Allseas’ unique Jacket lift system, capable of lifting and transporting the largest supporting structures, has entered the testing and commissioning phase on the Pioneering Spirit. With this system, Allseas says it is close to realising its vision of a construction vessel, unrivalled in capability and versatility that provides the energy industry with a total solution for offshore work.
The heavy-lift construction vessel Pioneering Spirit is capable of lifting entire platform topsides up to 48,000 tonnes. To enhance the vessel’s versatility and capability, Allseas has developed a second unique lifting system: the Jacket lift system (JLS).
In-harbour trials of the system include raising and lowering the 170-metre lifting beams individually and, when connected, simultaneously. This enables Allseas’ engineers to calibrate load measurements and verify the control modes and safety systems.
Current tests focus on the starboard beam, increasing the upend angle in phases to 110 degrees, the angle the beams reach during commercial jacket lifts. Up to 60 degrees, the upend system does most of the work. From 60 degrees, the centre of gravity moves outside the vessel, and the derrick wires control the tilting.
Up to 20,000 tonnes jackets
During operations, the aft-mounted beams lift and support entire jackets weighing up to 20,000 tonnes. This innovative technology enables direct transfer of structures to and from the quayside and eliminates the need for support barges. The significantly shorter operating times should translate to major emissions savings.