The world’s first floating submerged tunnel system is set to be built in Norway, in a $25 billion infrastructure project that aims to significantly reduce the amount of time it takes to travel across the country.
The route from the southern city of Kristiansand to Trondheim in the north, takes an average driver 21 hours to complete. A total of seven fjords cut into the route. As a result, travelers are forced to take ferries across the wide waterways.
— RT (@RT_com) July 28, 2016
However, if Norway’s Public Roads Administration (NPRA) successfully completes the project, the journey is expected to shorten to just over 10 hours. “This idea of Norway’s is sort of an intermediate technology of things that have been done before,” says Henry Petroski, a Duke University civil engineer who specializes in bridges. The world’s first floating submerged tunnel system about 30 meters (100ft) underwater. The underwater tunnels are said to be the most practical solution to the issue, as many of the waterways are too wide – with the largest being nearly a mile deep – for a typical bridge.
The tunnel system itself will be made up of two 1,200 meter (4,000ft) curved concrete tubes, floating up to 30 meters (100ft) below the surface. The tubes will be held up by pontoons on the surface, while connecting trusses keep them stable. In an effort to provide the tube with extra stability, the structure might also be bolted to the bedrock below.
Meanwhile, on the surface, wide gaps between the pontoons will allow ferries to pass through unhindered.
If you are wondering what It might feel like to drive underwater, the experience is said to feel the same as any other tunnel, according to Arianna Minoretti, a senior engineer with the country’s public roads administration.
The first underwater tunnel will connect Oppedal and Lavik. The tunnel will pass through the 1,300 meter (4,300ft) deep, 1,000 meter (3,300ft) wide Sognefjord.
Although the county regularly experiences rough weather, the NPRA is confident the submerged construction will be able to cope.
“Having this connection means that people there do not have to wait for a helicopter to go to the hospital,” Minoretti says.
As the system is positioned underwater, the surrounding landscape will remain intact, the agency says. The project is expected to be completed by 2035.