Olympic Subsea has confirmed two significant milestones in its newbuild programme for two subsea energy support vessels (SEVs)
The Norwegian company said April 2026 saw a keel-laying ceremony take place for the first of the SEVs, and a steel-cutting ceremony for the second, at CMHI Shenzhen shipyard in China.
Designed by Kongsberg Maritime, the UT7623 SEVs are designed for a high level of energy efficiency and reduced environmental impact.
At the core of the design is a flexible, automated power system in which engines will operate at optimal load under all normal conditions, reducing fuel consumption significantly. Heat recovery systems will repurpose waste energy for electricity and heating, further lowering the vessel’s environmental footprint. The SEVs will accommodate 120 people and have a hullform optimised for DP operations and subsea work, while maintaining efficiency during transit.
The vessels, which remain on track for delivery in summer of 2027, will have methanol-ready Caterpillar Marine variable-speed gensets supplied by Pon Power and a hybrid battery propulsion system. Pon Power was contracted to supply two four-stroke, high-speed Cat 3516E and three Cat 3512E variable speed generator sets to the Chinese yard.
The variable speed gensets will reduce fuel consumption and engine noise levels compared to conventional solutions. The choice of engines will also extend intervals between overhauls, increasing generator lifespan, and reducing operating costs.
Kongsberg Maritime will supply a wide range of technology for the new vessels, including rim-drive electric azimuth propulsors, retractable azimuth bow thrusters, switchboards and thruster drives. The company will also provide the hybrid battery power system, an integrated bridge, automation and control systems, dynamic positioning system, tank sounding, mooring winches and a launch and recovery system for remotely operated vehicles.
Huisman was awarded a contract to supply 250-tonne knuckleboom cranes for the vessels. The cranes have Huisman’s proprietary active heave compensation system that connects the crane’s electric setup to the vessel’s power grid, enabling efficient interaction with the vessel’s electrical energy storage system. This significantly reduces the net energy consumption required for offshore lifting operations.
The vessels are designed to operate in the offshore oil and gas and offshore renewables markets.
