Femern Bælt Fehmarnbelt Tunnel Project Denmark-Germany

Verdens lengste senkebru

The Fehmarnbelt Tunnel Project is a major infrastructure initiative aiming to connect Rødbyhavn in Denmark with Fehmarn in Germany through an 18-kilometer long immersed tunnel beneath the Baltic Sea. Upon completion, it will be the world's longest immersed tunnel, featuring two motorway tubes with two lanes in each direction as well as one railway track per tube. The total project cost is estimated at over 86 billion Norwegian kroner (approximately 7.4 billion euros).

Produksjon av 89 betongelementer

Construction involves producing 89 massive concrete tunnel elements at a dedicated factory site in Rødbyhavn spanning more than one million square meters. Of these, 79 are standard elements and 10 are special elements. Each standard element measures about 217 meters in length, 42 meters in width, and 9 meters in height, weighing approximately 73,000 tons. The construction requires around 3.2 million cubic meters of concrete and about 360,000 tons of reinforcement steel. Once cast and tested, the elements are equipped with ballast tanks and steel bulkheads, floated out to the harbor basin, and then lowered into a pre-dug trench on the seabed where they are connected underwater to form the tunnel.

Forsinkelser grunnet spesialfartøy

The project is managed by Femern A/S, a Danish state-owned company under Sund & Bælt Holding A/S. Construction works are carried out by the Femern Link Contractors consortium, which includes major European contractors such as Vinci Construction (France), BAM (Netherlands), Per Aarsleff A/S (Denmark), and Max Bögl (Germany). The Design Joint Venture, which comprises Rambøll, Arup, Cowi, and TEC, handles engineering consultancy. While construction started in 2021 with an initial opening target in 2029, progress has been hampered by delays related to the IVY, a specially designed, prototype sinking vessel essential for placing the tunnel elements. The vessel has faced technical challenges and incomplete regulatory approvals, causing an estimated delay of about 18 months.

110 km ny dobbeltspor jernbane

Besides the tunnel itself, related infrastructure includes approximately 110 kilometers of new double-track railway on the Danish side between Ringsted and Rødby, which is advancing according to schedule. However, full project completion remains contingent on obtaining necessary environmental and planning approvals from German authorities, particularly concerning underwater noise and sediment release in the Baltic Sea. Geological surveys have also revealed that sections of the tunnel seabed trench are deeper than expected, requiring additional gravel bedding to ensure a stable foundation for the tunnel elements.

Store gevinster, betydelige risikoer

The project promises significant benefits to regional connectivity and trade, providing a fixed link between Scandinavia and Central Europe and enhancing both road and rail transport capacity across the Fehmarnbelt. However, the project faces notable risks including political and environmental uncertainties-especially delays connected to German environmental approvals and potential legal challenges from environmental groups-which could increase costs by hundreds of millions of Danish kroner annually. Technical risks related to the bespoke construction methods, especially the sinking operation of enormous concrete elements using the specialized vessel, add complexity to the schedule and cost control.

Miljøtiltak med strengt tilsyn

Environmental considerations are a core focus throughout the project. Measures to mitigate impacts on marine ecosystems are being addressed via comprehensive planning, including managing sediment disturbance during seabed preparation and installation activities, as well as noise reduction strategies to protect wildlife. The project remains under close scrutiny by environmental stakeholders and authorities, making ongoing dialogue with German regulators critical to securing the remaining approvals and minimizing ecological impacts.