Swedish offshore wind farm project for Jan De Nul Group

Jan De Nul Group has been awarded a project for the design, the construction and the installation of 16 concrete foundations for an offshore wind farm in the Swedish part of the Baltic Sea, by order of E.ON (Sweden).

Jan De Nul Group already started the design of the foundations of the 3MW wind turbines, including fatigue calculations and physical modelling. The concrete foundations, 1,800 tons each, will be constructed in Zeebrugge (Belgium) March 2012 onwards. It will take 4 months to pour 10,000 m³ of concrete into the 24.5 m high foundations, which are in fact large hollow concrete constructions having a base diameter of 18 m. Subsequently, the foundations will be towed from Zeebrugge to Sweden May 2012 onwards on superpontoons of Jan De Nul Group.

On site in Sweden, Jan De Nul Group will mobilize a vessel to dredge a pit in the seabed up to sufficient bearing capacity of the subsoil, on which a rock layer will be placed by a stone dumping vessel. On top of this rock layer, the wind turbine foundations will be installed and ballasted (loaded) with sand and protected with rocks against waves, occurring every 50 years.

The completion of these combined civil and dredging works executed by Jan De Nul Group is expected to be in the autumn of 2012.