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man engine
A man engine is a mechanism of reciprocating ladders and stationary platforms installed in mines to assist the miners' journeys to and from the working levels. It was invented in Germany in the 19th century and was a prominent feature of tin and copper mines in Cornwall until the beginning of the twentieth century.
==History==
The earliest known examples of this device were from the first half of the nineteenth century in the silver mining area of the Harz mountains, Germany, where they were driven by cranks connected to water wheels, although bucket hoists using the same method of operation had been used in Swedish iron mines since the 17th century.〔("Samson Pit Museum" ) at Sankt Andreasberg〕 They appear to have evolved from an informal modification to the beam pumps, where the miners used spikes stuck into the wooden pump rods to get themselves carried up the shaft.〔 As beam pumps were universal in deep mines, it was a then simple development to make proper platforms to carry the miners. The first formal engine was installed in 1833 at a mine at Clausthal, Lower Saxony, where inspector Wilhelm Albert and manager Georg Dörell (1793–1854) fastened foot platforms and hand-holds to adjacent, reciprocating pump rods, using a waterwheel-driven pump put out of use when a new drainage adit was made at a lower level.〔 The 1837 man engine at the Samson Pit in Sankt Andreasberg in the same region is still in use, although converted from water to electric power in 1922.
The device was introduced to Cornwall in January 1842, following the award of a premium for the best design, by the Royal Cornwall Polytechnic Society. The winner, Michael Loam, built one for the proprietors of the Tresavean Mine, in Lanner near Redruth.〔The main proprietor of Tresavean Mine was John Rogers.〕〔(''Cornish Mining World Heritage'' )〕 He used a double-rod design, driven by a waterwheel.〔 In October of that year Loam proposed that the water wheel be replaced by a steam engine. A 36-inch bore, 6-foot stroke, double-action steam engine was employed, through reduction spur gearing of 5:1. At the same time the stroke of the man-engine beams was increased from 6 feet to 12.〔 Coal consumption was 24 hundredweight (1,200 kg) per day; the engine was in use for only six hours a day, but the boiler was kept at operating temperature continuously. The miners' journey time (in either direction) was reduced from about an hour to twenty-four minutes and output per shift increased by one fifth.〔''Manchester Guardian'', 10 January 1844.〕
More than a dozen examples were installed in Cornish mines by the end of the century, but these were usually of the single-rod type, which was perceived as safer in use.〔 When cable operated winding gear became available the man engines continued in use, particularly in cases where the mineshaft was not truly vertical and winding engines drawing suspended cages could not be used: with the provision of a few well-placed rollers, and “fend offs” mounted on trunnions, the rods could reach the bottom of a shaft even at a substantial deviation from the vertical. Economics also played a part: the rods needed for pumping could be used for this extra function at little increased cost. Even when skips or "kibbles" were used in such shafts, (running on "skipways") the tipping motion would make them impractical for carrying men.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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