Rope (hardware)

“ The uses that wire ropes are now put to, and the ways and occupations they are employed in, are so various, that it is almost a necessity for a man to be engaged in their manufacture to have a thorough knowledge of the different methods of handling them. For instance, it would be just as consistent to expect a sailor, used only to eye-splicing, to go to a colliery and put a long splice into a rope, to withstand the enormous stress there applied, as it would be to expect a colliery man to go aboard ship to splice the mainbrace, or any other brace. ”

“ 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. ”

“ As already explained, the laying-machine is used in the same way when three ropes are made into a cable. When a four-strand rope is to be turned out the machine89 has four strand-reels. If the strands are to be laid around a heart rope, as in transmission goods, the heart feeds directly into the twist tube from a smaller reel placed on the top-piece previously mentioned.
All the foregoing machines are equipped with ingenious devices for measuring the strand or rope as it is made, so that the attendant can tell instantly from the gauge how many feet have been run. ”

“ When the machine is in operation the whole lower portion, from the tube down, revolves, either to the right or left as the goods require, and thus puts the twist into the rope. This twist being opposite, always, to that of the strands, the natural tendency of the latter as they are laid together would be to loosen up. To regulate this, each flyer is made to revolve on its own axis—in a direction opposite to the general direction of the machine. Each reel revolves also on its axis to feed out the strand—the effect of the changing load being met as before by a friction attachment. ”

“ The fibre cores, for this reason, are usually treated with some lubricant. In the majority of ropes hemp is used for a core but in those intended for stationary service the core may be of steel. This will add from seven to ten per cent to strength and very largely to rigidity.
When we speak of wire rope most of us have a mental picture of a round fabric, but there are flat ropes as well, for use in mines or quarries where the haul is from great depths and twisting is to be avoided. ”

“ Forming and Laying of Ropes—Factory Method, Single-Machine System 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 as already described. Fewer machines are required for a given output,—hence less floor space and fewer workmen. ”

“ Cotton rope is seldom used save for small hand-lines, clothes-lines, twine, etc., while wire rope is largely used nowadays for rigging vessels, derricks, winches, etc., but as splicing wire rope is different from the method employed in fibre rope, and as knots have no place in wire rigging, we will not consider it. ”

“ The rapid strides made by electricity have furnished another large branch of what may be termed wire rope manufacture. The ropes used for electrical purposes are almost invariably termed cables, and there are many different kinds and sizes of them. The wire must necessarily possess good conducting power, and be comparatively cheap. ”

“ FITTING THE ROPE TO ITS WORK Of the tricks in making ropes, there is no end. They are fitted for their work like a soldier or a gymnast, and built for it. A tiller rope must be flexible to the last degree, but it must be strong enough so it will stand up under the swift tensions of a storm or in the lightning manœuvers of a race. Therefore, like a few ropes built for other purposes, the composite parts are not mere strands of wire, but little ropes in themselves, complete in all parts. ”

“ These are led from the bobbins in toward the center, and pass into the column, which carries also the core and which in its turning twists the strands together. The complete rope passes out over a pulley on to the spools. Machines for the smaller sizes of rope are strung out in a long file. The larger ones require elbow room; each of those for the making of the largest rope has a room to itself and is installed on a foundation of steel and concrete.
HOISTING A HUGE NAVAL GUN WITH WIRE ROPE SLING
When the mechanism is at work it suggests somehow the solar rotations. ”

“ Several corrective devices have been suggested, such as wearing two ropes, keeping a hand-loop ready near our hand on the rope, etc.—devices which are now used in the confidence that they form a genuine safeguard. The intention of the double rope is that if one man falls through, the other will untie one rope from his waist, and fasten it to his axe, which he will drive in securely as a belay. The man below will then pull on this rope, and the man above on the rope still attached to him ”

“ In the case of a common right-laid rope, the forming twist is left hand. A change to right hand can be made simply by shifting clutches. The amount of turn or twist depends on the diameter of the drum, which is adjustable.
Behind the machine follows a man who swings out the stakes, placed at intervals along the walk, and throws the strands over them. When the process is completed the strands are cut away at either end and transferred to the laying ground, the stakes being pushed back to allow the return of the forming machine for another trip. ”

“ It is not as durable as round rope and is heavier for the same working strength. As the sewing wires soon begin to break, a flat rope must usually be ripped apart and resewed every six or eight months. Numerous patent ropes, some having wires and strands of special shapes, have been introduced with the idea of improving the wearing properties. Such, for example, are the Lang-lay, locked-coil and flattened strand rope. Hoisting ropes are weakened by deterioration and breakage of the wires, due to corrosion and, repeated bending, and should be kept under careful inspection. ”

“ But one rope is no more like another than Jones is like Brown or Smith like Robinson. Wire rope is a combination of twisted wires, just as men are bipeds. That is where the similarity ends. In outward appearance as well as inward character, habit, tendencies and behavior in emergencies, wire ropes differ as widely as do people, and each has a meaning of its own. ”

“ The finished strands are wound in turn upon large bobbins, and mounted in the flyers or disks of the rope closing machine. These machines are similar in design to the stranding machine, but are naturally much heavier in construction, and, therefore revolve at a proportionate speed. The speed of the machines varies according to the weight of material, the size of the strands and the construction of the finished rope. The modern machine, or the type most generally used, makes about fifty revolutions per minute, whilst three times this speed is often obtained when spinning the strands. ”

“ Rope making has been treated as an exact science, because it dealt with materials that were more or less standardized. They are learning now that rope has a large unknown quantity that defies formula past a certain point. For the lack of a better term, they call it “personality.” The labor of today, and many years to come, is to identify these intangible factors and bring them where they can be computed to the end of securing greater endurance and safety. ”

“ Ropemaking is a trade carried on in many places, but there are few establishments that can equal the Universe Works in Garrison Lane, where, in addition to hundreds of tons of twine and cord, there are manufactured all sorts of wire and hemp ropes for colliery and other purpose^, ocean telegraph cables included. Messrs. Wright introduced steam machinery early in 1853, and in the following year they patented a rope made of best hemp and galvanised wire spun together by machinery. On a test one of these novelties, 4|in. circumference attached to two engines, drew a train of 300 tons weight. ”

“ No man ever made a machine that would pull [2097] a large rope one moment, and the next pull a fine thread, and do the one just as well as the other. But that wonderful machine, the hand, can do this. It can grasp the rope firmly, and yet can take between its thumb and finger a thread so fine that you can hardly see it. ”

“ If the strand be drawn more swiftly through, while the machine is revolving with a given velocity, the intensity or closeness of the twist is diminished, if less swiftly then the twist is increased. Such are some of the beautiful results of machinery.
To twist the strands into a rope is called “laying” a rope. In the laying walk a revolving wheel placed near the end is provided with hooks, whereon the three strands to form the rope are fixed. These hooks are made to rotate by the action of the wheel, its prime mover being horse or steam-power. ”

“ JOURNEYING THROUGH THE ROEBLING PLANTS For exercise, a journey through any one of the Roebling plants, and especially the great Upper Works, is as good as thirty-six holes of golf. It is upstairs and downstairs, over an interminable number of thousands of square feet, through the mazes of a picture that is always changing its detail and its rate of speed, but which is all centered on one idea, to keep the stream of wire and wire rope, of all sizes, kinds and colors, moving toward the shipping room. ”

“ From molecular condition, as revealed by the microscope, down to the last petty detail in the plan of construction, there is never an end to the problems, and gravity has to be figured into the lifetime of a rope as surely as the elusive trace of sulphuric and muriatic acid producing hydrogen occlusion. Wire rope is a business of exactitude and eternal vigilance. ”

“ Like all human devices, however, the guide rope, along with its advantages, has its inconveniences. Its rubbing along the uneven surfaces of the ground—over fields and meadows, hills and valleys, roads and houses, hedges and telegraph wires—gives violent shocks to the balloon. Or it may happen that the guide rope, rapidly unravelling the snarl in which it has twisted itself, catches hold of some asperity of the surface or winds itself around the trunk or branches of a tree. ”

“ To the average man or woman, the elevators in tall buildings suggest danger. The rope engineer counts them highly safe because each elevator is equipped with a multiplicity of ropes and safety devices. What taxes his conscience and spurs him to the last possible effort, is the rope that goes to the “deep shaft” service, where the lives of men going up and down in five thousand feet or more of subterranean darkness, hang on the accuracy of his calculation.
Only now, the Roebling engineers will tell you, is wire rope being perfected. ”

“ The manufacture of rope is carried on on a very extensive scale. A building 1,360 feet long, contains a rope walk where a length of upwards of 1,200 feet of rope may be made. There are also the means of making 24-inch cables.
Machinery is used for making sheaves for ship blocks. An ingenious machine is employed for boring the sheaf, and recessing it on both sides for receiving the bush. Two lathe headstocks are mounted on a frame, and carry the small revolving cutters for making the recesses. ”

“ When cables for street railways were discarded in favor of trolley, wire rope men thought the day of doom had come, but the field for wire rope for other uses has widened so fast and so far, in a rapidly widening world, that the cable orders, big as they were, have never been missed. It furnishes a significant index of the growth in all industrial activity, for there is no new phase of development or manufacture or work of any kind in which wire rope, or wire in some form or other, does not play an indispensable part. ”

“ The resulting tendency of the strands to untwist is counteracted, partly by a left-hand revolution of the foreturn spindles, and partly by the presence of the “hard” or surplus twist just described.
As the top truck is forced ahead by the twisting process, the rope-maker preserves a correct lay in the rope by means of greater or less leverage on the “tails”—the loose ropes shown in our picture. The stakes on which the strands rest are removed one by one to allow the top truck to pass and are then replaced to support the rope until the laying is finished and the reeling in of the rope begun. ”

“ The apparatus referred to is known as a chain hoist. These are built to use chain instead of rope and are designed to operate slowly, but with great mechanical advantage. Different types embody different design of movements, some being merely a train of gears attached to a sheave wheel and driven by a worm gear. Others employ the differential principle in which the hoisting chain is double, one end running over a small pulley and the other end running in the opposite direction over a larger pulley on the same shaft. ”

“ Rope is usually three-stranded and the strands turn from left to right or "with the sun," while cable is left-handed or twisted "against the sun" (E, Fig. 1) . Certain ropes, such as "bolt-rope" and most cables, are laid around a "core" (F, Fig. 2) or central strand and in many cases are four-stranded (Fig. 2) .
The strength of a rope depends largely upon the strength and length of the fibres from which it is made, but the amount each yarn and strand is twisted, as well as the method used in bleaching or preparing the fibres, has much to do with the strength of the finished line. ”