Hydraulic jigger

A hydraulic jigger is a hydraulically-powered mechanical winch.

From the mid-19th century, hydraulic power became available throughout the increasingly modern dockyards and warehouses. This was generated centrally and distributed by pipework, either around a dock estate, or across a city by the new hydraulic power networks.

The jigger was developed by William Armstrong, around 1840, as part of his hydraulic crane The hydraulic crane was the invention that first made his fortune and established the engineering and armaments firm of Armstrongs of Elswick. Armstrong's original invention of the jigger has been questioned, but he was the first to make widespread use of it.