Forewind hands Dogger Bank debut to new foundation design

Wind-power consortium Forewind will test a new foundation design for the first time next year when it installs two meteorological masts at its giant Dogger Bank zone, off the northeast coast of England.

The metmasts, which will be used to monitor wave and wind conditions at Dogger Bank, will be based on a suction-installed bucket foundation from Norway’s Fred Olsen United.

The foundation revolves around an assembly of hundreds of variable-pressure water jets built into its base, which allows an operator to guide the structure to the seabed, after which a vacuum system sucks it into soil to anchor the structure in place.

Fred Olsen United’s design is said to be less expensive than conventional foundations, because it uses less steel and removes the need for pile driving, seabed preparations, scour protection and a transition piece between substructure and tower.

“We have taken our requirements for met masts to look beyond the standard approach, and instead use the opportunity to demonstrate a new, and potentially very exciting, technology with possible benefits well beyond just the Dogger Bank development,” says Forewind general manager Lee Clarke.

“The size and scale of the Dogger Bank project means Forewind has to look for innovative flexible solutions,” he adds. The wind farm has a targeted capacity of 9GW.

One of the foundations will be equipped with strain gauges, meters and other data collection systems to monitor performance of the suction-installed bucket concept under the extreme conditions at the offshore site, where water depths range from 18-63 metres.

UK outfit SeaRoc will deliver the metmasts, with Irish shipyard Harland and Wolff fabricating the substructures.

The foundations will be installed on Dogger Bank, located 125-290km off North Yorkshire, using a new jack-up vessel, Brave Tern, which is currently under construction.

The Forewind consortium includes RWE Npower Renewables, Scottish & Southern Energy and Statkraft.