Due for completion in 2021, the 18km tunnel will be the world's longest immersed tube tunnel and the longest combined road and railway tunnel, with foundation depths reaching more than 40m below the surface. A trench 80m wide and 15m deep will be excavated from the seabed to accommodate the tunnel, and the spoil will be used for land reclamation on the Danish coast.
The immersed section of the tunnel is being tendered as two equally-sized contracts with the aim of achieving greater competition between bidders.
Nine major consortia prequalified in May for the four major civil works contracts and Femern A/S, the company owned by the Danish Ministry of Transport which is responsible for developing the project, says it expects to receive the preliminary bids early next year. This will allow the final bids and prices to be included in the Danish government's forthcoming Construction Act, which will be debated in parliament at the end of next year. Construction will commence immediately after the contracts are signed in 2014.
The total estimated construction cost of the tunnel, excluding connecting road and rail links, is €5.5bn at 2008 prices. The total value of the four civil works contracts is around €4.5bn.
Preparation of tender documents, as well as the early development of the tunnel and connecting infrastructure has been carried out by a joint venture of Arup, Rambøll and TEC.
Contracts for the construction of railway infrastructure will be tendered by Femern A/S at a later date.