Belgium’s Jan de Nul group has installed both gravity based foundations (GBFs) for the high voltage station of Vattenfall’s 600MW Kriegers Flak offshore project in the Danish part of the Baltic Sea.

Jan de Nul on Friday said it has installed the second and with 10,000 tonnes larger one of the two GBFs according to plan, after installing a smaller one earlier this week.

Kriegers Flak consists of two sites, the Western section Kriegers Flak A with a capacity of 200MW, and an Eastern section with a capacity of 400MW – each with its own substation serving the future offshore wind farm as well as an interconnector between the Danish and German power net.

By 2022, the Baltic Sea’s to date largest offshore wind farm will start generating CO ₂-free electricity for approx. 600,000 households. The interconnector project is funded by the European Energy Programme for Recovery.

Denmark’s government in the spring is likely to unveil a new national energy agreement for the post-2020 period that is expected to include further offshore developments beyond Kriegers Flak.

Jan de Nul explained that with a barge containing the GBF submerged, its heavy lift vessel Rambiz connected to the foundation through its crane hooks and towed out the structure once it started to float.

An assisting tug subsequently towed the Rambiz together with the structure to its final installation location where the vessel in combination with an in-house designed ballast module set the structure down onto the seabed.

The multipurpose vessel Adhémar de Saint-Venant will now start with the ballasting of the structures and the scour protection works around them.

Both foundations were constructed by Jan De Nul Group on a barge in the Port of Ostend in Belgium that was towed to Denmark on 8 January 2018.

Wind

Jan de Nul installs Kriegers Flak gravity based foundations