Hunter's patent floating crane, 1886.
© Science Museum / Science & Society Picture Library
Model. The crane was built for use at Tilbury Docks on the River Thames near London. It has a lifting capacity of 50 tonnes and is mounted on a floating platform. The tubular steel jib is strengthened by a wrought iron framework and rests on a circle of steel rollers. The rollers are supported on an iron cylinder built into the hull. The crane's lifting tackle consists of a compound pulley system through which the cable runs. The cable is raised and lowered by a hoisting drum powered by a two-cylinder engine.