Verdens lengste nedsenkningstunnel

The Fehmarnbelt Tunnel and Railway Connection Project is a major infrastructure initiative designed to link Rødbyhavn in Denmark with Fehmarn in Germany via an 18-kilometer-long immersed tunnel beneath the Baltic Sea. Upon completion, this will be the world's longest immersed tunnel, featuring two motorways with two lanes each and two railway tracks, one in each tunnel tube. The project is estimated to cost over 86 billion Norwegian kroner (approximately 7.4 billion euros) and aims to significantly improve transportation between Denmark and Germany, enhancing regional connectivity and economic integration.

89 prefabrikkerte betongelementer

The tunnel consists of 89 massive precast concrete elements produced at a dedicated factory in Rødbyhavn spanning over one million square meters. Among these, 79 are standard elements and 10 are specialized. Each standard element measures 217 meters in length, 42 meters in width, and 9 meters in height, constructed from nine segments of 24 meters each, weighing around 73,000 tons. The entire construction requires about 3.2 million cubic meters of concrete and approximately 360,000 tons of steel reinforcement. After casting and testing, the elements are outfitted with ballast tanks and steel doors, then carefully floated out and immersed into a pre-dredged trench on the seabed, where they are connected underwater to form the tunnel.

Prosjektledelse og fremdriftsutfordringer

The project is led by Femern A/S, a company wholly owned by Sund & Bælt Holding A/S under the Danish state. Construction is carried out by the Femern Link Contractors consortium, which includes major European companies such as Vinci Construction (France), BAM (Netherlands), Per Aarsleff A/S (Denmark), and Max Bögl (Germany). Engineering design and consultation are managed by Design Joint Venture, comprising Rambøll, Arup, Cowi, and TEC. The construction commenced in 2021 with a planned opening in 2029, but progress faces risks including delays related to the specialized heavy-lifting vessel IVY, which is crucial for sinking the tunnel elements; this vessel has yet to complete testing and approval, causing about an eighteen-month setback.

Banebygging og miljøhensyn

Besides the tunnel itself, the project encompasses extensive railway infrastructure improvements, notably the construction of approximately 110 kilometers of new double-track railway between Ringsted and Rødby in Denmark. This component is progressing according to schedule, but the overall project remains dependent on obtaining final environmental approvals from German authorities. Key environmental considerations include managing underwater noise and controlling sediment disturbances in German waters during construction. Technical challenges such as unexpected deeper seabed trenches requiring additional gravel backfilling also demand careful attention to ensure structural stability.

Samfunnsgevinster og risikoer

The project carries significant societal benefits by drastically reducing travel times between Scandinavia and continental Europe, enhancing freight and passenger transport efficiency, and fostering economic growth in the region. However, it also faces substantial risks, including legal challenges from German environmental groups, which have delayed key permits, and the potential for escalating costs due to these delays. Market analyses suggest that construction postponements could incur annual costs of approximately 500 million Danish kroner, in addition to compensation claims from contractors. Thus, timely resolution of regulatory and technical issues is critical to maintaining the project's viability and timely completion.