Norway's floating tunnel concept is both brilliant and terrifying

[Stephane Dumas]

I saw that article on Autoweek about the proposed floating tunnels in Norway. http://autoweek.com/article/technology/norway-plans-worlds-first-submerged-floating-bridges

[Chris]

This report has surfaced on many media outlets, not one bothers to do any fact checking.

The quoted $ 25 billion is not for this single crossing, but a large number of fjord crossings in western Norway as part of the 'ferry-free E39' that spans 1100 kilometers from Kristiansand to Trondheim.

Furthermore, the floating submerged tunnel is just one of several solutions being explored for the Sognefjord crossing. Others are a very long suspension bridge (4 km) or a 22 kilometer tunnel that makes a U-turn to cross a section of the fjord that is not as deep. These are 'conventional' (but record-breaking) solutions. Other non-conventional solutions are floating bridges, for example a pontoon bridge with a larger floating cable-stayed bridge for shipping, or a multi-span floating suspension bridge. Norway already has a few floating bridges.

[cpzilliacus]

Furthermore, the floating submerged tunnel is just one of several solutions being explored for the Sognefjord crossing. Others are a very long suspension bridge (4 km) or a 22 kilometer tunnel that makes a U-turn to cross a section of the fjord that is not as deep. These are 'conventional' (but record-breaking) solutions.

Was this the  proposed suspension span in Norway that would feature skyscraper-scale suspension towers?

[Chris]

A conventional suspension bridge would require a 4000 meter main span (twice the current longest span) and towers between 450 and 500 meters tall, which is higher than the roof of the new World Trade Center.

So they're looking at floating suspension bridges, which would be anchored with cables to the bottom of the fjord. Norway has a lot of experience with this kind of technique due to the large offshore oil industry, though a large-scale floating suspension bridge has never been built before. There are a few other floating bridges in Norway, including a cable-stayed bridge (though the main pylon is on land).

[nexus73]

The Fjord Freeway would be an interesting drive for both the natural and manmade aspects. 

Will there be a spur to Murmansk?  LOL!

Rick