ROPE CONSTRUCTION

There are several types of rope constructions manufactured. The twisted rope is usually made with three or four strands (Fig. 43.1). A twisted rope is manufactured by first producing the strands, using a specific number of yarns per strand which are placed in a laying machine which controls the strand twist as the finished rope is formed. Braided ropes are mainly 2-in-1 or double-braided, single or hollow braid, 8-strand or 12-strand braided or plaited ropes. The double-braided rope contains a braided core over which a cover is braided, the single or hollow braid consists of one single braid containing no core, and the 8-strand and 12-strand braided or plaited rope consists of eight or twelve strands braided in pairs in a maypole fashion on a plaiting machine. Parallel ropes are produced by utilizing parallel yarns as the strength members that are bonded and/or jacketed to form the finished rope (Fig. 43.2). Parallel yarns will provide almost 100 percent of the available strength from the fibers. Parallel rope is stronger, size for size, than twisted or braided rope, but it has much lower elongation and is stiffer (Fig. 43.3). The 8-strand and 12-strand braided synthetic fiber ropes are commonly used for slings, pilot lines, and hand lines. The 2-in-1 or double-braided synthetic fiber ropes...