Fugro to clear unexploded ordnance along 50Hertz's German North Sea cable routes

Overview

Updated 2 hours ago

The German North Sea floor is littered with munitions from two world wars. Before 50Hertz can land 4 gigawatts of new offshore wind power, someone has to find and remove them. Fugro now has that job.

Fugro will survey, identify, and clear unexploded ordnance (UXO) along the routes of 50Hertz's LanWin3 and LanWin6 high-voltage direct current (HVDC) grid connections. The survey starts in the second quarter of 2027, scanning 200-metre-wide corridors with magnetic sensors; target inspection follows in 2028. Each connection is built to carry 2 gigawatts, for a combined 4 gigawatts of capacity.

The work is ordered early because the problem is unknown until measured. '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. Surveying before cable-laying turns an unknown hazard into a target list you can plan around.

Why it matters

If UXO blocks these routes, 4 GW of offshore wind can't reach the German grid — a direct hit to the country's coal-phaseout schedule.

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Key Indicators

4 GW

Combined capacity of LanWin3 and LanWin6

Each of the two HVDC connections is built to carry 2 GW of offshore wind to Germany's grid.

1.3M tonnes

Estimated unexploded munitions in the world's oceans

Fugro cites 1.3 million tonnes of unexploded munitions remaining in marine environments globally.

200 m

Survey corridor width

Fugro will map 200-metre-wide corridors along both cable routes starting in Q2 2027.

Geowing magnetic sensor arrays

Each Geowing towed array carries 10 magnetic sensors to detect objects on or beneath the seabed.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Ronny Bøhn

Director of Marine Geophysics for Europe and Africa, Fugro

Oversees the 50Hertz UXO survey and clearance program

Organizations Involved

Fugro

Survey and geoscience company

Awarded UXO survey, identification and clearance contract

A Dutch geoscience and survey company that maps the seabed and inspects subsea infrastructure for offshore energy projects.

50Hertz

Transmission system operator

Client awarding the UXO survey and clearance contract

One of Germany's four transmission system operators, running the high-voltage grid in the country's east and northeast, including Berlin.

Timeline

August 2026 2028

5 events Latest: Yesterday

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2028
Target inspection and clearance
Upcoming Project milestone

Remotely operated vehicles investigate selected targets, remove debris, and support disposal of confirmed unexploded ordnance.
2028
April 2027
UXO survey campaign begins
Upcoming Project milestone

Fugro starts mapping the 200-metre-wide corridors using two Geowing magnetic gradiometer arrays, each with 10 sensors.
April 2027
October 2026
Fugro announces the award
Latest Announcement

Fugro confirms plans for 200-metre survey corridors starting in Q2 2027, with target inspection in 2028.
Yesterday
August 2026
Contract award notice published on TED
Notice

The EU procurement database lists the award for subsurface surveying services in the German North Sea.
August 27th, 2026
50Hertz awards UXO survey contract to Fugro
Contract

50Hertz Offshore GmbH selects Fugro Netherlands Marine B.V. for UXO survey, identification and clearance, after receiving four tenders.
August 24th, 2026

Scenarios

Survey and clearance finish as planned, no rerouting

Possible Resolves by End of 2028

Discussed by: Fugro and 50Hertz, which sequenced the survey before laying any cable

Fugro maps both corridors in 2027, ROVs inspect targets in 2028, and clearance removes manageable amounts of ordnance. 50Hertz confirms the routes are clear and cable installation proceeds without redrawing the corridors. This is the intended outcome of a survey-first approach.

Extra ordnance triggers delays, installation slips past 2029

Likely Resolves by End of 2028

Discussed by: Offshore wind trade press (offshorewind.biz), industry analysts

The survey finds more targets than expected, clearance runs past 2028, and cable-laying is pushed into 2029 or 2030. This is routine in North Sea projects where seabed contamination is uneven across corridors.

Heavy contamination forces corridor reroutes

Unlikely Resolves by End of 2029

Discussed by: Fugro's own framing, which stresses the hazard is unknown until surveyed

If target density is too high to clear cost-effectively, 50Hertz redraws corridor segments. Fresh surveys would follow, adding a year or more to the timeline.

Historical Context

2 moments from history that rhyme with this story — and how they unfolded.

1939-1945

WWII mine warfare in the North Sea (1939-1945)

Germany and the Allies laid tens of thousands of naval mines across the North Sea during the war, sinking hundreds of ships. Post-war clearing operations swept shipping channels for years, but mines and other munitions were left behind or dumped at sea.

Then

Post-war minesweeping reopened shipping lanes but never fully cleared the seabed.

Now

Decades of wartime munitions remain on the floor of the North Sea, a hazard for any new undersea infrastructure.

Why this matters now

Today's HVDC cable installers confront the same leftover ordnance that has sat on the seabed since the 1940s — the problem Fugro's survey is meant to locate before cable-laying begins.

1940s-1970s

Post-war dumping of munitions at sea (1940s-1970s)

After 1945, militaries dumped large quantities of captured and surplus conventional and chemical munitions at designated offshore sites, including in the North Sea and Baltic Sea.

Then

Dumping removed weapons from land cheaply in the short term.

Now

The dumps remain in place, and some now sit in the path of offshore wind farms and cable corridors.

Why this matters now

Fugro's survey corridors run through waters that saw decades of shipping, mining, and dumping — the conditions that scatter UXO unpredictably across the seabed.