ASME-Landmark:Reversible Waterwheel & Man Engine

Two features of past technology are preserved and displayed at Germany's historic silver mine "Grube Samson"—the Samson Mine—opened in the later Middle Ages. The reversible overshot waterwheel of the ore hoist is probably the only survivor of its kind, and even more unique is the man-engine with an even larger overshot waterwheel that in the nineteenth century moved the miners between the surface and the working levels, sparing them the extraordinary exertion of climbing hundreds of meters of ladders.

The reversible waterwheel was suited to ore-hoisting as well as drainage operations, as water could be lifted in the huge buckets. The 36-foot (11 meter) diameter double wheel is mounted on a two-foot square timber axle 35 feet long, terminating in small iron journals secured by wrought iron hoops. It required a five-man crew to operate, including a brake man and a man underground to take care of loading the bucket sent down.

The man-engine has been likened to a man-pump, for there were two neighboring vertical rods that moved up and down in opposite senses. At intervals along each rod were small platforms for the miner to stand on. At the end of a stroke the platforms of the two rods would be at the same level and momentarily at rest as the rods halted between strokes, allowing the miner to step from his rod over to the platform of the other rod to ride to the next rendezvous. This reduced the miners' upward trip from an exhausting 150-minute climb to a relatively effortless 45-minute ascent. See ASME website for more information