_1F»S >S,»rv1F»0^- T/MNT. TO GCT TMC mAXIMUm HOl-OINS RONVCR CUlPS SHOUI_D BE. F'L.ACCD- AS SMQW/N AfcOVt.^T UtAST THRCE CUlPS SHOULD BE USE-D. THIP^BL-EI AND CURS F'uATE: NO.3. HO S. -23— Socketing Wire Rope. The Hist step ill attacliiny" a socket to a wire rope is that of placing the rope through the socket bowl and then serving the rope with annealed wire bands. One of these bands should be placed at a distance from end of rope etjual to the length of bowl of socket, and a second band about one inch from lower end of socket, and a third band is placed about one inch below this second band. These bands keep the lay of the rope from opening. Figure i, Plate No. 4, shows the rope in bowl of socket with two of the bands. The second step is to open the rope by unlaying the strands and then cutting out the hemp core. Figure 2 shows the wire rope opened up to first band. The third step is to open up the wire rope strands and bend out the wires as shown in Figure 3. After opening the wires the grease must be removed. This is readily accomplished by swab- bing the loose wires in gasoline. The wires are then dipped in a solution of muriatic acid. This acid bath removes any grease which the gasoline failed to remove and permits the zinc to adhere strongly to the individual wires. The rope is then pulled down into the socket and the loose wires are separated wherever there is a tendency for them to stick together so as to permit the zinc to flow freely around the wires. Figure 4 shows the socket ready to receive the molten zinc. Some authorities recommend that the inside of socket bowl be given an acid bath so as to insure better adhesion of metal. In cold weather the socket should be heated so as to prevent too rapid cooling of the molten metal. The damming shown at upper end and lower end of socket bowl prevents the molten metal from escaping. The metal usually used for wire rope socketing consists of a high grade commercial zinc. For attaching a ^-inch socket to a -^^-inch rope about 2^^ to 2^ lbs. of zinc is required. The zinc is usually placed in a melting pot and heated on a stove or furnace. To determine the proper temperature of the metal for pouring the "stick method" is the one most commonly used. This method con- sists in taking a dry soft pine stick, dipping same into the hot metal and then quickly withdrawing it. The stick should not be badly burned or charred nor should it have any metal adhering to it. If the stick appears to be badly burned the metal is too hot for pouring. If the metal adheres to the stick it is too cold. The right temperatiu-e is obtained when the stick shows no sign of metal adhesion or of the stick charring or burning. With the socket properly placed, the metal is poured slowly and evenly in order to give it a chance to distribute freely. The act of pouring is shown in Figure 5. The finished socket is shown in Figure 6 (Plate 4). —23— IIMS lN»tR-rc.D IN SOCKET. ^EIND OUT. B^MMINQ \A/II?E. ROPC PUt.l.E.D BACKA.ND DArlMCD F^OW POUR»r«e SOC»t.C.T. Fis. 6 1^1 N I SHED SOCKET SOCKEITtN© vs/irelrope: PU.ATE: No.4 H.a.s. —24- The Long Splice. The length of sphce is gu\erned l)y the size of rope. The hirger the diameter of rope, the longer will be the splice. The length of the splice for ropes ^ in. to % in. in diameter should not be less than 25 feet; from % in. to i]/^ in. in diameter 35 feet; and from 1]/% in- to ij^ in. in diameter 40 feet. In ordering rope which is to be spliced, extra length of rope must be ordered equal to length of splice. For example: It is found necessary to add 200 feet to a length of 400 feet of ^ in. diameter rope to get a total length of 600 feet. The length of splice for ^ in. rope is 25 feet and the total length of rope to be ordered should therefore be 225 feet. The tools required for making a splice are as follows: One pair of wire cutters for cutting the strands; one pair of [)liers for pulling them and straightening the ends of strands; two marline spikes, one round and one oval ; a knife to cut out the hemp core; two clamps to untwist rope to insert ends of strands; a wooden mallet and some twine. A bench and vise can also be used to good advantage. The splice is started by securely wrapping and tying a piece of twine around the rope. This serving or wrapping should be placed back from the end of each rope equal to one-half the length of the total splice, or 12 feet 6 inches for a ^-inch diameter rope. Each end of the rope is then unlayed back to the twine serving and the hemp cores cut out. The two ends are then brought together as close as possible, placing the strands of the one end between the strands of the other end, as shown in Figure i, Plate No. 5. The twine serving is then removed from rope "X" (see Fig. i) and a strand as i is unlayed and is followed up with strand i^ of rope "Y," placing strand i^ in the space that was occupied by strand i. This operation is continued up to about 16 in. from end of strand i\ About 16 in. of strand i is left projecting by cutting the strand I about 16 in. from the solid rope. Strand i^ and i will then project 16 in. from the rope and a twine serving is placed on each side of the juncture of the two strands, as shown in Figure 2. To prevent unraveling of the strands the twine serving is again replaced on rope "X" at center of splice. The twine serving is then removed from rope "Y" and the strand 2 is unlayed, followed up and re- placed by strand 2' of rope "X." The ends of these strands are left projecting out 16 in. from rope as described from strand i and i\ The twine serving is again removed from rope "X" and strand 3 is unlayed, followed up and replaced by strand 3' or rope "Y." This unlaying and replacing of strand 3 and 3' is stopped 5 feet from the juncture of strands i and i\ This operation is continued with the remaining 6 strands stopping 5 feet short of the preceding set —25— "HE. L_ONG SRL_ICE1 9 .WJ f } ^f /r' t ^■■u^^^■^l■^^t■.^>.>.l.^ll^I A VERV ROOR WIRE. ROPE CONNECTION t .'^«'-'ri'^,-r',',-,7r^ C bj»^y5J ^ ^^^^^^^^^r^f^>^,•f^•^ r-ics.6 Wire: rof»e. conmec-tjon wi-th "th»mb\_e. 8«cu»f=»s VJ^^^.'^^^^J^^^JJ'ffff^ ^^Iff>>,\ c^I> VV^'^^'-'^V-'^V'^'^'^'-«^''V'^'^'«-'-«-« F-JG.7 wiREi ROf='E: corMtsE-CTion WITH uooR «* of»e;is SO CKCTS ^^zz "^qgivi'Wift^agaas^ ff a}' (;d ij ^g iaas^ffiisaiiiii^^^'- •'''•' '>'»'''>''•'■« Fie. 8 vviKE f?of>e: corsNE:cTior>t with str/\f» bi_ock PL-ATEIMO.S wes. -20— or juncture each time. The strands are then in their proper places, with the ends passing each other, as shown in Figure 3. To dispose of the loose ends, a clamp is placed on rope about 20 in. on each side of juncture. The twine serving which holds down the strands is then removed, after which the clamp is turned in opposite direction to which the rope is laid or twisted, thereby untwisting the rope, as shown in Figure 4. The rope is untwisted sufficiently to allow its hemp core to be pulled out with a pair of nippers. The core is cut otT 18 in. at each side of the intersection of the strands i and i' and the ends of these strands are then laid into the rope in place of the hemp core, as shown in Figure 4. The rope is then allowed to twist back in its original shape and the clamps are then removed. After the rope has been allowed to twist up, the strands that are tucked in will bulge somewhat. This bulging is reduced by lightly tapping the bulged part of the strand with a wooden mallet, which forces their ends further into the rope. The ends of the other strands are tucked in in like manner. Wire Rope Connections. Figure 5 on Plate No. 5 shows a very poor method of connect- ing two wire ropes. With this connection it is impossible to get a uniform strain on all the strands and the rope is further bent out of shape where the ropes cross each other. Figure 6 shows a connection made with thimbles and wire rope clips which overcomes to a great extent the faults of the connection shown in Figure 5. The connection shown in Figure 6 is not a very strong one and should only be used where the strains are very light. Figure 7 shows a connection made with a loop socket and an open socket. If the sockets are properly attached this connection win develop the full strength of the rope. Figure 8 shows a connection made by bringing the ropes around thimble sheaves of a strap block and clipping same with three or more wire rope clips. If the trap block is of proper design and a sufficient number of clips are used, this connection will de- velop nearly the strength of the rope. The connections shown in Figures 5, 6, 7 and 8 cannot be used where the rope is required to pass over sheaves or drums. Tackle Blocks. Theoretically, the power necessary to balance a load by means of a tackle consisting of two blocks, is equal to the load divided by the number of ropes at the moving block, including the standing- part of rope if attached to the moving block. To produce motion, however, a greater power is necessary to overcome the friction and -28- stiffness of rope. Experiments show that to produce motion about lo per cent of the theoretical power must be added for each of the sheaves over which the rope passes. On Plate No. 6 the different tackles are designated by the num- ber of ropes at the moving block. Figure i shows an ordinary sheave block with a rope passing over the sheave. It is very evi- dent that, theoretically, it will require a pull of 15,000 lbs. to balance the 15,000 lb. load. Figure 2 shows a tackle consisting of two single blocks. The rope is attached to the upper block and then passes around moving block and up over standing block. This con- stitutes a two part line tackle and, theoretically, the power required to balance the load of 15,000 lbs. is 7,500 lbs. or the load divided by 2. I'igure 3 shows a three part line tackle. Figure 4 shows a four part line tackle, and Figure 5 shows shows a five part line tackle. In using- tackle blocks, all twisting of ropes should be avoided. A complete turn or twist with two single blocks may produce a fric- tional resistance of 40 per cent. A Home-Made Rope Lubricant. (From "Mines and Minerals.") To prevent the corrosive action of mine water, or rust from any cause, hoisting ropes must be treated with some kind of solu- tion-proof material which will at the same time act as a lubricant. Such lubricants must be free from acids or other substances that will corrode the wire. A good lubricant for hoisting ropes is made by mixing i bushel of freshly slaked lime to a barrel of coal tar, or a mixture of pure tar and tallow can be used. When pine tar which contains no acid is used as a base, lime is unnecessary, as tar is solution-proof to ordi- nary mine water. Another good mixture contains tar, summer oil, axle grease, and a little pulverized mica, mixed to a consistency that will penetrate between the wires to the core and will not dry or strip off. The lubricant should not be so thick as to plaster and pre- vent a thorough inspection of the rope, and after the first applica- tion the lubricant should be used sparingly, so that the rope may be kept clean and free from grit. Graphite mixed with grease is also used successfully for the lubrication of hoisting ropes, and pulverized asbestos, mixed with grease, will also make an excellent lubricant. It will be found more satisfactory to purchase graphite greases than to attempt its manu- facture. Where ropes are used on slopes, care must be observed to keep them from the ground, as lubricated ropes will pick up grit more readily than unlubricated. If a box is placed near the top of the incline so that the hoisting rope can run through a groove, and come in contact with oiled waste in it, the rope may be cleaned automatically. —20— THE DRAGLINE CABLEWAY EXCAVATOR Cableway Engineering is a special branch of engineering, and practice has proved that it requires considerable study and experi- ence to properly design a cableway which will operate efficiently and economically. Many otherwise competent and experienced en- gineers have attempted the design of a cableway, but owing to their lack of experience in cableway design, produced a complete failure or a cableway which did not come up to the requirements in efficiency and economy in operation. The dragline cableway excavator may be considered as one of the more recent types of cableways. This cableway primarily con- sists of a well guyed mast or tower, an inclined track cable with the upper end supported at top of mast or tower by means of tension blocks, and the lower end anchored to a suitable ground anchorage system. This anchorage is usually set at a distance of 400 to 600 feet from the mast. A carrier is mounted on the track cable; this carrier supports a scraper bucket, preferably by means of a flexible connection. A load cable is attached to the front of the bucket and carrier. This cable performs the operation of loading the bucket and con- veying same along track cable to the dumping point. A tension cable is provided for operating the tension blocks at top of mast. This cable and the blocks tighten and slacken the track cable. Both the load and tension cables lead from guide blocks at top of mast down to a double drum friction hoist usually located at ground level. See Plate No. 7. The operation with the track cable taut and the empty bucket near top of machine is as follows : The operator releases the friction of the front drum of the hoist which operates the load cable. This operation allows the carrier and bucket to travel down the inclined track cable by gravity; the speed of the carrier and bucket is controlled by the brake on this friction drum. When the point of excavation has been reached the operator holds the bucket and carrier by means of the brake on front drum and then releases the rear drum. By releasing the rear drum the track cable is slackened and the bucket and carrier are thus lowered into the pit. When the bucket comes in contact with the material, the operator puts the front drum into operation by throwing in the friction. This pulls the bucket forward into the material and fills it. After the bucket is filled the operator throws in the friction of the rear drmn. This operation tightens the track cable and thus lifts the bucket clear of the excavation. The bucket is pulled forwardly at the same time that the track cable is tightened, and in this way the bucket is con- —30— ■^ / > 3 \^ c "^k z vK < V i ^ \ ■ Ant) M.VW y ^ >' o w u,??^^^^ —31- veyed and elevated to the dumping point, where the load is dis- charged automatically. Conditions sometime require the load to be delivered and dis- charged at the foot of the inclined track cable, in which case the loaded bucket travels down the incline by gravity, the load is auto- matically discharged and the empty bucket is then pulled back up the incline and then lowered into the excavation. Masts and Towers. For the small dragline cableway excavator, masts can ofttimes be secured by cutting down a tall large tree and trimming same to meet the requirements. Oak, long-leaf 3'ellow pine or fir, free from large or unsound knots, will best meet the requirements. For the larger dragline cal^leway excavators masts are usually built up from stock timber and trussed with either rods or cable. Steel masts are also used where the requirements and conditions warrant the expense. In designing a mast special attention must be given to stiffness and rigidity; the ordinary column formulas used in the usual design of buildings cannot be used in mast design for this work. For ordinary conditions a timber mast built of I4xi4-inch tim- bers properly reinforced and trussed will support a cableway ex- cavator of 500 ft. span equipped with a % cu. yd. bucket. For larger cableway excavators it will require i6xi6-inch timbers thor- oughly reinforced and trussed. Steel masts are usually built with four corner angles varying from 33/^x3^-inch angles to 6x6-inch angles in size. The corner angles are braced their entire length on the four sides, with the angles usually 2x2-inch or 2j/2X2j^-inch in size. The masts usually rest on a concrete foundation. The smaller masts can be supported on a wood platform made by nailing to- gether crosswise 3 layers of 4x1 2-inch plank 4 feet long. This will make a platform i foot thick and 4 feet square. Stationary towers have also been installed to good advantage. For cableway excavators of large bucket capacity and large spans the stationary tower will ofttimes be the safest solution. These towers are usually built with a large center timber with lighter timbers for bracing and stift'ening. The movable tower is installed where the conditions require considerable shifting. If properly designed such towers require very little ballasting. These towers are designed to move on ordi- nary railroad trucks and rails or on rollers and planking. The rails and trucks have been found to give more satisfactory service than the roller mounting, owing to the fact that the towers on rollers will have a tendency to slide off from the rollers. —32— Guy Cables. The guy cables for guying the mast are usually placed as shown on Plate No. 7. One main guy cal)le is placed directly in rear of the track cable, a second main guy cable is ])laced at right angles to this first main guy cable and opposite the hoist, the third main guy cable is placed midway between these two guy cables. The auxiliary guy cables are placed as shown on Plate No. 7. They are used to stead}^ the mast and keep same from falling, while the main guy cables take the stress produced by the track cable and hoist. The guy cables should be of sufficient length to permit the anchors to be placed at a distance from the foot of the mast ecfual to about twice the height of the mast. For example, if the mast is 60 feet in height the anchors should be set about 120 feet from the mast. It should be impressed upon the erector that the shorter the distance between mast and anchor the greater will be the strain on both guys and mast. The uplift on anchors will necessarily also be greater. Anchors. The anchors usually consist of logs 12 to 18 inches in diameter and from 12 to 18 feet in length. These logs are placed from 8 feet to 12 feet in the ground, the depth depending on the nature and firmness of the soil. Log anchors are safe for stresses up to 60,000 lbs. For higher stresses concrete anchors are usually placed. Track Cable. The track cable of a dragline cableway excavator receives very severe service. No hard and fast rule can l)e laid down regarding the specification and construction of this cable, for the reason that the construction and grade of cable should depend very much upon the local conditions that obtain in the diiiferent excavation work. The author cannot recommend too strongly that owners of cable- ways get in touch with experienced wire rope engineers and have them specify the cable best suited for their requirements and condi- tions. Plate No. 7 shows a diagram of the dragline cableway excava- tor. The incline of the track cable, as indicated on this diagram, should be 14 feet in 100 feet. This is necessary to return the empty bucket by gravity. The track cable should further have a deflection or sag of 5 feet for every 100 feet of span. For example, for a 500- foot span the track cable should have a deflection or sag of 25 feet in the center when the loaded bucket is at that point. If the track cable is pulled up tighter and the deflection or sag reduced to less than 25 feet, the track cable and all the other parts of the equip- —33— ment will be overstrained. This overstraining will reduce the life of the cableway and increase the repair bill. Every operator should mark his tension cable to prevent this overstraining. To do this, he should proceed as follows: The first step is to get the difterence of elevation between top of mast and lower end of track cable. This will give him the in- clination of the track cable. The second step is to divide this difference of elevation by 2. This will give him the distance that the track cable would be below the top of mast at center of span if the track cable was pulled taut and in a perfectly straight line. This condition can never be ob- tained, so we must make an allowance for deflection or sag so as not to overstrain the cable. The third step is to figure the sag or deflection and, as stated before, this sag or deflection should be at least 5 feet for every 100 feet of span. For a span of 400 feet this deflection would be 20 feet and for a span of 500 feet it would be 25 feet, as shown on diagram. By adding together the distance of track cable below top of mast (obtained in second step) to the deflection just figured, we get the total distance of the track cable at center of span below top of mast. For example, on the diagram (Plate No. 7) we find that the difference of elevation between top of mast and lower point of track cable where it passes over "A" frame is 70 feet. Dividing this dif- ference of elevation by 2 we find that the track cable at center of span would be 35 feet below top of mast if it were pulled taut in a perfectly straight line, as shown in dotted lines on diagram. Figuring the deflection or sag at 5 feet for every 100 feet of span, we find that for 500 feet the total sag will be 25 feet at center of span. Adding this sag of 25 feet to the 35 feet we get 60 feet, the 'distance that the track cable should be below top of mast at center of span when the loaded bucket is at this point. We now measure down from top of the mast a distance of 60 feet and mark same. A man provided with a hand level or ordinary carpenter's level, places the level at this mark and brings the bubble of level to the cross mark; in other words, brings the instrument to the level position. The operator then fills the bucket, brings it to center of span and then starts raising the bucket and carrier by operating the tension cable and thus raises the track cable. The man at level sights along the track cable and when the junction of the front carrier wheel and track cable come in line with his sight- ing, he signals the operator who locks his drums and then marks his tension line about 3 feet from the drum. The mark of minimum deflection is now established and the operator should never wind the tension cable on drum beyond the point or mark just established. —34— The track cable is also in some cases subjected to needless abuse by careless operation or by installing carriers and dumping devices which, due to their faulty construction, will wear out a track cable in a very short period of time. By dropping the track cable and then suddenly applying the brake to drum a careless operator will produce a whip in the cable, as shown in Figure 13. This operation is bound to ruin the best cable. An "A" Frame should always be installed at foot of incline when conditions require that the bucket and carrier be brought to the extreme end of the track cable. The height of this frame will depend upon the local ground conditions. When the ground is level it will only be necessary to have the frame of sufficient height to allow the loaded bucket to travel from the lowest point without hitting the ground when the track cable has the proper sag or deflection. When a rise of ground is encountered between anchor- age and mast, it will be necessary to raise the height of frame in order to get the clearance as described above. Bridle Cable. In order to provide an easy means for shifting the lower end of track cable, a bridle cable is usually installed. This bridle cable is installed by placing two anchors some distance apart, the usual distance being about 150 feet. One end of the bridle cable is brought around one of the anchor logs and is then fastened with four clips. The other end of bridle cable is then threaded through bridle frame and is then brought around the other anchor log. This cable is then adjusted so that it will have a deflection equal to one- third of the span. For a span of 150 feet the deflection would be 50 feet when the track cable is pulled taut. If the deflection is less than one-third of the span this cable will be overstrained when full tension is brought on the track cable. , Bridle Frame. The bridle frame usually consists of two heavy plates with a curved casting or rollers placed between them. The curved casting or rollers form the seat for the bridle cable. For attaching the bridle cable these frames are provided with a shackle, link and thimble sheave. The track cable is brought around this thimble sheave and is then fastened with four or five clips. Shifting the Bridle Frame. Where very little shifting is required, the bridle frame is held in place on bridle cable by means of special clamps. When consid- —35— erable shifting is reqmred the frame is provided with extra hnks for attaching a wire rope sheave block. Another block is attached to one of the anchors. A cable is then threaded or reeved through these blocks and the frame is moved along bridle cable by either exerting a pull on this block and tackle or letting out on same. For operating the tackle hand-winches can ofttimes be installed to good advanatge. The Load and Tension Cables. The load and tension cables are usually of the 6 strand, 19 wire construction. The selection of the grade of wires to be used in these cables should be left to the judgment of a competent cable- way engineer. Tension and Guide Blocks. Probably the greatest trouble experienced in the operation of the dragline cableway excavator is in the rapid wear, breakage and renewals of the sheaves. The ordinary common derrick block is entirely inadequate to withstand the severe and constant service of this class of work. The tendency has been and is still to use sheaves of insufficient strength and too small a diameter, resulting in con- stant breakdowns, delays and short life of the wire ropes passing- over these sheaves. It has been the author's experience and obser- vation that it paj'^s to buy the best blocks possible for this service, as the successful and efficient operation of the machine depends in no small measure on the proper specifications and installation of the blocks. The sheaves in the blocks should be extra heavy pattern and provided with special bushings. The sheave pin should he extra large and should be center-bored and provided with com- pression grease cups. For continuous heavy duty the block sheaves should be of the hollow web pattern with a large capacity oil cham- ber in the web, or of the end bearing type with keyed axle. The blocks should be attached to mast in such a manner so as to allow the greatest freedom of movement between cable and blocks. Cable Fastenings. The author recommends four clips for every cable fastening. The clips must be drawn up tight. A loose clip is entirely worth- less. The cables and their fastenings should be frequently and care- fully examined. The safety and success of a cableway excavator depends very much upon careful and frequent inspection. Bucket, Carrier and Dumping Device. It is very apparent that the successful and economic operation of a dragline cableway excavator depends very much upon the — :iG— bucket, the carrier and the dum])iiit;' device. As in all other mate- rial handling machinery, substantial design and simpHcity of con- struction and operation are the essential features for a successful equipment. Past experience has brought out the following facts regarding cableway excavator buckets and carriers: The work that a dragline bucket is called ui)(>n to perform is very hard and severe. This recpiires extra strong and substantially built buckets. Lightly constructed buckets have not been al)le to withstand this severe service. Many purchasers of light equipment have found to their sorrow, even when operating under the most favorable conditions, they saved nickels in the first cost by buying light equipment, but they spent dollars in delays, loss of business and repairs later on. Buckets that are latched directly to carrier to hold them in load carrying position are not very satisfactory, as considerable time is lost in latching the bucket, with a resulting decrease in handling capacity. Buckets that depend on the tension of the drag or load line to hold them in load carrying position have the disadvantage of scat- tering material the entire length of the span, as it is difficult to maintain a uniform tension on load cable. Buckets should assume a vertical position when dumping to insure the material leaving the bucket. Buckets dumping from front are to be preferred to buckets equipjied with rear gates. Rear gates bend and bind and the rear gate l)ucket does not assume a vertical position when dumping. When sticky or wet material is encountered some of the material will not leave this type of bucket. If the front of the bucket and cutter edge are of the proper design, no shoes are necessary in rear of bucket to tilt the front forwardly. Flexible chain connections between the bucket and carrier are to be preferred to the rigid connections. Where the carrier is rigidly attached to the bucket, the equipment becomes top heavy and when digging alongside of a hill or trench it will fall over. Flexible connections also prolong the life of the cables and the other equipment, as the main cable need not be lowered entirely into the excavation and the Ijucket can follow its own course when digging. . The dumping operation of the bucket should be under the positive control of the operator, and the dumping arrangement should permit of either a slow or instantaneous discharge. Carriers with more than two wheels should be designed so as to allow the track wheels to automatically adjust themselves to the curve of the track cable. —37— Hoists. This type of excavator can be operated l^y either steam, electric or gasoline power. The type and size of hoist should be determined by the individualand local requirements. To get the best and most economical results, the hoist must have ample power to meet the speedy operation recjuired for the maximum capacity. The exca- vator requires a double drum hoist, preferably with a two-speed arrangement, a slow speed when digging and a high speed when hauling in the bucket. The hoist should have sufficient power to operate both drums at the same time. The front drum should have a rope speed of 125 to 200 feet per minute when the bucket is dig- ging, and a rope speed of 300 to 600 feet per minute for conveying the loaded bucket along track cable. The rear drum should have a rope speed of 150 to 200 feet per minute. Provision should be made on the hoist foundation to allow for some shifting and adjustment of the hoist. In almost all cases it will be found necessar}' to do some adjusting after the cableway excavator has been erected, in order to jjroperly align the hoist drums with the guide blocks at top of mast or tower. The stretch in guy cables, the "set" in the anchors, etc., make this adjustment necessary. Adaptability. The development of the dragline cableway excavator has made it possible for owners of gravel deposits with limited capital to in- stall plants for preparing gravel and sand for the market, as the cost of digging the gravel and delivering it to the plant was pro- hibitive with the type of machinery generally sold for this purpose, except on a large yardage basis. Some small jilants were located along rivers and creeks where it was ])ossible to employ small ])um])s for pumping the gravel to the liins. If these beds contained boulders larger than the pump could handle, the pit soon became lined with boulders, which made it inqtossible for the i)ump to reach the gravel beneath the layer of boulders. That the dragline cable- way is more economical and efficient for digging sand and gravel from under water is proved by the fact that the cableways have replaced a great many pumps. The dragline cableway was developed for digging material which cannot be economically excavated with steam shovels or dragline boom line excavators. The steam shovel is limited to the reach of the di])per arm and the machine itself must be mounted on a track or hrm ground. The boom line excavator has a greater reach, but it is also limited to the length of the boom. The drag- line cableway greatly exceeds the reach of the steam shovel and the boom line excavator, thereby making it possible to dig over long —38— spans and dii^' the nuUcrial In s^Tcatcr (lci)lhs. Inasmuch as the dig- ging, con\eying and elevating is all dune 1)\- one machine, the handling capacity per hour of the cableway excavator is not as great as that of the steam shovel or a boom line, which carry their load a comi)arati\'e]}- short distance. The dragline cahlewa}' excavator will dig and convey the ma- terial within a radius of 600 feet from the ])lant at less cost than the combination of machiner_\' where it is necessar\- to handle the ma- terial several times. Where large capacity is re(|uircd, two or more cableways can be installed and operated at as low a cost as a com- bination of other machinery to get the same capacit\-. This is very apparent, as only one man is required to operate the cablewav. The steam can be furnished by a central boiler plant. The cableway is. very economically operated 1)}- electricity, as the current consump- tion is very low, due to the intermittent service of the hoist. Gas and oil engines are also being used to good advantage. The cost of digging the gravel and conveying it to the i)lant witli a drag- line cableway will \-ary from 3 to 10 cents per yard, depending upon the installation and conditions. When operating two or more cablewavs for large capacity one can readil}' see that the cost of production when the demand is low will remain the same, as only one unit need be operated. The jiroducer does not have to keep an expensive crew for ])roduc- ing only a small }-ardage with one big excavator. The cableways are installed in \arious manners in connection with the gravel plant. Where it is possible it is advisable to deliver the material direct to the hopper feeding the screens. AVhere manv boulders are encountered, it is sometimes advisable to duni]) into a hopper some distance from the plant. The boulders can here be sepa- rated from the gravel by passing the material over grizzly bars and by passing the boulders to the crusher. The sand, gravel and crushed rock is then delivered to the screens by means of a belt conveyor. In some places where only one cableway is in- stalled for delivering to a producing plant which has a larger capac- ity than the cablewa}', it is advisable to have the cablewav deliver to a storage pile from which the material is delivered to the screens, by means of a belt conveyor. An economical arrangement for reclaiming from the storage pile is to have a concrete tunnel under the storage pile. The belt conveyor in the tunnel is fed by open- ings in the top of the tunnel. Under most conditions the maximum economical span is from 500 to 700 feet. This, of course, will vary under special conditions. The machines are used for excavating material from under water or from the dry. They will dig, elevate, convey and dump the ma- terial from pits to bins, screens, cars, stock piles or spoil banks. —39— Uses. The following is a partial list of the classes of work for which dragline cableway excavators have been installed: Excavating sand and gravel from nndcr water and from dry pits. Loading ballast dirct from pits to cars. Back-filling retaining walls. Reclaiming ore and material from stock piles. Deepening river beds. Building levees. Handling road material. Stripping clay beds and removing overburden. Removing sand bars, islands and earth dams from rivers. The dragline cableway excavator has its limitations like all other material moving machinery. The author has found the cableway excavator installed in places where the conditions and requirements were entirely unsuitable for this type of excavator. A thorough investigation of the individual requirements and con- ditions of any proposed work is very essential in securing the equipment which will produce the most economical results. The man}- successful installations of dragline cableway ex- cavators, and the low cost of handling material by means of these machines, leads the author to believe that the engineering pro- fession as a whole should study the uses and proi)erties of wire ro]ie as applied to material handling ]ilants. It should also encourage the engineers and sui)crinlendents in charge of plants to study and carefully consider the use and care of wire rope as api^lied to the different problems confronting them in their dailv work. -40- LIBRftRY OF CONGRESS 018 445 303 4