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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.
Do tell!
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.
What sort of failsafes are in place for a tunnel section collapsing? Are there emergency bulkheads that can shut to keep the rest of the tube network from filling if a single segment/module fails?
If not, have they factored in the cost for evacuating and repairing the tunnels in the event of a module failure? If not have they factored in the lost time and cost should they have to return to ferries for the months and/or years it would take to repair and empty one of these tunnels should it fail and flood?
Inquiring minds want to know!
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.
Do you really have to link to some other news site that only repeated stuff? Can't you follow the chain and link to the original source?
I tried: Slashdot quoted TheNextWeb who quoted Hackaday who quoted Wired who quoted [disable your adblocker to know the end of the story].
I thought that the bridge would be above water and be supported by tubes that were below the surface and anchored to bed rock. I did not assume that the tubes carried traffic.
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.
Ask Sweden, they're real! Maybe!
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.
These two tiny cities of Trondheim and Kristiansand appear to be about 11 or 12 hours apart by car. The combined population of both cities is under 300,000. If somehow some improvement in transportation is needed between these two places it would probably be cheaper to set up a subsidized airplane service than build tunnels or floating submerged bridges.
https://www.google.com/maps/dir/Kristiansand,+Norway/Trondheim,+Norway/@58.2811154,8.0353103,10z/data=!4m13!4m12!1m5!1m1!1s0x46380258d5607a5b:0xdf0c0d6fc81c58a4!2m2!1d8.0182064!2d58.1599119!1m5!1m1!1s0x466d319747037e53:0xbf7c8288f3cf3d4!2m2!1d10.3950528!2d63.4305149
I don't think I'd feel safe about driving in this. What if it is hit by a ship or gets a leak or a giant wave or storm disrupts it?
You stated ...building normal bridges would cost significantly less ... which means normal bridges would be the sensible choice, by default, no matter the fjords and difficult terrain!
So, all they have to do is take a sub up a very long fjord with a very narrow entrance and then spend hours getting out again during a time of war.
There were anti-submarine measures like booms and nets at narrow inlets a century ago during World War One FFS!
You may want to remove your "missing an idiot" sig for utterly stupid posts to avoid a truly epic failure.
ithinkthatwebsitecoulddowithsomedashesorunderscoresintheirpagenames.html
They would figure out the maximum load capacity and design the tunnel size such you couldn't overwhelm the integrity and any one point (at least as far as the line of brick trucks theory goes).
Of course, they want to connect closer towns, but this conversation is reminding me of Norway. Norway is such a great place.
"First they came for the slanderers and i said nothing."
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.
I am pretty sure this should be "Kristiansund" and not "Kristiansand". The road from Kristiansand to Trondheim goes over no fjords, but rather cross-country. Kristiansund is another issue with ferry rides all the time.
Why do they want to further encourage automobilism, instead of trains? Apart from the environmental pollution, driving 21 or even 10 hours is stupid and dangerous, because of course nobody is taking intermediate rests, but pushes to absorb the whole trip in one long etap with, max. 5 minutes spent at the gas pump. They get tired and crash. With well-regulated industries like railways and airlines, the safe work and rest balance of crews is strictly enforced.
...until another Joe Hazelwood drives another Exxon Valdez into one of the pontoons, breaking the tunnel, flooding it in mere seconds, and killing everyone inside. Will this captain cry to the Nordic appeals court that he's not responsible because he called for help before the collision? That strategy kept good ol' Capt. Hazelwood out of jail. Will Norway's system of justice work better than USA's? Given that I'm an American, how embarrassing would that be?
Trondheim and Sor-Trondelag accounts for 75% of Norway's GDP. Salaries there match the South Coast of England.
Why is this better than sitting the tubes on the bottom?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Yes. They also spent more time asking those questions than you did.
They also thought of several completely different solutions and no final decision has been made yet.
a trip from Kristiansand to Trondheim (680 miles)
fact: The distance is 808 km (~ 502 miles).
due to the seven ferry trips required along the way
fact: There are no ferry trips on the shortest route.
could take as long as 21 hours [...] This $25 billion tunnel project could cut the trip time to just 10 hours by 2035.
fact: Today it already only takes 10h48m.
As others have mentioned, the article fails to metion that this is ONE of FOUR proposals - AND it is a solution for a connection up along the west coast.
What would engineers do without the smart people on Slashdot! I think you just single handidly averted a disaster.
Here's another interesting project they're cooking up... a Ship tunnel which is, if anything, more impressive.
Picture
Isn't the central norwegian road regularly closed in winter?
Yes, the point is connecting the coastal cities but it does provide all-weather paths where ferries and existing roads cannot.
If you are driving from Kristiansand to Trondheim wouldn't you just take E18 over to Oslo and then Route 3 up to Trondheim?
If they do this right, they can convert these to hyperloop instead of slow cars.
I prefer the "u" in honour as it seems to be missing these days.
Much of the ferry traffic is tractor trailers full of heavy goods. Tunnels or bridges would provide much faster, more reliable, and lower cost transport.
Man, you really need that seminar!
Boy, can you imagine one of these springing a leak?
Those are my principles, and if you don't like them... well, I have others.
Great, now we need the Northern Canada to Greenland and Greenland to France or Scotland tubes so we can drive to Europe.
The system of having an underwater roadway suspended from floating pontoons sounds a whole lot cheaper to install than extensive hyperbaric work in caissons to install a tunnel on the floor of a waterway. You would only need short sections of underwater tunnel anyway. Just enough to allow for a shipping channel. The rest of the transit could be floating pontoon roadway as has been used for decades. On the other hand, having the whole span underwater minimizes storm effects on the roadway.
How deep would the underwater section need to be? Hmmm, the record for keel depth is 28.5 meters.
https://en.wikipedia.org/wiki/Batillus-class_supertankers
Are we missing any other factors? http://ascelibrary.org/doi/abs/10.1061/9780784407707.ch06
Putting a hefty margin of error on it; go for a nominal 50 meter depth. What is the water depth in the proposed channel?
If you consider the depth of some of the fjords in Norway; it becomes patently obvious why you would consider floating subsurface tunnels. It is too bloody deep to put one on the floor of the ocean in many places.
"Norway's Hardangerfjord drops to 2,624 feet (800 m) below sea level, while the depth of Sogn Fjord (also Norway) measures 4,290 feet (1,308 m) deep, and Canal Messier in Chile is 4,167 feet (1,270 m). The great depth of these submerged valleys is due to their glacial origins.Oct 31, 2013"
http://www.newworldencyclopedia.org/entry/Fjord
A very interesting proposition. Very much a problem in dynamic engineering.
NRRPT/RCT