Norwegian design for wind farm installer
The NorWind Installer proposal installing jacket foundations. Image: Ulstein
Two well known Norwegian marine engineering companies have revealed a proposal for a tidal turbine and wind turbine foundation installation vessel.
It adds to the growing list of designs involving free-floating DP vessels as an alternative to conventional jack-ups.
Bergen based NorWind Installer is familiar with the marine renewable industry, having installed a drilled-in tidal turbine monopile foundation structure for the European Marine Energy Centre in Orkney, Scotland. The company also delivered and installed six of the twelve jacket foundations at Alpha Ventus, Germany’s first offshore windfarm. Ulsteinvik based Ulstein Group has nearly 100 years of experience in shipbuilding and ship design, including innovative solutions for the offshore energy industry.
NorWind Installer has contracted Ulstein’s Netherlands based design subsidiaries, Ulstein Sea of Solutions BV and Ulstein Idea Equipment Solutions BV, to develop the vessel based on a customized version of Ulstein’s generic Deepwater Enabler design and capable of pre-piling and installing jacket and tripod, along with monopile and transition piece foundations. Designed for wordwide operations, the vessel combines state-of-the-art technology with the speed and seakeeping abilities of a DP vessel, capable of operating year round in seas up to 2.5m Hs.
Incorporating the Ulstein X-Bow, the vessel is 160m LOA with a draught of 8m. Total installed power is 28,060 kW and propulsion by Voith Schneider propellers, providing a top speed of 13 knots. An 800t active heave compensated crane is also included.
Intended to deliver maximum efficiency and cost effectiveness, particular attention has been paid to design of the crane for the various elements of the foundation installation. When pre-piling for space frame foundations, a pre-piling template (transported to the site on a support structure overhanging the vessel’s stern) is lowered to the seabed. In parallel, a pile is positioned in the up-ending frame by a gantry crane on the starboard side of the vessel, where it is elevated to the vertical. Ulstein has modified the crane to first pick up the piling hammer with its main hook, and then pick up the upended pile with its auxiliary hook. The next pile in the sequence is upended and prepared while the piling operation is under way. The vessel’s anti-heeling system has been designed to allow the main crane to revolve over 180 degrees in five minutes with a full load such as a large jacket suspended.
The vessel will have capacity for four jackets, or at least 24 piles, or up to twelve transition pieces and, as with other similar proposed vessels, employment in the subsea and offshore markets has also been considered. Below deck, two large holds will provide space suitable for carrousels, along with an alternative deck layout configuration allowing installation of tidal turbines.
By Peter Barker
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