CHAPTER X

ROPES AND ROPE MAKING; YARN NUMBERING

A considerable quantity of the smaller-sized ropes are now made on what are termed “house machines.” These machines perform the same function as those in the rope-walk but they occupy a much smaller space; they are adapted to deal with a great range of sizes although, in general, it is not necessary to use one machine for a large range of work; there is such a variety of ropes in use that in a well-equipped rope works it is possible to keep each machine almost constantly on ropes within a small range of size. These remarks refer, as indicated, to ropes which come within the limit of, say 2 to 3 in. in circumference. In the manufacture of the larger sizes of ropes, it is usual to use two distinct machines, one termed the “strander,” and the other the “closer,” and, although the house-machine made ropes are often considered inferior to those made in the rope-walk, many of the objections urged against the untarred ropes made in the house-machine are more imaginary than real.

Fig. 29 is illustrative of a number of machines of a type used for the making of ropes in which twelve to forty-five threads may be combined in one operation during the manufacture of a three-strand or a four-strand rope. The bobbins are placed in creel flyers of which there may be three or four according as the rope is to be a three-strand or a four-strand one. The creel flyers are composed of two parts, one of which carries the bobbins, and the other carries the hauling and twisting gear. All the three or the four strands are made at the same time; when formed, they leave their respective flyers and converge towards the top and the die or central tube where they are formed into a rope by the proper degree of twist according to the purpose for which the rope is to be used. Finally, the finished rope is drawn forward by a series of hauling pulleys which also conduct the rope to the winding-on reel or bobbin, and by suitable mechanism the rope is wound into a temporary form of coil. As the bobbins are filled with rope they are removed from the machine and conveyed to special coiling machines where they are measured when necessary as they are made up into coils suitable for the particular purposes desired. A common length of coil is 120 fathoms.

[Illustration: _By permission of the Edinburgh Roperie Co._ FIG. 29 ROPE-MAKING (HOUSE MACHINES)]

Although the various house machines represent the latest developments in the art of stranding and closing--the two essential operations of rope making--a modern rope and cordage works is provided not only with the various machines which have been illustrated and described, but also with a well-equipped rope-walk so that the products may include a great variety of cordage from the finest lines to the mammoth ropes for ships, steamers, harbours and heavy hauling purposes generally.

The combination of the house machines and the modern rope-walk makes present arrangements very complete when compared with the old type of rope-walk, but the apparatus employed in these old rope-walk machines embodies all the principles of construction which are present in the new machines for the same class of work.

Rope-walks are, naturally, long, narrow buildings because the full length of the rope is in one stretch.

The work which is conducted in such places and the type of building is admirably portrayed in the first three verses of Longfellow’s poem--

THE ROPE-WALK.

In that building long and low, With its windows all a row, Like the port-holes of a hulk, Human spiders spin and spin, Backward down their threads so thin, Dropping, each, a hempen bulk.

At the end an open door; Squares of sunshine on the floor Light the long and dusky lane; And the whirling of the wheel, Dull and drowsy, makes me feel All its spokes are in my brain.

As the spinners to the end Downward go and re-ascend, Gleam the long threads in the sun; While within this brain of mine Cobwebs brighter and more fine By the busy wheel are spun.

At the top of the rope-walk is a stand or bank which contains the bobbins of yarn, and this yarn may be dry or tarred according to requirements. The bobbins are arranged on pins and the necessary number of yarns for each strand are drawn from the bobbins and passed, in their proper order for ensuring a uniform strand, through a number of holes in a “register plate” immediately behind the machine. In a modern machine any number of strands up to six can be formed at the same time, and hence there will be six register plates for the yarns. For the larger-sized ropes only one strand can be drawn out in one operation.

A machine termed a “traveller,” is employed to draw out the strands, and this machine is provided with a series of hooks as well as a central spindle. The strands may be attached as required either to the hooks or to the spindle. A rope-driving gear causes this traveller to move on rails down the walk and for the distance required, and it will be evident that as the traveller recedes from the bank it will draw the groups of threads from the bobbins and through the register plates; at the same time the several hooks are caused to rotate, and thus each strand is twisted and hauled simultaneously.

When the traveller has moved backwards or downwards for the necessary distance to form the length of strand, the strands are removed from the hooks and attached to suitable supports until a sufficient number has been made for closing or laying-up.

To form the strands into a rope, it is essential to use a fixed or stationary machine along with the traveller and a top-cart. The stationary machine is substantially built, and, _inter alia_, is provided with a central spindle around which are grouped a set of hooks--usually in sections of two circles. Two wheels on the central spindle drive a number of pinions, one behind each hook, the ratio of one wheel to half the pinions is 34 to 16, while the ratio of the other wheel to the other half of the pinions is 54 to 11. Thus, the revolutions may be--

1 to 1 when the strand is on the central spindle, 34 to 16 or approx. 2 to 1 when on large hooks, and 54 to 11 „ „ 5 to 1 when on small hooks.

When the necessary strands to form the rope are stretched between the stationary machine and the traveller, an extra amount of twist is imparted to each strand, an operation which is termed “hardening the strand”; the amount of twist can be judged only by past experience, although it is common to give instructions in the words “harden so many fathoms”; at other times the strands are hardened until the threads form a desired angle. In all cases the strands should be twisted equally so that the same tensile stress is on each strand. After this twist has been applied, all the strands are placed either on one of the hooks or on the central spindle of the traveller. A top-shaped block is put into position inside the three strands--this top is in full view in Fig. 30, which, by the way, illustrates the laying of a 28-in. circumference four-strand hawser with a central core--and the machines started for a few revolutions. When the first make of the rope is formed, the top is brought back to its proper place, a few pieces of rope, termed tails, are placed round the newly-formed portion of the rope, and these may be collected and held in position by a bar as shown; one of these tails was removed when the photograph was taken in order to show the finished part of the rope between the top-cart and the traveller. The traveller is now braked to keep the rope taut while the rope-maker lays the strands, the hooks of the stationary machine at the top of the walk as well as the hooks on the traveller being rotated meanwhile at a speed which is suitable for the make or lay of the rope. The hooks in the two machines rotate relatively about 7 to 9 or 7 to 11.

[Illustration: FIG. 30 LAYING OF A FOUR-STRAND CABLE-LAID ROPE IN THE ROPE-WALK]

When a hawser or cable-laid rope or a “trawl warp” is desired, the formed ropes are again placed in position, and the whole routine repeated, while if the warp is to consist of more than three strands, a heart must be inserted, as exemplified in Fig. 30, upon which to lay or build the strands. It will be understood that the view in Fig. 30 is the interior of “a rope-walk,” and that the operative is looking towards the top of the walk where the stationary machine is situated.

After the laying is completed, the finished rope must be made into a coil ready for transportation. The coiling machines are often in close proximity to the house machine or the rope-walk, and for the coiling of such ropes as that illustrated in Fig. 30, it is obvious that the machine must be of substantial build. When such a large rope is complete and ready for despatch, it resembles the 18-in. circumference mooring rope in Fig. 31; this rope was 90 fathoms long and two tons weight, and was coiled in about ten minutes by a machine specially designed for the purpose.

[Illustration: FIG. 31 VIEWS OF LARGE AND MEDIUM-SIZED COILS OF ROPE]

Rope driving has practically revolutionized the construction of modern mills since ropes are used not only as a direct drive from the rope pulley on the engine or motor shaft, but at many intermediate places, and have replaced many installations of wheel-gearing. These mill-driving ropes, which are invariably from 1½ to 2 in. in diameter, are made extensively of cotton, hemp or manila. In exceptional cases more than forty such ropes are used on the same pulley. The frontispiece illustrates a rope drive in which seven ropes each of 1¾ in. diameter, are utilized on the shaft of a motor for conveying the motion to a mill shaft seen in the distance. Other ropes are seen in the next rope alley. Somewhat similar ropes, but of a smaller diameter, are used for hauling in the baling press illustrated in Fig. 15.

There are several methods of numbering yarns, most of which involve a direct relation between the weight and length. Thus, to quote six of the most widely-practised methods in the textile industry we have

Silk: count no. = the no. of hanks of 840 yards each in 1 lb. Cotton: „ = „ hanks „ 840 „ „ „ 1 „ Wool: „ = „ skeins „ 256 „ „ „ 1 „ Worsted: „ = „ hanks „ 560 „ „ „ 1 „ Linen: „ = „ leas „ 300 „ „ „ 1 „ Jute: „ = the weight in lbs. of 14,400 yards

Hemp is sometimes reckoned according to the linen system and sometimes by the jute system.

An entirely different method of counting or numbering obtains in regard to ropes. The system of yarn numbering for ropes depends upon the number of single yarns or threads required to make one strand of a 3-in. 3-strand rope. Thus, if 25 yarns are required to form such a strand, the yarn is 25’s, while if 30 yarns were required for the same thickness of strand, the yarn would be 30’s, and so on. The tube through which the yarns are drawn is nearly half an inch bore.

If the yarn number is multiplied by 5, the product represents the number of yards of yarn in 1 lb. Thus, in the above 25’s yarn there are

25’s × 5 = 125 yd., or 375 ft. per lb.

Ropes are usually designated by their circumferences in inches, and also by the number of strands neglecting the heart if such is required.