Denmark to start work on world’s longest submerged tunnel

Denmark announced Friday that construction of the world’s longest submerged tunnel, to Germany, would begin on January 1 next year.

Work on the Fehmarnbelt, a link of 10 minutes or less for cars and trains, would begin on the Danish island of Lolland, the Ministry of Transport and Housing said.

The underwater tunnel, almost 18 kilometres (11 miles) in length, will link the Danish region of Lolland-Falster with Schleswig-Holstein in Germany.

“The Fehmarnbelt link will be a new gateway to Europe and a new gateway for future green transport solutions,” transport minister Benny Engelbrecht said in a statement.

Unlike other underwater tunnels, such as the Channel Tunnel under the English Channel and Japan’s Seikan Tunnel under the Tsugaru Strait, which both have longer underwater sections, the Fehmarnbelt will not lie under the seabed.

Instead the tunnel is constructed in hollow concrete sections that are to be submerged and placed in a trench dug into the Baltic Sea floor.

The consortium in charge of the project had planned to start construction in mid-2020, but “among other things because of the coronacrisis this had not proved possible,” the ministry said in the statement.

The tunnel, which should be operational by mid-2029, will link the German and Danish regions in 10 minutes by car and seven minutes by train, instead of an hour by ferry, or a 160-kilometre detour through the Danish region of Jutland.

On the German side, the launch of work awaits a court decision to validate approval already given by authorities.