Dredger deploys for Danish windfarm

Belgium based dredging and marine construction major Jan De Nul will deploy a dredger as part of its contribution to an offshore wind farm/interconnector project in the Danish Baltic Sea.

Steel construction company Iemants joins with the Jan De Nul Group for the engineering, construction and installation of two Gravity Based Foundations (GBFs) for two offshore substations, serving both for the future Krieger Flaks offshore wind farm as well as an interconnector between the Danish and German power net. The interconnector project is funded by the European Energy Programme for Recovery.

The wind farm consists of two sections, each with its own substation. Kriegers Flak A, the west section, will have a total capacity of 200 MW. The east section, Kriegers Flak B, will have a total capacity of 400 MW.

Jan De Nul Group is in charge of the design, construction, transport and installation of the GBFs, while Iemants will take care of the detailed design, fabrication and transportation of the steel shafts and decks which will be placed on top of the GBFs. The steel structures will be prefabricated at Iemants’ facilities in Belgium.

The GBFs will be constructed on a pontoon based in the port of Zeebrugge and towed to the Baltic Sea. In Denmark, Jan De Nul’s backhoe dredger Gian Lorenzo Bernini and the fallpipe vessel Adhémar de Saint-Venant will take care of the excavation of the foundation pit and installation of the gravel bed.

Once the pontoon with GBFs arrives in Denmark, it will be immersed to offload the structures upon which the foundations will be installed onto the gravel bed. Finally, the GBFs will be ballasted and protected through scour installation by means of the Adhémar de Saint-Venant.

The Gravity Based Foundations will be installed offshore by the end of 2017. By 2022, Denmark's largest offshore wind farm to date will start generating CO2-free electricity for some 600,000 households.