The Story in a Coil of Rope
How many have ever given a thought to the question of where rope comes from and how it is made, or realize what a variety of uses it is put to, and how dependent we are upon it in many of the everyday affairs of life? But let us suppose for a moment that the world were suddenly deprived of its supply of this very commonplace material, and of its smaller relatives, cords and twine. We should then begin to realize the importance of a seemingly unimportant thing, and to appreciate the difficulty in getting along without it.
Ancient civilized peoples had their ropes and cordage, made from such materials as were available in their respective countries. The Egyptians are said to have made rope from leather thongs, and our will be found interesting in this connection. This is from a sculpture taken from a tomb in Thebes of the time of the Pharaoh of the Exodus.
While this scene is said by the best authority to represent the preparation of leather cords for use in lacing sandals, it has been supposed by some to be a representation of rope making. In any event the process is undoubtedly the same as that used in making rope.
The scene is depicted with the true Egyptian faculty for showing details, making words almost unnecessary to an understanding of their pictorial records. We see the raw material in the shape of the hide, and also two well-made coils of the finished product. One of the workmen is cutting a strand from a hide by revolving it and cutting as it turns. Any one who has not tried it will be surprised to see what a good, even string can be cut from a piece of leather in this way.
Another man is arranging and paying out the thongs to a third, who is evidently walking backward in time-honored fashion, twisting as he goes.
Coming down to more recent times we find that rope-making had been going on for centuries with probably very little change, up to the time of the introduction of machinery and the establishment of the factory system.
HOW ROPE WAS LONG MADE BY HAND
In the early days to which we have referred, all the yarn for rope-making was spun by hand in the time-honored way. We are able to represent to our readers by the photographs shown, this now almost lost art. The material shown in the pictures is American hemp, which because the earlier machines were not adapted to working this softer fiber, continued to be spun by hand long after manila was spun chiefly on machines.
The hemp was first hackled, as is also shown by our photograph, the hackle or “hechel” being simply a board having long, sharp steel teeth set into it. This combed out the tow or short, matted fiber, leaving the clean, straight hemp. This “strike” of hemp the spinner wrapped about his waist, bringing the ends around his back and tucking them into his belt, thus keeping the material in place without knot or twist, and allowing the fibers to pay out freely.
SCENE IN AN EGYPTIAN KITCHEN SHOWING USE OF A LARGE ROPE TO SUPPORT A SORT OF HANGING SHELF.
The workman in our picture is Johnny Moores, an old-time expert hand-spinner, who can walk off backward from the wheel with his wad of hemp, spinning with each hand a thread as fine and even as can be asked for. In the photograph, in order to show the process more clearly, one large yarn is being spun.
The large wheel, usually turned by a boy, is used to convey power to the “whirls,” or small spindles carrying hooks upon which the fiber is fastened. These whirls, revolving, give the twist to the yarn as the spinner deftly pays out the fiber, regulating it with skillful fingers to preserve the uniformity and proper size of the yarn. As he goes backward down the long walk through the “squares of sunlight on the floor” he throws the trailing yarns over the “stakes” placed at intervals along the walk for the purpose.
The spinning “grounds” were usually arranged with wheels at either end, so that spinners reaching the farther end, could go back to their starting point spinning another set of yarns.
Then in the case of small ropes, the strands could be made by attaching two or more yarns to the “whirl” and twisting them together, reversing the motion to give the strands a twist opposite to that given the yarns. These strands were twisted together, again reversing the motion, making a rope. Thus it will be seen that, reduced to its lowest terms, rope-making consists simply of a series of twisting processes. The twisting of the yarns into the strand is known as “forming” or putting in the “foreturn.” The final process is “laying,” “closing” or putting in the “after turn.” Horse-power was used in old times for forming and laying rope which was too large to be made by hand.
How all this work is now done in a modern rope factory by ingeniously devised machinery we shall now see.
The opening room where the fiber is made ready for the preparation machinery is a reminder of the days when all rope-making processes were hand work. The bales are first opened up—in the case of Manila this means cutting the straw matting put on to protect the fiber in shipment. Then the hanks which are packed in various ways—sometimes doubled, sometimes twisted—are taken out and straightened and the band at the end of the hank removed.
No machinery has yet been perfected for doing the work just described but the first of the preparation processes, a short step beyond, tells quite a different story. Here the hanks of such fibers as require a special cleaning treatment are placed on fast working hackling machines which comb away most of the snarls, loose tow and dirt.
At this point hard fibers—Manila, Sisal and New Zealand—are usually oiled to soften them and to make them more workable for the operations that follow. The oil, furthermore, acts as a preservative. It is a matter of importance to the buyer, however, that the fiber should not be too heavily oiled, for that merely increases the weight and cost of the rope without improving its quality.
The wonder of modernism in rope-making is nowhere more striking than in the preparation room. To pass from one end, where the raw hemp is received just as it left the hands of the native Filipino laborer with his crude methods, down through the long rows of machines to the draw frames from which the sliver is delivered in a form that can be likened to a stream of molten metal, is to cover decades of inventive genius and mechanical development.
The mechanism performs its work so accurately that at first glance the man feeding the fiber into the machine and all the other men, busy about their various duties, would appear to be playing very minor parts in modern rope making. In reality, expert workmanship and watchfulness are very important factors. Good rope depends no more upon scientific machine processes than upon ceaseless attention to the little details, and this is especially true in the preparation room.
Before taking up the distinctly modern machines so largely used now in the final processes of rope-making—the forming of strands, laying of common ropes and closing of cable-laid goods—we will describe the rope-walk where much of this work is still best carried on.
For making tarred goods in all but the smaller sizes the walk has certain advantages not afforded by newer methods. It also provides efficient equipment for turning out the largest ropes, which would otherwise require special machinery.
A MODERN ROPE WALK
INTERIOR OF ROPE WALK, PLYMOUTH CORDAGE CO.
The long alleys or grounds where the work takes place are usually laid out in pairs, one for forming, the other for laying and closing. Each ground has a track to accommodate the machines used and an endless band-rope which conveys the power.
HOW ROPE IS FORMED AND TWISTED
At the head of the forming ground stand frames holding the bobbins of yarn. The yarns for each strand first pass through a plate perforated in concentric circles. This arrangement gives each yarn the correct angle of delivery into a tube where the whole mass gets a certain amount of compression.
As the top truck is forced ahead by the twisting process, the ropemaker by means of greater or less leverage on the “tails”—the loose ropes shown in our picture—preserves a correct lay in the rope. The stakes on which the strands rest are removed one by one to allow the top truck to pass, and then replaced to support the rope until the laying is finished and the reeling in of the rope begun.
The closing process on cable-laid goods is like the laying except that the twist is reversed. The work now being with three complete ropes—frequently very large—a heavier top truck is necessary, and this must often be ballasted, as shown in our, to keep down the vibration which would otherwise tend to lift the truck off the track.
Modern rope-making ingenuity reaches its high-water mark in the compound laying-machine where the two operations of forming the strands and laying them into a rope are combined. Up to a certain point this method is more economical than that in which the forming and laying are unconnected. Fewer machines are required for a given output—hence, less floor space and fewer workmen. The time-saving element also enters in.
PREPARING THE FIBER IN ROPE MAKING
OPENING BALES OF MANILA FIBER FOR PREPARATION.
PREPARATION ROOM.
Here the fiber is carefully cleaned and combed by a series of fine tooth machinery through which it passes.
COUNTLESS SLIVERS STREAM FROM THE ROPE MACHINE
FORMATION OF SLIVER—FIRST BREAKER.
The hanks of fiber are fed by hand into this machine several at a time, where it is grasped by steel pins fitted to a slowly revolving endless chain. A second set of pins moving more rapidly draws out the individual fibers and combs them into a continuous form.
The operations which follow are very similar. A number of “ropings” are allowed to feed together into a first slowly revolving set of pins and are drawn out again by a high speed set into a smaller sliver, the pins becoming finer on each succeeding machine until the draw frame is reached. Here the fiber is pulled from a single set of pins between two rapidly moving leather belts called aprons. On all of these machines the fiber passes between rollers as it goes onto and leaves the pins and the sliver is given its cylindrical form by being drawn through a circular opening.
A finished sliver must conform to the special size desired for spinning.
SPREADER.
SECOND BREAKER.
DRAW FRAME.
The compound laying machine must, however, be stopped each time that the supply of yarn on any bobbin is so low as to call for a fresh one. This would occur so frequently in the case of the larger ropes as to offset the advantages just mentioned, hence the machine is used on a limited range of sizes only.
As can be seen in the picture, the machine contains a vertical shaft with upper and lower projecting arms which support the bobbin-flyers—four in number in this particular case. The bobbins within each flyer turn on separate spindles, allowing the yarns to pass up through small guide plates and thence into a tube.
Each flyer is geared to revolve on its own axis, thus twisting its set of yarns into a compact strand. At the same time all the flyers revolve with the main shaft in an opposite direction and form a rope out of the strands as the latter come together in a central tube still higher up.
The rope is drawn through this tube by a series of pulleys which exert a steady pull and so keep the proper twist in the rope. From these pulleys the finished product is delivered onto a separately-driven coiling reel, an automatic device registering meanwhile on a dial the number of fathoms run.
The small reel, seen near the head of the main shaft, holds the small heart rope which is fed into the center of certain four-strand ropes to act as a bed for the strands.
Pure Manila rope is the very best and the most satisfactory for all around use. The character of good Manila fiber is such as to impart to a properly made rope such necessary factors as strength, pliability, and wearing qualities.
Regular 3-strand Manila rope is universally used for all general purposes.
For certain special uses, however, and particularly where the rope is to be used for any kind of sheave work, a 4-strand type of construction will be found the most suitable, as such a rope presents a much firmer, rounder, and greater wearing surface than the ordinary 3-strand. There are many different types of 4-strand rope.
The picture shown on this page represents a coil of 4-strand Manila called “Best Fall.” This rope is made of carefully selected fiber; is 4-strand with heart, and is harder twisted than ordinary goods. Best Fall is adapted for heavy hoisting work, as on coal and grain elevators, cargo and quarry hoists and for pile-driver hammer lines.
AN AVERAGE COIL OF ROPE—1200 FEET
The standard length coil of rope is 1,200 feet, although extra long lengths are every day made for such purposes as oil-well drilling, the transmission of power, etc., etc.
KNOTS.
From Knight’s American Mechanical Dictionary.
| 1. | Simple over hand knot. |
| 2. | Slip-knot, seized. |
| 3. | Single bow-knot. |
| 4. | Square or reef knot. |
| 5. | Square or bow-knot. |
| 6. | Weaver’s knot. |
| 7. | German or figure-of-8 knot. |
| 8. | Two half-hitches, or artificer’s knot. |
| 9. | Double artificer’s knot. |
| 10. | Simple galley-knot. |
| 11. | Capstan or prolonge knot. |
| 12. | Bowline-knot. |
| 13. | Rolling-hitch. |
| 14. | Clove-hitch. |
| 15. | Blackwall-hitch. |
| 16. | Timber-hitch. |
| 17. | Bowline on a bight. |
| 18. | Running-bowline. |
| 19. | Catspaw. |
| 20. | Double running-knot. |
| 21. | Double-knot. |
| 22. | Sixfold-knot. |
| 23. | Boat-knot. |
| 24. | Lark’s head. |
| 25. | Lark’s head. |
| 26. | Simple boat-knot. |
| 27. | Loop-knot. |
| 28. | Double Flemish knot. |
| 29. | Running knot, checked. |
| 30. | Croned running-knot. |
| 31. | Lashing-knot. |
| 32. | Rosette. |
| 33. | Chain-knot. |
| 34. | Double chain-knot. |
| 35. | Double running-knot with check-knot. |
| 36. | Double twist-knot. |
| 37. | Builder’s knot. |
| 38. | Double Flemish knot. |
| 39. | English knot. |
| 40. | Shortening knot. |
| 41. | Shortening knot. |
| 42. | Sheep-shank. |
| 43. | Dog-shank. |
| 44. | Mooring-knot. |
| 45. | Mooring-knot. |
| 46. | Mooring-knot. |
| 47. | Pig-tail, worked on the end of a rope. |
| 48. | Shroud-knot. |
| 49. | Sailor’s bend. |
| 50. | A granny’s knot. |
| 51. | A weaver’s knot. |
HOW TO SPLICE A ROPE
ENGLISH SPLICE.
For transmission rope.
The successive operations for splicing a 1³⁄₄-inch rope by this method are as follows:
1. Tie a piece of twine (9 and 10, figure 6) around the rope to be spliced, about six feet from each end. Then unlay the strands of each end back to the twine.
2. Butt the ropes together, and twist each corresponding pair of strands loosely, to keep them from being tangled, as shown (a) figure 6.
3. The twine 10 is now cut, and the strand 8 unlaid, and strand 7 carefully laid in its place for a distance of four and a half feet from the junction.
4. The strand 6 is next unlaid about one and a half feet, and strand 5 laid in its place.
5. The ends of the cores are now cut off so they just meet.
6. Unlay strand 1 four and a half feet, laying strand 2 in its place.
7. Unlay strand 3 one and a half feet, laying in strand 4.
8. Cut all the strands off to a length of about twenty inches, for convenience in manipulation. The rope now assumes the form shown in b, with the meeting-points of the strands three feet apart.
Each pair of strands is now successively subjected to the following operations:
9. From the point of meeting of the strands 8 and 7, unlay each one three turns; split both the strands 8 and 7 in halves, as far back as they are now unlaid, and “whip” the end of each half strand with a small piece of twine.
10. The half of the strand 7 is now laid in three turns, and the half of 8 also laid in three turns.
The half strands now meet and are tied in a simple knot, 11 (c) making the rope at this point its original size.
11. The rope is now opened with a marlin-spike, and the half strand of 7 worked around the half strand of 8 by passing the end of the half strand through the rope, as shown, drawn taut, and again worked around this half strand until it reaches the half strand 13 that was not laid in. This half strand 13 is now split, and the half strand 7 drawn through the opening thus made, and then tucked under the two adjacent strands as shown in d.
12. The other half of the strand 8 is now wound around the other half strand 7 in the same way. After each pair of strands has been treated in this manner, the ends are cut off at 12, leaving them about four inches long. After a few days’ wear they will all draw into the body of the rope or wear off, so that the locality of the splice can scarcely be detected.