Why Ultra-Efficient 4,000 mph Vacuum-Tube Trains Aren't Being Built 625
cylonlover writes "In the 1800s, when pneumatic tubes shot telegrams and small items all around buildings and sometimes small cities, the future of mass transit seemed clear: we'd be firing people around through these sealed tubes at high speeds. And it turns out we've got the technology to do that today – mag-lev rail lines remove all rolling friction from the energy equation for a train, and accelerating them through a vacuum tunnel can eliminate wind resistance to the point where it's theoretically possible to reach blistering speeds over 4,000 mph (6,437 km/h) using a fraction of the energy an airliner uses – and recapturing a lot of that energy upon deceleration. Ultra-fast, high efficiency ground transport is technologically within reach – so why isn't anybody building it? This article looks into some of the problems."
Re:Simple (Score:5, Insightful)
Yes, like aeroplanes and submarines...
If you don't reach for the stars you will never get there, if you try, you might.
Re:The only answer for the USA (Score:4, Insightful)
Re:Perhaps.. (Score:2, Insightful)
Safety is not an issue (Score:5, Insightful)
Use it for cargo first, and if there are no problems we can start using it for passengers. But the cost is a big obstacle.
kinetic energy (Score:4, Insightful)
No, kinetic energy goes with the square of velocity. So to accellerate from 3000 to 3050 mph takes as much as to get from 0 to 550 mph. The rest of the article may be interesting, but it's strange they make errors like that.
Re:Liability (Score:5, Insightful)
Re:Perhaps.. (Score:5, Insightful)
Someday maybe the Japanese can figure out how to build a bullet train in an earthquake zone.
Re:Simple (Score:5, Insightful)
Because the simple-minded mythology that people create for themselves is just that: feel-good pseudo-engineering that makes no sense whatsoever.
For an AC that was a brilliant post. However a little brief. As a "real engineer" who can do estimation and think thru technical problems the biggest problem is the vacuum tube is a waste of money and time and land. For a much smaller scale example you could reduce the "indicated air speed" as a pilot would call it of the TGV in France merely by installing gigawatts worth of walmart kitchen fans pointing such that the train gets a nice tailwind. However if you run the numbers it turns out you can get the same performance increase with merely megawatts of extra train power. Similarly, you could invest in terawatts of distributed vacuum pumps, but it turns out you can go just as fast merely by using gigawatts of train power...
Generally speaking in engineering making the immense part more expensive to make the little part cheaper doesn't pay off, for sufficient value of immense. For example, it turns out to be way the heck cheaper to make a long distance transmission line HVDC than to upgrade every tower long the route higher dielectric strength and taller and bigger footings etc etc. To a crude first approximation this is why sea transport is cheaper per ton-mile than train transport. Another example in the US outside hyperurbanized areas its cheaper to buy each user a taxi and taxi driver than to build passenger rail. I like trains and I like riding in trains but even I realize they're an economic disaster.
In fact it turns out to be cheaper to build a self-levitating and self propelling vehicle than to build a really long and terribly complicated track. I think I shall call my new invention the aeroplane.
The other problem is economic. Any 4000 MPH solution is terrifyingly expensive, so even zero interest expense makes it horrendously expensive. If you can get it cheaper than merely hiring someone far away, or booting up a PC running skype... For example, even during the Concorde era it didn't make financial sense to ship a salesman between NYC and London on the Concorde, it turns out to be cheaper to simply open a sales office in both cities and hire staff in each. Somehow this tremendously more expensive solution is supposed to work even better under conditions where cheaper solutions miserably failed?
Why the exagerated speed? (Score:4, Insightful)
I don't get what the author of this article wins by proposing such ridiculously exagerated speeds. Sadly, this kind of nonse plagues sci-fi-like tech news since tech news exists.
I see no need for a train going at 6000 km/h. But the idea could be interesting even at much lower speeds. A vaccuum tunel based maglev going at 600 km/h would already be quite at win for energy efficiency. But as long as it costs less to build and maintain reactors to power electical trains, you won't see any of these around.
Will never happen because (Score:2, Insightful)
Will never happen because:
one- The United States is broke. They pissed away all their money on permanent unwinnable wars, housing scams, and Wall-Street bank bailouts. The idea that they would be able to spend trillions of dollars to build 1000 mile long tubes to convey peasants across North America at 4000 MPH is absurd.
two: Present company excepted, but Americans are technologically incompetent at long-term projects. All their bridges and highways are in disrepair, and they can't even get 50MPH trains to run competently. Didn't they once even have a space program?
three: What's the point of moving thousands of people around? For every person in one place, there is a another person in just like them in any place that you would send them to.
four: Walk to any corner and there's a McDonalds, a Bank of America, a Chevron gas station, and a Starbucks. Travel a thousand miles in any direction and you're on a corner with a McDonalds, a Bank of America, a Chevron gas station, and a Starbucks. What's the point of travel?
Re:Liability (Score:5, Insightful)
A run from NY to LA would run you several billion dollars just to get started and several hundred million every year after that for maintenance and repair. So, the real question is: is there enough traffic between NY and LA (for example) to recuperate the cost of construction and operations. I highly, highly doubt the answer is yes.
If it were that cheap it'd be "yes, absolutely, and we're going to hook up every major city as well."
They're talking about spending over $150 billion for the high-speed rail from San Francisco to Los Angeles, and Amtrak's discussing $100 million in track improvements to get TGV-level speeds from Boston to Washington, DC.
Those are the nicest train routes in the country, but they're peanuts compared to how profitable a NY-to-LA in under an hour route would be if it only cost a few billion to get going and several hundred million a year to operate.
Re:Liability (Score:5, Insightful)
The article mentions this... the problem is, it sets up a false dichotomy. The options aren't no vacuum trains or ones that go at 4k mph... there is a whole range of speeds that these trains could be effective and efficient, and not all will turn passengers into goo if it crashes.
Sadly in this case, no. You can't financially handle the R+D and building costs to make this thing and plod along at 100 MPH like the Milwaukee to Chicago run does today. Also cannot operate at a mere 500 MPH like a aircraft given the high costs. So you need to run over 500 MPH. The effects on the passengers of a derailment at 550 MPH are not likely to be a lot better than derailment at 4000 MPH. Sort of like how falling 10 stories off a building doesn't turn out ten times better than falling 100 stories.
Re:Related questions... (Score:3, Insightful)
Re:Simple (Score:5, Insightful)
Trains are an economic bonanza in the US. Freight trains are still trains.
Limit your comments to passenger trains, and you might think it is true. Then you realize they're competition g with heavily subsidized highways.
Re:The only answer for the USA (Score:5, Insightful)
Not necessarily. Bear in mind that when you're talking about accelerating to 4,000 MPH, you're limited to very-long-distance travel. Bear in mind, we're talking about Los Angeles to New York City in a little over half an hour. This wouldn't replace subways, but rather would replace jets and trains.
Also, when public transit is used by people who can afford cars, it is usually because driving is unholy in those cities. It would be more precise to say that public transit doesn't work unless the normal road system is hopelessly broken, which is not the case in the suburbs.
Re:Simple (Score:5, Insightful)
Airlocks? Docking a train in a near-vacuum tunnel to a station has to be considerably easier than docking two spacecraft in a vacuum.
Re:Why? (Score:5, Insightful)
Re:Simple (Score:5, Insightful)
The point is things like planes weren't possible until gasoline engines, very quickly powered flight went from impossible to possible due to one technology and some smart people.
So:
1. Don't stop dreaming
2. Your Religion of Pessimism is just as bad, so STFU
Re:Simple (Score:5, Insightful)
Trains work in the US when shipping freight. The work for passengers in the northeast. However, cars are far more convenient everywhere else.
Case study:
Trip to Norfolk, VA from NYC area.
Fly: ~$300 per person round trip. You get one carry-on bag per person. 1.5 hrs each way + 4 hrs of transit/wait time.
Train: ~$250 per person round trip. You can carry more on. 8 hrs each way + 2 hrs of transit/wait time.
Car: ~$75 per car round trip. You can carry even more. 6 hrs each way; no wait time.
Now, if I didn't already have a car with sunken capital costs, then there is an argument. But even then, I would rent a car. Either way, it is cheaper and takes less time to drive than take the train.
In contrast, it would be crazy to drive into NYC when the train station is right next to where I am. Flight is almost always better if time is a factor.
And don't tell me "it's different in Europe". I was in Germany. I can drive from Munich to Berlin faster than the ICE train. And the train ride costs $150+ each way per person.
Outside of heavily subsidized metro area trains, I have not seen a train compete with the cost, let alone the time and convenience of driving alone. When you add a 2nd person, it just gets crazy to take a train.
Re:Simple (Score:4, Insightful)
Throw enough ridiculously cheap fuel at them (and comparisons that ignore the cost of ownership), and almost anything looks worse than an automobile.
Re:Simple (Score:4, Insightful)
Amtrak. US passenger train service is owned by the US Government and is MASSIVELY subsidized.
Americans only like looking at trains and thinking to themselves "If it were more like my car I would love to ride a train."
Trains do not work in the US because of who Americans are.
Re:Simple (Score:4, Insightful)
There is a small, but important difference between daydreaming and actually setting out to make something real with the technologies you have at your disposal. In the first case, you get the starship Enterprise movie. In the second case, you get the space shuttle Enterprise.
People were daydreaming about flying around for ages. Around the end of the 19th century, a whole body of junk science about how airplanes were supposed to fly had developed, resulting in a lot of money and effort wasted in unsuccessful airplane projects.
Alas, flight did not happen until the Wright brothers built a testing rig, threw out all the junk theories and designed something that could use technologies available at the time to actually take off.
Eureka doesn't simply happen from staring at your navel for many days.
Re:Not buying my tickets yet .. (Score:4, Insightful)
Wake me up when someone actually manages to build a tunnel anywhere near that size that's vacuum tight and has a realistic notion of what size and number of vacuum pumps would be required to keep a high enough vacuum in it.
Consider the Large Hadron Collider. It doesn't have significant volume compared to a piece of the tube train track discussed in the article, but they have figured how to maintain vacuum over a 17 mile long tubular ring. And the quality of vacuum in the LHC would be better.
Re:Perhaps.. (Score:4, Insightful)
The train has a lot of inertia. Those magnets would have to be insanely strong to keep the train in the center if there was a shift in the tunnel.
Either that, or the tunnel would have to be built some percentage larger than the train, so that the train could wander farther from the center of the tunnel without touching the tunnel wall.
Even then, imagine going 4,000mph and then getting shifted say, four inches to the right all of a sudden. You'd have a hard time keeping your internal organs, well, internal.
I don't really see how the forward speed of the train would amplify the effects of lateral shifts. 747s shift four inches to the right every day when there is turbulence, with little damage beyond airsickness. Heck, the Earth is speeding at 67,062 an hour on its journey around the sun, and yet I can shift in my chair as often as I like without losing any internal organs.
Re:Simple (Score:4, Insightful)
Unless you *find* the energy source, all you have is DREAMS. ... our energy base for the entire planet is decayed plant matter
Wait, where did all the nuclear reactors go?
Re:Simple (Score:4, Insightful)
Such things are better run as cost centres. They must meet targets like safety, efficiency, availability, reliability, coverage, etc but I don't see why they must be profitable. If after the other targets are met and they are still profitable, that's icing on the cake.