Ulstein Design & Solutions AS has signed a contract with Tersan Shipyard for two methanol-fuelled ULSTEIN SX216 Construction Service Operating Vessel (CSOV) designs.
The vessels will be constructed for the Netherlands-based ship owner Acta Marine and will be number 3 and 4 with the novel TWIN X-STERN solution in the Acta fleet.
Acta Marine has already signed a long-term contract for a 12-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.
The TWIN X-STERN vessels have two sterns and two main propeller units at each end. Placing either end towards the weather results in excellent operability without limitation on vessel speed.
The TWIN X-STERN solution leads to improved fuel efficiency whilst reducing the motions, which is important for technicians who need quality rest to perform safe operations.
The TWIN X-STERN offers larger flexibility regarding the choice of propeller type, a bi-symmetric hull shape and propulsion setup with fewer propulsion units is possible.
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.
The system integration allows the most fuel-efficient modes of operation. Combining the fuel-efficient TWIN X-STERN and the dual-fuel methanol/diesel power generators will help reduce the emissions in offshore wind farm operations.