Part 81

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.

MANILA HEMP IN WAREHOUSE.]

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.

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 illustration, 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.

OPENING BALES OF MANILA FIBER FOR PREPARATION.]

Here the fiber is carefully cleaned and combed by a series of fine tooth machinery through which it passes.]

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.]

FOUR-STRAND COMPOUND LAYING-MACHINE.]

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.