dcsimg Fehmarn: The world's longest road/rail tunnel - Ramboll Group
Engineers discussing the Fehmarnbelt tunnel
Project data
Client: Femern Bælt A/S

Services we provided
Building physics
Electrical engineering
Construction and Contract Management
Digital design
Fire & safety
Ground engineering
Geophysical services
Ground engineering
Immersed tunnels
Infrastructure Asset Management
Landscape architecture
Landscape architecture
Lighting design
Mechanical engineering
Tunnel engineering
Road & motorway engineering
Ports & marine structures
Project management
Rail engineering
Structural engineering
Transport planning, traffic engineering and traffic safety
Tunnel safety

Fehmarn: The world's longest road/rail tunnel

Fehmarnbelt between Denmark and Germany ¤

In the future Scandinavia and the rest of Europe will be connected by the world's longest road and rail tunnel.

The fixed immersed tunnel link across the Fehmarnbelt will be more than 18 km long and carry a four-lane motorway alongside a twin track-electrified railway.

The fixed link will reduce the travel time between Scandinavia and Continental Europe. At a speed of 110 km per hour, this will offer motorists a journey time of approximately 10 minutes through the tunnel. For train passengers, the journey will take seven minutes from coast to coast. The duration of a train journey between Hamburg and Copenhagen will be cut short from about four and a half to merely three hours.

The immersed tunnel solution under Fehmarnbelt is a study in innovative thinking, as it challenges existing tunnel building standards. It improves functionality through its pioneering longitudinal ventilation system and state-of-the-art safety and security features.

The Fehmarnbelt tunnel will be more than five times the length of the tunnel under Øresund linking Denmark and Sweden, and more than three times the length of the Trans-Bay Tube Bart Tunnel in San Francisco in California, the current world record holder.

In close collaboration with Tunnel Engineering Consultants (TEC) og Arup, Ramboll is advising Fehmarn A/S on the design of the immersed tunnel solution.

More on this project




Learn more about immersed tunnels

Visualisation of the immersed tunnel under Fehmarnbelt
Immersed tunnels

Ramboll is main consultant on Fehmarn belt, one of the world's biggest projects with immersed tunnels. Read more about how we solve this and other world class immersed tunnels projects.

Immersed tunnels
Logo of Femern AS
Femern Belt

Visit Femern Sund Bælt's website to read more background about the project and see their many videos and visualisations.


NCE International Tunnelling Award

At the recent International Tunnelling Awards 2013, a team of innovative experts from Ramboll won the “Ground Investigation and Monitoring Award” for the "exceptional geotechnical consultancy work" on the Fehmarn Fixed Link project.

NCE International Tunnelling Award