World’s first underwater floating tunnel could link up Norwegian cities

A new concept of tunnels might cross the country’s beautiful fjords

A new concept of tunnels might cross the country’s beautiful fjords

Norway’s Public Roads Administration (NPRA) has an ambitious planto construct the world’s first floating submerged tunnel system in an attempt to overcome the transportation challenges in the fjords. The tunnel will be part of the E39 Coastal Highway, which is considered by experts to be one of the biggest engineering projects in the world. The highway will connect Kristiansand in the south to Trondheim in the north in just 11 hours. The same journey currently requires 21 hours and includes seven ferry crossings, and it is a rather dangerous trip especially when the weather conditions are bad.

The floating tunnel, which will be built 30 meters (100ft) under the water surface, will consist of two suspended 1,200 m (4,000 ft) curved concrete tubes, supported by pontoons on the surface and kept stable with connecting trusses. Between the pontoons, there would be wide gaps to allow ferries to pass through. This first-of-its-kind structure might also be bolted to the bedrock for extra stability. Every tube will have two lanes, one for traffic and the other for emergencies, maintenance and bike lanes. There will also be ventilation and a light system.

In the beginning, the idea was to build bridges all along the coast by connecting fjords, but it was rejected as this would be impractical and more expensive due to fjords’ large width (3,000 feet) and great depth (more than 4,000 ft). The new E39 Coastal Highway will reduce transport costs and allow easier access to rural communities. If the government decides to proceed to its construction, the $25 billion project will be completed by 2035.

Source: Business Insider

Images: The Norwegian Public Roads Administration