The record-breaking tunnel being built from Denmark to Germany

A groundbreaking tunnel is currently under construction beneath the Baltic Sea, connecting Denmark and Germany. This impressive project aims to significantly reduce travel times between Hamburg and Copenhagen. The tunnel, which stretches for 18 kilometers, or about 11 miles, will become the longest pre-fabricated road and rail tunnel in the world. The construction involves placing segments of the tunnel on the sea floor and then connecting them together. The main construction site is located on Lolland island in southeastern Denmark, covering an area of over 500 hectares, equivalent to 1,235 acres. This facility includes a harbor and a factory where the tunnel sections, referred to as 'elements', are being manufactured. Henrik Vincentsen, the chief executive of Femern, the state-owned company responsible for the tunnel's construction, states, 'It’s a huge facility here. ' Each element measures 217 meters in length and 42 meters in width. Unlike most underwater tunnels, which are typically dug deep beneath the seabed, this project will involve linking 90 individual elements together, much like assembling Lego bricks. Mr. Vincentsen proudly declares, 'We are breaking records with this project. ' The tunnel will consist of five parallel tubes, designed for both rail and road traffic. With an estimated cost of around €7. 4 billion, or $8. 1 billion, the project is primarily funded by Denmark, with an additional €1. 3 billion provided by the European Commission. This initiative is one of the largest infrastructure projects in the region and is part of a broader European Union plan to enhance travel connections across the continent while promoting environmentally friendly transportation options. Once completed, the journey between Rødbyhavn in southern Denmark and Puttgarten in northern Germany will take just 10 minutes by car or seven minutes by train, replacing the current 45-minute ferry ride. The new rail route will also cut travel times between Copenhagen and Hamburg in half, reducing the journey from five hours to just 2. 5 hours. Mr. Vincentsen emphasizes, 'It’s not only linking Denmark to Germany; it’s linking Scandinavia to central Europe. ' He believes that everyone will benefit from this project, as it will also help reduce carbon emissions by allowing travelers to cover 160 kilometers less. The entrance to the tunnel is a massive structure, surrounded by cranes and construction equipment. Senior construction manager Anders Gert Wede explains, 'So now we are in the first part of the tunnel. ' Inside, there are five parallel tubes within each element: two for railway lines, two for roads with two lanes in each direction, and a maintenance and emergency corridor. At the far end of the tunnel, enormous steel doors prevent water from entering. Mr. Wede describes the thickness of the doors, saying, 'As you can hear, it’s quite thick. ' Once a completed element is ready at the harbor, it will be towed out to the designated location and carefully immersed behind the steel doors. Each element is not only long but also incredibly heavy, weighing over 73,000 tonnes. To facilitate transportation, the ends of the elements are sealed watertight and fitted with ballast tanks, providing enough buoyancy to tow them with tugboats. The next step involves a complex process of lowering the elements 40 meters into a trench dug on the sea floor, using underwater cameras and GPS-guided equipment to ensure precise alignment within 15 millimeters. Mr. Wede stresses the importance of precision, stating, 'We have to be very, very careful. ' They employ a system called 'pin and catch', which uses a V-shaped structure and arms to grab onto the element and guide it into place. The tunnel is being constructed from north to south, with the construction facility located at the northern entrance. Denmark is situated at the mouth of the Baltic Sea, where busy shipping lanes exist. The ground beneath the sea consists of soft clay and chalk bedrock, making it unsuitable for traditional drilling methods. Per Goltermann, a professor in concrete and structures at the Technical University of Denmark, explains that a bridge was initially considered, but strong winds could disrupt traffic, and safety concerns regarding ships colliding with bridges were significant. 'There was the risk of ships crashing into bridges,' he notes. 'We can build the bridge to withstand it, but this is rather deep water, and the biggest ships can sail there. ' Consequently, the decision was made to proceed with an immersed tunnel. In 2008, Denmark and Germany signed an agreement to build the tunnel, but the project faced delays due to opposition from ferry operators and environmental groups concerned about its ecological impact. One such group, Nabu (The Nature And Biodiversity Conservation Union), argued that the Baltic Sea is a crucial habitat for larvae and harbor porpoises, which are sensitive to underwater noise. However, in 2020, a federal court in Germany dismissed their legal challenge, allowing construction to move forward. Mr. Vincentsen assures that they have implemented numerous initiatives to minimize the project's environmental impact, including plans for a 300-hectare wetland nature and recreational area created from dredged sand and rock. When the tunnel opens in 2029, it is estimated that over 100 trains and 12,000 cars will use it daily. The revenue generated from toll fees will be used to repay the state-backed loans taken out for construction, which Mr. Vincentsen estimates will take around four decades. 'Ultimately, the users are going to pay,' he states. This significant investment is also expected to boost jobs, businesses, and tourism in Lolland, one of Denmark's less affluent regions. Mr. Wede, who grew up nearby, shares, 'The locals down here have been waiting for this project for a lot of years. ' They are eager for the new businesses that will come to their area.