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Wire rope is a type of cable which consists of several strands of metal wire laid (twisted) into a helix. The term cable is often used interchangeably with wire rope. However, in general, "wire rope" refers to diameter larger than 3/8 inch (9.52 mm). Sizes smaller than this are designated cable or cords.〔(Bergen Cable Technology -- Cable 101 )〕 Initially wrought iron wires were used, but today steel is the main material used for wire ropes. Historically wire rope evolved from steel 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. 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. ==History== 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.〔(【引用サイトリンク】 title=Wilhelm Albert )〕 It was quickly accepted because it proved superior to ropes made of hemp or to metal chains, such as had been used before.〔(Modern History of Wire Rope - Donald Sayenga )〕 Wilhelm Albert's first ropes consisted of three strands consisting of four wires each. In 1840, Scotsman Robert Stirling Newall improved the process further.〔''Iron: An illustrated weekly journal for iron and steel'', Volume 63 by Sholto Percy〕 In the last half of the 19th century, wire rope systems were used as a means of transmitting mechanical power〔(The Mechanical Transmission of Power: Endless Rope Drives by Kris De Decker, March 27, 2013 )〕 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Wire rope」の詳細全文を読む スポンサード リンク
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