Rope and

The crude methods of rope-making of centuries ago are still used in many parts of the world to-day. Improved rope-walk methods are used extensively to-day for making extra large ropes and all but the smaller sizes of tarred hemp ropes; it is also an economical and quick method of making ropes to special order for immediate delivery.

Raw Materials.

In the United States and European coun tries soft fibres, principally hemp (coming mostly from Russia, Italy and the United States) and flax were used for rope until the second quarter of the 19th century. Hemp is still used for tarred hemp rope and fittings for marine purposes. Abaca com monly referred to as Manila fibre, because it is grown almost exclusively in the Philippine Islands and exported principally from the port of Manila, has established itself as the best ma terial for rope-making where strength and durability are the prime requirements. Henequen, sometimes misnamed sisal, is next in importance as a rope fibre, and comes from Yucatan, Mexico and Cuba. Sisals are important rope fibres and come principally from Java, Africa, Bahamas. Other fibres used are New Zealand, Mauritius, Maguey and Istle fibres. Jute and cotton are used to a limited extent in the manufacture of ropes of stranded construction. Cotton is used to a greater extent in the manufacture of braided cords.

Present Manufacturing Processes.

The primary object of twisting fibres together in a rope is that, by mutual friction, they may be held together when a strain is applied to the whole. Hard twisting has the further advantage of compacting the fibres and preventing, to some extent, the penetration of moisture when the ropes are exposed to water; but the yield of rope from a given length of yarn diminishes in proportion to the increase of twist. The rope-making process is essentially the same, no matter what kind of fibre is used. The process divides itself into five operations. First, selection of fibre; second, preparing the sliver; third, spinning the yarn; fourth, forming the strands; fifth, lay ing the strands into rope. With cable-laid ropes there is another operation, laying the strands of the cable, which are in fact com pleted ropes, into the finished cable.

At the start of the manufacturing process the bales of fibre are opened and heads of fibre shaken out. The fibre is put through several processes of combing and straightening. These

operations are, in general, all of the same kind. The fibre is slowly carried along on a series of bars connected by endless chains, the bars being studded with sharp steel pins, like combs, that stand upright as the fibre passes along with them. A similar set of combs, moving very much faster, pulls the fibre rapidly away from the first set, combing it out at the same time. Fine jets of lubricant are sprayed on the fibre as it enters the first machine.

The fibre is delivered from the machine in a heavy, con tinuous stream or sliver which is coiled by hand or machine into a receptacle, or on the floor. Several of these slivers are then fed into a similar machine, and the kinks and unevenness further removed by a repetition of the same process. This preparation or combing is repeated from 8 to 12 times on five different machines, each operation combing the fibre and produc ing a smaller and more even sliver, until finally it comes out of the finisher in a continuous stream as water flows from a hose.

The thoroughness with which these operations are carried out— the care taken in preparing the fibre—is largely responsible for the uniformity and excellence of the finished product.

In the preparation of the sliver, the object has been merely to eliminate all sorts of dirt and foreign matter and to lay these fine, thread-like strands parallel with one another so that they can be more easily spun together. As the sliver enters the spinning machine it is taken from the rollers by another series of fine combs. From the combs it passes through a funnel-shaped tube and is then wound about a little capstan. It is between the tube and the capstan that the yarn comes into being. The friction on the revolving capstans draws the yarn through the machine. From the capstans it is automatically wound on a large spool about 12 in. long, named a bobbin. The capstans and the bobbin whirl very fast, and the combination of this whirling motion and the drawing forward of the revolving capstans, spins the heretofore parallel fibres into what is known as a yarn. For different sizes of yarn and for yarns designed for various pur poses, a varying number of twists per foot are imparted to the yarn. This yarn is the first merchantable product of the cordage mill and may be sold in this original form or used as the basis of other cordage products.