The SX216 vessel series has a length of 89.9 metres, a beam of 19.2 metres, and accommodates up to 135 people on board.

It features a walk-to-work motion-compensated gangway for safe personnel transfer to the turbines, a 3D-motion compensated crane for cargo transfer, and it can carry a daughter craft for in-farm transfers.

The TWIN X-STERN vessels have two sterns and two main propeller units at each end. The TWIN X-STERN offers larger flexibility regarding the choice of propeller type, a bi-symmetric hull shape, and a propulsion setup with fewer propulsion units is possible, said Ulstein.

The hybrid power solution in these vessels, with green methanol intended as the main energy source, has dual-fuel engines supported by a battery package.

Combining the fuel-efficient TWIN X-STERN and the dual-fuel methanol/diesel power generators could reduce the emissions in offshore wind farm operations.

The ship owner Acta Marine has already signed a long-term contract for a twelve-year basis with RWE for the two vessels to support North Sea wind farms.

The vessels are expected to begin operation from the Port of Grimsby in early 2025 and 2026, respectively.

The ships will support the day-to-day operations and maintenance of two of RWE’s largest offshore wind projects, the newly operational 857 MW Triton Knoll and the 1.4 GW Sofia offshore wind farm which is now under construction in the UK.

“We are excited to announce the order of two more Ulstein-designed SX216 SOVs”, said Rob Boer, Managing Director of Acta Marine.

“These vessels represent the culmination of extensive research by Acta Marine in combination with Ulstein’s engineering excellence. With the vessel’s advanced features and cutting-edge technology, they will play a pivotal role in supporting the TK and Sofia projects for RWE, providing efficient and reliable services while minimizing environmental impact.”

Yesterday, Tersan Shipyard held a keel-laying ceremony for the second of two CSOVs that the company is building for Acta Marine. The first two vessels are planned to be delivered next year.