An ambitious engineering project is currently underway in Europe that will revolutionize travel between Germany and Denmark. The Fehmarnbelt Tunnel, an 18-km (roughly 11.2-mile) underwater road and rail link, is set to become the world’s longest immersed tunnel, enabling seamless travel under the Baltic Sea.
The Fehmarnbelt Tunnel is a collaborative effort by Femern A/S, Rambøll, Arup, and TEC. Unlike other undersea tunnels, such as the Channel Tunnel, this project involves building tunnel sections on land and then immersing them in the sea. This approach makes it both the longest and deepest immersed tunnel globally that accommodates road and rail traffic. This innovative method underscores the project’s uniqueness and the engineering prowess behind it.
Upon completion, the tunnel will connect Rødbyhavn in Denmark with Fehmarn in Germany, significantly shortening travel time between Scandinavia and mainland Europe. The journey through the tunnel will take just seven minutes by train or 10 minutes by car, compared to the 45-minute ferry ride currently required. This substantial reduction in travel time is expected to boost economic ties and ease movement between the regions.
To comprehend the scale of the Fehmarnbelt Tunnel, consider that its construction requires 360,000 tonnes (396,832 short tons) of rebar, equivalent to almost 50 times the weight of the Eiffel Tower’s metal structure. The build site in Denmark spans the area of 373 soccer pitches. Up to 70 vessels participated in dredging the tunnel trench, and approximately 12 million cubic meters (almost 424 million cubic feet) of soil were removed from the seabed to make way for the tunnel.
The tunnel comprises 79 standard sections and 10 special sections. Each standard section weighs around 73,000 tonnes (80,468 short tons) and measures 217 m (711 ft) in length, 42 m (138 ft) in width, and 10 m (33 ft) in height. The special sections, though shorter, are wider and taller. These sections are cast on land, floated into position using a barge, then submerged and sealed on the sea bed at depths of up to 40 m (131 ft). This meticulous process ensures the tunnel’s stability and longevity.
The budget for the Fehmarnbelt Tunnel is approximately DKK8.4 billion (roughly US$1.2 billion). Denmark’s King Frederik X recently inaugurated the first section during a special ceremony, marking a significant milestone in the project. The tunnel is expected to be operational by 2029, with a minimum operational lifespan of 120 years. This extended lifespan ensures long-term benefits for both regions.
The Fehmarnbelt Tunnel is poised to become a crucial infrastructural link in Europe, fostering greater connectivity and economic integration between Scandinavia and the rest of the continent. Its completion will not only symbolize engineering excellence but also mark a significant step towards a more interconnected Europe.
