Offshore personnel transfer company Windcat has ordered a series of Commissioning Service Operation Vessels (CSOVs) with Damen Shipyards. The vessels will be powered by hydrogen and are to be delivered from 2025.

The “Elevation Series” CSOVs have been designed by Damen Shipyards in cooperation with Windcat and CMB.Tech. The result is a revolutionary new design with increased capabilities and flexibility compared to existing vessels. The vessels are 87 metres long, 20 metres wide and can accommodate 120 people.

The CSOVs will be built at Ha Long Shipyard, Vietnam, and will be delivered to Windcat Offshore, a new business unit within Windcat that will focus on offshore energy commissioning and services. Initially, two vessels have been ordered with options for further vessels.

A CSOV is a vessel that remains in an offshore wind farm for an extended period of up to thirty days, providing maintenance materials and housing technicians in hotel-style accommodation.

Also read: Volvo Penta partners with CMB.Tech to develop dual-fuel hydrogen engines

Damen to build CSOVs for Windcat.


To significantly reduce the vessels’ CO2 footprint, Windcat and CMB.Tech will provide the same dual-fuel hydrogen technology for the Elevation Series as on board of the Hydrocat, the world’s first hydrogen powered CTV (Crew Transfer Vessel). This approach will also make a critical contribution to the development of rules and regulations related to the use of hydrogen as a fuel in medium-sized vessels.

‘Damen is committed to becoming the world’s most sustainable shipbuilder and is a recognised pioneer in the development of Service Operation Vessels, having designed and built one of the world’s first dedicated walk-to-work vessels five years ago,’ says Joost van der Weiden, sales manager Benelux at Damen Shipyards. ‘These vessels have set a benchmark in the offshore renewables market and are still performing very well in the North Sea.’

Also read: Damen, Caterpillar and Pon Power to develop methanol-powered tugs

State-of-the art CSOVs

The Elevation Series will be equipped with the latest gangway, crane, thrusters, hybrid battery technology and offshore charging capability, among other industry-leading features to be announced in the next weeks. Windcat believes these vessels are the next logical step in the fast-growing offshore wind energy sector.

Stephen Bolton, Managing Director Windcat Offshore: ‘I truly believe the Elevation Series is an industry-leading design, a real game changer. A design that will lead the sector in exploring hydrogen as a fuel while delivering best-in-class performance and flexibility. Only with the combined team of Windcat, CMB.Tech and Damen has this been possible. Together we have addressed the current and future CSOV sector needs while starting to answer the greater maritime industry’s challenge: How to significantly reduce our industry’s greenhouse gas emissions.’

Also read: Damen on TIME’s Best Inventions List 2022 with first electric tug