VOLUME IV DECEMBER, 1921 NUMBER 7

The Use of Ropes and Tackle

By H. J. DANA Specialist in Experimental Engineering and W. A. PEARL Instructor in Mechanical Engineering

ENGINEERING BULLETIN NO. 8 Engineering Experiment Station H. V. CARPENTER, Director 1922

Entered as second-class matter September 5, 1919, at the postoffice at Pullman, Wash., under Act of Aug. 24, 1912

The ENGINEERING EXPERIMENT STATION of the State College of Washington was established on the authority of the act passed by the first Legislature of the State of Washington, March 28th, 1890, which established a “State Agricultural College and School of Science”, and instructed its commission “=to further the application of the principles of physical science to industrial pursuits=.” The spirit of this act has been followed out for many years by the Engineering Staff, which has carried on experimental investigations and published the results in the form of bulletins. The first adoption of a definite program in Engineering research, with an appropriation for its maintenance, was made by the Board of Regents, June 21st, 1911. This was followed by later appropriations. In April, 1919, this department was officially designated, Engineering Experiment Station.

The scope of the Engineering Experiment Station covers research in engineering problems of general interest to the citizens of the State of Washington. The work of the station is made available to the public through technical reports, popular bulletins, and public service. The last named includes tests and analyses of coal, tests and analyses of road materials, testing of commercial steam pipe coverings, calibration of electrical instruments, testing of strength of materials, efficiency studies in power plants, testing of hydraulic machinery, testing of small engines and motors, consultation with regard to theory and design of experimental apparatus, preliminary advice to inventors, etc.

Requests for copies of the engineering bulletins and inquiries for information on engineering and industrial problems should be addressed to Director, The Engineering Experiment Station, State College of Washington, Pullman, Washington.

The Control of the Engineering Experiment Station is vested in the Board of Regents of the State College of Washington.

BOARD OF REGENTS

Hon. Louis F. Hart, Governor of the State, Olympia R. C. McCroskey, Garfield Adam Duncan Dunn, Wapato Edwin A. Ritz, Walla Walla A. W. Davis, Spokane J. H. Hulbert, Mt. Vernon E. O. Holland, Secretary Ex-Officio, President State College Pullman

ENGINEERING EXPERIMENT STATION STAFF

Director, H. V. Carpenter, B. S., M. S. Experimental Engineering, Homer J. Dana, B. S., M. S., M. E. Electrical Applications, Philip S. Biegler, B. S., M. S., E. E. Electrical Standardizations, Harry F. Lickey, B. S. Automotive Engineering Aschel C. Abell, B. S. Steam Engineering, A. R. Nottingham, M. M. E. Mechanical Design, E. B. Parker, B. S. Engineering Materials, G. Everett Thorton, B. S. Gas Power, William A. Pearl, B. S. Steam Power, Robert L. Rhoads, M. S. Mining Engineering, Louis O. Howard, A. B., M. E. Metallurgical Engineering, Chester G. Warfel, M. E. Economic Geology, Olaf P. Jenkins, A. B., A. M. Irrigation and Structures, Osmar L. Waller, Ph. B., Ph. M. Municipal Engineering, Morris K. Snyder, B. S. Highway Engineering, Howard E. Phelps, B. S., C. E. Topographical Engineering, Frederic W. Welch, B. S., C. E. Architectural Engineering, Rudolph Weaver, B. S. Agricultural Engineering, L. J. Smith, B. S. Physics, Brenton L. Steele, B. A., M. A. Chemical Engineering, Clare Chrisman Todd, B. S., Ph. D.

TABLE OF CONTENTS

LIST OF ILLUSTRATIONS 5 SOURCES OF MATERIAL 7 INTRODUCTION 8 KNOTS 9 SPLICES 25 HITCHES 28 LASHINGS 43 TACKLE SETS 45 HOISTS 53 TRANSMISSION CABLES 55 TEXTILE ROPE DATA 57 WIRE ROPE DATA 58 SPLICING TRANSMISSION CABLES 62 POWER TRANSMISSION TABLES 66 LIST OF ENGINEERING BULLETINS 68

LIST OF ILLUSTRATIONS

=Fastening Knots=. 1. Over-hand knot. 2. Double knot. 3. Figure 8 knot. 4. Double Figure 8 knot. 5. Square knot. 6. Reef knot. 7. Sq. served or whipped knot. 8. Slipped Square knot. 9. Open-hand knot. 10. Granny knot. 11. Fisherman’s knot. 12. Ordinary knot. 13. Ordinary knot whipped. 14. Weaver’s knot. 15. Hawser knot, or Sheet Bend. 16. Double Sheet Bend. 17. Garrick Bend knot. 18. Half-hitch and whipping knot. 19. Slip knot. 20. Bowline knot. 21. Running Bowline knot. 22. Loop knot. 23. Tom-fool knot. 24. Boat knot. 25. Surgeon’s knot. 26. Bowline on the bight. 27. Spanish Bowline. 28. Flemish Bowline. 29. Hawser knot with toggle.

=Ending Knots=. 30. Whipping. 31. Single Crown Tucked. 32. Wall knot Tucked. 33. Matthew Walker. 34. Double Wall or Crown knot. 35. Stevedore. 36. Chain knot.

=Shortening Knots=. 37. Whipped Shortening. 38. Three fold shortening. 39. Sheepshank. 40. Sheepshank for free end rope. 41. Sheepshank with toggle. 42. Sheepshank ends whipped. 43. Bow Shortening.

=Splices=. 44. Short Splice. 45. Eye Splice. 46. Long Splice. 47. Chain Splice. 48. Cut Splice.

=Hitches=. 49. Half hitch. 50. Timber hitch. 51. Clove or Builder’s hitch. 52. Rolling Hitch (A). 53. Rolling Hitch (B). 54. Snubbing hitch. 55. Timber hitch and half-hitch. 56. Chain hitch. 57. Twist hitch. 58. Twist and bow hitch. 59. Blackwall hitch. 60. Lark’s head with toggle. 61. Round turn and half-hitch. 62. Fisherman’s hitch. 63. Cat’s paw hitch. 64. Slippery hitch. 65. Double Blackwall. 66. Slip knot and half-hitch. 67. Fisherman’s bend. 68. Taut line hitch. 69. Jam hitch. 70. Scaffold hitch. 71. Studding sail bend. 72. Midshipman’s hitch. 73. Bale sling. 74. Hamburger hitch. 75. Sling a cask head up. 76. Well pipe hitch. 77. Hackamore hitch. 78. Halter tie. 79. Horse hitch or tie. 80. Manger Tie. 81. Figure 8 Manger tie. 82. Harness hitch. 83. Strap hitch or line. 84. Clevis hitch. 85. Two-man Diamond hitch. 86. Two-man Diamond hitch. 87. Two-man Diamond hitch. 88. Packer’s knot. 89. One-man Diamond hitch. 90. One-man Diamond hitch. 91. One-man Diamond hitch. 92. Two-man Diamond hitch. 93. Spar and Transom lashing. 94. Tripod lashing.

=Tackle Sets and Hoists=. 95. Single Whip. 96. Running Tackle. 97. Gun Tackle (A). 98. Gun Tackle (B). 99. Whip on Whip. 100. Luff. 101. Port Tackle. 102. Double Luff. 103. Single Burton (A). 104. Single Burton (B). 105. Three Fold Purchase. 106. Four Fold Purchase. 107. Double Burton (A). 108. Double Burton (B). 109. Double Burton (C). 110. Double Burton (D). 111. Luff on Luff. 112. Double Burton (E). 113. Geared Chain Hoist. 114. Differential Chain hoist. 115. Chinese hoist or Capstan. 116. Snatch Block on Hay Rope.

=Transmission Cables=. 117. Cable splice. 118. Cable Splice. 119. Cable Splice. 120. Cable Splice. 121. Cable Splice. 122. Splicing Tools. 123. Splicing Tools.

SOURCES OF MATERIAL

In the compilation of this bulletin free use was made of the material given in the following books, bulletins, catalogs, etc.

Knotting and Splicing Ropes and Cordage, Paul M. Hashuk--Cassel & Co., New York.

Knots, A. F. Aldridge, The Rudder Pub. Co., New York.

Knots, Splices, and Rope Work, A. Hyatt Verril,--Norman W. Henly Pub. Co., New York.

Rope and its Use on the Farm, J. B. Frior--Ag. Exp. Sta. Bul. No. 136, Univ. of Minn.

Knots, Hitches and Splices, Howard W. Riley, Cornell Reading Courses, New York State College of Agriculture, Ithaca, New York.

Story of Rope, Plymouth Cordage Co., North Plymouth, Mass.

Rope Knots and Hitches, MacGreggor Smith, College of Agriculture, Univ. of Saskatchewan, Saskatoon, Canada.

Problems in Physics, War Department Committee on Education and Special Training, Washington, D. C.

Kent’s Mechanical Engineers Hand Book, John Wiley & Sons, New York.

Encyclopedia Britannica.

Rope and Its Uses, Iowa State College of Agriculture and Mechanic Arts.

American Wire Rope, American Steel and Wire Company.

Boy Scout Manual.

Engineer Field Manual, Fifth Edition, Government Printing Office, Washington, D. C.

Rope Work, L. M. Roehl, The Bruce Publishing Co., Milwaukee, Wis.

R. O. T. C. Engineer.

Columbia Knots and Splices, Columbia Rope Co., Auburn, New York.

American Boy Magazine--July 1917.

INTRODUCTION

Each year, old industries keep expanding and new ones are created. In many of these, the use of hoists, tackle, rope transmissions, etc. is ever increasing in extent and importance. Information on the selection and use of ropes and tackles and the tying of knots is very scattering and incomplete. The purpose of this bulletin is to collect information from all the different sources possible and assemble it under one cover, in the hope that it may be valuable to people in many different fields of activity. It is not meant to be an advanced treatise for those who consider themselves already proficient in the use of rope and tackle but is designed as an aid and reference to those less skilled in the art.

A variety of knots and splices are shown with occasional suggestions as to their use and application. Some knots tie easily and are very secure but are not so easy to untie; others are easily and quickly tied--are secure and yet are not difficult to untie. Some knots are suitable for small cords only, and others are adapted to large ship’s hawsers. For these and other reasons, it is desirable to select the right knot for the job in hand.

Nearly every individual at some time or other has gone camping. If he chanced to select a remote or inaccessible mountain side for a vacation trip, he probably had one or more pack animals to take in the supplies and camp outfit. How many could use the famous Diamond hitch to fasten the pack on the horse’s back so that it will not shift or fall off in transit?

The desirability of correct selection with reference to the work to be done is also true of tackle sets. One type of tackle will give great mechanical advantage, but requires an excessive amount of rope or requires frequent overhauling to complete the job, while another type, using the same equipment, will not give such great mechanical advantage but does not require overhauling so often during the progress of the load.

Rope is coming more and more into favor for the transmission of power--replacing gears and heavy leather belts. It is important that the proper sized sheave wheel be used with a rope of given diameter in order to secure the longest service from the transmission. It is also important that speed be considered in the calculation for necessary strength to transmit a certain amount of power. It is evident from these two instances alone that it is desirable that the selection of a rope transmission should be governed by the use of complete sets of data on the subject.

Some of the knots, splices, etc. shown in this bulletin were found to have more than one name, or were called by different names by different authors. In such case only the most commonly used term was selected.

KNOTS

A knowledge of knots has saved many a life in storm and wreck, and if everyone knew how to tie a knot quickly and securely there would be fewer casualties in hotel and similar fires where a false knot in the fire escape rope has slipped at the critical moment and plunged the victim to the ground. Many an accident has occurred through a knot or splice being improperly formed. Even in tying or roping a trunk, few people tie a knot that is secure and quickly made and yet readily undone. How many can tie a tow rope to a car so it will be secure and yet is easily untied after the car has been hauled out of the mud? Or suppose a rope was under strain holding a large timber in midair and a strand in the derrick guy rope shows signs of parting. How many could attach a rope each side of the weak spot to take the strain?

The principle of a knot is that no two parts which lie adjacent shall travel in the same direction if the knot should slip. Knots are employed for several purposes, such as, to attach two rope ends together, to form an enlarged end on a rope, to shorten a rope without cutting it, or to attach a rope to another rope or object. Desirable features of knots are that they may be quickly tied, easily untied and will not slip under a strain. In a number of cases a toggle is used either to aid in making the knot or make it easier to untie after a strain has been applied.

A number of terms are commonly used in tying knots. The “standing” part is the principal portion, or longest part of the rope. The “bight” is the part curved, looped or bent, while working or handling the rope in making a knot, and the “end” is that part used in forming the knot or hitch. The loose, or free end, of a rope should be knotted or whipped to prevent it from raveling while in use.

Strength of Knots

If a knot or hitch of any kind is tied in a rope its failure under stress is sure to occur at that place. Each fiber in the straight part of the rope takes its proper share of the load, but in all knots the rope is cramped or has a short bend, which throws an overload on those fibers that are on the outside of the bend and one fiber after another breaks until the rope is torn apart. The shorter the bend in the standing rope the weaker the knot. The approximate strength of several types of knots in percent, of full strength of a rope is given in the table below, as an average of four tests.

1. Full strength of dry rope 100% 2. Eye splice over an iron thimble 90% 3. Short splice in rope 80% 4. Timber hitch, round turn and half hitch 65% 5. Bowline, slip knot, clove hitch 60% 6. Square knot, weaver’s knot, sheet bend 50% 7. Flemish loop, over--hand knot 45%

Fastening Knots

Fig. 1. The over-hand knot is the simplest of all knots to make. It is made by passing the lose end of the rope over the standing part and back through the loop.

Fig. 2. The Double knot is made by passing the free end of the rope through the loop twice instead of but once as in making an over-hand knot. This is used for shortening or for a stop on a rope, and is more easily untied than the over-hand knot. It is also known as a blood knot, from its use on whip lashes by slave drivers, etc.

Fig. 3. The Figure Eight knot is similar to the over-hand knot except that the loose end of the rope is passed through the loop from the opposite side. It is commonly used to prevent a rope running through an eye or ring or tackle block. It is also used as the basis for ornamental knots, etc.

Fig. 4. The Double Figure Eight knot is made by forming a regular figure eight and then following around with the end of the other rope as shown.

Fig. 5. The Square knot is probably the commonest and most useful of all knots. It is strong and does not become jammed when being strained. Take the ends of the two ropes and pass the left end over and under the right end, then the right end over and under the left. Beware of the granny knot which is often mistaken for the square knot but is sure to slip under strain.

Fig. 6. The Reef knot is a slight modification of the square knot. It consists merely of using the bight of the left or right end instead of the end itself, and is tied exactly as is the square knot. This makes the knot easy to untie by pulling the free end of the bight or loop.

Fig. 7. If the Square or reef knot is used to join two ropes of unequal diameter, the knot is apt to slip unless the ends of the rope are whipped as shown.

Fig. 8. A Square knot joining two ropes of unequal size is apt to slip with a result similar to that shown.

Fig. 9. The Open-hand knot is made by tying an over-hand knot with two rope ends lying parallel. It is better than a square knot for joining two ropes of unequal diameter. Grain binders use this knot.

Fig. 10. The Granny knot is often mistaken for a square knot and its use should by all means be avoided as it is almost sure to slip when a strain is applied, unless the ends are whipped. For large rope, a granny knot with ends whipped will hold securely and is easy to untie.

Fig. 11. The Fisherman’s knot is a simple type of knot formed by two simple over-hand knots slipped over the standing parts of the two ropes, and drawn tight. It is valuable for anglers as the two lines may be drawn apart by merely pulling on the loose ends of the rope.

Fig. 12. The Ordinary knot is used for fastening two heavy ropes together and is made by forming a simple knot with the end of one rope and then interlacing the other rope around it, as shown.

Fig. 13. Whipping the two ends of an Ordinary knot makes it more secure.

Fig. 14. The Weaver’s knot is used to join small lines or threads and is made by forming a bight in one rope, passing the end of the second rope around the bight, back over itself and through the bight. Weavers use this knot in tying broken threads. When pulled tight, both ends point backward, and do not catch when pulled thru the loom.

Fig. 15. The Hawser knot or sheet bend is used for joining stiff or heavy ropes and is not to be confused with the weaver’s knot. It resembles the bowline, and is easily untied.

Fig. 16. The Double Sheet Bend is similar to the Hawser knot and is useful for the same purposes.

Fig. 17. The Garrick bend is commonly used for joining two heavy hawsers which are too stiff to bend easily.

Fig. 18. Another method of joining stiff hawsers is to use the Half-hitch and whipping. This is a satisfactory method of making a joint to be used for a considerable time.

Fig. 19. The Slip knot as shown is a knot with many uses.

Fig. 20. The Bowline knot is useful for forming a loop on the end of a rope. It is used frequently by stockmen to tie a horse or cow so that they will not choke themselves. It is always secure and easily untied. Use this knot in tying a tow rope to a car.

Fig. 21. The Running Bowline is used for the same purposes as the slip knot in Fig. 19, but is much more secure. It will always run freely on the standing part of the rope, and is easily untied.

Fig. 22. A Loop knot is useful for making fast to the middle of a rope where the ends are not free. It will pull tight under strain, and is not easily untied.

Fig. 23. The Tom-fool knot is formed in the middle of a rope and may be used for the same purpose as the loop knot, except in this case either standing part of the rope may be strained without the knot failing, or slipping. It can be used for holding hogs. Place one loop over the hog’s snout and hold onto one rope. Release by pulling other rope. Can also be used from the ground for releasing hoisting tackle which has been used on a flag pole or other tall object.

Fig. 24. The Boat knot is formed by the aid of a toggle on a rope whose ends are not free, and is used for shortening or for stopping a ring on a taut line.

Fig. 25. The Surgeon’s knot is a modified form of the square knot, and if used with smooth cord, as in tying bundles, it holds very securely. The object of the double twist is to make the knot easy to tie without holding with the end of the finger.

Fig. 26. Bowline on the bight is easily made on the looped part of a rope which is double. It is used where a loop is desired which will not pull tight or choke and is easily untied. May be used for casting harness for horses.

Fig. 27. The Spanish Bowline is a knot which may be made in the middle of a long rope or in a bight at the end, and gives two single loops that may be thrown over two separate posts or both thrown over one. Either loop will hold without slipping and is easily untied.

Fig. 28. The Flemish loop is similar to the Fisherman’s knot, Fig. 11, except that it is used for forming a loop on the end of a rope instead of joining two ropes. The loop or eye will not close up when strained.

Fig. 29. The Hawser knot with toggle is formed exactly the same as the regular Hawser knot except that the toggle is inserted for the purpose of making it easy to loosen the knot after a strain has been applied.

Ending Knots

A group of knots somewhat different from those already described, are those used for ending ropes. Ending knots not only serve the purpose of giving a large end on the rope, but also take the place of whipping, in that they prevent the rope from unraveling. Sometimes an ending knot is also used for its ornamental value.

Fig. 30. A Whipping applied as shown is employed for keeping loose ends from fraying or unraveling, where the use to which the rope is to be put will not permit of a knot on the end. Strong cord is used for whipping. In splicing ropes, the whipping is removed before the splice may be considered complete.

Fig. 31. The Single Crown, tucked, makes the rope end but slightly larger than the standing part, and serves to prevent the strands from unraveling. This gives a neat appearing end. To make this type of knot, leave the ends long enough so they can be brought down and tucked under the strands of the standing part. After tucking them under the first strand, as shown, halve each strand and tuck it again under the next strand of the standing part and continue this until the ends are completely tucked the whole length, thus giving a gradual taper to the end of the rope and also giving a knot that will stand by itself. The single crown not tucked, is not a good ending for a rope.

Fig. 32. The Wall knot is frequently used as an ending knot to prevent unraveling. It is very satisfactory where the rope does not need to pass through a block or hole which is but slightly larger than itself. The Wall knot may be tucked similar to the Crown and makes a very secure ending for a rope. For small ropes unlay the strands back, each three inches, and on larger ropes in proportion. Hold the rope in the left hand with the loose strands upward. With the right hand take the end of strand number one and bring it across the loose end in position with the thumb of the left hand, then take the rope, forming a loop and allowing the end to hang free. Hold strand number two and pass it under strand number one and hold it against the rope with the thumb of the left hand. Again with the right hand take strand number three and pass it under strand number two and up through the first loop formed. Then draw each of the strands gradually until the knot is tightened.

Fig. 33. The Matthew Walker knot or Stopper knot is similar to the Wall knot except the ends are inserted through two loops instead of one as in the Wall knot. It can readily be made by loosely constructing the Wall knot as explained before and continuing as follows: pass the end number one through the loop with two, then end number two through the loop with three, and number three through the loop with one, then gradually tighten the knot by drawing in a little at a time on each strand.

Fig. 34. The Double Wall or Crown knot is made exactly the same as the Single Crown or Wall knot, but instead of trimming off or tucking the ends in, they are carried around a second time, following the lay of the first as shown, and then the knot is pulled tight. When completed, the ends may be tucked in as was done in the Single Crown, or they may be trimmed off.

Fig. 35. The Stevedore knot is similar to the Over-hand knot shown in Fig. 1, except that the end of the rope is served around the standing