Tunnel Engineering Consultants (TEC) is one of the leading companies in the world specialising in immersed tunnels. TEC is a joint venture formed with Royal HaskoningDHV and Witteveen+Bos and has been supplying expertise for projects around the world for more than 20 years. As part of the Design Consortium Ramboll-Arup-TEC (RAT) joint venture, TEC is providing specific input to the design and tender preparation for the prestigious Fehmarnbelt tunnel.
This under-sea immersed tunnel is one of the worlds' largest construction projects to date. From 2021 the tunnel will reduce the distance between Denmark and Germany to a mere 10 minutes by car. At 19 kilometres, the Fehmarnbelt tunnel will be the longest combined road/rail immersed tunnel in the world. It consists of a 2x2-lane motorway with hard shoulders, an escape annex cable duct and a two-track rail tube. The cost of constructing the tunnel is estimated at 5.5 billion euros and construction will take approximately six years.
Under the bilateral agreement concluded between the two countries, Denmark will bear the entire cost of the project, with the exception of a European subsidy, and acquires the right to charge a toll.
Tunnel comes out on top
The client, Femern A/S, is responsible for the development and future operation of the tunnel. Dick Kevelam of TEC (Royal HaskoningDHV) is the project manager of the Design Consortium and responsible on behalf of the RAT joint venture: "At the start of the project, the Danes still favoured a cable stayed bridge solution. However, as a precautionary measure, a study considering a tunnel solution was commissioned alongside that for a bridge. The studies were to be carried out separately and by different consortia. The application of a cost-saving longitudinal ventilation system meant that an artificial island for the purpose of tunnel ventilation would not be needed in the Fehmarn Belt. As a result, the tunnel proved to be cheaper than the cable stayed bridge. Moreover, the tunnel solution is safer than the average Danish motorway and would not present an obstacle to shipping. As a result of the study, in February 2011 the Danish government decided to accept the recommendation of Femern A/S, with the tunnel as the preferred solution. A success story that many people would think impossible only a few years ago."
After the immersed tunnel option was selected TEC prepared the detailed documentation for the German plan approval procedure and those for the German and Danish environmental impact assessments. The plans are made available to the public and for interested parties to comment.
In parallel with the permitting procedure, further detail was added to the project and TEC assisted the Client in the preparation of the tender documentation. The tender process will start late 2013 using the principle of a competitive dialogue during which shortlisted construction consortia are challenged to introduce innovative and competitive ideas. If everything runs to schedule, the construction will start in 2015 and the tunnel will be open for traffic in 2021.
"We welcome the political support for our recommendation that the future link will be designed as an immersed tunnel" stated Leo Larsen, CEO of Femern A/S. "As our conceptual design projects are based on an extremely thorough, technical foundation we can now focus on ensuring that the authorities approve the project, taking into account an environmental perspective. The aim is to build and operate one of Europe's safest and most modern tunnels for both trains and cars. The tunnel will create opportunities for increased growth and prosperity for more than 10 million residents in the Fehmarn Belt Region."
- At 18km from tunnel portal to tunnel portal, it will be the world's longest tunnel of its kind
- Its deepest point will be over 40m
- 15.5 million cubic metres of seabed will be dredged to form a 'virtually' straight trench
- 89 precast concrete elements will be floated and immersed to form the tunnel
- Each element will weigh 73,500 tonnes, measure 217m long, 8.9m high, and 42.2m wide
- It will take 6.5 years to build
- When it opens in 2021 it will include a four lane motorway and a two-track rail link
- It will take 7 minutes for rail passengers and 10 minutes for motorists to travel coast to coast.
"TEC has already proved itself as a consultant for major projects in Sweden/Denmark, South Korea and China. This, and our contribution to the Fehmarn tunnel puts us in an excellent position to be involved in similar fixed link projects around the world."
Hans de Wit, TEC Director