Ulstein Verft has secured a contract from Norway-based Olympic Group to build two construction service operation vessels (CSOVs).

The contract also includes an option for two additional CSOVs. The carriers will incorporate the Ulstein SX222 design with Twin X-Stern from Ulstein Design and Solutions.

Featuring hybrid battery propulsion, the vessels will have a length of 89.6m and beam of 19.2m.

With a capacity to accommodate 126 people in 91 cabins, the vessels are being designed to meet future needs at offshore wind farms.

They will be fuelled by variable speed diesel-electric propulsion in combination with large battery energy storage systems.

Furthermore, they will have space for additional battery capacity for complete-electric repowering and be prepared to use methanol in the future.

The hull shape and hybrid propulsion system will help deliver ‘high operational performances and seakeeping’ as well as significantly lower the environmental footprint, stated the Norwegian shipbuilder.

Olympic Group CEO Stig Remøy said: “The Twin X-Stern is a smart concept, optimised for low energy consumption.

“As a shipowner in the Norwegian maritime cluster, it is important for us to invest in this cluster. With a shipyard, ship designer, suppliers and Vartdal Invest as a co-investor, this is a project with a strong local ownership.”

In January, Ulstein Design and Solutions won a contract from China’s ZPMC shipyard to design two types of service operation vessels for Shanghai Electric Windpower Group.