How the Fehmarnbelt tunnel will be built
The Fehmarnbelt link will be built as an immersed tunnel between Rødbyhavn on Lolland and the German island of Fehmarn. In contrast to a bored tunnel, an immersed tunnel is made up of hollow concrete elements, cast on land and assembled section by section to form the tunnel.
A trench for the tunnel must first be dug in the seabed in order to build the Fehmarnbelt link. This trench will be up to 60 metres wide, 16 metres deep and 18 kilometres long. In total, some 19 million cubic metres of stone and sand will be excavated from the seabed. This will be used to establish approximately three square kilometres of new natural areas on Lolland and, to a lesser extent, on Fehmarn.
Read more about the natural areas on Lolland here.
When the trench in the seabed is ready, the work of putting the tunnel elements in place can go ahead. Each tunnel element weighs 73,000 tonnes, however it can float in the water because it is hollow and sealed with bulkheads,. Large tugboats will tow the elements out into the Fehmarnbelt, where they will be lowered down onto the seabed with a high degree of precision and then assembled.
A FURTHER DEVELOPMENT IN RELATION TO THE ØRESUND TUNNEL MEANS THAT THE FEHMARNBELT TUNNEL WILL HAVE 10 SPECIAL ELEMENTS WITH AN EXTRA "BASEMENT FLOOR”.
Did you know that...
... the immersed tunnel was chosen as the preferred technical solution in 2011.
... Femern A/S examined four technical solutions? An immersed tunnel, a bored tunnel, a cable-stayed bridge and a suspension bridge.
A special element will be located approximately every two kilometres of tunnel and will have equipment for operation and maintenance. This means that the Fehmarnbelt tunnel will be cheaper and easier to maintain, and will require significantly less concrete since the standard elements can be made smaller.
This is what a special element could look like:
This video shows, how the Fehmarnbelt tunnel will be built: