Wire rope and its Strands

A wire rope is a composite rope formed by twisting several strands of metal wire into a helix, the pattern of which is called laying the rope.Larger diameter wire ropes consist of several strands of this laid rope, the laying of which is called cable laying.In a stricter sense, the term wire rope refers to wire rope or rope with a diameter greater than 9.5 mm (3⁄8 in).Wrought iron wire was used initially, but today steel is the dominant material for wire rope.Historically, wire ropes evolved from wrought iron chains, which had a history of mechanical failure. While imperfections in chain links or solid rebar can cause catastrophic failure, imperfections in the wires that make up the cable are less serious because the other wires can easily carry the load.While friction between individual wires and strands causes wear throughout the life of the rope, it also helps compensate for short-term minor failures.

The development of wire ropes began in the 1830s for mining hoist applications.Wire ropes are dynamically used for hoisting and lifting of cranes and elevators, as well as for the transmission of mechanical power.Wire ropes are also used to transmit force in mechanisms such as Bowden wires or aircraft control surfaces connected to levers and pedals in the cockpit.Only aircraft cables have WSC (Wire Stranded Core).In addition, aircraft cables have a smaller diameter than steel wire ropes.For example, aircraft cables are 1.2 mm (3⁄64 in) in diameter, while most steel wire ropes are 6.4 mm (1⁄4 in) in diameter.Static wire ropes are used to support structures such as suspension bridges or as guy wires to support towers. Aerial ropeways rely on wire ropes to support and move cargo.

Wire

Steel wire for steel wire rope is generally made of non-alloy carbon steel with a carbon content of 0.4 to 0.95%.The high strength of the wire rope enables the wire rope to withstand high tensile forces and run on relatively small diameter pulleys.

Strands

In so-called cross strands, the threads of different layers cross each other.In the most commonly used parallel strands, the lay lengths of all conductor layers are equal, and the conductors of any two laminated layers are parallel to form line contact.The wires of the outer layer are supported by two wires of the inner layer.These lines are contiguous throughout the length of the strand.Parallel strands are made in one operation. Ropes of such strands are always much more durable than those of (rarely used) cross-strand ropes.Parallel strands with two layers of wire are available in Filler, Seale or Warrington construction.

Spiral rope

In principle, spiral ropes are round-strand, since they have a steel wire layer assembly laid helically on the center, wherein at least one layer of steel wires is laid in the opposite direction to the direction of the outer layer.Spiral ropes can be sized in such a way that they do not rotate, which means that under tension the rope has almost zero torque.Open spiral rope consists of round steel wires only.The center of half and full beadlock ropes is always made of round wire.Locking coil ropes have one or more outer layers of profiled wire. Their advantage is that their construction provides greater protection against the penetration of dirt and water, and also prevents lubricant loss.In addition, they have a very important advantage, because if the size is correct, the end of the broken outer wire will not leave the rope.