UK-based North Star is the first offshore operator to adopt the Midi-SOV, a new offshore wind ship design developed by Chartwell Marine and VARD to bridge the gap between crew transfer vessels and full-size service operations vessels.

The 55-meter (180’) Midi-SOV is designed to provide “enhanced comfort and workability while offering a cost-effective alternative to full scale SOVs,” according to the designers. “With a design that has been optimized based on operational data to meet the niche requirements of offshore wind developers and operators, the Midi-SOV is intended to directly complement existing fleets.”

North Star entered an agreement with Chartwell and VARD becoming the first to adopt and utilize the Midi-SOV on offshore wind projects, investing in upfront design fees to facilitate vessel construction for European operations.

On June 12 the three companies hosted a collaborative evening working group at the Royal Southern Yacht Club during the Seawork boat show, attended by more than 50 offshore wind developers, turbine manufacturers, and supply chain representatives.

‘The event was hosted in an ‘Art Gallery’ format with drawings, diagrams and renderings on display,’ according to the designers. “Individuals reviewed and critiqued the design, offering direct feedback on its strengths and areas for refinement to enhance the operational capability of the Midi-SOV.”

The Midi-SOV can enhance project economics through increased yield and scalability, while also improving access with year-round availability, even in adverse weather conditions. That sea capability can provide 13 additional hours of access per day compared to some CTV models during winter months, designers say.

“The operational efficiency of the Midi-SOV was also identified as one of its key advantages, evidenced by lower technician attrition rates due to the comfortable and spacious working environments provided. Furthermore, discussion included the Midi-SOV's robust safety performance, particularly in reducing risks during technician transfers and crane operations.”

“We designed the Midi-SOV with a clear vision of its integration into future offshore wind fleets, filling the gap that had emerged between CTVs and SOVs and addressing key operational challenges as the wind industry evolves,” said Andy Page, managing director at Chartwell Marine.

“Together with VARD, we have been very encouraged by the positive response we’ve received from offshore wind operators, underscoring the industry’s readiness for new solutions that enhance efficiency, safety, and overall project costs.”

"Our assessment has shown that the Midi-SOV has a key role to play in European offshore wind vessel fleets, particularly as activity ramps up in the North Sea and the Baltics,” said Andrew Duncan, renewables and innovations director at North Star. “We’re excited about the operational versatility the design can give us, as well as the high standards of safety, availability and cost efficiency it promises – and proud to play our part in bringing the first Midi-SOVs to market.”