Jacking Systems

Jack-up rigs are mobile offshore structure/platforms used for exploration and drilling of oil and gas deposits. These platforms are normally provided with three legs which extend through openings in a floatable hull of the jack-up rig. Each leg is provided with jacking assemblies for moving the leg vertically with respect to the hull. As the legs are “jacked”, the hull is elevated or lowered.

A typical rig has nine jacking assemblies; three assemblies per leg, with one located at each leg chord of the triangularly shaped legs. Our Jacking System utilizes the rack and pinion principle and consists of a set of simultaneously operated jacking units, allowing lifting and lowering of jack-up type platforms.

Each elevating jacking assembly is provided with four to eight pinions, which operationally engage teeth of racks on the legs. Our jacking units are fitted pairs on each side of a rack welded to the leg chord of the rig. The units can be used on square, triangular lattice, or tubular legs.

Our jacking units are typically self-contained. The unit consists of a planetary gear box that is driven by an electric motor. The gear box drives the main jacking pinion that meshes with the rack. It provides a very efficient, safe and reliable jacking system.

Each jacking unit incorporates one planetary reduction gear in a compact and space-saving design.
All gears are totally enclosed and completely filled with oil. They come with ABS Classification and are suitable for temperatures from -20oC to +50oC.
Each unit can be easily removed from the jack frame as a single component with the motor and climbing pinion.

We provide a full range of jacking units that can be arranged on the rig at various heights, in order to meet the exact lifting requirement for the rig. The jacking units are fitted into jacking frames, which are either welded to the hull (fixed system) or installed in a jack house with shock pads (floating system).