Jackup rig

A jackup rig or a self-elevating unit is a type of mobile platform that consists of a buoyant hull fitted with a number of movable legs, capable of raising its hull over the surface of the sea. The buoyant hull enables transportation of the unit and all attached machinery to a desired location. Once on location the hull is raised to the required elevation above the sea surface supported by the sea bed. The legs of such units may be designed to penetrate the sea bed, may be fitted with enlarged sections or footings, or may be attached to a bottom mat.^[1] Generally jackup rigs are not self-propelled and rely on tugs or heavy lift ships for transportation.

Jackup platforms are almost exclusively used as exploratory oil and gas drilling platforms and as offshore and wind farm service platforms.^[2] Jackup rigs can either be triangular in shape with three legs or square in shape with four legs.^[2] Jackup platforms have been the most popular and numerous of various mobile types in existence. The total number of jackup drilling rigs in operation numbered about 540 at the end of 2013. The tallest jackup rig built to date is the Noble Lloyd Noble, completed in 2016^[3] with legs 214 metres (702 feet) tall.^[4]