Jacking and Skidding Systems

We design and build jacking, skidding, and fixation solutions tailored to drilling, well intervention, heavy lift, production, accommodation, offshore wind installation, and maintenance.

National series rack-and-pinion jacking system

BLM jacking systems use the rack-and-pinion principle and consist of a set of simultaneously operated units, allowing lifting and lowering of jackup-type platforms. The units can be used on square, triangular-lattice, or tubular legs. They are typically self contained and consist of a gearbox driven by an electric motor designed and built at NOV's BLM facility. The gearbox drives the main jacking pinion that meshes with the rack. They can be arranged on the rig at various heights to meet the exact lifting requirement for the rig.

VSD rack-and-pinion jacking system

Our GustoMSC patented Variable Speed Drive (VSD) version of the rack-and-pinion jacking system is designed for vessels with truss legs. Safe, smooth, and quick relocations depend on the leg jacking speed, effective automation, and a high system availability. By ensuring that the torque is equally shared by all motors and pinions on the entire platform, the operation is smoother with less stress and less wear and tear. The optimized hardening process for the pinions and high-quality gearboxes further add to a long, reliable life.

Hydraulic jacking system

GustoMSC hydraulic jacking systems use positive engagement with double-acting hydraulic cylinders. The systems, based on the pin-in-the-hole principle, operate on smooth circular legs that minimize wave, wind, and current forces in elevated, transit, and installation conditions with their beneficial hydrodynamic and aerodynamic characteristics. The circular leg guides in the hull and jack house ensure proper guidance of the legs with hardly any wear. For protection against mechanical damage and environmental hazards, the jacking system is enclosed inside a jack house.

Continuous hydraulic jacking system

The continuous hydraulic jacking system consists of four individual yokes. Each yoke is equipped with a jacking pin and two double-acting hydraulic cylinders. The jacking speed is continuous. During normal jacking three out of four yokes are active and one is in the return stroke. In the preload position all yokes are active. The same applies for normal operation and survival condition.

Rack-and-pinion skidding systems

Rack-and-pinion skidding systems are used for moving the cantilever and the drill floor of a jackup rig to locate the well center at correct position. Our BLM skidding units are installed above the main deck and are based on the same proven technology used in our jackup elevating systems. They can be vertically or horizontally mounted. This advantage, along with the reduced size of the skidding unit, makes it possible to install the unit where space is limited. The modular design allows each unit to be removed from its support as a single assembly with motor and pinion.

X-Y skidding system

The X-Y cantilever can move in two directions instead of one. The cantilever extends with the derrick in a longitudinal direction (the X-direction) and can also move in a transverse direction over the width of the deck (the Y-direction). This design offers approximately twice the drilling envelope of a conventional cantilever. The jackup rig therefore needs to be moved less frequently. An additional advantage is that the derrick is always located near the center line of the cantilever; thus, the weight and loads are always evenly distributed. As a result, the cantilever steel weight is lower, the combined load is constant over the transverse reach, and the longitudinal reach is greater. The capacity of the X-Y cantilever is approximately 1.5 times higher than a comparable conventional cantilever.