Crank machine

The crank machine was a penal labour device used in England in the 19th century. It consisted of a hand-turned crank which forced four large cups or ladles through sand inside a drum, doing nothing useful.

Cell, with Prisoner at Crank-Labour, In the Surrey House of Correction, 1851

Crank machine model, from the Oxford Prison & Castle museum.

The prisoner would typically be forced to do 6,000–14,400 revolutions over the period of six hours per day (1.5–3.6 seconds per revolution). The prison warden could make the task harder by tightening an adjusting screw.

In 1895, there were 29 crank machines in use, but by 1901 there were only 5.^[1]

See also

• Penal treadmill