Vattenfall has completed the removal of three Second World War sea mines from its 1.6GW Nordlicht offshore wind farm site after geophysical surveys flagged magnetic anomalies later confirmed as unexploded ordnance.
The developer said remotely operated vehicle inspections in spring found each device contained the equivalent of 200–300kg of TNT. Following a complex permitting process, the mines were disposed of in September via controlled detonations.
“Clearing the seabed of wartime ordnance is one of those invisible but vital steps in developing offshore wind,” said Tobias Kulgemeyer, senior UXO engineer at Vattenfall Business Area Wind and technical lead for the campaign.
He added that the successful operation lays the groundwork for safe construction of the project.
Vattenfall said a 90-metre bubble curtain vessel was deployed to dampen sound during detonations, with coordination required alongside other offshore activities, including RWE pile-driving, to avoid overlapping noise events. Seven vessels took part in the disposal campaign, clearing the way for installation works.
