Two tunnels? Oookay. Let's add that up, one big duel track tunnel, or two (three) separate tunnels side by side. Personally I'll go with the big one, it may be more expensive, but there's going to be plenty of room in there for maintenance (vacuum maintenance, plus sensors, plus airlocks) and survival equipment, and no possibility of it getting damaged by another tunnel's support cables.
Trans Atlantic Tunnel?
- Thread starter Ironstark
- Start date
No I meant like the small emergency tunnels that are built into the structure of tunnels like in every other tunnel, not like the Chunnel's system with a separate tunnel for the emergency system.
There's no easy way to deal with this question in either direction.
The immersed tube / pipe consists of joint sections. In case of catastrophic failure ( and it shall be catastrophic in any case due to the orbital speeds involved ), simply detach the sections from one another ( after the capsules are safely emergency braked in there... ), shut their open ends closed with iris locks and float them up the surface.
Each section would be like separate double-/triple-walled submarine and there will be active control on their mutual positions. In fact the forces which try to bend the resulting whole pipe could be used as wave-powergens.
Plasma window -- see http://en.wikipedia.org/wiki/Plasma_window
Imagine mesh-pipe as innermost layer. The mesh pipe can hold vacuum or near vacuum while between it and the next solid wall could be played out pressure gradients. Thus the vacuum will be mostly where needed - not everywhere.
Each section would be like separate double-/triple-walled submarine and there will be active control on their mutual positions. In fact the forces which try to bend the resulting whole pipe could be used as wave-powergens.
Plasma window -- see http://en.wikipedia.org/wiki/Plasma_window
Imagine mesh-pipe as innermost layer. The mesh pipe can hold vacuum or near vacuum while between it and the next solid wall could be played out pressure gradients. Thus the vacuum will be mostly where needed - not everywhere.
Oh joy, do you have any idea how much extra costs that's going to add, and how many more chances for leaks to spring up?
Except you need to evacuate each section individually, which is going to add even more costs, and this adds even more power to the already none-too-small requirements, and the sheer complexity is going to raise the costs as well.
JRScott
Banned
As far as rescue goes it would depend on the nature of the failure. However a tug train of some sort that could push or come and pull the train to the destination would probably be the most feasible for engine failure. No matter where it breaks down its no more than around half hour from either end. Each car would be equipped with emergency oxygen mask much like a plane.
Tunnel failure would be another matter, while unlikely it is possible especially after decades under the surface or war. The tunnel would probably be tripled sheathed if not more. Given investment and time you probably could develop remote controlled/robotic entities to maintain and repair the tunnel. Each section would probably have to have emergency doors to close it from the rest, and pumps to pump out the water.
Tunnel failure would be another matter, while unlikely it is possible especially after decades under the surface or war. The tunnel would probably be tripled sheathed if not more. Given investment and time you probably could develop remote controlled/robotic entities to maintain and repair the tunnel. Each section would probably have to have emergency doors to close it from the rest, and pumps to pump out the water.
The notion about "train" and "rails" is wrong.
The rails are the tube itself.
The train consists of separate capsules.
Imagine a bullet in a barrel.
The rails are the tube itself.
The train consists of separate capsules.
Imagine a bullet in a barrel.
JRScott
Banned
I was thinking that's what it was but I was replying to some of their concerns. You probably could still have some sort of tug car that could push or pull the other cars out if they got stuck or something, it might take longer.
My idea of vactubes is similar to what you see in Futurama except instead of people we send them on a train (where they can at least breath during the trip
).Ummm.. exactly what pressure do you have in mind? The Armstrong limit is 62mbar, which is the point at which passengers will die pretty much instantly if exposed to vacuum (blood and other body fluids boil and freeze at the same time – not a nice way to go). As you get a little lower then water leaks will go from a major problem to a showstopper – they’ll boil off instantly leaving ice and salt in any cracks, which in turn will widen them and make the leak worse.
A direct London-New York tunnel will also have power problems. Given that you won’t be able to do proper leak checks, you’re probably going to have a vacuum pump power draw of ~1kW/100m3 of tunnel. From the size of tunnel being proposed, that’s something like 500W/m – so you’re looking at maybe 2000 MW (a big coal fired power station, or two nuclear ones) just providing the vacuum. That’s about the size of the big interconnector between the UK and France – which is relatively new technology to do 20 miles. You’re after it being able to do 2000, even before you start adding in the power loads from trains.
Additionally, pumps need servicing every couple of years (so will need to be based in a service tunnel at atmospheric pressure) and will need to be able to exhaust to atmosphere (so you’ll need a series of buoys to ventilate the exhaust and provide fresh air in the tunnel).
The largest vacuum system on earth is a few hundred cubic metres, or roughly the size of a single 10m concrete section. You’re suggesting building something perhaps five orders of magnitude larger, which needs to be able to flex (something vacuum systems HATE) and will be in a wet environment. On land that’s an enormous engineering task, at sea it’s essentially science fiction for a few centuries to come.
If you’re willing to divert via Iceland and Greenland, the total travel distance doesn’t actually go up by very much (~500 miles on a 3500 mile great circle route). This then allows you to build a series of much shorter tunnels which are technically a lot less challenging. UK-Iceland via the Faroes is ~500 miles with the longest tunnel being about half that. Iceland-Greenland is a similar distance, although you are then faced with a rather long tunnel from Greenland-Labrador. Going via Baffin Island is a shorter and shallower underwater tunnel, but probably forces you to build a similarly long tunnel under the Greenland ice cap.
Total distance is well under half the great circle distance across the Atlantic, and enables use of much better understood technology – the seas are mostly not as deep and the tunnel runs are shorter.
There are also potential benefits to going via Iceland in that they have as much renewable energy as they can sell right now – a tunnel will inherently be a big interconnector anyway, so beefing it up to allow Iceland to supply parts of Europe makes a lot of sense.
A direct London-New York tunnel will also have power problems. Given that you won’t be able to do proper leak checks, you’re probably going to have a vacuum pump power draw of ~1kW/100m3 of tunnel. From the size of tunnel being proposed, that’s something like 500W/m – so you’re looking at maybe 2000 MW (a big coal fired power station, or two nuclear ones) just providing the vacuum. That’s about the size of the big interconnector between the UK and France – which is relatively new technology to do 20 miles. You’re after it being able to do 2000, even before you start adding in the power loads from trains.
Additionally, pumps need servicing every couple of years (so will need to be based in a service tunnel at atmospheric pressure) and will need to be able to exhaust to atmosphere (so you’ll need a series of buoys to ventilate the exhaust and provide fresh air in the tunnel).
The largest vacuum system on earth is a few hundred cubic metres, or roughly the size of a single 10m concrete section. You’re suggesting building something perhaps five orders of magnitude larger, which needs to be able to flex (something vacuum systems HATE) and will be in a wet environment. On land that’s an enormous engineering task, at sea it’s essentially science fiction for a few centuries to come.
If you’re willing to divert via Iceland and Greenland, the total travel distance doesn’t actually go up by very much (~500 miles on a 3500 mile great circle route). This then allows you to build a series of much shorter tunnels which are technically a lot less challenging. UK-Iceland via the Faroes is ~500 miles with the longest tunnel being about half that. Iceland-Greenland is a similar distance, although you are then faced with a rather long tunnel from Greenland-Labrador. Going via Baffin Island is a shorter and shallower underwater tunnel, but probably forces you to build a similarly long tunnel under the Greenland ice cap.
Total distance is well under half the great circle distance across the Atlantic, and enables use of much better understood technology – the seas are mostly not as deep and the tunnel runs are shorter.
There are also potential benefits to going via Iceland in that they have as much renewable energy as they can sell right now – a tunnel will inherently be a big interconnector anyway, so beefing it up to allow Iceland to supply parts of Europe makes a lot of sense.
Freight trains on a transatlantic tunnel
A 3500 mile tunnel with freight trains travelling at 100mph =36 hours to cross. Remote controlled (unmanned trains would be the answer).
Costs and speed.
The tunnel would have to compete with sea freight price wise and offer a similar point to point speed to air freight which is 10 -20 times more expensive per ton.
Technical and safety challenges are
1. How do you clear a freight train derailment 1600 miles out in the atlantic in a large metal tube possibly with a fire?
2. The Tunnel if floating will need to be located deeper than any iceberg that will float by.
3. How do you stop a large freighter from sinking above the tunnel and then crashing into it on its way to the bottom?
4. How do you prevent submarines crashing into the tunnel again with an accident?
5. Who would have territorial jurisdiction over the tunnel 1000 miles off shore in international waters?
6. How do you stop Al Qaeda or a James Bond "Blofeld" character from attacking the tunnel Depth charges or bomb in a freight container?
A Version of Isabad Kingdom Brunels vacuum system might be the answer from GWR where by the containers are torpedo shaped and are fired by pressure/ vacuum along the tunnel in a similar way to a "Pig" that are used to clean oil pipelines today. It would only really be viable as a freight link.
My preference for travel would be a metal tube 7 miles above the earth rather than 1 mile below !!
A 3500 mile tunnel with freight trains travelling at 100mph =36 hours to cross. Remote controlled (unmanned trains would be the answer).
Costs and speed.
The tunnel would have to compete with sea freight price wise and offer a similar point to point speed to air freight which is 10 -20 times more expensive per ton.
Technical and safety challenges are
1. How do you clear a freight train derailment 1600 miles out in the atlantic in a large metal tube possibly with a fire?
2. The Tunnel if floating will need to be located deeper than any iceberg that will float by.
3. How do you stop a large freighter from sinking above the tunnel and then crashing into it on its way to the bottom?
4. How do you prevent submarines crashing into the tunnel again with an accident?
5. Who would have territorial jurisdiction over the tunnel 1000 miles off shore in international waters?
6. How do you stop Al Qaeda or a James Bond "Blofeld" character from attacking the tunnel Depth charges or bomb in a freight container?
A Version of Isabad Kingdom Brunels vacuum system might be the answer from GWR where by the containers are torpedo shaped and are fired by pressure/ vacuum along the tunnel in a similar way to a "Pig" that are used to clean oil pipelines today. It would only really be viable as a freight link.
My preference for travel would be a metal tube 7 miles above the earth rather than 1 mile below !!
The OP called for a trans-Atlantic rail tunnel to be built BEFORE 2012, and know people are raising all sorts of potential solutions based on technology that either doesn't exist yet or has never been scaled to anything close to this size.
Plasma windows are highly expensive and have only been used for small dimension applications. You can't just say plasma windows will fix it without considering a couple of serious problems with them -
i) no one has generated a plasma window the size you are talking about to cover how many square meters of section of tubing, let alone tried to maintain one in an ocean,
ii) you're going to need two of them for each section of tube, how many tens of thousands will that be?
iii) and how much does that cost?
iv) since this is the passengers safety net you're going to have to keep those plasma windows all maintained to a high state of reliability otherwise the bad press and insurance premiums will kill the project. I've worked with high electric and magnetic fields much lower than what you would need for a plasma window, and I know people who work with plasmas. The technology breaks down all the time even in a carefully controlled research lab, trying to maintain thousands of these systems remotely in the middle of the ocean is just not feasible today.
v) if (when) you spring a leak remember to keep all the electrical systems and magnets required to generate your plasma window thoroughly waterproofed or it won't work. That's a technically solvable problem but further increases weight, costs and risk of a disasterous failure.
Robots may one day be able to automatically service breakdowns but not yet, so that's another technological leap required.
Current maglev trains still use tracks, at least as far as I know, so this 'bullet in a barrel' approach is further untried technology, particularly on this scale. It might work, but if it doesn't work 100% of the time what do you do?
The general idea for designing escape routes requires them to be independent of the system you want people to escape from, in case that's blocked or dangerous, so I think that means you need a second independent tunnel. Even then the people are trapped in a tube underwater so you need to get them out of there asap.
I still don't see how your articulated tunnel will cope with the forces exerted by currents and tides? At least articulation means it can flex and so better withstand oceanic stresses but that means the tunnel will adopt a series of curved, and probably moving trajectories. How much of an angle between connecting sections can a high speed train torrelate before it hits a wall and destroys the entire thing? I suspect that the answer is no one knows because this has never been tried before.
How far apart are the cables that tether the tunnel to the ocean floor? How many of those can fail before the tunnel becomes unstable? If a suboceanic earthquake or landslide pulls one or more of these down and the tether doesn't break can the tunnel withstand that new vertical stress? I know that many enginnering problems have solutions but the main problem with the trans-Atlantic tunnel idea is that just one mistake or accident could easily destroy the whole thing and kill thousands of people. So every single component of a very complex construction using unproven technologies must work every single minute of the day, or be supported by reliable backup systems, or the risks are too great. At least with our current technologies.
A minor point - if this tunnel was built doesn't that then become a major shipping hazard to any submarine?
Plasma windows are highly expensive and have only been used for small dimension applications. You can't just say plasma windows will fix it without considering a couple of serious problems with them -
i) no one has generated a plasma window the size you are talking about to cover how many square meters of section of tubing, let alone tried to maintain one in an ocean,
ii) you're going to need two of them for each section of tube, how many tens of thousands will that be?
iii) and how much does that cost?
iv) since this is the passengers safety net you're going to have to keep those plasma windows all maintained to a high state of reliability otherwise the bad press and insurance premiums will kill the project. I've worked with high electric and magnetic fields much lower than what you would need for a plasma window, and I know people who work with plasmas. The technology breaks down all the time even in a carefully controlled research lab, trying to maintain thousands of these systems remotely in the middle of the ocean is just not feasible today.
v) if (when) you spring a leak remember to keep all the electrical systems and magnets required to generate your plasma window thoroughly waterproofed or it won't work. That's a technically solvable problem but further increases weight, costs and risk of a disasterous failure.
Robots may one day be able to automatically service breakdowns but not yet, so that's another technological leap required.
Current maglev trains still use tracks, at least as far as I know, so this 'bullet in a barrel' approach is further untried technology, particularly on this scale. It might work, but if it doesn't work 100% of the time what do you do?
The general idea for designing escape routes requires them to be independent of the system you want people to escape from, in case that's blocked or dangerous, so I think that means you need a second independent tunnel. Even then the people are trapped in a tube underwater so you need to get them out of there asap.
I still don't see how your articulated tunnel will cope with the forces exerted by currents and tides? At least articulation means it can flex and so better withstand oceanic stresses but that means the tunnel will adopt a series of curved, and probably moving trajectories. How much of an angle between connecting sections can a high speed train torrelate before it hits a wall and destroys the entire thing? I suspect that the answer is no one knows because this has never been tried before.
How far apart are the cables that tether the tunnel to the ocean floor? How many of those can fail before the tunnel becomes unstable? If a suboceanic earthquake or landslide pulls one or more of these down and the tether doesn't break can the tunnel withstand that new vertical stress? I know that many enginnering problems have solutions but the main problem with the trans-Atlantic tunnel idea is that just one mistake or accident could easily destroy the whole thing and kill thousands of people. So every single component of a very complex construction using unproven technologies must work every single minute of the day, or be supported by reliable backup systems, or the risks are too great. At least with our current technologies.
A minor point - if this tunnel was built doesn't that then become a major shipping hazard to any submarine?
Yeah, because 1,500 miles is just a stroll to the shops.[/sarcasm]. Also, maglevs (rails wouldn't take the top speed), any power failure is going to be in the rail, which is going to mean metal-on-metal at probably between several hundred and several thousand mph. Not pretty.
The tunnel's floating in water, and due to having an internal diameter of at least 6m, will have to be built in sections.
Sheathed in what?
The tunnel has two have two sets of tracks, eastbound and westbound, so that's not going to work. Additionally, for speeds exceeding 3,000 mph (that's just your average), you're really going to be looking at mag-levs.
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JRScott
Banned
You have to understand what could have been done if 1% GDP had been applied to the project over decades, some of that would be R&D in fact construction would not start for at least a decade, it would be pure research the first decade.
That's largely a problem here because no one pursued them it is difficult to know what solutions would have been solved through R&D. Though I don't believe plasma windows would be possible in the time frame , I do believe vactrains would of been.
JRScott
Banned
You ever seen an old style message delivery system. Where you put the message in a container (usually metal cylinder) then pop it into a tube where it goes to its destination. Vactrain would work similar, in essence its a big vacuum cleaner. The message systems used stops. Obviously with a train you don't want to pull that much Gs. So you'd probably use electromagnets to slow down the train as it reaches its destination. Failure of that system could cause electromagnets on the train to be activated as a fail safe. As a third and final fail safe you could have a stop designed in such a way it could absorb the force without destroying the train or its passengers, probably a crumple zone on the stop to absorb impact.
Sheathed as in multiple layers with air between them, such that you'd have to penetrate all layers to affect the actual train.
As for a loss of vacuum power causing the train to get stuck half way, there's nothing preventing you from building a tug vehicle that can move out on its own power to tow or push it to the closest terminal. The train with oxygen masks and emergency food/water supplies could probably survive up to 72 hours for rescue which would be more time than they'd need. Safer than the Shuttle program was....
ahunter951 raises a series of other good questions.
1. That's the main problem, how do you deal with an accident or even an electrical fault in the middle of the ocean? I don't know.
2. I had wondered about icebergs too. I suppose if the tunnel was located far enough south that reduces that risk, but that has consequences too - added length, cost, and you then have to include other nations. Also, to what depth below the waves do the effects of a hurricane extend?
3. I don't think you can other than cross your fingers, shipping will cross the tunnel on a daily basis.
4. Ban submarines??
5. Sensible question about legal issues but probably the least serious issue at this stage.
6. Again, cross fingers. A trans-Atlantic tunnel is just too long to patrol effectively.
I agree that anything like these, were it feasible one day, would be better as an autometed freight transport system.
pdf27 also raises a good point that flexible containers don't hold a vacuum very well - the leak problem just gets worse and worse. Regular vacuum pumps need servicing every few years but high vacuum pumps are more temperamental. Actually that's another point - where are the pumps housed? In floating pontoons across the ocean?? You'd need a lot of pumps and they need to be close to the section that they are responsible for as it takes a long time to pump down a volume of space. Once you get down to a few millibars of pressure then reducing the pressure further becomes a matter of statistics as you are waiting for molecules to randomly wander out of the evacuation chamber. The longer the evacuation line i.e. the further the pump is from the chamber then the longer that takes. In lab-based high vacuum chambers of less than a cubic metre in volume with a few metres of narrow gauge tubing connecting to the pump, it usually takes quite a few hours to generate a proper vacuum.
1. That's the main problem, how do you deal with an accident or even an electrical fault in the middle of the ocean? I don't know.
2. I had wondered about icebergs too. I suppose if the tunnel was located far enough south that reduces that risk, but that has consequences too - added length, cost, and you then have to include other nations. Also, to what depth below the waves do the effects of a hurricane extend?
3. I don't think you can other than cross your fingers, shipping will cross the tunnel on a daily basis.
4. Ban submarines??
5. Sensible question about legal issues but probably the least serious issue at this stage.
6. Again, cross fingers. A trans-Atlantic tunnel is just too long to patrol effectively.
I agree that anything like these, were it feasible one day, would be better as an autometed freight transport system.
pdf27 also raises a good point that flexible containers don't hold a vacuum very well - the leak problem just gets worse and worse. Regular vacuum pumps need servicing every few years but high vacuum pumps are more temperamental. Actually that's another point - where are the pumps housed? In floating pontoons across the ocean?? You'd need a lot of pumps and they need to be close to the section that they are responsible for as it takes a long time to pump down a volume of space. Once you get down to a few millibars of pressure then reducing the pressure further becomes a matter of statistics as you are waiting for molecules to randomly wander out of the evacuation chamber. The longer the evacuation line i.e. the further the pump is from the chamber then the longer that takes. In lab-based high vacuum chambers of less than a cubic metre in volume with a few metres of narrow gauge tubing connecting to the pump, it usually takes quite a few hours to generate a proper vacuum.
Not really. This is a common misconception, but high levels of vacuum are not instantly lethal. Death by decompression is deadly enough, but it's not instant. Human body can survive one-two minutes of exposure to vacuum (well, as long as you don't have any open wound, then you will lose most of your blood quickly, and you have to actively hold your breath, not just stop breathing but block your orifices). Loss of consciousness is another matter should have happened earlier.
Also it's impossible to suffer freezing out of decompression, short or long term. In fact, vacuum is one of the best thermal insulators. Freezing means that you transfer your heat, the vibrational-kinetic energy of your atoms, to other particles with very low kinetic energy. In a good vacuum, there are very little particles to transfer energy to.
A surprisingly realistic example is what happens in 2001 when Dave Bowman must exit the space capsule to manually open the doors of the Discovery. He's wearing a spacesuit but without helmet, so he's basically doing an EVA without spacesuit as protection. Space is cold, very cold, -270ºC in the interstellar medium, and only a few degrees higher in the Jupiter/Saturn orbit. But because it's almost empty, without particles to rob you of your heat, there is no way to get frozen fast.
If i'm not wrong, in the vacuum, you first lose consciousness due to asphixia, then you die either of asphixia or decompression. And if you are on the space, after like 45 mins, the tissues of your corpse that are still at an hydrostatic pressure of 1atm, freeze (the tissues that have ruptured, instead, had their water boiled away much earlier).
Vactrains may indeed be possible, but this project would try to set one up under the most difficult of environments where one mistake means disaster. That's the main problem.
Just saying that spending 1% of GDP for a few decades on the R&D will solve the problems is not realistic. I am a scientist, I do research, but often challenges are not simply solved just by throwing more money at them. More funding certainly helps but it's far from a guarantee of success. With the various technical solutions required to make this project even technically feasible, 1% of GDP wouldn't be enough. Scientific funding is typically a few percent in most developed countries and we aren't close to making anything like this a reality.
Just saying that spending 1% of GDP for a few decades on the R&D will solve the problems is not realistic. I am a scientist, I do research, but often challenges are not simply solved just by throwing more money at them. More funding certainly helps but it's far from a guarantee of success. With the various technical solutions required to make this project even technically feasible, 1% of GDP wouldn't be enough. Scientific funding is typically a few percent in most developed countries and we aren't close to making anything like this a reality.
Stick a cup of water in a bell jar and pump it down. It will freeze within seconds if you've got a big enough pump on there. Human body is a bit tougher, but unless you're wearing a positive pressure mask then it'll start boiling off on the surface of your lungs and that will probably break some capillaries/veins open quite rapidly.
Not going to work, a mag-lev would be more efficient, and probably faster.
How are you fitting the sheath in place? And what's the sheath made of?
But more deaths and more expense if something goes wrong, and things are much more likely to go wrong.