Femern A/S announces construction start of subsea tunnel

Femern portal on Lolland. Femern

A subsidiary of the Danish ministry of transport, Femern A/S, has announced that construction work will commence on the Danish side for the planned Fehmarnbelt Tunnel during autumn 2019.
With an estimated budget of 52.6 billion Danish krone (USD7.9 billion) and a completion date of 2028, the tunnel will reduce the estimated travel time between Copenhagen to Hamburg from 4.5 hours to just 2.5 hours.

The project is a joint national development on behalf of both the German and Danish governments, which will connect Puttgarden in Germany with Rødbyhavn in Demark. There will be 18 km of immersed tunnel in the Baltic Sea, connecting the Danish island of Lolland with the German island of Fehmarn, this is known as the Fehmarnbelt fixed link project.
Special marine equipment will be needed to dredge the tunnel trenches, as well as the establishment of a work harbour in Rødbyhavn. The initial trench to be dug for the tunnel will be up to 60 m wide and 16 m deep, with an estimated evacuation of 19 million m3 of sand from the seabed.

The tunnel will be made up of four lanes of motorway and two electrified rail tracks, which will have rail speeds of up to 200 km/h. The construction of the tunnel will consist of 79 individual elements or tunnel tubes, each 217 m long and weighing 73,000 tonnes. The elements, however, will float in water due to their hollow nature and be towed out to sea, by large tugboats, then lowered onto the seabed to connect with the other elements in place.

Once sealed, the water will be pumped out of the connecting element, so that work can be carried out underwater, with the installation of tracks, lighting, communications systems and ventilation. There will be an additional 10 special elements, with a lower floor, reserved for equipment for maintenance and operational capacities. These will be situated every 2 km of tunnel and will reduce costs and ensure quicker response time and maintenance.

It is estimated that the tunnel will reduce CO2 emissions, due to this being the shortest and fastest route. The project was approved by the EU commission in 2015 and will finance part of the project through its trans-European transport network programme (TEN-T). The dredging and reclamation contracts for this project have been signed with Fehmarn Belt contractors.