Fugro has secured a contract from German transmission system operator 50Hertz to survey for, identify and clear unexploded ordnance (UXO) along the LanWin3 and LanWin6 offshore grid connection routes in the German North Sea.
The work will ready the routes for installing cables that link offshore wind farms to the German grid using high-voltage direct current. Each connection is designed to transmit up to two GW, giving a combined capacity of four GW.
Fugro said the initial survey will begin in the second quarter of 2027 and cover 200-metre-wide corridors along both routes.
The company will deploy two fixed magnetic-gradiometry systems, each carrying ten magnetic sensors; these will detect potential UXO, as well as objects on or beneath the seabed. The resulting data will be used to assemble a master target list.
Inspection and identification of selected targets will follow in 2028 using remotely operated vehicles and specialist detection systems.
Fugro will also assist with removing and disposing of confirmed UXO, and remove debris when necessary.
"On a project of this scale, the challenge is that the number and nature of potential UXO can only be known once the survey is complete," said Ronny Bøhn, Fugro's Director of Marine Geophysics for Europe and Africa.
Both cable routes will make landfall at Büsum, with grid connection points planned near Heide and Pöschendorf. Prysmian holds the LanWin3 submarine cable supply and installation contract, while NKT is supplying the 525kV cable system for LanWin6.