A groundbreaking engineering project is underway on the shores of the Baltic Sea in southern Denmark. The Fehmarnbelt Tunnel, currently under construction, will transform the road and rail systems in Europe when completed.
While it may not have gained the same level of fame as the Channel Tunnel between Britain and France, the Fehmarnbelt Tunnel is equally, if not more, impressive.
This ambitious structure will link Denmark and Germany, carrying a two-lane highway and two electrified rail lines beneath one of the world’s busiest shipping lanes. Spanning 18 kilometers (11.2 miles), it may not be as long as the 50-kilometer (31-mile) Channel Tunnel, but it will be the longest road and rail tunnel in the world. Additionally, it will hold the title of the longest immersed tunnel ever built.
Unlike traditional tunnels, which are dug through solid land, the Fehmarnbelt Tunnel is an “immersed” tunnel. Prefabricated concrete sections are produced on land, then dropped into a trench on the seafloor, linked together, and covered with soil. This method is what sets it apart from other major tunneling projects.
In February 2025, the first precast concrete tunnel sections, known as “elements,” left the factory in Rødbyhavn, Denmark. This marked the beginning of a historic journey that will continue until the tunnel’s completion in 2029.
The €7.4 billion ($7.7 billion) project is monumental. Each tunnel section is enormous, measuring 217 meters (712 feet) in length, 42 meters in width, and 9 meters in depth. Weighing 73,000 tons—about the same as 10 Eiffel Towers—these concrete structures are some of the largest ever constructed.
Altogether, 79 standard elements and 10 shorter special elements, which will house the tunnel’s electrical installations, will be connected from Rødbyhavn on Lolland Island to Puttgarden on the German island of Fehmarn. The tunnel will stretch up to 40 meters beneath the Baltic Sea when finished, creating a massive new link between Denmark and Germany.
Related topics:
- Celebrity Cruises Opens 2027 Galápagos Islands Voyages for Booking
- Ireland to Explain Decision to End Visa-Free Travel for Eswatini
- Virgin Group Plans £700m Rail Expansion to Compete with Eurostar
