Norwind Installer selects ULSTEIN to design foundation installation vesselVessel & ROV News // November 29, 2011
Artist's impression showing Norwind Installer's foundation installer.
Norway-based NorWind Installer has contracted with Ulstein Sea of Solutions and Ulstein IDEA Equipment Solutions as design partners for a new foundation installation vessel for the offshore wind industry. The vessel is a customized version of the Deepwater Enabler design from ULSTEIN.
The DP vessel is designed for world-wide operations with a focus on pre-piling and jacket/tripod/transition piece installation in northern Europe. Different deck layouts, based upon NorWind Installer’s installation experience from the Alpha Ventus offshore windfarm, have been developed for the various installation modes on top of the generic vessel platform provided by ULSTEIN.
”We are pleased with the concept as it is definitely in line with our vision of combining state-of-the-art technical solutions with the speed and seakeeping capacity of DP vessels. It gives us the opportunity to provide installation services all-year round in up to 2.5m Hs, as well as meeting our client’s cost targets”, said Thorbjørn Hansen, VP Product Development at NorWind Installer.
The design aims for maximum efficiency and cost-effectiveness and features an 800 tonne heave compensated offshore crane on the starboard side. A pre-piling template can be located on a support structure at the stern. The vessel can carry four jackets, or at least 24 piles, or up to 12 transition pieces on a large open aft deck.
To enhance operability, the anti-heeling system has been designed in such a way that the main crane can revolve through 180 degrees with a full load on its main hook in five minutes.
When operating in pre-piling mode, the pre-piling template is positioned on the seabed by the main crane; in parallell, a pile is picked up by a gantry crane, put in the upending frame on starboard side and upended. The main crane has been modified by ULSTEIN in such a way that it can first pick-up the piling hammer with its main hook and then connect to the upended pile with its auxiliary hook.
When the hammer is working on driving the pile into the seabed, the next pile is upended by the upending frame and made ready for crane lift out.
"The large aft deck and AHC crane provide flexibility for serving alternative subsea and offshore markets in the future," noted ULSTEIN, "which is further increased by the two large holds suitable for carousels below main deck. A deck layout version of the vessel has also been developed for tidal turbine installations.
Voith Schneider propellers of 3,900 kW each will allow for a cruising speed of 13 knots and enhance the DP capabilities of the vessel. To minimize the environmental footprint an NOx reduction system is installed in the exhaust lines.