After 10 years of planning, the construction of the world’s longest immersed tunnel has officially begun. The Fehmarnbelt Tunnel that will connect Denmark and Germany, is scheduled to be officially opened by 2029. It’s one of Europe’s largest ongoing infrastructure projects, with a budget of more than US$8 billion. The tunnel will have an 18 kilometers extension and will be built across the Fehmarn Belt, a strait between the German island of Fehmarn and the Danish island of Lolland. It will be an alternative to the current ferry service, which takes 45 minutes. Traveling through the tunnel will take seven minutes by train and ten minutes by car.
It will be the longest combined road and rail tunnel in the world, with two double-lane motorways, separated by a service passageway, and two electrified rail tracks. Besides the benefits to passenger trains and cars, it will have a positive impact on the flow of freight trucks and trains. The Fehmarnbelt Tunnel project started back in 2008 when Germany and Denmark signed a treaty to build the tunnel. But it took more than a decade for the necessary legislation to be passed by both countries and for geotechnical and environmental impact studies to be carried out. Still, many organizations have currently open appeals against the project.
In the meantime, amid precautions to keep workers safe from COVID-19, construction work started in the summer on the Danish side. Work will carry on for a few years in Denmark before moving into German territory. Workers are now building a new harbor in Lolland and in 2021 they will start construction of a factory, both meant to support work on the tunnel. Located behind the port, the factory will have six production lines to assemble the 89 massive concrete sections that will make up the tunnel. Each section will be 217 meters long, 42 meters wide, and 9 meters tall, weighing 73,000 metric tons each. They will be placed just beneath the seabed.