Abstract: A large diameter rope having improved fatigue life on a sheave, pulley, or drum is disclosed. This rope includes a blend of HMPE filaments and liquid crystal polymer filaments selected from the group of lyotropic polymer filaments and thermotropic polymer filaments. The rope may be constructed as a braided rope, a wire-lay rope, or a parallel core rope.

Abstract: A large diameter rope having improved fatigue life on a sheave, pulley, or drum is disclosed. This rope includes a blend of HMPE filaments and liquid crystal polymer filaments selected from the group of lyotropic polymer filaments and thermotropic polymer filaments. The rope may be constructed as a braided rope, a wire-lay rope, or a parallel core rope.

Abstract: A method for construction of a large diameter braided rope. The rope is formed of high strength, low elongation synthetic fibers which are twisted together at a twist factor in the range from about 125 to about 145 to form a plurality of comparatively small diameter yarns. The small diameter twisted yarns are then braided together at a pick multiplier in the range from about 1.0 to about 2.0 so as to form a plurality of braided strands, and the strands, in turn, are braided together with a pick multiplier of about 2.0-3.6 so as to form the large diameter braided rope. The braiding of the strands imparts a degree of coherence which permits a lower twist factor to be used in the yarns. This results in a significant increase in translational efficiency over conventional twisted-strand construction, by avoiding the over twisting of low elongation fibers which occurs when forming large diameter yarns.

Abstract: A method for forming a braided rope. Twisted yarns are first braided together to form braided strands, and the braided strands are then braided together to form the rope. The diameter of the individual twisted yarns is kept to a minimum, thereby reducing the number of twisting stages required to form the yarns and also permitting heat stretching treatment using existing systems. Moreover, in-line connections can be made within the individual strands using conventional braided rope splices, which both eliminates the need to use long splices during manufacture of the rope and enables individual strands to be spliced in the field to so as to repair snags, cuts, and other service damage without having to replace an entire length of the rope.

Abstract: A method and apparatus for heat stretching a synthetic fiber rope. The rope is buoyed in a vessel containing a liquid medium, and this is heated to a predetermined stretching temperature. Tension is applied to the heated portion of the rope so as to stretch this to a predetermined increase in length. The process may be batchwise, or it may be continuous. In the batch process, a length of the rope is stretched in the heating vessel by a draw rod. In the continuous process, feed and take-up capstans pass the rope through a heating chamber, and then through a cooling chamber. The capstans are operated at different speeds so that the rope is tensioned and stretched between them within the vessel.

Abstract: A method and apparatus for heat stretching a synthetic fiber rope. The rope is attached to tensioning members and suspended in a liquid medium so that this extends in a generally horizontal direction. The liquid medium has a specific gravity which is approximately equal to that of the rope at the desired stretching temperature, so that the rope is buoyed by this in order to relieve the weight of the segment from the tensioning members. The liquid medium is then heated so that the rope is uniformly heated to the stretching temperature, and tension is applied between the tensioning members so as to stretch the segment of rope to a predetermined increase in length.