derrick

A derrick is a lifting device consisting of a vertical post or mast with a movable horizontal arm, or boom, used to raise and lower heavy loads. The hoist is typically powered by a winch, hydraulic jack, or electric motor, with ropes or cables run over pulleys to provide mechanical advantage. Derricks are anchored to the ground or deck and stabilized by guy lines or other supports; many designs allow the boom to be angled or rotated to position loads.

In maritime and construction contexts, derricks were widely used before the advent of modern cranes. On ships, a derrick could be mounted on the deck to load cargo or handle heavy materials; on land, derricks were common at construction sites, in mining, and in other operations requiring vertical lifting of materials.

In the oil and gas industry, the term derrick denotes the tall framework on a drilling rig that houses the hoisting machinery and supports the drill string and associated equipment. The derrick provides the vertical height needed to raise and lower drill pipes and casing; while some rigs still use timber or steel derricks, contemporary drilling operations may employ alternative hoisting structures, but the term remains in use.

Other meanings include historical usage of the word to describe a gallows or scaffold used for executions. The word Derrick is also encountered as a surname and given name, with origins separate from its industrial sense.

Etymology is uncertain; the term has been in use since the 17th or 18th century to describe hoisting gear, with various theories about its origin.