The Biggest Underwater Tunnel on the Planet: Fehmarnbelt Fixed Link and its Mega Project to Connect Countries
This project will connect the islands of Fehmarn in Germany and Lolland in Denmark, under the Baltic Sea, promising to transform travel between the two countries by significantly reducing travel times.
The tunnel will be 18 kilometers long, making it a monumental work compared to other European underwater tunnels. Submerged up to 40 meters below sea level, it will have five galleries, two for road, two for railway, and one for emergencies and services. With an estimated budget of 7 billion euros, this project began construction in 2022 and is expected to be completed by 2029.
Innovation in underwater construction
The construction of this tunnel is innovative and monumental. Instead of using gigantic tunnel boring machines to excavate the seabed, the tunnel is formed by prefabricated concrete modules, each 217 meters long, 42 meters wide, and weighing 73,000 tons. These pieces, a total of 89, will be assembled directly on the seabed after a long dredging process that has taken more than two years to complete.
Steel plays a key role in this project, with a weekly production of 1,500 tons to reinforce the modules. The total amount of steel used is equivalent to the construction of 50 Eiffel Towers. An essential part of the construction is carried out by the Spanish company DMC-Wire, responsible for welding tasks. Using robotic technology, this company performs over 70% of the metal joints, ensuring the strength of the modules. The process is complemented by a magnetic crane capable of handling up to five tons of steel, lowering the necessary bars to the seabed.
Impact of the tunnel on European transportation
The impact of this tunnel on European transportation will be significant. Currently, crossing the strait between Fehmarn and Lolland by car requires a ferry that takes around 45 minutes, not including waiting time. Once the tunnel is completed, this journey will be reduced to just 10 minutes by car or seven minutes by train, with speeds of up to 200 km/h. In addition, the travel time between Hamburg and Copenhagen will be reduced from almost five hours to just two and a half hours, boosting regional and economic connectivity.
