gin

A gin is a rotating drum mounted on a vertical or near-vertical axis, used to wind rope or cable that lifts material, typically ore, rock, or personnel, from underground workings. The drum itself is usually wooden or metal, built up from a central axle with a large diameter to increase mechanical advantage and line speed. As the drum turns, multiple layers of rope wrap around it, drawing load upward through a shaft opening or borehole.

Gins come in two main classes: hand gins, turned by manual labor through a crank or treadle, and horse gins or power gins, driven by animals or steam engines. The mechanical advantage comes from the large drum diameter relative to the load attachment point, allowing a small force applied at the rim to lift heavy weights. Rope diameter typically ranges from 10 to 25 millimeters for underground gins; the drum itself may be 1.5 to 2.5 meters in diameter depending on shaft depth and expected load.

The term whim is synonymous and still used in British mining, though gin has become the standard industrial term. The name derives from Middle English and Old French, reflecting medieval machinery. A gin differs from a whip (a simpler single-pulley hoist) in having its lifting power concentrated in the rotating drum rather than distributed across a frame.

Practical operation and wear

In active use, rope wraps helically around the drum, with each turn of the drum lifting the load by one rope circumference. The rope takes significant abrasion and shock loads, especially when raising broken rock or sudden changes in weight distribution. Drum surfaces must be maintained to prevent rope slippage; wooden drums were often grooved or fitted with raised bands to key the rope in place. As rope wears, it shreds and its diameter reduces, requiring rewinding higher on the drum or rope replacement.

Gins were gradually displaced by electric and diesel-powered hoist systems from the early 20th century onward, but remain common in small-scale and artisanal mines in developing regions. The simplicity of the mechanism, drum, axle, bearings, and rope, makes repair possible without industrial infrastructure, and the efficiency of large-diameter drums kept gin hoists competitive against early powered alternatives on shallow shafts.