You weould need aitlocks ever y while, in case of breaks. Also, you would need motels/hotles/food/gas stations.
Trans Atlantic Tunnel?
- Thread starter Ironstark
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Airlocks would be needed, yes, with some sort of automatic control, ans just hope the stem works perfectly every time because the door only has to be closed at the wrong time once and the whole thing's gone. Also, lot's and lots of sensors to detect any water, which is going to add both cost and power, on top of the airlocks.
I don't think this train is a good idea, not in the way it's presented in the video anyway. But i think it's an inevitability. Not as a single lifeline between New York and London, but as an extensive worldwide network of maglevs, that would eventually include transoceanic bridges.
Unless we finish the biosphere off early, this planet still has more than a couple thousand million years ahead, so don't discount it so fast. And while we live here, there's no need for us to go and fetch stuff presentially, that's what unmanned spaceships are for. By the point we need minerals from the asteroid belt, we will surely have decent enough AIs as to do the job without human supervision. So the need for a space elevator and orbital ring isn't immediate, and certainly, designing them to be habitable is a waste of money. Maybe for turists...
I am think it's more likely that the reduction of the price of creating maglev networks happens much sooner than the space elevator.
Of course, it doesn't matter that the trip between NY and London lasts one hour if moving from the maglev station to the city center takes two. We might want to solve the problem of traffic first.
I doubt it, running a length of vacuum tunnel underwater for any distance is just asking for trouble, and a bridge is little better. Personally my money's on a Bering Strait bridge/tunnel, which would be fairly expensive (proposals come to 66 billion all told (including building connections to existing networks), and that with technology that's pretty much around today.
Never underestimate the limits of human stupidity, it's quite possible we will screw the biosphere up in short order.
There was a norwegian fjord crossing that did extensive work on this tech, although they apparently did something else.
If we could get 500 passengers a train, leaving every half hour or so, thats about 25k passengers per day or 9M passengers per year.
If the capital cost is 180G$, and we paid off 5% per year, interest and capital, a low figure, a one way trip would be 10000$ just for capital cost, without figuring iin operating expenses.
Very pricy tickets. So, no i dont see it being at all economical.
If we could get 500 passengers a train, leaving every half hour or so, thats about 25k passengers per day or 9M passengers per year.
If the capital cost is 180G$, and we paid off 5% per year, interest and capital, a low figure, a one way trip would be 10000$ just for capital cost, without figuring iin operating expenses.
Very pricy tickets. So, no i dont see it being at all economical.
A couple of billion years? I think that might be reaching a bit, the Earth is going to suffer some pretty major changes before the Sun starts really expanding. According to Wikipedia, increased solar radiation in around a billion years is going to evaporate the oceans, and another 600 million is going to see all life die out.
Still, that's a long way off.
This is a really good point. If these trains are supposed to be any kind of replacement for aeroplanes, you're going to recreate the congestion you see in and around airports on a massive scale. It's not enough to move people from one specific place to another really quickly, you have to more them from where they are to where they want to go quickly.
What kind of trains are people thinking of though? The proposals I found in a quick googling show small capsules where people are just strapped in for the ride, which is a very different prospect from just making a very fast train. If London to NY in an hour is the benchmark, I think it would be possible to create a pretty normal train experience, at least looking at what's happening in the cabin alone. That's about 0,1g acceleration, if my calculations aren't completely messed up. (Wouldn't surprise me if they are, I really need to get something to eat.) The larger cabin/capsule might represent a technical issue though.
Such a system also seems less flexible than airtravel to me, since it's reliant on everyone travelling through some very specific corridors. In comparison, air travel allows some degree of adjustment in case of disasters/other issues, by routing around affected areas more easily. Perhaps those supersonic submarines I've been hearing about would be a better idea?
I doubt we'll completely screw it up, but enough to screw over Mankind doesn't seem completely unreasonable. Especially not if you can settle for civilization to fall apart enough that we can't dig ourselves out of the hole again. We have used up quite a lot of natural resources, especially the ones that were easy to get to. If we somehow regressed into an early-industrial society I'm not sure we really have the resources to claw our way up again.
Yes, 600 million years or several billions is really the same thing, for the increase rate of our technology and ability to gather and manipulate energy. But i thought that our biggest problem was the Sun going red giant... could you tell me which wiki article is that?
It is way less flexible than airtravel. Especially because of the long acceleration/deceleration times. The advantages train have even in medium distance transport over planes is that they have several stops, and you can get quicker to your destination than trying to find the nearest airport and then grabbing a bus. The trans-atlantic tunnel negates this advantage, unless...Such a system also seems less flexible than airtravel to me, since it's reliant on everyone travelling through some very specific corridors. In comparison, air travel allows some degree of adjustment in case of disasters/other issues, by routing around affected areas more easily. Perhaps those supersonic submarines I've been hearing about would be a better idea?
Sci-fi time: if we are going to go to a future where maglevs can be created cheaply and extensively, we might have learned by then how to reduce the mass of bodies. Doing so, if we reduce the mass of the train (including the passengers), accelerations and speed can be made much higher, making the maglev trip from NY to London in roughly 5 minutes, including one minute to board and one to leave the train
Btw, better than submarines would be the suborbital spaceliners. I don't know if they would be efficient for "short trips" like the transatlantic one, but longer distances, like 1/3 of the Earth circumference or more could be done in time windows of one hour, according to marketing
And at least, the Bering strait doesn't expand between 1 and 10 cm per year... which could put severe strain on the tunnel-bridge-whatever very very fast.
I'm fairly confident on humanity
I think we bypassed our worst crisis, which was the first development of weapons capable of causing our own extinction. We are also more conscious of our damage to the biosphere than ever before, and we are taking our first baby steps to become more like shepherds of the biosphere and less like locusts.
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As to the bering bridge/tunnel- a bit more realistic but utterly pointless and uneconomic.
This is a big problem with such projects, what seems awesome in theory in practice isn't. Sure, it may be technically possible to take a train from LA to Shanghai with such a crossing...but who on Earth is going to do that? It'll take forever?
I see the same problem with the sometimes muttered about Great Britain-Ireland crossing. So many people like to place this at the shortest crossing, between Northern Ireland and Scotland- when the only place it could begin to be economical would be one of the Wales-Dublin area routes despite this on paper seeming much harder and more expensive.
This is a big problem with such projects, what seems awesome in theory in practice isn't. Sure, it may be technically possible to take a train from LA to Shanghai with such a crossing...but who on Earth is going to do that? It'll take forever?
I see the same problem with the sometimes muttered about Great Britain-Ireland crossing. So many people like to place this at the shortest crossing, between Northern Ireland and Scotland- when the only place it could begin to be economical would be one of the Wales-Dublin area routes despite this on paper seeming much harder and more expensive.
The aptly named Timeline of the far future:
http://en.wikipedia.org/wiki/Timeline_of_the_far_future
Haven't checked the citations, because it's not like it truly matters like you say. The gist is that the sun is going to radiate more and more heat over time, which by 1 GY is going to reach 110% of current output. That will raise the Earth's mean temperature from 13 degrees C to 47 degrees C. Then at some point, the increased outwards pressure from the reactions in its core will begin to overpower the reduced weight of the Sun, causing it to expand and possibly engulf the Earth. Even if it doesn't completely reach us, the Earth is going to turn into a larger version of Mercury.
Pretty much. High-speed maglev like we have now, and perhaps even significantly faster ones can make sense in a competition against aeroplanes, especially since they can run on any energy source instead of jetfuel. The ability to arrive much more directly at your destination is a huge advantage against airtravel like you say.
I just really like the ridiculous image of submarines speeding along in the ocean.Btw, better than submarines would be the suborbital spaceliners. I don't know if they would be efficient for "short trips" like the transatlantic one, but longer distances, like 1/3 of the Earth circumference or more could be done in time windows of one hour, according to marketing
Some of us just don't have the confidence that these baby steps are enough.I'm fairly confident on humanity
Sure, for saving civilization we'll probably figure something out, but I expect the poorer regions of the Earth to be the test case that causes the richer states to really take it seriously. Just consider the death toll in India alone when the subcontinent starts to dry out.Well, I guess the new dustbowl in the US might force the US to rethink its policies as well.You're ignoring a very important thing here; the curvature of the Earth. Here's the great circle between LA and Beijing plotted in, which is close enough really. Add to this that these trains would travel much faster than our (admittedly present day) aeroplanes, and a trip across the Bering Strait doesn't seem that stupid. Not if looking at distance alone at least.
putting a tunnel through a mountain (that an aeroplane will just fly over) costs a lot though. Plus which, a maglev requires constant electricity, but a hydrogen jet requires electricity only to make its fuel, which means it can get by on intermittent power.
That assumes your station is where you actually need to get the stuff to.
Of course once we get semi-orbital craft that can make the journey in say half-an hour (and that's at current orbital rates). Also, this runs into exactly the same problems as one under the Atlantic, namely maintaining a vacuum while multiple bars of water pressure are trying to get in.
You're right. In a world where you have the capability to make these trains, you can probably figure out some way to produce large amounts of fuel straight out of the atmosphere. You'll need some impressive energy generation, but that's true for a lot of futuristic visions.
Yeah, it only really works on the regional scale. It's really a problem of pretty much any kind of transportation; the faster it is, the less likely it is that you're going to be able to go exactly where you want to go with it.
Don't get me wrong, I don't really have much faith in the vacuum train idea. I'm just pointing out the parts of the idea which are more solid than others.
To my mind, high-speed suborbital flights replacing aeroplanes for intercontinental travel, while (very) high-speed trains deal with intracontinental travel seem like a more sensible solution. Planes (in whatever form they take) avoids chokepoints and single points of failure, while trains allow inter-connectivity on the regional scale.
Actually I was thinking more of a futuristic version of electrolysis, you know, water + power = hydrogen fuel.
Not to mention, you can link the airport to the city with trains (there's a 15 minute regular service between Heathrow and Paddington).
That could work too. The important point is really that if you have enough electricity, then converting it into a storage medium like fuel (in whatever form) isn't that big a problem.
You still have the delay of actually getting your baggage though, which can be a pretty significant part of the journey. Even more so when you cut the actual travel time down. All that waiting around before and after the journey is really where trains gain the advantage, which is why they make a lot of sense for shorter journeys. (You can't really mention Heathrow without bringing this to mind.
)I'm not an engineer but I do have experience of working with vacuum chambers. Frankly, they're a bitch. MatIII is correct, a vacuum tunnel the width of the Atlantic will leak and continue to develop leaks constantly. It's a technical problem when air leaks into a vacuum chamber, when seawater leaks in at high pressure to your vacuum tunnel it's a major financial disaster. When there are passengers involved it's a human tragedy, followed by a series of lawsuits.
Am I the only who sees another inherent problem in "vacuum tunnel" + "passengers"? And I realise the passengers won't be expected to hold their breath, but if there is a breakdown, and every train breaks down sooner or later, what do your passengers do? They can't evacuate themselves because they can't navigate through a vacuum, how do you plan to get them out to a place of safety? How quickly can it be done?
I also agree with many of the other criticisms raised; how do you do timely repairs, the cost of planned maglev trains on dry land are $50-70million per km so how much will that figure blowout when you try to set it up in a floating vacuum chamber? Evacuation stations would also be required at periodic distances but that's doable at least.
As well as problems with fishing nets, subs and floating debris snagging the tunnel or it's tethering cables, I'm unclear how much stress would be applied by the ocean currents on this thing and how that's dealt with? As well as the famous one - the Gulf Stream - there are a series of other Atlantic currents, some monodirectional and some vortexing, with changing positions and speeds. The currents are typically faster near the surface, which isn't going to help to preserve the integrity of the tunnel. A quick www search says that many of these currents travel at up to 30 cm per second, while in some places you get vortexing eddies of up to 70 cm per second. Based on that alone I am unclear just how stable a floating tunnel is going to be?
Am I the only who sees another inherent problem in "vacuum tunnel" + "passengers"? And I realise the passengers won't be expected to hold their breath, but if there is a breakdown, and every train breaks down sooner or later, what do your passengers do? They can't evacuate themselves because they can't navigate through a vacuum, how do you plan to get them out to a place of safety? How quickly can it be done?
I also agree with many of the other criticisms raised; how do you do timely repairs, the cost of planned maglev trains on dry land are $50-70million per km so how much will that figure blowout when you try to set it up in a floating vacuum chamber? Evacuation stations would also be required at periodic distances but that's doable at least.
As well as problems with fishing nets, subs and floating debris snagging the tunnel or it's tethering cables, I'm unclear how much stress would be applied by the ocean currents on this thing and how that's dealt with? As well as the famous one - the Gulf Stream - there are a series of other Atlantic currents, some monodirectional and some vortexing, with changing positions and speeds. The currents are typically faster near the surface, which isn't going to help to preserve the integrity of the tunnel. A quick www search says that many of these currents travel at up to 30 cm per second, while in some places you get vortexing eddies of up to 70 cm per second. Based on that alone I am unclear just how stable a floating tunnel is going to be?
I completely hadn't thought of that. I suppose if you had Airlocks at regular intervals you could seal off the section the passengers are in and repressurised it from compressed air tanks stored near the airlocks. Of course, that probably gives a few extra hours at best.
If you are building something of this size and scale of this tunnel it shouldn't be too hard to build in an emergency tunnel shaft in-between the main tunnels which would be pressurised.
While as a MegaScale project it seems like a great idea, I can't see this ever being more than a paper project.