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Norway Is Building The World's First 'Floating' Underwater Tunnels (thenextweb.com)
An anonymous reader writes from a report via The Next Web: Norway plans to build "submerged floating bridges" to allow drivers to cross its bodies of water. The Next Web reports: "The 'submerged floating bridges' would consist of large tubes suspended by pontoon-like support structures 100 feet below water. Each will be wide enough for two lanes of traffic, and the floating structures should ease the congestion on numerous ferries currently 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." A trip from Kristiansand to Trondheim is roughly 680 miles and could take as long as 21 hours due to the seven ferry trips required along the way. While building normal bridges would cost significantly less than the $25 billion in funds required for the tunnel project, the fjords and difficult terrain make them unsuitable candidates. The pricey tunnel project could cut the trip time to just 10 hours when it's expected to be finished in 2035.
San Francisco's Transbay Tube does this. It's a bunch of segments bolted together, and then it was weighted down with thousands of pounds of granite fill/gravel and they pumped all the water out of it. The bottom of the San Francisco bay is pretty flat and muddy compared to Norway, I suspect, so they just let it sit on the bottom, rather than precariously suspend it in the water(?!?)
https://en.wikipedia.org/wiki/Transbay_Tube
moox. for a new generation.
Such a tunnel seems to be an even easier target for a Russian submarine or a well-equipped terrorist, than a regular bridge or a tunnel in solid soil.
And the results will be spectacular — once a wall is breached, everybody inside drowns... No escape, no rescue... Unless, maybe, individual segments can somehow be made to self-seal and automatically surface in an emergency.
In Soviet Washington the swamp drains you.
Buoyancy making the tunnel 'want' to move towards the surface, but since it's secured to structures on the bottom it doesn't get to come all the way up.
-=This sig has nothing to do with my comment. Move along now=-
Do you also think that cruise liners and battleships and so on don't float because a portion of the structure is under water?
A trip from Kristiansand to Trondheim is roughly 680 miles
So the road to Trondheim will be a series of tubes? Ted would be proud.
As described in Harry Harrison's prophetic _Tunnel Through the Deeps_ (also published as _A Transatlantic Tunnel, Hurrah!_)
sPh
You can already make this trip on a highway that is 4 lanes for a large portion of it by going up through oslo and central Norway. The reason it would take so long with the path they are wanting to connect is that this path is along the coast. Even after getting rid of the ferries it's still going to be winding and longer mileage. I suppose the coast might be a bit warmer and less likely to have winter conditions, but a gale along the coast already shuts down the highway in quite a few parts as it is.
They really just want to connect all the cities along the coast without having to take a ferry (down if bad weather) or having to drive a hundred kilometers or more inland and back out again.
No need to jump to the terrorism scenarios. Consider a ship riding lower than expected (sinking), a fishing net or other debris caught on a shipt, stormy seas moving heavy debris around, etc..
A whole lot of bad can happen, but people will I assume be happy with the risk.
-The wise argue that there are few absolutes, the fool argues that there are no probabilities.
Here is Norwegian Public Roads Administration video of the proposals. The underwater tunnel is one of the four proposals https://www.youtube.com/watch?... (great watch)
There is no decision on which of those will be implemented yet. Article is simply running with the fanciest option.
What would engineers do without the smart people on Slashdot! I think you just single handidly averted a disaster.
Submarines float underwater...
Yes it's an anecdote! Were you expecting original research in a Slashdot comment?
Here's another interesting project they're cooking up... a Ship tunnel which is, if anything, more impressive.
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