Allseas is equipping Pioneering Spirit with a second unique lift system capable of removing and installing complete offshore jackets weighing up to 20,000 t in one go. After several months of installation works, the sheer size of the “Jacket lift system” (JLS) is becoming apparent!
Recent activities have focused on the “hang-off and upend system” (HOUS), the function of which is to raise and tilt the 170-m lifting beams. The HOUS comprises integrated upend systems, each with a pair of 50-m skid tracks fitted with “push-pull” mechanisms. Hydraulic cylinders drive the push-pull devices along the tracks, moving the beams up, while transom-mounted hang-off frame (HoF) assemblies function as hinges around which the beams rotate.
While the technology is ground-breaking, the way the system works is rather simple. After cuts are made to a jacket’s foundation piles at seabed level, hoisting blocks suspended from the lifting beams raise the jacket at the main legs. The jacket is subsequently aligned with the beams, reclined, and skidded further inboard before transit.
The Jacket lift system will further enhance Pioneering Spirit’s unrivalled versatility and capability, and provide the offshore energy market with a total solution for heavy lift work.
Pioneering Spirit (formerly Pieter Schelte) is the largest construction vessel in the world. Inspired by the offshore heavy lifting pioneer Pieter Schelte Heerema (1908–81) and designed completely in-house, the vessel is designed for the single-lift installation and removal of large oil and gas platforms and the installation of record-weight pipelines.
Built at the DSME shipyard in South Korea (2011–14), the vessel commenced offshore operations in 2016 with removal of the 13,500 t Yme production unit offshore Norway.
The vessel redefined heavy lifting with the single-lift removal of Shell’s iconic 24,000 t Brent Delta platform topsides from the North Sea in April 2017 – a world record for an offshore lift.
In June 2018 Pioneering Spirit executed the fastest installation of a large, fully completed topside, and heaviest single-lift installation to date, when it set down Equinor’s 22,000 ton Johan Sverdrup DP topsides on its jacket offshore Norway.
(Source and image: Allseas – Pioneering Spirit at Tyra field offshore Denmark)