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Hoist atop an elevator. A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium.
Now many hoists are package hoists, built as one unit in a single housing, generally designed for ten-year life, but the life calculation is based on an industry standard when calculating actual life. See the Hoists Manufacturers Institute site [2] for true life calculation, which is based on load and hours used. In today's modern world for the ...
Hoist controller, a machine for raising and lowering goods or personnel by means of a cable; Hydraulic hooklift hoist, another machine; Hoist (mining), another machine; Hoist (flag), the half of a flag nearer to the flagpole; Hoist, by Phish; USS Hoist (ARS-40), a Bolster class rescue and salvage ship acquired by the U.S. Navy during World War II
Also Abrams' water-cement ratio law. A law which states that the strength of a concrete mix is inversely related to the mass ratio of water to cement. As the water content increases, the strength of the concrete decreases. abrasion The process of scuffing, scratching, wearing down, marring, or rubbing away a substance or substrate. It can be intentionally imposed in a controlled process using ...
A drum hoist (steel wire rope visible) and motor. In underground mining a hoist or winder [1] is used to raise and lower conveyances within the mine shaft.Modern hoists are normally powered using electric motors, historically with direct current drives utilizing Ward Leonard control machines and later solid-state converters (), however modern large hoists use alternating current drives that ...
In a simpler construction, a shearleg derrick can be assembled from two posts to form A-frame shear legs without any crossbar. The bottom of the legs are set in two holes on the ground, spreading them apart. There is a rope to tie the two legs together near the bottom to prevent them from spreading apart further.
Construction management (CM) aims to control the quality of a project's scope, time, and cost (sometimes referred to as a project management triangle or "triple constraints") to maximize the project owner's satisfaction.
Major construction projects such as the Panama Canal and Mount Rushmore used cranes from American Hoist & Derrick. [5] American Hoist & Derrick reached 467 on the Fortune 500 list with a total revenue of $464.2 million. [6]