Construction of the nearly 18-km sunken-tube road and rail tunnel link between north Germany and Denmark is now set to start following project approval late December by the German Ministry of Transport of Schleswig-Holstein state.

Copenhagen-based project sponsor Femern A/S will take 14 days to review the construction requirements set out in the 1,000-page German approval document. The company plans to publish a strategy to comply with the approval requirements in spring, leading to some 8.5 years’ construction.

Seventy nine, 217-m-long precast concrete elements weighing about 73,000 tonnes each will be strung together to form the $8-billion immersed Femern Belt fixed-link tunnel between the islands of Lolland in Denmark and Fehmarn in Germany. With Denmark funding most of the work, Femern A/S is the project owner.

Denmark's state planning company was able to secure Danish approval for the project in 2015, but has taken longer to comply with more complicated German procedures while facing stiff environmental opposition in Schleswig-Holstein. The Danes began the German permitting process five years ago, submitting a final application that ran to 14,000 pages, according to Femern A/S.

German project opponents still have a chance to appeal against the approval in the Federal Administrative Court in Leipzig. The pace of any court action would determine when construction could start on the German side.

Because of the permitting uncertainty, Femern A/S was able to award only conditional contracts, worth around $4.6 billion, for the tunnel construction and dredging, in May 2016. The contract allowed for a review in 2019 in case of delayed approval.

An eight-firm international consortium, led by Paris-based VINCI Grands Projets, won both contracts to build the tunnel and the element fabrication facility in Rødbyhavn, Denmark. A four-firm Dutch/German consortium led by Boskalis International B.V. Papendrecht, Netherlands, won the dredging contract.