Offshore Wind Developers Help Solve a Century-Old Mystery

Whilst undertaking detailed seabed scanning for the development of wind farm projects in the East Anglia Zone, off the coast of Norfolk and Suffolk, wind farm developers ScottishPower Renewables (SPR) and Vattenfall uncovered something they weren’t expecting – an ‘uncharted’ wreck of a WWI German submarine, missing in action since 1915.

At first it was suspected that the wreckage is a Dutch military submarine HNLMS O13, which went missing in action in June 1940, after the crew were tasked to patrol the waters between Denmark and Norway.

However, GoPro footage taken by the Dutch Navy divers highlighted clear images of the conning tower and deck lay-out, which suggested the wreck was of German origin. From German drawings it was identified that this was a WWI German submarine: Type U-31. A database of reference books shows that only U-boats U-31 and U-34 had been lost in this area of the North Sea.

Mark Dunkley, marine archaeologist at Historic England, said: “SM U-31 was commissioned into the Imperial German Navy in September 1914. On 13th January 1915, the U-31 slipped its mooring and sailed north-west from Wilhelmshaven for a routine patrol and disappeared. It is thought that U-31 had struck a mine off England’s east coast and sank with the loss of its entire complement of 4 officers, 31 men.”

The wreck was officially identified as the German submarine U-31 three years after its initial discovery in September 2012. The wreck is approximately 90km offshore in the North Sea but sits on the seabed at a depth of only 30 metres.

“Unravelling the whole story behind the submarine has been fascinating and it’s heartening to know that the discovery will provide closure to relatives and descendants of the submariners lost who may have always wondered what had happened to their loved ones,” Charlie Jordan, ScottishPower Renewables’ project director for the East Anglia ONE wind farm, said.

As an official military maritime grave, the wreck of U-31 will remain in its final resting place and plans for any offshore wind farm development will be progressed ensuring no disturbance to the area.

SPR and Vattenfall used advanced sonar technology to scan over 6,000km2 of the seabed in the Southern North Sea over two years, which is nearly 4 times the size of Greater London (1,583km2).

This work is critical to understand seabed conditions, and allow the companies to design the layout of their proposed projects. Although more than 60 wrecks were discovered during the scanning work, most of these were anticipated, but the uncharted submarine 90km from shore was entirely unexpected, SPR said in a release.