To describe this equipment in detail would require an entire book. We shall attempt, in this chapter and the next, to give an idea of the principal machines only.
There are two methods to the modern system: that in which the strands are formed on one type of machine and twisted into a rope on another; and that in which both operations are performed on a single machine. The second method carries with it the advantage of economy in space and equipment, but is not followed so generally with the larger sizes of rope as is the first.
A complete set for the two-part method comprises two or more horizontal strand-forming machines, several bobbin frames and a vertical laying-machine. In our illustration, the latter is shown making three ropes into a cable—a process essentially the same as where three strands are united into a single rope.
Three men usually suffice on the strand-making—one to tend the machines, the others to tend the bobbins which turn on fixed posts and can be renewed as needed without interrupting the process.
The yarns are first drawn from the bobbins through the perforated plates seen in the lower section of the picture, the entire number being so distributed as to converge in layers and at the proper angles around one central yarn. They next pass into a tube. Here the whole mass is compressed and at the same time is twisted by the revolution of the long carriage or flyer, which, as our picture shows, supports a winding-reel and two capstans.
The strand can be twisted right or left hand as called for. The amount of twist is regulated by the flyer’s speed—easily varied by the use of different gears.
The two capstans are geared to pull the strand through the tube and, by holding it taut, keep the twist uniform. The reel also has its separate gears and revolution. Whenever the increasing diameter of the load tends to make it exert too much strain on the strand, the reel is slowed down by an ingenious friction device. The strand is guided into even layers on the reel by an arm which is made to travel from side to side.
Here, then, are four distinct operations going on at once and all in perfect harmony. From this may be judged the many difficulties which had to be overcome before strands could be manufactured in such small space.
HORIZONTAL FORMING MACHINES MAKING STRANDS