Sognefjord, under the waters of which the proposed infrastructure would pass, is the world’s second-longest one.
Advertisement
Using information and experience from deep sea foundations in connection with bridge constructions, The Norwegian Public Roads Administration (NPRA) announced the plans for their concrete Submerged Floating Tunnel (SFT) back in 2011. The tunnel would shorten the trip to just over 10 hours. Each will be wide enough for two lanes of traffic, and the floating structures should ease the congestion on numerous ferries now required to get commuters from Point A to Point B. Each support pontoon would then be secured to a truss or bolted to the bedrock below to keep things stable. The depth of the fjord prohibits conventional tunnels, but a suspended underwater passageway would split the difference nicely. Planners say that if the long-term models and computer simulations hold up, underwater floating tunnels could cut north-south cross-country drive time in half, from 22 hours to 11 hours.
The structure is officially called a submerged floating tube-bridge but is also known as a Archimedes Bridge.
Traveling along the new route would feel like driving through any other tunnel, according to Arianna Minoretti, a senior engineer with the NPRA.
With minimal above water presence, the tunnels would preserve the landscape’s natural beauty.
Advertisement
Last fall, the administration revisited the proposal for the Bjørnafjorden, a crossing of on the busy route between Stavanger and Bergen, Norway’s second largest city. As long as no errant Russian submarines ram the submerged tunnels, long-distance travel for Norwegians should be improving hugely in the coming decades. But Kjersti Kvalheim Dunham, project manager overseeing the road revamp project told Wired that “Norwegians are quite used to going underwater in tunnels”.
