Project partners Dong Energy, E.on and Masdar announced today that the first of 177 foundations has been installed at the London Array Offshore Wind Farm, in the Thames Estuary.
Installation of the 268T monopile, weighing 268 tonnes was supplied and installed by joint venture company Per Arsleff Bilfinger Berger Ingeniurbeu a jack-up barge called Seaworker.
The transition piece was then lifted into place, completing the project’s first full foundation installation.
“This is a significant milestone for London Array, off the shore and into the water,” said Dong Energy chief executive officer Anders Eldrup.
London Array is being built around 20km off the coasts of Kent and Essex. The wind farm will be installed on a 245km2 site and will be built in two phases. Phase One will cover 90km2 and include 175 turbines with a combined capacity of 630MW.
The consortium plans to complete the first phase by the end of 2012. If approved, the second phase will add enough capacity to bring the total to 1,000MW.
Each foundation consists of a tubular steel monopile, driven 20m to 50m into the seabed, and a large yellow transition piece, which is fixed over the top of the monopile to provide the base for the wind turbine.
The monopiles are between 33m and 65m long and weigh between 200t to 650t, while the transition pieces are between 20m to 28m high and weigh between 245t to 345t.
The piles were lifted off the deck of the vessel using a 60m crane and driven into the seabed with a 225t anvil and hydraulic ram.
In the summer, the Seaworker will have been joined by the MPI Adventure, a new self-propelled jack-up vessel. Over the next nine months both vessels will continue to install the remaining 176 foundations in preparation for the installation of the two offshore substations in the summer and the start of installation of the 175 wind turbines towards the end of the year.