A world-class tunnel under the Fehmarnbelt
The tunnel will be five times the length of the Øresund tunnel between Copenhagen and Malmö and three times the length of the Trans-Bay Tube Bart Tunnel in San Francisco, which is currently the world's longest immersed tunnel. The total length of the Fehmarnbelt tunnel will be approx. 18 km from tunnel mouth to tunnel mouth. 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.
Femern A/S has recommended an immersed tunnel solution because this entails the fewest risks during both the construction period and when in operation. The recommendation is based on a preliminary, comprehensive assessment of, not least, environmental and safety issues including navigational safety but also technical, traffic, time and financial issues.
The immersed tunnel solution comprises 89 tunnel elements in total, made of waterproof concrete. The elements will be manufactured on land and then transported by ship to be placed in the dredged channel and connected to the preceding element. The immersed tunnel will be placed in a channel dredged in the seabed and will be protected by a layer of stones 1.2 m thick as protection against sinking ships or ships’ anchors.
On completion, the tunnel will be a reliable facility that will be open all year round, also on windy days and when it snows.
One of the most advanced and safest tunnels in the world
Thorough safety analyses have been conducted and the proposed tunnel more than meets all relevant safety standards – including the EU’s tunnel safety directive – because of the end-to-end emergency lane, among other features. The requirements for road tunnels have increased a great deal over the last decade. The design of the forthcoming Fehmarnbelt tunnel takes all the new requirements into account.
For motorists, the immersed tunnel will be at least as safe as a standard motorway or railway section on land. All traffic will run in separate tunnel tubes so there is no oncoming traffic. To minimise the risk of accidents, a computerised traffic control system will be installed and there will be a 24-hour manned control centre. Moreover, traffic information will be available on FM radio, signage for motorists and varied architectural lighting will be installed in the tunnel so drivers can maintain concentration.
Studies show that some users may feel slight discomfort when driving in tunnels. For a few users, the discomfort is so intense that it will make them choose an alternative route. A similar number of users experience anxiety driving across long bridges. Any discomfort when driving in tunnels can be relieved with creative and good lighting, decoration, clear information with frequent signage and a welcoming and reassuringly safe design for the tunnel portals.
With the dramatic decrease in hazardous emissions from cars and trucks in the last ten years, the 'piston effect' – longitudinal ventilation – of the vehicle traffic will be sufficient to comply with the requirements for air quality in the tunnel during normal operation. In the event of irregular operation, a fire or discharge of toxic fumes, the ventilation system will ensure that motorists can get safely out of the tunnel and that rescue and emergency teams can work safely. In addition, a sprinkler system will be installed in the tunnel, which will limit the extent of any fire and smoke.
There will be a central gallery between the road tunnel tubes to which the motorists can go in the event of an accident. Approximately every 100 metres there will be cross-connections between the tunnels, which means that there will be, no more than around 50 metres to the nearest emergency exit. The over-pressure ventilation in the central gallery will ensure that there is fresh air and no smoke in the gallery in the event of a fire.
Blends in with the landscape
The tunnel will be almost invisible in the landscape, with the exception of the portal buildings and landfills. The tunnel will not impact the marine environment once it has been built. The preliminary environmental investigations show that an immersed tunnel has the least permanent environmental effects and thus also requires fewer measures to minimise environmental impacts.
The proposal is for the tunnel to be constructed almost in a straight line from coast-to-coast. On the German side, motorists will drive over a small hill and then downwards into a green valley before arriving at the mouth of the tunnel. After a gradual transition to artificial lighting, they will continue into a tunnel with light-coloured walls and architectural decoration. The approach on the Danish side will be characterised by Lolland's manmade landscape and will be marked by a portal containing the control and monitoring centre. In this way, the portal building on the Danish side is envisaged as a landmark for travellers en route to Germany.
Cost and timeframe
The cost of a tunnel solution is EUR 5.1 billion, while a bridge will cost EUR 5.2 billion. In January 2011, a political decision will be made on the recommendation from Femern A/S to build a tunnel. Subsequently, Femern A/S will apply for the authorities’ permission for the construction and an EIA consultation will be conducted before the Danish Parliament can enact a construction act. Following this, construction will get underway. It will take six and a half years to build an immersed tunnel and six years to build a bridge. According to the schedule, the fixed link across the Fehmarnbelt will open in 2020.
