The UK-based CWind has contracted aluminum vessel builder Wight Shipyard Co (WSC) to build a hybrid surface effect crew transfer vessel. The vessel will service the Borssele 1 and 2 offshore wind farm located 23 km off the Dutch coast.
WSC will carry out the construction project from its development stage right through to the delivery. The vessel is designed to handle 2-metres wave height during technician transfer. WSC stated that it it will also decrease fuel consumption and CO2 emissions.
The Hybrid SES propulsion engine offers sprint speed and bollard push from its 1,600 kW installed diesel engines, which can be battery boosted up to 1,500 kW. WSC claims fuel savings will be achieved through balancing engine and inefficient low engine power running hours, with battery drive modes which include wind farm standby and low speed/harbour operations. It is expected that this will lead to an engine operating hour reduction of 50% during wind farm battery standby.
The Hybrid SES crew transfer vessel was developed in partnership with the operator CWind and ESNA. The vessel consists of two catamaran hulls with the area between the hulls closed by flexible reinforced rubber fingers in the bow and an inflated rubber bag in the stern. Centrifugal fans blow air into this enclosed space, providing an air cushion that supports up to 80% of the vessel weight. The remaining 20% is supported by hull buoyancy, which allows higher speed of the vessel as the hull resistance is decreased. It also reduces motion owing to less wave contact. Additionally, the air cushion acts as a large shock absorber, improving the seakeeping and reducing seasickness.
CWind’s long-term charter contract agreement with Ørsted, which operates the Borssele 1 and 2 offshore wind farms, will start in the middle of 2020. The agreement will cover an initial 3-year firm charter with options available for a further 2 years. The hybrid transfer vessel will operate from the Dutch port of Vlissingen.