Chartwell Marine and VARD join forces to deliver original ‘Midi-SOV’ design for offshore wind

Chartwell Marine, trusted UK pioneer of next-generation vessel design, announces its partnership with one of the world’s leading designers and shipbuilders of specialized vessels VARD to introduce the Midi-SOV: a revolutionary 55-metre offshore wind craft. Coming to both the US and European markets in 2024, the vessel represents the combined expertise of the respective crew transfer vessel (CTV) and SOV design leaders — providing a brand-new solution to the ongoing challenge of expanding wind power across the globe. The vessel is designed Jones Act Compliant, Americanised, ready for production in US 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, merely 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 prioritise 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 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.

Perfectly proportioned for offshore wind, the vessel’s size hits the ‘sweet spot’ for commercial and operational viability. It incorporates a low waterplane shape that broadens above waterline, effectively minimising 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, boasting a capacity of 36 single bunk cabins for SPS crew, 20 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. Its innovative design, balanced displacement, and advanced features position the Midi-SOV as a versatile and forward-thinking solution for offshore wind, marrying crew well-being and environmental responsibility with resolutely high performance.

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 in Summer 2023, recognised its potential as a game-changing solution and committed to developing the design to market.

Andy Page, Director, Chartwell Marine, said: “Never before has there been such a pressing need to develop offshore wind vessels that are reactive to evolving operational and financial conditions. Far from being a disaster, we see the failure of the UK’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. We’re putting a strong emphasis on having these vessels manufactured locally, with US-built vessels Americanised for the US market and Europe-built vessels for European operations. Chartwell is leading the charge in CTVs; VARD are a pioneer in the SOV space — so the Midi-SOV is the best of both worlds.”

Runar Vågnes, Senior Vice President Sales 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 specialised roles that are emerging in markets across the globe.”