The Fehmarnbelt tunnel project: three years into construction
Works began three years ago on one of Europe’s major infrastructure projects: the Fehmarnbelt tunnel, which will form a shortcut between Germany and Denmark. What strides have been made in the past construction year?
Scheduled to open in 2029, the Fehmarnbelt tunnel project aims to link Hamburg to Copenhagen faster, without the necessity of ferries. Until now, the quickest route to reach the two cities passes via Puttgarden and Rødby, two small ports linked by a ferry that makes the crossing in an hour.
When the tunnel and the two connecting railway lines in Germany and Denmark are finished, the journey time between Hamburg and Copenhagen will be reduced to 2 hours and 30 minutes, a two-hour reduction from the current 4,5-hour train journey. The journey through the Fehmarnbelt tunnel itself will only take seven minutes by train and ten minutes by car.
In late 2010, after feasibility studies, the Danish project planners declared that an immersed tunnel would be the solution to link the two shores. The Fehmarnnelt Tunnel includes a railway section and is a priority project of the Trans-European Transport Network (TEN-T)
An immersed tunnel
The technique used is the immersed tunnel. This involves dredging the bottom of the Fehmarnbelt over a distance of more than 17 kilometres to lay pre-constructed elements. Construction of the factory to produce these elements was carried out by the main contractor, Femern Link Contractors, FLC, who have now commenced production of the tunnel elements. The construction of the factory began in the summer of 2021 and was completed in August 2023. The tunnel factory has a total of six production lines.
The first tunnel element was finished in December 2023 and is expected to be immersed in the Fehmarnbelt in 2024 in the special tunnel trench. Production of the tunnel elements will continue until 2027 when the final tunnel element for the Fehmarnbelt link is expected to be ready.
Outside the factory, three immense basins have been filled with water: they form the link between the factory and the work harbour, from where the elements are shipped out. Large gates ensure that the dry dock and basins can be filled with water and emptied as needed, allowing the elements to float from the factory to the work harbour and further out into the Fehmarnbelt.
Railway line in Germany
Deutsche Bahn (DB) has started construction of the railway connection last December. On the construction site on the island of Fehmarn, the first permanent structures have been cast. The lateral support wall for the trough of the new railway line forms the side wall of the approx. 250 m long trough, which will be several metres deep. In future, trains will travel here at speeds of up to 200 kilometres per hour in the direction of Denmark.
The current line is still partly single-track and not electrified. The entire rail project from Lübeck to Puttgarden is 88 kilometres long and involves 10 construction phases. Deutsche Bahn is planning 55 kilometres of new construction with a two-track line running at 200km/h. Works will be expected to begin in 2026.
The initial work currently underway consists of a double-track extension and electrification over 11.4 kilometres between Puttgarden and the Fehmarnsund bridge.
Railway line in Denmark
Danish rail infrastructure manager Banedanmark is upgrading and modernising the Ringsted-Fehmarn Railway, an approximately 120-kilometre railway line between Ringsted and Rødby. This is one of the biggest infrastructure projects in Denmark’s history, which will together with the tunnel majorly improve connectivity.
Several existing stations and platforms have been modified with new access roads, lifts and road infrastructure. To accommodate for the traction power supply and the additional tracks, more than 100 bridges and roads will be modified. The railway line will also be electrified with a new traction power supply, and a brand new signalling system has been launched between Mogenstrup and Nykøbing F.
The video of Femarn A/S below shows the highlights of 2023 and what awaits the project in 2024.