Allseas hits home stretch on Pioneering Spirit JLS upgrade

Allseas is entering the final weeks of the installation phase for the jacket lift system on its Pioneering Spirit, the largest construction vessel. The company’s engineers and crew are working full throttle to slot the final pieces of this epic jigsaw into place.

11,000 tonnes of high-density ballast has been mixed and pumped into the two main beams and two steel ballast frames, a 24-hour operation that took a week to complete. The ballast is required to help upend the massive 170-metre beams.

100 km of electrical cables have been thread through the beams and upend system, connecting the many different drives, winches, pumps and push pull skids to power-up and control the entire system. A further 20, 4-km steel wire ropes have been reeved through the main hoist blocks and derrick hoist. Fixed and adjustable grillages, which will distribute force along the beams during jacket lift operations, were fitted in parallel.

Now preparations are ongoing to upend the beams, a challenging operation requiring the upend system, derrick hoist and water ballast systems to work simultaneously for the first time.

Equipped with unique motion compensated, single-lift technology, Pioneering Spirit can lift and transport entire platform topsides and offshore substations in one piece, significantly reducing the amount of offshore work, moving it onshore where it is safer, more cost effective and poses less environmental risk.

The jacket lift system that the vessel is being upgraded with eliminates the need for barges, offering greater capacity, stability and workability in hostile environments. Allseas has released the first video in a series that will show the journey from the inception of this new system to the installation onboard the Pioneering Spirit.