Germany and Denmark are building the longest submerged tunnel in the world

The world’s longest submerged tunnel, which will descend up to 40 meters under the Baltic Sea, will connect Denmark and Germany and dramatically reduce travel time between the two countries when it opens in 2029. After more than a decade of planning, construction of the Fehmarn belt tunnel began in 2020 and a temporary port on the Danish side was completed in the months that followed. The factory that will soon build the 89 concrete sections that will make up the tunnel will be located there. It is expected that the first production line will be ready by the end of the year or the beginning of next year,” said Henrik Vincent Sen, CEO of Fehmarn A/S, the public company Danish company in charge of the project. “By early 2024, we must be ready to submerge the first section of the tunnel.
The tunnel, which will be 18 kilometers long, is one of the biggest infrastructure projects in Europe, with a construction budget of more than 7 billion euros ($7.1 billion). By comparison, the 50-kilometre Channel Tunnel linking England and France, completed in 1993, cost the equivalent of 12 billion pounds (about $13.6 million) in today’s money. Although longer than the Fehmarn belt Tunnel, the Channel Tunnel was made with a boring machine, rather than submerging previously constructed sections of tunnel.
The new tunnel will be built through the Fehmarn Belt, a strait between the German island of Fehmarn and the Danish Island of Lolland, and is designed as an alternative to the current ferry service from Rudy and Putt Garden, which carries millions of passengers each year. Where it now takes 45 minutes by ferry, it will only take seven minutes by train and 10 minutes by car.
A faster journey
The tunnel, whose official name is Fehmarn belt Fixed Link, will also be the longest combined road and rail tunnel in the world. It will consist of two dual-lane highways, separated by a level crossing, and two electric railway tracks. Today, if you took a train from Copenhagen to Hamburg, it would take about four and a half hours,” explains Jens Ole Kaslund, technical director of Fehmarn A/S, the Danish public company in charge of the project. “When the tunnel is finished, the same journey will take two and a half hours. Today many people fly between the two cities, but in the future, it will be better to take the train. The same drive will be about an hour faster than it is now, considering the time saved by not queuing for the ferry.
In addition to the benefits for passenger trains and cars, the tunnel will have a positive impact for trucks and freight trains, Kaslund explains, as it creates an overland route between Sweden and central Europe that will be 160 kilometers than the current one. Currently, traffic between the Scandinavian Peninsula and Germany via Denmark can take the ferry across the Fehmarn belt or a longer route via bridges between the islands of Zealand, Funen and the Jutland Peninsula.
Work begins
The project dates back to 2008, when Germany and Denmark signed a treaty to build the tunnel. From then on, it took more than a decade for the two countries to adopt the necessary legislation and carry out the geotechnical and environmental impact studies. While the process went smoothly on the Danish side, in Germany various organizations, including ferry companies, environmental groups and local municipalities, challenged the approval of the project citing unfair competition or environmental concerns. and sound. In November 2020, a German federal court dismissed the complaints: The decision comes with a number of conditions, which we somewhat expected and were prepared for, on how we control the environment during construction. on things like noise and sediment dumping I think we need to make sure the impact on the environment is as low as possible. Now that the temporary port on the Danish side has been completed, other phases of the project are underway, such as the excavation of the actual trench that will house the tunnel, as well as the construction of the factory that will build the sections of the tunnel. Each section will be 217 meters long (about half the length of the world’s largest container ship), 42 meters wide and 9 meters high. Weighing 73,000 tons each, they will be as heavy as more than 13,000 elephants. They will have six production lines and the factory will consist of three halls, the first of which is already 95% complete. The sections will be placed just below the seabed, approximately 40 meters below sea level at the deepest point, and placed in place by barge and crane. The establishment of the sections will take approximately three years.
A wider impact
Up to 2,500 people will work directly on the construction project, which has been affected by global supply chain issues. The supply chain is difficult at the moment because the price of steel and other raw materials has increased. We get the materials we need, but it’s difficult and our contractors have had to increase the number of suppliers to ensure they can get what they need. That’s one of the things we’re really watching right now, because having a constant supply of raw materials is crucial. The Fehmarn belt Tunnel will create a strategic corridor between Scandinavia and Central Europe. Improved rail transfer means more goods will move from road to rail, promoting a climate-friendly mode of transport. We see cross-border connections as a tool for growth and jobs not just locally, but nationally. Although some environmental groups have expressed concerns about the tunnel’s impact on porpoises that inhabit the Fehmarn Belt, Michael Levendale Kruse of the Danish Nature Conservation Society believes the project will have environmental benefits. As part of the Fehmarn belt tunnel, new nature areas and stone reefs will be created on the Danish and German side. Nature needs space and so there will be more space for nature. But the biggest benefit will be the climate benefit. The faster pace will make trains a serious competitor for air traffic, and charging electric trains is by far the best solution for the environment.