The Fehmarnbelt tunnel, also known as the Fehmarn Belt Fixed Link, is an under-construction immersed tunnel connecting the Danish Island of Lolland with the German island of Fehmarn by crossing the Baltic Sea’s 18-kilometre-wide (11-mile) Fehmarn Belt.

Project in-depth: Fehmarnbelt tunnel - Sheet1
Fehmarnbelt Tunnel-world’s longest immersed tunnel_©World Highways

It will be the world’s longest road and rail tunnel, connecting northern Germany to Lolland and then to the Danish Island of Zealand and Copenhagen. The tunnel will serve as a vital link between Central Europe and Scandinavia. Travel time between Lolland and Fehmarn will be reduced from 45 minutes by ferry (excluding waiting and boarding time) to 10 minutes by car and seven minutes by train. The electrified high-speed rail line will have a top speed of 200 km/h (125 mph).

Process | Fehmarnbelt tunnel

Work on the tunnel portal construction pit on the Danish side began in 2020, followed by work on the German side the following year. The tunnel portal itself began construction in 2022.

  • Casting the tunnel elements- Once the factory is operational, a standard element will be produced every other week for the next three and a half years. A total of 79 standards and ten special elements will be required. Each unique element will have a ‘basement’ for technology. This will make the construction process and tunnel maintenance easier.
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Casting the tunnel elements_©Femern
  • A laser focus on quality- The elements will be cast in the factory in steps of approximately 24 meters. One standard element comprises nine segments, and the entire process takes about nine weeks.
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Laser focus on quality_©Femern
  • The elements will be immersed and coupled together- When an element is ready for shipment, it is fitted with waterproof bulkheads on both ends and towed into position with tugs. The elements are then precisely lowered to the seafloor and carefully coupled together. There is a sealed space between the bulkheads, so huge external pressure pushes them together when the water is pumped out.
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Elements immersed and coupled together_©Femern
  • Tunnel interiors installation- Once the elements are assembled, work on the tunnel’s technical and mechanical installations can begin. Railway tracks, ventilation, cameras, communication systems, signage, painting, and other features are among them. Each of these systems will be thoroughly tested in the final stages of construction before the expected opening date of mid-2029.
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Working on tunnel interiors_©Femern

Project Status 

Danish side of the project- FBC is in charge of dredging the tunnel trench, reclamation, and the construction of new breakwaters on Lolland, which will result in the creation of approximately 300 hectares of new land. Femern A/S has also begun contract negotiations with the contractor consortium, Femern Link Contractors (FLC), to establish the tunnel element factory in the summer of 2021, with completion expected by the end of 2022.

The German side of the project- In the spring of 2021, work on preparing the small-scale construction site on Fehmarn began on the German side. A small-scale harbour and portal building will be built here as well. This project began in 2022.

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This full-scale trial cast of a tunnel element was built in July 2022_©Femern AS

Stakeholder | Fehmarnbelt tunnel

The Interreg project TENTacle aims to improve stakeholders’ capacity to reap the benefits of TEN-T core network corridors (CNCs) implementation for Baltic Sea Region (BSR) prosperity, growth, and cohesion. The CNCs are an EU transport policy instrument aiming to improve mobility, intramodality, and interoperability on major transport axes across Europe by identifying and removing the most critical physical, technical, operational, and administrative bottlenecks along these corridors by 2030. With formal partners and associated organisations from all eleven BSR countries, the project partnership organises a joint response to identified capacity challenges and assists public and market players throughout the BSR with solutions that improve their ability to capitalise on CNCs, regardless of geographical location.


Users pay for the Fehmarnbelt tunnel. Users support the Fehmarnbelt link. The revenue generated by traffic passing through the Fehmarnbelt tunnel will be used to repay the construction loans. In short, those who use the link will pay for it, similar to how the Storeblt and refund fixed links were funded.

Denmark’s Transport Minister will determine the cost of using the Fehmarnbelt tunnel shortly before the link opens.

The EU Commission approved the financing model for the Fehmarnbelt link in the spring of 2020. The most recent financial analysis from November 2020 is available here.

The overall financial framework for the Fehmarnbelt link was determined in the 2015 Construction Act at DKK 55.1 billion (2015 prices).

Benefits in the future | Fehmarnbelt tunnel

  • A future transportation corridor- The Fehmarnbelt link is part of the so-called European TEN-T network, which aims to streamline infrastructure so that the EU’s internal market operates more efficiently and with less environmental impact.

The network is made up of nine transport corridors that run across Europe. The Fehmarnbelt Tunnel connects Helsinki, Finland, to Valetta, Malta, as part of the central north-south corridor.

TEN-T also aims to shift more goods from the road to rail to reduce energy consumption and relieve traffic congestion on local roads and in cities.

Future transport corridor_©Forbes Romania
Future transport corridor_©Forbes Romania
  • A boost for rail transport- The Fehmarnbelt project will boost rail transport, making it far more competitive on a European and regional scale. When the tunnel opens, freight transport between Scandinavia and Europe will no longer have to detour across Storeblt, and the rail freight journey will be cut by 160 kilometres.

Commuters using the new railway can also expect shorter travel times between Hamburg and Copenhagen. The tunnel and the upgrade and expansion of rail links on both sides of the Fehmarnbelt will significantly reduce travel time for passenger and freight traffic, lowering fuel costs and CO2 emissions.

Fehmarnbelt tunnel train_©CNN Travel



Deepshikha Chatterjee is a final year student of architecture studying in Raman Bhakta School of Architecture (UTU). Besides from her architectural background, she keeps keen interest in critic writing or writing in general. Her nerdiness is one of her special talents.