Jackup systems are used to lift offshore platforms and installation vessels across large stroke ranges. This project involved performing studies of the configuration and optimisation of hydraulic drives and the design of suitable closed-loop control strategies.
This system has two separate lifting stages. One of these stages is in contact with the mast and lifts the platform. The second stage has no contact with the mast and is pre-accelerated to the speed of the active stage following a rapid return stroke. Once the speed has been reached, the second stage is locked with the mast and takes over the lifting function.
This alternating stage operation allows a constant lifting motion to be realised, shortening the stroke times in comparison with conventional systems.