Edison Chouest Offshore Building 'Mini' CTV

U.S. offshore vessel operator, builder and owner Edison Chouest Offshore (ECO) is constructing the U.S. offshore wind industry’s first ever mini-crew transfer vessel (CTV), designed by U.K.-based Chartwell Marine.

Set to enter service in summer 2024, the 39-foot catamaran will serve as a daughter craft deployed from ECO's ECO Edison, the first U.S.-built service operation vessel (SOV). The vessel has capacity for up to 12 personnel and is designed to be deployed from ECO Edison during extended offshore stays, offering access to turbines, vessels and other project infrastructure across the Revolution Wind, South Fork Wind and Sunrise Wind offshore wind farms being developed by Ørsted and its joint venture partner Eversource Energy in the U.S. Northeast.

Michael Braid, vice president of renewables at ECO, said, “As we look to further expand our fleet and activate it across a growing number of offshore wind projects, maintaining the efficiency of our transfers and our high level of technical availability will be key. Diversifying the range of vessels we use is one of the ways we can achieve that, but making sure they’re best-in-class is equally important.”

According to Chartwell, the catamaran’s optimized hull form offers efficient fuel use as well as stability and maneuverability in choppy waters. The vessel is equipped with Volvo Penta IPS (integrated propulsion system), which features forward-facing, twin counter-rotating propellers with an individually steerable IPS under the hull.

Working with Ørsted throughout the design process, Chartwell conducted model testing in January 2023 to simulate and adapt to the specifications of the wind turbines that will be installed at the U.S. Northeast project sites. Considerations were made to facilitate Ørsted’s Get Up Safe system, a motion-compensated hoist solution for transferring technicians between small moving vessels and offshore wind turbines without a ladder.

Andy Page, managing director of Chartwell, said, “This vessel is the small but essential chain connecting SOVs and turbines together. Engineers need to safely transition from larger vessels to turbines quickly and safely, and we set out to design an agile and streamlined vessel that has both bases covered.

“But it’s not a one-size-fits-all — turbines come in different configurations, with different requirements for effective crew transfer. That’s why we collaborated with Ørsted to thoroughly test and tweak our design to the joint venture portfolio’s particular needs.”

Construction commenced in July 2023 at Edison Chouest’s Louisiana shipyard, employing an estimated 15 workers while drawing components from U.S. suppliers in five states. ECO will manage the entire pipeline of construction and operation, supported by the incentives provided by the Inflation Reduction Act (IRA).

Mikkel Mæhlisen, head of U.S. operations for Ørsted, said, “This vessel is yet another example that American offshore wind energy is providing economic opportunity and creating jobs across the U.S. Working with Chartwell and Edison Chouest to deliver an innovative design that accommodates Ørsted’s Get Up Safe system, the vessel represents the ingenuity of businesses in the maritime space to supply cutting-edge, purpose-built offshore wind vessels for safe and efficient operations offshore. This partnership is an innovative collaboration, one ready to serve the future growth of the American offshore wind industry.”

Mike Ausere, vice president of business development at Eversource Energy, said, “These vessels represent the incredible power of offshore wind to create American jobs in the industries of the future, deliver clean, renewable energy and establish a U.S.-based supply chain that will benefit workers and communities for generations yet to come.”