Steel Wire Rope – How, Where, What and Why

steel wire rope

Steel wire rope is several strands of metal wire twisted into a helix forming a composite “rope”, in a pattern known as “laid rope”. Larger diameter wire rope consists of multiple strands of such laid rope in a pattern known as “cable laid”.

In stricter senses the term “steel wire rope” refers to diameter larger than 3/8 inch (9.52 mm), with smaller gauges designated cable or cords. Initially wrought iron wires were used, but today steel is the main material used for wire ropes.

Historically, steel wire rope evolved from wrought iron chains, which had a record of mechanical failure. While Fraying_steel_wire_ropeflaws 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. While friction between the individual wires and strands causes wear over the life of the rope, it also helps to compensate for minor failures in the short run.

Steel 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 steel 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.

History

Modern steel 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 Stirling Newall improved the process further. In America wire rope was manufactured by John A. Roebling, starting in 1841 and 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. Ever with an ear to technology developments in mining and railroading, Josiah White and Erskine Hazard, principal owners[9] of the Lehigh Coal & Navigation Company (LC&N Co.) — as they had with the first blast furnaces in the Lehigh Valley — built a Wire Rope factory in Mauch Chunk, Pennsylvania in 1848, which provided lift cables for the Ashley Planes project, then the back track planes of the Summit Hill & Mauch Chunk Railroad, improving its attractiveness as a premier tourism destination, and vastly improving the throughput of the coal capacity since return of cars dropped from nearly four hours to less than 20 minutes. The decades were witness to a burgeoning increase in deep shaft mining in both Europe and North America as surface mineral deposits were exhausted and miners had to chase layers along inclined layers. The era was early in railroad development and steam engines lacked sufficient tractive effort to climb steep slopes, so incline plane railways were common. This pushed development of cable hoists rapidly in the United States as surface deposits in the Anthracite Coal Region north and south dove deeper every year, and even the rich deposits in the Panther Creek Valley required LC&N Co. to drive their first shafts into lower slopes beginning Lansford and its Schuylkill County twin-town Coaldale.

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, 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, steel 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.

Safety

The steel wire ropes are stressed by fluctuating forces, by wear, by corrosion and in seldom cases by extreme forces. The rope life is finite and the safety is only ensured by inspection for the detection of wire breaks on a reference rope length, of cross-section loss, as well as other failures so that the wire rope can be replaced before a dangerous situation occurs. Installations should be designed to facilitate the inspection of the wire ropes.

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Hercules SLR is part of the Hercules Group of Companies which offers a unique portfolio of businesses nationally with locations from coast to coast. Our companies provide an extensive coverage of products and services that support the success of a wide range of business sectors across Canada including the energy, oil & gas, manufacturing, construction, aerospace, infrastructure, utilities, oil and gas, mining and marine industries.

Hercules Group of Companies is comprised of: Hercules SLR, Hercules Machining & Millwright Services, Spartan Industrial Marine, Stellar Industrial Sales and Wire Rope Atlantic.

We have the ability to provide any solution your business or project will need. Call us today for more information. 1-877-461-4876. Don’t forget to follow us on Twitter LinkedIn and Facebook for more news and upcoming events.

Skyscrapers – A History of Early High Rise Construction

Early-Skyscrapers

The early skyscrapers were a range of tall, commercial buildings built between 1884 and 1939, predominantly in the American cities of New York City and Chicago. Cities in the United States were traditionally made up of low-rise buildings, but significant economic growth after the Civil War and increasingly intensive use of urban land encouraged the development of taller buildings beginning in the 1870s. Technological improvements enabled the construction of fireproofed iron-framed structures with deep foundations, equipped with new inventions such as the elevator and electric lighting. These made it both technically and commercially viable to build a new class of taller buildings, the first of which, Chicago’s 138-foot (42 m) tall Home Insurance Building, opened in 1885. Their numbers grew rapidly, and by 1888 they were being labelled skyscrapers.

Chicago initially led the way in skyscraper design, with many constructed in the center of the financial district during the late 1880s and early 1890s. Sometimes termed the products of the Chicago school of architecture, these skyscrapers attempted to balance aesthetic concerns with practical commercial design, producing large, square palazzo-styled buildings hosting shops and restaurants on the ground level and containing rentable offices on the upper floors. In contrast, New York’s skyscrapers were frequently narrower towers which, more eclectic in style, were often criticized for their lack of elegance. In 1892, Chicago banned the construction of new skyscrapers taller than 150 feet (46 m), leaving the development of taller buildings to New York.

A new wave of skyscraper construction emerged in the first decade of the 20th century. The demand for new office space to hold America’s expanding workforce of white-collar staff continued to grow. Engineering developments made it easier to build and live in yet taller buildings. Chicago built new skyscrapers in its existing style, while New York experimented further with tower design. Iconic buildings such as the Flatiron were followed by the 612-foot (187 m) tall Singer Tower, the 700-foot (210 m) Metropolitan Life Insurance Company Tower and the 792-foot (241 m) Woolworth Building. Though these skyscrapers were commercial successes, criticism mounted as they broke up the ordered city skyline and plunged neighboring streets and buildings into perpetual shadow. Combined with an economic downturn, this led to the introduction of zoning restraints in New York in 1916.

In the interwar years, skyscrapers spread to nearly all major U.S. cities, while a handful were built in other Western countries. The economic boom of the 1920s and extensive real estate speculation encouraged a wave of new skyscraper projects in New York and Chicago. New York City’s 1916 Zoning Resolution helped shape the Art Deco or “set-back” style of skyscrapers, leading to structures that focused on volume and striking silhouettes, often richly decorated. Skyscraper heights continued to grow, with the Chrysler and the Empire State Building each claiming new records, reaching 1,046 feet (319 m) and 1,250 feet (380 m) respectively. With the onset of the Great Depression, the real estate market collapsed, and new builds stuttered to a halt. Popular and academic culture embraced the skyscraper through films, photography, literature and ballet, seeing the buildings as either positive symbols of modernity and science, or alternatively examples of the ills of modern life and society. Skyscraper projects after World War II typically rejected the designs of the early skyscrapers, instead embracing the international style; many older skyscrapers were redesigned to suit contemporary tastes or even demolished—such as the Singer Tower, once the world’s tallest skyscraper.

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Hercules SLR is part of the Hercules Group of Companies which offers a unique portfolio of businesses nationally with locations from coast to coast. Our companies provide an extensive coverage of products and services that support the success of a wide range of business sectors across Canada including the energy, oil & gas, manufacturing, construction, aerospace, infrastructure, utilities, oil and gas, mining and marine industries.

Hercules Group of Companies is comprised of: Hercules SLR, Hercules Machining & Millwright Services, Spartan Industrial Marine, Stellar Industrial Sales and Wire Rope Atlantic.

We have the ability to provide any solution your business or project will need. Call us today for more information. 1-877-461-4876. Don’t forget to follow us on Twitter LinkedIn and Facebook for more news and upcoming events.