They’d hang about 70 to 100 feet below the water’s surface.
Due to Norway’s geographical features — the land has over 1,100 fjords, which are deep glacial water inlets that divide land masses — it can be particularly difficult for drivers to get from one place to another.
Working towards a solution to the problem, Norway has plans to build a completely submerged floating traffic tunnel beneath Sognefjord, a large body of water that runs 3,300 feet wide and 4,300 feet deep.
The Norwegian Public Roads Administration will be overseeing the ambitious project, and this marks the first time in history that such a project will be attempted.
Credit: NPRA / Vianova
The structure will consist of two curved concrete tubes, about 3,940 feet (1200 meters) long, connected to massive floating pontoons to stabilize the structure. The tubes would allow for uninterrupted traffic in both directions of the underwater tunnel, and the enclosed motorway would hang about 70 to 100 feet below the surface of the water.
An advantage to the underwater tunnels is that they would keep the waterway clear for commercial ships and Navy vessels. What’s more, the planners say that long-term models and computer simulations suggest that the underwater tunnels could cut the cross-country drive time in half, from 22 hours to 11 hours.
The tunnel would improve the quality of life for many nearby inhabitants who can end up stranded from the water-restricted area. “Having this connection means that people there do not have to wait for a helicopter to go to the hospital,” Arianna Minoretti, a senior engineer on the project, told WIRED.
Norway has already pledged $25 billion in funding money towards the project, and if all goes according to plan, the underwater tunnels will be completed by 2035.
Then, depending on the success of the new structure, Norway will consider installing additional floating tunnels to help smooth out the problems with their unique geographical location.
“For an engineer working on this structure, it’s like being on the Discovery Channel every day,” Minoretti said.
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