Wire Rope Cable

Wire rope is rope made from wire. It consists of several strands of metal wire laid (twisted) into a helix. The term “cable” is often used interchangeably with “wire rope”, but narrower senses exist in which “wire rope” refers to diameter larger than 3/8 inch (9.52 mm), whereas sizes smaller than this are designated cable or cords. Initially wrought iron wires were used, but today steel is the main material used for wire ropes.

Historically wire rope evolved from wrought iron chains, which had a record of mechanical failure. While flaws in chain links or solid steel bars can lead to catastrophic failure, flaws in the wires making up a steel cable are less critical as the other wires easily take up the load.

Friction between the individual wires and strands, as a consequence of their twist, further compensates for any flaws. Wire ropes were developed starting with mining hoist applications in the 1830s.

Wire ropes are used dynamically for lifting and hoisting in cranes and elevators, and for transmission of mechanical power. Wire rope is also used to transmit force in mechanisms, such as a Bowden cable or the control surfaces of an airplane connected to levers and pedals in the cockpit. Only aircraft cables have WSC (wire strand core).

Also, aircraft cables are available in smaller diameters than wire rope. For example, aircraft cables are available in 3/64 in. diameter while most wire ropes begin at a 1/4 in. diameter. Static wire ropes are used to support structures such as suspension bridges or as guy wires to support towers. An aerial tramway relies on wire rope to support and move cargo overhead.

Modern wire rope was invented by the German mining engineer Wilhelm Albert in the years between 1831 and 1834 for use in mining in the Harz Mountains in Clausthal, Lower Saxony, Germany.

It was quickly accepted because it proved superior to ropes made of hemp or to metal chains, such as had been used before. Wilhelm Albert’s first ropes consisted of three strands consisting of four wires each. In 1840, Scotsman Robert Sterling Newell improved the process further

The German engineering firm of Adolf Bleichert & Co. was founded in 1874 and began to build bicable aerial tramways for mining in the Ruhr Valley. With important patents, and dozens of working systems in Europe, Bleichert dominated the global industry, later licensing its designs and manufacturing techniques to Trenton Iron Works, New Jersey, and USA which built systems across America.

Adolf Bleichert & Co. went on to build hundreds of aerial tramways around the world: from Alaska to Argentina, Australia and Spitsbergen. The Bleichert Company also built hundreds of aerial tramways for both the Imperial German Army and the Wehrmacht.

In the last half of the 19th century, wire rope systems were used as a means of transmitting mechanical power including for the new cable cars. Wire rope systems cost one-tenth as much and had lower friction losses than line shafts. Because of these advantages, wire rope systems were used to transmit power for a distance of a few miles or kilometers.

In America wire rope was later manufactured by John A. Roebling, forming the basis for his success in suspension bridge building. Roebling introduced a number of innovations in the design, materials and manufacture of wire rope.