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Trans-Oceanic Tunnel

High Speed Train Tunnel for ocean travel
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(+10, -4)
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Now that Europe and Britain have been connected by the Chunnel and other projects of that nature are under study, it's time to consider connecting the continents.

I imagine an underwater tunnel which traverses the ocean. It would be suspended from the ocean floor by wires. The tunnel would sit about 30M (about 100ft) below the surface of the water, deep enough that a large ship would not have any problems passing over it. Also, deep enough so that it would be below the rough seas above. There would be flexible tubes which would go up to the surface every so often for ventilation or as an escape route. The tunnel would be anchored to the ocean floor to keep it from floating up or moving significantly.

I see the tunnel being used solely for high speed trains. A high speed train could traverse the atlantic ocean in about 18 hours. Such trains could carry freight, passengers, and automobiles. It would cut the shipping time between continents to a fraction of what can be done by boat at hopefully a reasonable cost.

The construction would be done in pieces and extruded into place. In other words, as new sections are built, the tunnel is extended or dragged, floating it into place over time. Alternatively, sections could be floating into place and attached to the end.

Superconductors would be used to carry electricity to the center of the tunnel to power the trains and the other tunnel mechanics.

I believe that a similar idea was considered for the Channel Tunnel project but was turned down in lieu of drilling through the chalk beneath the Channel.

The main drawback to this idea is that air travel is very inexpensive compared to the initial cost of building such a tunnel. Air travel is also quicker, but the cost of moving freight by air is expensive compared with land travel via train. It's unclear whether the cost of using such a tunnel would be cheaper.

mgrant, Apr 12 2001

Trans-Lake Washington Tunnel Assessment http://www.wsdot.wa...nnelAssessment2.pdf
A presentation outlining the reasons why a tunnel underneath or through Seattle's Lake Washington is a bad idea. Discusses bored tunnels underneath the lake, sunken tunnels on the lake bottom, and floating tunnels. Notes that no floating tunnels have been built, but that they're theoretically possible. If this highly congested region decides that it's not worthwhile to build a tunnel across Lake Washington, imagine the response to a proposal to build a tunnel across the Atlantic! [egnor, Apr 12 2001, last modified Oct 21 2004]

International Tunnelling Association: Immersed Tunnels Working Group http://www.ita-aites.org/tritu/tritu.html
Some good information and illustrated diagrams on the state of the art in immersed (underwater) tunnel construction. Includes photos of actual immersed tunnels under construction. [egnor, Apr 12 2001, last modified Oct 21 2004]

The Submerged Floating Tunnel http://www.ita-aite...gi?d=tritu&p=p8&s=8
From the site above, but worth calling out. Discusses techniques for floating tunnels. Notes, again, that none have been built, but says that Norway has a floating tunnel project in the design phase. [egnor]

Øresund Bridge Photo Archive http://www.bridgephoto.dk/sund/index.htm
The Øresund Bridge is a recently built connection between Denmark and Sweden. Part of this connection is not a bridge at all, but a submerged tunnel. Navigate using the tree control to "Construction:Immersed Tunnel" to see lots of pretty pictures of a modern immersed tunnel under construction. [egnor, Apr 12 2001, last modified Oct 21 2004]

Øresund Bridge Photo Archive http://www.bridgephoto.dk/sund/index.htm
The Øresund Bridge is a recently built connection between Denmark and Sweden. Part of this connection is not a bridge at all, but a submerged tunnel. Navigate using the tree control to "Construction:Immersed Tunnel" to see lots of pretty pictures of a modern immersed tunnel under construction. [egnor, Apr 12 2001, last modified Oct 04 2004]

Baking... http://www.angel.no...my.co.uk/train.html
...from last Tuesday's Daily Mail (26/06/01) [angel, Oct 04 2004, last modified Oct 21 2004]

Trans-Atlantic cable cart http://www.halfbake...ntic_20Cable_20Cart
derived from this idea [rrr, Oct 04 2004]

Trans-Atlantic Tunnel http://www.scifi.co...sue200/classic.html
disaster movie [Shz, Oct 04 2004, last modified Oct 21 2004]

Trans-Atlantic Tunnel http://www.barterbo...76B80256B8B003B54B4
The book [Shz, Oct 04 2004, last modified Oct 21 2004]

Seikan http://www.pref.aom...line-e/sin-e08.html
One hell of a tunnel; many died building it; losing money [FloridaManatee, Oct 04 2004, last modified Oct 21 2004]

Eurotunnel http://www3.eurotun...gateway_1/index.jsp
Never paid a cash dividend AFAIK [FloridaManatee, Oct 04 2004, last modified Oct 21 2004]

Trans-Atlantic Tunnel http://dsc.discover...ve/interactive.html
54 minutes to traverse, and nice visual. [Shz, Oct 04 2004, last modified Oct 21 2004]

Transatlantys (in french) http://www.transatlantys.com/
Not sure if this is a joke site or not. They claim they're starting constuction in june 2005! 54,000 tube-sections of 110M each to be linked between France and NY. [mgrant, May 29 2005]


       Such a tunnel featured in Starlord's and 2000AD's RoBuster series if I recall correctly. An interesting idea but could be a major problem as terrorists could man a submarine and threatend to torpedo it.
Aristotle, Apr 12 2001

       <pedant> sub-oceanic, surely?

As you point out mgrant, the cost of mobilising resources to carry out your project would be prohibitive if conventional methods were used. But how about unconventional methods? I propose that an inexpensive selective breeding program be undertaken in order to create a species of giant earthworms. These could then be used to dig the tunnel, probably controlled by 'worm cowboys' using cattle prods to make sure that they dig in the right direction.
Hmm! Sounds like a good idea for a science fiction plot line. Now if only I can think of a useful worm by-product...
DrBob, Apr 12 2001

       If 100' isn't deep enough, then I guess it'll have to be deeper, but I suspect that the deeper you go, the more expensive it's going to be to build. I realize that a straight line between Europe and North America takes one pretty far north, but there's no reason a longer, farther southern route couldn't be used except for additional cost. How far south do icebergs come anyway?   

       I think that 150' waves are rare. Most of this harsh activity is close to the surface.   

       I think you're absolutly correct that such an idea needs to be proven by first tackeling a small project.   

       There's nothing wrong with cheap ocean freight for what they do. If you can wait for the boat to arrive, then ocean freight is perfect. Why did they build the Channel Tunnel if there was a perfectly good system of ferries in place? (Many people still are asking this question). It was to cut down the travel time.
mgrant, Apr 12 2001

       The force of the waves is trivial compared to the force of oceanic currents, which, I'd guess, run quite deep. To connect North America with Europe, you'd have to cross the Gulf Stream. I can't imagine any man-made structure that could withstand the force of a relatively rapid cross-current that must be over a hundred miles across.
beauxeault, Apr 12 2001

       I read recently somewhere that the ocean currents are actually not so deep.
mgrant, Apr 12 2001

       Would there really be a danger of it floating? Wouldn't it be more likely to sink?
PotatoStew, Apr 12 2001

       Depends how you do it. See links.
egnor, Apr 12 2001

       Very cool links egnor.   

       I'm not sure I would feel very comfortable driving or riding through a floating tunnel though. I'm sure it would probably be fine, but it just seems a bit too vulnerable.
PotatoStew, Apr 12 2001

       Great links egnor! Looks like this may happen one day!
mgrant, Apr 12 2001

       DrBob: If you're going to be that picky about it, then it's not 'suboceanic', as that would be 'beneath the ocean', where this is just 'beneath the surface'.   

       Waves don't move the water as such; a 150 foot wave is 150 feet above sea level, not preceded and followed by a 150 foot deep trench. But suddenly making the effective depth of the water the tunnel is in 150 feet deeper could cause problems...
StarChaser, Apr 14 2001

       Wouldn't such a tunnel snap? I mean, America is moving away from Europe (or vice versa), so this tunnel would snap and/or would need very frequent maintenance. (This is what happens to transatlantic telephone cables, but snapping tunnels are more dangerous and costly than snapping telephone cables).   

       Having said that, if they can get the trains fast enough and frequent enough and the tunnel strong enough (and succeed in stopping the movement of tectonic plates - this is like Canute trying to turn back the tide), it's a great idea. Just as long as Railtrack don't run it...
simonrose, Jun 29 2001

       You also forgot the mid atlantic ridge!! Highly volcanic and spreading, And very high undersea mountains. Mmmmm
sid, Jun 29 2001

       Groovey idea I totally agree. Hey you can use those Japanese bullet trains and then the trains will be supconducting and very fast.
Monkeyboy2, Jul 26 2001

       baked in 'MASK' (i forget which one but i did have a casette of it)   

       in a documentary i saw it was describing how when (between 10 - 200+ years) 1/4 of the largest of the canary islands will collapse into the sea and cause a 620 metre wave to hit the east coast of america (it has already happened a couple of times in a bay in Alaska with surviving eye-witnesses)
chud, Jul 31 2001

       right now this is imposible not so much because of the distance but because of Geology. The titonic plates on the bottom of the Atlantic and Pacific are always shifting positions. And also bcause of the atlantic ridge, I think there are hundreds of under water gyserss here and also hundreds of volcanoes on the bottom of the Paciffic.   

       An option would be to make the tunnel not lying on the bottom but floating at a mid ocean depth. and have under water elevators on both sides rather than a ramp. This is possible but trust me it would be way to expensive to build, imagine the toll you would have to pay.
wood2coal, Aug 29 2001

       Already suggested by several people. Might want to read the annotations.
StarChaser, Aug 30 2001

       It's all fun and games until the giant squid come along...
Jeremi, Mar 11 2002

       Why the concept of a tunnel? Most of the volume you create for it is not used most of the time anyway. Better have smaller volumes that are launched connected to a cable (which can contain fiberoptic lines at the same time).   

       You sink the line when it is not used (ships and ice can pass) and you let it float when such a 'train' approaches.   

       The train itself is a combination of a submarine and a floating ship. It's main characteristic is that it can cut through water at top speeds. Maybe even flies a little above the water. But when the line can't float (stormy sea, ship, whales or ice in the way) it goes under water just as easily.   

       The cable itself measures, records, films all kinds of things every mile or so. Valuable information for meteologists, oceonographers and those who study maritime life.   

       You can also imagine a way to make the cable generate electricity using the power of the seawaves.   

       [see the link to a seperate entry for this idea]
rrr, Jan 13 2003

       [wood2coal] tell us more about these titonic plates, they sound fascinating. Those gyserss too huh? they can be problematic can't they?
Zircon, Jan 13 2003

       With today's TBM technologies, It's cheaper to tunnel through the seabed than run a straight tube from A-B underwater.   

       There's one mega-long submersible tunnel under the English channel "Euro Tunnel" linking the island of Europe to the continent of Britain; and one linking Hokkaido to Honshu in Japan "Seikan" (links).   

       Neither have proved to be particularly economically successful.   

       Croissant for the application concept, though.
FloridaManatee, Jan 24 2003

       [Rods]: //a 'craft' given a slight boost, would glide to the other side in about 49 mins//   

       The equitorial circumference of the Earth is about 24,902 mi / 40,076 km. Average velocity needed = c. 30,500mph / 49,100kph. Assuming a standing start and constant acceleration, you would need to reach a peak speed of c. 60,100 mph or 98,100 kph within 49 mins. That's 61,000 mph or 98,200 kph, equivalent to an acceleration of 9.3 m/s/s, or roughly equivalent to acceleration due to gravity.   

       In the absence of friction, your craft would only need to overcome momentum forces.   

       In layman's terms, it could reach (and pass) a point on the opposite side of the planet in 49 mins if it were to receive a constant boost equivalent to its own weight for the duration of its journey. i.e. A craft the size of a 1.5 ton car would need 1.5tons of force propelling it. A craft the size of a 100ton train would require 100tons. I guess that was probably your teacher's/ book's analogy.   

       Incidentally, your craft would take only another 20.3 mins to reach its starting point, if it continuted to accelerate at the same rate.   

       If the craft wanted to stop (and could brake as fast as it could accelerate), the trip would require twice the time or require twice the force.   

       There are a couple of teeny flaws in this theory, not least of which is I've never seen a train run on time.
FloridaManatee, Jan 24 2003

       Well if the on board catering doesn't make you hurl, the acceleration/deceleration might make you feel a bit queezy.
briandamage, Jan 24 2003

       Allow me to be the partypooper here: the Eurotunnel is almost bankrupt. It should have begun generating profits long ago, but the whole project seems to become a financial failure.
django, May 29 2005

       "I'm not sure I would feel very comfortable driving or riding through a floating tunnel though. I'm sure it would probably be fine, but it just seems a bit too vulnerable." -PotatoStew   

       And flying miles above the surface of the earth in a hunk of metal makes you feel that much safer?
Weirdo55, Oct 20 2005

       This would work better if it went over the top. With the added benefit of an Arctic cooling system to make the circuitry more efficient. It would also create much needed jobs for Polar Bears. (You'd better not be stingey on the tips though)
Jacob Marley, Oct 21 2005

       Couldn't you run a maglev bed just under the surface of the sea? Possibly not more than just a few inches under, linking the continents. The actual train would never submerge.   

       By putting it a few inches under, this would avoid making the satellite images of earth being uglified.   

       I would also imagine it wouldn't be too difficult to plan the bed so that it can extend and bend to a degree, what with the continents floating around.
Snuffkin, Mar 13 2006

       Except for introducing water resistance to maglev, blocking shipping lanes, supporting it, and the fact that it would show up on satellite images but be difficult for boats to spot, that's a great idea, [Snuffkin]. ;)
Shz, Mar 13 2006

simonj, Nov 30 2007


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