Solid foundation for offshore turbines

The Carbon Trust has unveiled seven new offshore wind turbine foundation design concepts and methods for transporting them off Britain’s coast.

The designs were shortlisted by the Carbon Trust from more than 100 participants in its global competition aimed at slashing the costs of construction of offshore wind farms and opening up deeper waters for development.

An Anglo-Franco collaboration of Gifford, BMT Nigel Gee and Freyssinet is behind one of the shortlisted designs.

The team’s design centres on a concrete foundation with a large base that allows the structure to self-stabilise under forces of gravity in water depths up to 45m.

Mark Willbourn, marketing director of BMT Nigel Gee, said BMT developed a concept for a submersible barge that would tow these foundations to the wind-farm site. It would then lower the foundation, which would weigh more than 3,000 tonnes, to the sea bed.

He said: ‘There has been a number of concrete gravity base foundations put in over the years but they have been lifted in by very specialised heavy lift barges in one-off operations.’