Femern Bælt Tunnel Project Between Denmark and Germany

Verdens lengste nedsenkningstunnel

The Femern Bælt Tunnel Project is a major infrastructure development connecting Rødbyhavn in Denmark with Fehmarn in Germany through an 18-kilometer long immersed tunnel beneath the Baltic Sea. This tunnel will be the world's longest immersed tunnel and includes two motorway lanes in each direction plus two single-track railway lines within separate tunnel tubes. The cost of the project is estimated at over 86 billion Norwegian kroner (approximately 7.4 billion euros). It involves the construction of 89 massive precast concrete tunnel elements, measuring 217 meters in length, 42 meters in width, and nine meters in height, with a weight of about 73,000 tons each.

Produksjon og plassering av elementer

The tunnel elements are being produced at a large fabrication yard located in Rødbyhavn, covering over one million square meters. Of the 89 elements, 79 are standard types while 10 are special elements designed for specific sections. The construction process involves casting massive quantities of concrete (3.2 million cubic meters) and reinforcement steel (around 360,000 tons). Once cast and cured, the elements are outfitted with ballast tanks and steel bulkheads before they are floated out into a harbor basin. There, they are carefully lowered into a pre-dug trench on the seabed and joined underwater to form a watertight tunnel. Geotechnical investigations have revealed that parts of the trench are deeper than anticipated by about 30 centimeters, requiring additional leveling with gravel to ensure safe and stable placement of the elements.

Konsortium og planstatus

The project is led by Femern A/S, a Danish state-owned company under Sund & Bælt Holding A/S. Construction is carried out by a consortium named Femern Link Contractors (FLC), comprising European contractors Vinci Construction (France), BAM (Netherlands), Per Aarsleff (Denmark), and Max Bögl (Germany). The project also relies on expert consultancy from a Design Joint Venture (DJV), which includes Rambøll, Arup, Cowi, and TEC. Work on the supporting Danish rail infrastructure is proceeding on schedule, consisting of about 110 kilometers of new double-track railway between Ringsted and Rødby to connect to the tunnel. However, the project is still pending planning approvals, particularly in Germany, where environmental concerns such as underwater noise and sediment disturbances are under discussion.

Forsinkelse grunnet senkevessel IVY

One of the significant risks currently affecting the project timeline is the delay in completion and approval of the specialized sinking vessel named IVY, which is designed explicitly for lowering the tunnel elements. IVY has experienced unforeseen technical issues and has not yet passed full testing or received regulatory certification. This delay has postponed the start of the immersion works by roughly eighteen months, putting the original 2029 opening date at risk. The project team continues to address technical and environmental challenges to mitigate impact and ensure construction safety and reliability.

Transportforbedring og samfunnsnytte

The Femern Bælt Tunnel will provide substantial societal benefits by greatly improving transport connectivity between Denmark and Germany. It will facilitate faster and more reliable road and rail freight and passenger movements across the Fehmarn Belt region, promoting economic growth, cross-border cooperation, and regional integration. Additionally, the project emphasizes sustainability by carefully managing environmental impacts through ongoing dialogue with authorities and mitigation efforts related to marine ecosystems and water quality during construction.