page_title: Hoist (mining)
section_title: Friction hoist
hierarchical_section_title: Hoist (mining) / Friction hoist
caption_attribution_description: English: The elevator tower at the Cliffs Shaft Mine in Ishpeming, Michigan, United States. The mine is listed on the US National Register of Historic Places (NRHP).
context_page_description: In underground mining a hoist or winder 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 are variable frequency controlled. There are three principal types of hoists used in mining applications:
context_section_description: Friction (or Koepe) hoists are the most common type of hoist used in Europe, Asia and Australia.  The friction hoist was invented in 1877 by Frederick Koepe.  Friction hoists are mounted on the ground above the mine shaft, or at the top of the headframe.  Friction hoists utilize tail ropes and counterweights and do not have the haulage rope fixed to the wheel, but instead passed around it. The tailropes and weights offset the need for the motor to overcome the weight of the conveyance and hoisting rope, thereby reducing the required horsepower of the hoisting motor by up to 30%, with the overall power consumption remaining the same.  Friction hoists, unlike drum hoists, can and normally do use multiple ropes giving them a larger payload capacity, however since they require a larger safety factor, they are impractical for very deep shafts.
caption: A headframe housing a friction hoist
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