The monopole wind turbine foundation was installed by the twin-hulled heavy lift vessel Svanen, which has been used for similar operations at other offshore wind farms.
The transition piece was then lifted into place completing the project’s first full foundation installation. MTHøjgaard is the contractor managing the overall foundation engineering, fabrication and installation process.
For the next 9 months, Svanen will continue to install the remaining 89 wind turbine foundations in preparation for the installation of the two substations and 88 offshore wind turbines in 2011.
Each foundation consists of a tubular steel monopile, driven 32-36 m into the seabed, and a bright-yellow transition piece mounted on top. The monopiles are 50-55 m long and weigh 400-600 tonnes while the transition pieces are 22 m high and weigh about 200 tonnes each.
The monopile and the transition piece were brought to the offshore wind farm site from the Netherlands.
The wind turbine foundations will now begin to arrive in a sequential order, and be installed in a pre-determined pattern, each one having been designed and fabricated specifically for its installation site.
Project Director Rune Rønvik, says: “The licence for the wind farm site was granted in 2004 and so it is a great achievement to now be at the stage where we are starting a continuous process to install the 90 required foundations.”
The Sheringham Shoal Offshore Wind Farm is owned equally by Statoil and Statkraft through the joint venture company Scira Offshore Energy Ltd.