Denmark and Germany are now building the world’s longest submerged tunnel


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(CNN)- Plunging up to 40 meters beneath the Baltic Sea, the world’s longest submerged tunnel will connect Denmark and Germany, cutting travel times between the two countries when it opens in 2029.

After more than a decade of planning, construction of the Fehmarnbelt tunnel began in 2020, and a temporary harbor on the Danish side was completed over the course of several months. It will host the factory that will soon produce the 89 massive concrete sections that will make up the tunnel.

“The expectation is that the first production line will be ready by the end of the year or early next year,” said Henrik Vincentsen, CEO of Femaron A/S, the state-owned Danish company in charge of the project. “We should be ready to submerge the first tunnel material by early 2024.”

The tunnel, which will be 18 kilometers (11.1 miles) long, is one of the largest infrastructure projects in Europe, with a construction budget of 7 billion euros ($7.1 billion).

By comparison, the 50-kilometer (31-mile) Channel Tunnel connecting England and France, completed in 1993, cost the equivalent of £12 billion ($13.6 billion) in today’s money. Although longer than the Fehmarnbelt Tunnel, the Channel Tunnel was built using a boring machine rather than sinking pre-built tunnel sections.

It will be built across the Fehmarn Belt, a strait between the German island of Fehmarn and the Danish island of Lolland, and is designed to replace the current ferry services from Rodby and Puttgarden, which carry millions of passengers each year. Where the crossing now takes 45 minutes by ferry, it will take just seven minutes by train and 10 minutes by car.

The roof of the first production hall where the tunnel sections will be built in Denmark was completed on June 8, 2022.

Famern A/S

fast travel

The tunnel, officially named Fehmarnbelt Fixed Link, will be the longest combined road and rail tunnel anywhere in the world. It will have two double-lane motorways — separated by a service passageway — and two electrified rail tracks.

“Today, if you want to take a train trip from Copenhagen to Hamburg, it will take you about four and a half hours,” said Jens Ole Kaslund, technical director of Femaron A/S, the state-owned Danish company in charge of the project “when the tunnel is complete. , the same journey would take two and a half hours.

“Today many people fly between the two cities, but in the future it will be better to just go by train,” he added. The same trip by car would be about an hour faster than today, taking into account the time saved by not having to stand in line for the ferry.

In addition to the convenience of passenger trains and cars, the tunnel will have a positive effect on freight trucks and trains, Kaslund said, because it creates a land route between Sweden and Central Europe that will be 160 kilometers shorter than today.

At the moment, traffic between the Scandinavian peninsula and Germany via Denmark can either take ferries across the Fehmarnbelt or take the long route via bridges between the islands of Zeeland, Funen and the Jutland peninsula.

Work begins

The project dates back to 2008, when Germany and Denmark signed an agreement to build the tunnel. It then took more than a decade for both countries to pass the necessary legislation and carry out geotechnical and environmental impact studies.

While the process went smoothly on the Danish side, in Germany a number of organizations – including ferry companies, environmental groups and local municipalities – have appealed the approval of the project, claiming unfair competition or environmental and noise concerns.

Dredging work began off the German coast in the fall of 2021.

Dredging work began off the German coast in the fall of 2021.

Famern A/S

In November 2020, a German federal court dismissed the charges: “This ruling came with a condition, which we expected and we were prepared for, on how we monitor the environment during construction, on things like noise and sediment. I believe that our Really need to make sure that the impact on the environment is as low as possible,” says Vincentsen.

Now that the temporary harbor at the Danish site has been completed, several other phases of the project are underway, including the excavation of the actual trench that will host the tunnel, as well as the construction of the factory that will manufacture the tunnel sections. Each section will be 217 meters long (about half the length of the world’s largest container ship), 42 meters wide and 9 meters tall. Weighing 73,000 metric tons each, they would be as heavy as 13,000 elephants.

“We will have six production lines and the factory will consist of three halls, the first of which is now 95% complete,” says Vincentsen. The sections will be placed just below the seabed, about 40 meters below sea level at the deepest point, and moved by barges and cranes. It will take about three years to locate the departments.

A massive impact

2,500 people will work directly on construction projects, which have been affected by global supply chain issues.

“Supply chain is a challenge at the moment, because the price of steel and other raw materials has gone up. We can get the materials we need, but it’s difficult and we’ve had to increase the number of suppliers to our contractors to make sure they get what they need. It’s something that We are really looking now, because a continuous supply of raw materials is very important,” says Vincentsen.

Michael Sven of the Confederation of Danish Industry, one of Denmark’s largest trade associations, believes the tunnel will also benefit businesses outside of Denmark.

This full-scale trial cast of a tunnel element was constructed in July 2022.

This full-scale trial cast of a tunnel element was constructed in July 2022.

Famern A/S

“The Fehmarnbelt Tunnel will create a strategic corridor between Scandinavia and Central Europe. Upgraded railways mean shifting more freight from road to rail, which supports climate-friendly modes of transport. We see cross-border connectivity as a tool for growth and job creation. Not only locally, Nationally as well,” he told CNN.

While some environmental groups have expressed concern about the tunnel’s impact on porpoises in the Fehmarn Belt, Michael Løvendal Kruse of the Danish Society for Nature Conservation thinks the project will have environmental benefits.

“As part of the Fehmarnbelt tunnel, new natural areas and rock walls will be built on the Danish and German sides. Nature needs space and this will make more space for nature,” he says.

“But the biggest benefit will be the climate benefits. The rapid passage of the belt will make trains a strong challenger to aviation, and electric trains are the best solution for the cargo environment.”