Jan De Nul has completed the offshore cable works connecting the Nordseecluster 1 and 2 wind farms to TenneT Germany’s DolWin kappa offshore converter platform in the German North Sea.
The project, carried out under the DolWin6 programme, included the transport, installation and protection of three high-voltage alternating current (HVAC) subsea cables. Together, the cables will transmit nearly 660 MW of renewable electricity, enough to supply more than 800,000 German households.
The three cables, with a combined length of 37 km, were transported from Hellenic Cables’ manufacturing facility in Corinth to the project site by Jan De Nul’s cable-laying vessel Isaac Newton. After installation on the seabed, the vessel returned this year to recover the cable ends and connect them to the Nordseecluster 1 and 2 offshore platforms.
Cable burial operations were carried out by the trenching support vessel Symphony and the Swordfish trencher, which used high-pressure water jetting to install the cables below the seabed for protection against external damage.
Additional protection was provided by the rock installation vessel Simon Stevin, which placed 2,000 tonnes of rock around the cable connections at the platform foundations. During an earlier campaign, the vessel had already installed a further 25,000 tonnes of rock along the cable route.
The completion of the project marks another milestone in Jan De Nul’s ongoing partnership with German transmission system operator TenneT to expand offshore renewable energy infrastructure in the North Sea.
