Fehmarnbelt Fixed Link – the world’s longest immersed tunnel
The Fehmarnbelt Fixed Link is an 18 km immersed tunnel connecting Denmark and Germany, setting a new global benchmark for cross‑border infrastructure. Combining road and rail in a single structure, the project will dramatically reduce travel time, strengthen European transport corridors.
Project details
Client
Femern A/S
Location
Denmark / Germany
contact
Susanne Kalmar Pedersen
Partners
Ramboll-Arup-TEC Joint Venture
Client advisory

This shortcut reduces journeys by 160 kilometres. This will save time for individuals, provide a faster, shorter and lower emission freight route for businesses, and create economic growth for the region by opening up for tourism.
Project Director Ramboll
Halving travel time between Copenhagen and Hamburg
World’s longest immersed tunnel
The Fehmarnbelt tunnel applies a proven immersed tunnel method on an unprecedented scale. Prefabricated concrete elements are cast on land, floated to site, and immersed with millimetre precision into a dredged trench on the seabed. This approach enables high construction quality while reducing disruption to shipping routes and surface landscapes compared to alternative bridge solutions.

Fehmarnbelt in numbers
- Fact: 7 minutes
Time it will take a train to pass through the tunnel
- Fact: € 7.4 bn
Total project budget (at 2015 price levels) - largest infrastructure in Denmark to date
- Fact: 18 km
World’s longest immersed tunnel
Fehmarnbelt image carousel
Fehmarnbelt image carousel
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Tunnel factory and harbour
Copyright Femern A/S and Sund & Bælt Holding A/S
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Puttgarden portal area under construction
Copyright Femern A/S and Sund & Bælt Holding A/S
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Tunnel element construction
Copyright Femern A/S and Sund & Bælt Holding A/S
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Transporting tunnel elements
Copyright Femern A/S and Sund & Bælt Holding A/S
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Sinking tunnel elements
Copyright Femern A/S and Sund & Bælt Holding A/S
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Tunnel interior
Copyright Femern A/S and Sund & Bælt Holding A/S
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Portal area
Copyright Femern A/S and Sund & Bælt Holding A/S
Tunnel factory and harbour
Copyright Femern A/S and Sund & Bælt Holding A/S
Puttgarden portal area under construction
Copyright Femern A/S and Sund & Bælt Holding A/S
Tunnel element construction
Copyright Femern A/S and Sund & Bælt Holding A/S
Transporting tunnel elements
Copyright Femern A/S and Sund & Bælt Holding A/S
Sinking tunnel elements
Copyright Femern A/S and Sund & Bælt Holding A/S
Tunnel interior
Copyright Femern A/S and Sund & Bælt Holding A/S
Portal area
Copyright Femern A/S and Sund & Bælt Holding A/S
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Tunnel factory and harbour
Copyright Femern A/S and Sund & Bælt Holding A/S
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Susanne Kalmar Pedersen
Project Director
Transport
