The 18 km long railway and road tunnel currently under construction at the bottom of the Baltic Sea will connect Germany and Denmark, significantly reducing travel time from 45 minutes to just 7-10 minutes.
Simulation of the Fehmarnbelt Tunnel under the Baltic Sea. (Photo: Femern A/S).
The Fehmarnbelt Tunnel, constructed by Femern A/S, Rambøll, Arup, and TEC, is set to be the world’s longest and deepest immersed tube tunnel that will accommodate both rail and road traffic. Once completed, the tunnel will connect the town of Rødbyhavn in Denmark to the island of Fehmarn in Germany, creating the shortest route between Scandinavia and the rest of Europe. Passengers will only need 7 minutes by train or 10 minutes by car to cross the Fehmarn Tunnel, as opposed to the 45 minutes required by ferry, as reported by New Atlas on June 25.
The construction of the tunnel requires 360,000 tons of rebar, nearly 50 times the weight of the metal structure of the Eiffel Tower. The construction site on the Danish side is equivalent to 373 football fields. The dredging operation for the 18 km tunnel requires the participation of 70 ships, with a total of approximately 12 million cubic meters of earth excavated from the seabed.
The immersed tube tunnel consists of 79 standard segments and 10 special segments. Each standard segment weighs about 73,000 tons and measures 217 meters long, 42 meters wide, and 10 meters high. The special segments are about half the length but are wider and slightly taller than the standard segments. These tunnel segments are precast on land and then positioned using barges, ultimately being submerged and sealed at the seabed at depths of up to 40 meters.
The estimated cost of constructing the Fehmarnbelt Tunnel is around $1.2 billion. Recently, King Frederik X of Denmark inaugurated the first segment of the tunnel in a special ceremony, with the segments expected to be placed underwater in the coming weeks. The Fehmarnbelt Tunnel is projected to be completed by 2029 and will operate for a minimum of 120 years.
