Chartwell and Vard team up on new CTV design

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.

“Never before has there been such a pressing need to develop offshore wind vessels that are reactive to evolving operational and financial conditions,” said Andy Page, director, Chartwell Marine.

“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.”

Filling the gap

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.

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 windfarm operators to meet the changing needs of the industry.

The vessel has been designed to hit the ‘sweet spot’ for commercial and operational viability. It’s also designed as Jones Act Compliant, ready for production in US shipyards.

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.

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 conducted due diligence on the vessel design in summer 2023.

The vessel will be coming to both the US and European markets in 2024.