Dutch firm Jan De Nul Group and Belgium's Smulders worked together to build two gravity-based foundations (GBF) for the high voltage station of the Danish offshore wind farm Kriegers Flak. 

The foundations, weighing 10,000-tonne and 8000-tonne each, have been constructed on top of a barge in the port of Ostend.

The foundations consist of a concrete section with a steel structure on top. Jan De Nul is responsible for the design and construction of the concrete GBF, while Smulders is in charge of the design and construction of the steel shafts and decks to be placed on top. The steel structures were constructed on the site of Smulders in Hoboken and were shipped to the port of Ostend last weekend.

This week the steel structure will be placed on top of the concrete structure, a milestone for the project.

By the end of December, the foundations will be finished and ready to be transported to Denmark. Jan De Nul will be in charge of the installation of the foundations, the ballasting and the placement of scour protection.

Jan de Nul was also involved in the installation of two gravity based pilot wind farms in north west Europe, offshore England and offshore Finland, and both firsts of their kind. Read more here.

The Danish wind farm Kriegers Flak, in the Baltic Sea, will consist out of two parts, Kriegers Flak A, the west section, with 200MW capacity, and the east section, Kriegers Flak B, with 400MW capacity.

Each section will dispose of its own substation, serving both for the future Krieger Flaks offshore wind farm as well as an interconnector between the Danish and German power grids. 

Read more about European gravity based wind farm developments here