Article Source: IMechE
They were once called ‘monstrous,’ by US President Donald Trump, and constructing the turbines of the European Offshore Wind Deployment Centre in the North Sea off the coast of Scotland was certainly a monster-sized challenge.
But installation of the centre’s 11 MHI Vestas turbines – nine 8.4MW and two 8.8MW models, the most powerful commercially installed turbines in the world – took just nine weeks. Adam Ezzamel, project director at energy company Vattenfall, has described this as a “magnificent offshore engineering feat”.
The incredible accomplishment was achieved using “game-changing” suction bucket jacket foundations weighing 1,800 tonnes, equivalent to almost 10 Boeing 747s. The three-legged structures were lowered to the sea floor, where operators pumped water and air from three large “buckets” at their base.
The resulting suction embedded them into the ground, creating secure foundations without the noisy hydraulic rams that typically drive piles into the sea floor, bringing “considerable” environmental benefits from reduced noise pollution.
The team installed one of the foundations in a potential world-record time of just two hours and 40 minutes. Vattenfall said the structures, supporting the turbines off the coast of Aberdeen, can also reduce costs, give more options in challenging sites and allow easier decommissioning.