Gunfleet Sands

MT Højgaard has constructed the wind turbine foundations for the Gunfleet Sands offshore wind farm off the east coast of Britain.

Gunfleet Sands offshore wind farm lies 7 kilometres outside the Thames Estuary close to Clacton-on-Sea on the east coast of Britain. The offshore wind farm, operated by DONG Energy, provides electricity to 75,000 households in the county of Essex. We have built the foundations for the offshore wind farm.

Monopiles driven into the sea bed

The design and fabrication of the foundations took place in 2008, while the installation of the foundations was carried out in late 2008 and early 2009. The foundation is based on the monopile principle, where a single pile is driven into the sea bed. The monopile foundation consists of a steel cylinder which is driven into the sea bed with a hydraulic hammer.

Floating crane and jack-up vessel

Due to the different water depths, the installation was executed with the help of the floating crane "The Swan" and the jack-up vessel "Excalibur". Some of the monopiles were transported by barge direct to "The Swan".

Lifting was accomplished offshore direct from the barge with the help of an A-frame to "The Swan" while other monopiles were transported by flotation to "Excalibur".

To minimise transport time, we established our own floating harbour nearby. Using a crane on the floating harbour, the monopiles were equipped with end-sealing caps and then towed out to "Excalibur" for installation.