Could Midi-SOV be an offshore wind game changer?

Chartwell Marine and Vard say that 55-meter Midi-SOV is a cost-efficient alternative to full scale SOVs. [Image: Vard]

Southampton, U.K., based Chartwell Marine has partnered with Fincantieri’s Norwegian headquartered Vard subsidiary to introduce the Midi-SOV. The 55-meter offshore wind service vessel combines the two companies’ expertise in crew transfer vessels (CTV) and service operation vessels (SOV). The design will be offered on both the U.S. and European markets in 2024 and Chartwell, which already has a track record in designing CTVs for the U.S. market, says that the vessel is “designed Jones Act compliant, Americanized and ready for production in U.S. shipyards.”

As the offshore wind industry continues to grow, the demand for ever-larger CTVs has surged, with larger teams of technicians operating on increasingly scaled-up turbines. However, owing to challenges in seakeeping and hospitality requirements, simply increasing the dimensions of current CTV designs to create more capacity is not feasible.

The Midi SOV has been designed from the ground up to prioritize stability and operability, and to be a cost-effective solution as the offshore wind industry tackles high inflation and increasing costs in its development pipeline. In taking the Midi-SOV design forward, Chartwell says that it consciously adopted the mindset of a small bespoke architect and started from scratch, taking into consideration the insights of vessel owners, technical suppliers, and wind farm operators to meet the changing needs of the industry.

Proportioned for offshore wind, the vessel is sized to hit the ‘sweet spot’ for commercial and operational viability. It incorporates a low waterplane shape that broadens above waterline, effectively minimizing and dampening roll motion. This allows the vessel to remain stable during operations, facilitating walk-to-work capabilities that were previously challenging for smaller scaled traditional SOV forms. Workability and comfort are bolstered by a spacious superstructure, with a capacity of 36 single bunk cabins for service personnel crew, 20 vessel crew cabins, and extensive crew facilities, which include a gym, auditorium, meeting rooms, and spacious day rooms.

With a strong focus on energy efficiency, this vessel can be equipped with methanol-diesel dual-fuel engines, electric propulsion, and a supporting energy storage system.

To prove the Midi-SOV’s suitability, extensive simulation and model testing was conducted in collaboration with Seaspeed Marine Consulting. Throughout the development phase, Chartwell received invaluable support from leading marine firms, including Clarksons, North Star, Seaspeed and Voith.

Vard, after conducting due diligence on the vessel design this summer, recognized its potential as a game-changing solution and committed to developing the design to market.

“Never before has there been such a pressing need to develop offshore wind vessels that are reactive to evolving operational and financial conditions,” says Chartwell Marine director Andy Page. “Far from being a disaster, we see the failure of the U.K.’s Round 5 offshore wind CfD auctions as an opportunity for the maritime industry to respond to the fact that developer costs are skyrocketing.”

“The Midi-SOV offers a cost-efficient alternative to full-sized SOVs, contributing to the industry’s overall sustainability,” says Page. “We’re putting a strong emphasis on having these vessels manufactured locally, with U.S.-built vessels Americanized for the U.S. market and Europe-built vessels for European operations. Chartwell is leading the charge in CTVs; Vard is a pioneer in the SOV space — so the Midi-SOV is the best of both worlds.”

Runar Vågnes, senior vice president sales at Vard, said: “With the introduction of the Midi-SOV, Chartwell Marine and Vard are leading the way in opening up a new segment in the offshore wind industry enabling sustainable business at sea, bringing forth a vessel that combines innovation, efficiency, and sustainability. Our partnership signifies a commitment to providing operators with state-of-the-art solutions that slot into new and specialized roles that are emerging in markets across the globe.”