Wire rope

“ 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. ”

“ 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. ”

“ 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 flexibility of a wire rope depends upon the number of wires of which it is formed; consequently the use to which a rope is to be put will partly determine the number of wires used in its construction. In some cases nearly 400 individual wires are employed in making one rope. Fig. 8 shows in section ten different types of construction, the particulars of which appear below:—
1. Laid rope made of 6 strands of 7 wires each. This is the class of rope most frequently used for hauling ropes where the size of the barrel and sheave will permit ”

“ WIRE ROPE TRANSMISSION [13]
Wire ropes are extensively and successfully used in the horizontal and inclined transmission of great power of unlimited amount, the advantages over hemp rope belting being: driving at very long distances, comparatively small loss through slipping and the possibility of driving in the open air.
[13] Contributed to Power by C. Boysen, M. E.
Vertical transmission of power, on account of the weight of the rope, is excluded. ”

“ 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 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. ”

“ Each also is the fruit of long study and repeated test of the work it is to do not alone on machines and in the laboratory, but under actual conditions of operation. The wire rope engineer will tell you every rope has temperament. He spends his life knowing other people’s business—rope business—and working out their rope problems. The answers to these problems are the four hundred different sizes and kinds of rope that the Roebling Company manufactures on its regular schedules. The rest are specials. Go where you will in the world nowadays, you will find wire rope doing the work. ”

“ For aerial ropeways they are extensively employed, and are of high value in bridge building, the suspension bridge being sustained by them. The strength of the steel wire used for ropes varies from seventy to over one hundred tons per square inch of sectional area, the weight of a hemp rope being about three times that of a wire rope of equal strength. ”

“ As the material for wire gauze and cloth, wire rope, cable, piano strings, springs of all sorts, pins, needles, nails, fence, barbed wire, and the myriad of other things, wire really is one of our great products.
It was mentioned that piano wire had been made which had a tensile strength as high as 400,000 pounds per square inch, which is six or seven times the strength of an equivalent cross-section of steel rail or plate. Wire is undoubtedly the strongest product which is made from steel. This is why wire rope or cable is so strong. ”

“ 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. ”

“ Even the core is figured in the number of days it will add to the rope’s life under varying conditions. The wide difference in ropes consists not only in the materials employed, which have much to do with their resistance to divers strains and the manner of their use, but in skillful selection of sizes in the wire and arrangement in the strands of which they are composed ”

“ To prevent rusting, the wire ropes receive a coat of boiled linseed oil, or a hot mixture consisting of three parts of drip oil and one part of resin is applied. This latter mixture at the same time improves the adhesion between the rope and the lining placed in the bottom of the pulleys, thus reducing the loss caused by slipping of the rope. Wire ropes used for the transmission of power should never be galvanized. ”

“ At present, however, the stays of aeroplane wings are almost invariably solid steel wire, or ribbon, while marine shrouds are always of stranded wire rope, solid wire not having been found satisfactory. Weight for weight, the solid wire will stand a greater strain when tried in a testing machine than will the stranded rope, but practice has always demonstrated that it is not so reliable. ”

“ No thinkable effort is omitted that will help to make the wire material perfect in quality and service condition, but the proof of the pudding in the making of wire is in the Olsen machines—miraculous things that will smash a big wire rope or snap a hair of wire and register to a decimal the breaking strength of each. There are tests for tensile strength, for torsion to show how many twists a piece of wire will stand, and for bending. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ To carry the load, a single endless wire rope, 3 / 8 inch in diameter and 2,000 feet long, is employed. It spans the distance between collier and ship twice, giving an inward track for full sacks, and an outward track for their return to the collier. On one vessel are two winches, the drums of which both turn in the same direction; but while one drum is rigidly attached to its axle, the other slips under a stress greater than that needed to keep the rope sufficiently taut. ”

“ There is no twist in these ponderous cables, as there is in a wire rope. Every reach of wire lies flat and separate, and when all were in place they were laboriously bound together, first the strands, then when all the strands were up, the whole fabric, into cylindrical form. There are other strange things about these cables; one is that they make practically no strain on the towers save to sustain their weight. ”

“ With proper precautions, however, wire guides are perfectly safe for use at the highest travelling speed.
The cage is connected with the drawing-rope by short lengths of chain from the corners, known as tackling chains, gathered into a central ring to which the rope is attached. Round steel wire-ropes, about 2 in. in diameter, are Cage. now commonly used; but in very deep pits they are sometimes tapered in section to reduce the dead weight lifted. Flat ropes of steel or iron wire were and are still used to a great extent, but round ones are now generally preferred. ”

“ He advocates the use of iron as the best metal to use, specifying a weight of 2 lbs. per foot. He thinks wire ropes are more easily applied than rods, ribbons, or tubes, and prefers a rope 1·2 in. diam. of six strands of seven No. 11 B.W.G. wire, each round a hemp core—costing about 5d. per foot. Conductors should be specified in terms of electrical units, viz.: ·3 ohms per 1000 yards, and be continuous. Every unavoidable joint should be soldered. He has found in practice many bad joints, especially in copper conductors. ”

“ Wire-rope transmission commences at the point where the belt and shafting become too long or heavy to be useful. It is much cheaper than its equivalent of shafting or belting. In fact, a long line of shafting would cost more for oil in a year than a wire rope would in fifteen. ”

“ It is all like a Maypole, and the bobbins go in and out like children carrying each its ribbon. As the wire climbs, the whirling fingers braid around it a coating, tight fitting and impervious. Sometimes, where double insulation is required, there are two sets of arms, one above the other, the upper one putting on a second covering outside the first, of cotton of one color or another, or hemp or whatever else the experimentalists have found best for the purpose. You wonder how the bellcord in the railroad train can ever stand the pulling and jerking and wear and tear it gets. ”

“ It is important that sharp bends be avoided. A string course, for instance, should be drilled, and the rod or rope passed straight through. Also, that any metal bodies in the line of the conductor should be connected with it by staples screwed into such bodies. It is most necessary that the ends of vane bolts or rods should be joined to the conductor, or, where this is impossible, should be fitted with an independent wire or rod to the earth. ”

“ Crucible wire is made in the same manner, except that the strands are wire throughout.
Crucible wire is used for standing rigging and flexible wire for purchases, etc.
In splicing wire all tucks are made with the lay of the rope.
In making an eye splice the rope is handled better if hung up in a convenient position so that when standing up the eye will be at about the level of the chest of the person working.
A long tapering steel marline-spike is required, and after placing it under a strand do not withdraw it until the tuck is made and all the slack of the strand drawn through. ”

“ Rope grip pulleys, for driving a vertical rope, the large pulley has a V groove into which the rope is pressed by the small pulley.
1209. Jigger hoisting rope gear, used for whip cranes, &c., instead of spur gearing.
Wire rope transmission. Endless wire ropes of small diameter are used running over large pulleys and driven at a high speed (usually 3000 to 4000 feet per minute) . This kind of power may be carried considerable distances and over uneven ground, but it is not desirable to have horizontal angles in the direction of the rope.
Section 67.—RESERVOIRS OF POWER. ACCUMULATORS.
a. ”

“ The repairing people were very smart at their job, fixed a rope and tackle from one cut end to the other, and then hauled taut the great length of wire between the two nearest telegraph-posts, mounting their portable ladders and fixing things in a most seamanlike way, until they had the wire as taut as they could haul it, with six or seven feet of rope tackle bridging the gap and the two cut ends of the wire hanging down. ”

“ No joint can possibly be perfect that is not metallically continuous. Careful soldering is the only certain mode of securing this, and that this is practicable is evident from the millions of perfect joints in telegraph wires. To scrape the ends of wire bright, and cover the whole with thin sheet lead, as is done by one firm, is simply to court danger. The absence of joints in wire rope is one great element in its favour.
(21) 5. Attachment to building, how made. Some attach the conductor to the building by copper straps and nails; some use holdfasts, either of copper wire or gun metal ”

“ In the main, the entire volume produced either goes to market as wire of one sort and another, to be applied to its various objects or for sale, or else it is twisted into rope, of which the Roebling Company manufactures four hundred kinds, sizes and many qualities. The common fence wires are not among the Roebling specialties, but wire nettings are manufactured from a soft variety of basic steel which lends itself to the weaving process with almost the ease of animal and vegetable fibres. ”