Wärtsilä, in consortium with IMS Ingenieurgesellschaft mbH, has been engaged by RWE Innogy, the renewable energy arm of the German utility company RWE, as its designer to provide the basic design and consultancy services for a jack up crane vessel. Two such vessels with GL class-approval have been ordered by RWE Innogy to be used for constructing offshore wind farms. The shipbuilding contracts have been awarded to Daewoo Shipbuilding & Marine Engineering Co. Ltd. (DSME) and delivery of the vessels is scheduled for late 2011.
Tailored specifically for year-round construction of offshore wind farms, the Wärtsilä-IMS advanced jack-up crane vessel is designed to remain operational under harsh Northern European sea and wind conditions. It also sets new standards for reliability and environmentally sound operation.
The basic design by Wärtsilä-IMS takes into account the specialized needs involved for the construction of offshore wind farms. The vessels are 328 ft long and 131.2 ft wide, and feature an 800-ton crane for transporting and handling the foundations for the latest generation of up to 5MW and 6MW offshore wind turbines, as well as the turbine towers, nacelles, rotors and blades. The vessels have sufficient deck area and deadweight capacity to carry the components for up to four complete wind turbine units or several foundations. For operation in shallow water, a four-point mooring system is used, while in deeper waters a DP2 dynamic positioning system controlling steerable thrusters is employed.
The vessels are designated to undertake foundation and turbine installation at RWE Innogy's currently planned wind farms - North Sea East, Innogy North Sea 1 and Gwynt y Môr.