Wind Energy – New Installation Vessel
Subsea 7’s recently delivered Seaway Alfa Lift offshore wind foundation installation vessel is in transit to Europe and is expected to join Subsea 7’s fleet in the third quarter of 2023.
The semi-submersible heavy installation vessel will be used to install the next-generation XXL offshore wind foundations.
The newbuild heavy lift crane vessel Seaway Alfa Lift (CMHI-207), was originally ordered in 2018 by OHT on speculation. OHT eventually became part of Subsea 7’s Seaway 7 branch.
The vessel itself was floated out from drydock at the China Merchants Heavy Industry (CMHI) shipyard in Jiangsu, China in February 2021, and had been scheduled for delivery during the same year, and for debut in the UK offshore wind sector in 2022, installing wind turbine foundations at the Dogger Bank wind farm.
However, an October 2021 crane incident delayed the delivery, and Subsea 7 then said that the Seaway Strashnov vessel would be deployed on what was supposed to be Alfa Lift’s project for a full 2023 campaign.
The semi-submersible vessel features a large, 3,000 mt lifting capacity main crane, and can perform heavy lift crane operations with the main deck submerged.
The vessel will be able to transport and install up to 10 x 1,500t ultra-large jacket foundations or 11 x 2,000t XXL monopiles plus transition pieces for the largest anticipated wind turbine generators.
The vessel’s crane has a maximum lifting capacity of 3,000 tonnes at 30 meters and 1,000 tonnes at 76 meters outreach. The 216.3-meter vessel will also have a 10,000+ m² “smart deck” that can carry up to 14 giant monopiles per trip and will be fully submersible to a depth of 14.66 meters.
The vessel is planned to be deployed on transition piece installation on Dogger Bank A & B and C from 2023 to 2025, while monopile installation will continue throughout the period with the Seaway Strashnov.
