The record-breaking tunnel being built from Denmark to Germany

A groundbreaking tunnel is under construction beneath the Baltic Sea connecting Denmark and Germany, which will reduce travel durations and enhance Scandinavia’s connections to the rest of Europe. Extending 18km (11 miles), the Fehmarnbelt will be the longest pre-fabricated tunnel for road and rail in the world.

It’s also an impressive engineering achievement, where sections of the tunnel will be positioned on the seafloor and then connected. The primary construction location for the project is positioned at the northern portal of the tunnel, along the shoreline of Lolland island in the southeastern part of Denmark.

The site covers over 500 hectares (1,235 acres) and features a harbor along with a factory producing the tunnel sections referred to as “elements.” To create each 217m (712ft) long and 42m wide component, reinforced steel is molded with concrete.

The majority of underwater tunnels – such as the 50km Channel Tunnel connecting the UK and France – dig into bedrock that lies beneath the ocean floor. In this case, 90 separate components will be connected together, one by one, similar to Lego bricks.

“We are breaking records with this project,” says Mr Vincentsen. “Immersed tunnels have been built before, but never on this scale.”

At a cost of approximately €7.4bn ($8.1bn; £6.3bn), the project has primarily been funded by Denmark, alongside €1.3bn from the European Commission. It ranks as one of the largest infrastructure projects in the area, and is part of a broader EU initiative aimed at enhancing travel connections throughout the continent while minimizing air travel.

When finished, the trip from Rødbyhavn in southern Denmark to Puttgarten in northern Germany will last only 10 minutes by car or seven minutes by train, replacing a ferry ride that currently takes 45 minutes. Avoiding western Denmark, the new railway will cut travel durations between Copenhagen and Hamburg from five hours to 2.5 hours and offer a more environmentally friendly route for both goods and travelers.