Jan De Nul has installed the first gravity-based foundation for the offshore substations at Vattenfall's 600MW Kriegers Flak offshore wind farm off the coast of Denmark. 

The 8000-tonne foundation was floated off a semisubmersible barge and towed to the project site where heavy lift vessel Rambiz in combination with a ballast module installed the structure on the seabed. 

The second foundation, which weighs 10,000 tonnes, will be installed “as soon as possible, depending on the weather conditions”, Jan De Nul said.

Once installation is complete, the company's multipurpose vessel Adhemar de Saint-Venant will start ballasting and scour protection.

Jan De Nul was responsible for building the foundations along with Smulders.

Kriegers Flak, which will feature Siemens Gamesa turbines, is due to go live by 2022.

Image: Jan De Nul