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Transportation Technology

Why Ultra-Efficient 4,000 mph Vacuum-Tube Trains Aren't Being Built 625

Posted by Soulskill
from the all-about-the-benjamins dept.
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."
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Why Ultra-Efficient 4,000 mph Vacuum-Tube Trains Aren't Being Built

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  • Liability (Score:5, Interesting)

    by robinsonne (952701) on Wednesday July 11, 2012 @04:52PM (#40619989)
    Who wants to accept the liability if passengers/surrounding objects get turned into goo when a tiny defect causes the 4000 mph object to decelerate in a not-quite-so-planned manner?
    • Re:Liability (Score:5, Interesting)

      by geogob (569250) on Wednesday July 11, 2012 @04:59PM (#40620103)

      Airlines?

    • Re:Liability (Score:5, Insightful)

      by O('_')O_Bush (1162487) on Wednesday July 11, 2012 @05:02PM (#40620159)
      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.
      • Re:Liability (Score:5, Insightful)

        by vlm (69642) on Wednesday July 11, 2012 @05:19PM (#40620507)

        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:Liability (Score:4, Interesting)

          by garyebickford (222422) <gar37bic AT gmail DOT com> on Wednesday July 11, 2012 @07:00PM (#40622207)

          I dunno - considering the level of catastrophe that happens to vehicles going 4000 miles through air when a paint chip strikes them, making a vehicle that operates a minuscule fraction of a millimeter from walls going by at that speed without turning into molten slag seems pretty difficult. I can argue that it _might_ be possible to extend our present knowledge and technology to build a 550 MPH (800 KMH?) vehicle that could survive most minor events - I would think that making derailment impossible would be one useful approach. But at 4000 MPH even a bump a millimeter high - anywhere on the hundreds of miles of wall - would be beyond fatal as any minor removal of material would cause the removed material to propagate and become a storm of removed material.

          I will note that many stores still have very useful vacuum-based paperwork distribution systems to ship receipts or something from checkstands to the central office. So vacuum systems do work - I just think 4000 MPH is beyond fantasy.

    • Re:Liability (Score:5, Interesting)

      by MozeeToby (1163751) on Wednesday July 11, 2012 @05:04PM (#40620197)

      You're not any more dead than if your airliner falls out of the sky at 500 mph.

      Safety is not the real problem. If you really put some research and development into it, you could probably get maglev down to $500,000 per km and probably a similar amount (if not more) for the vacuum tube (compare to $100 million per km right now). Then there's the cost of the trains, running the lines, maintaining vacuum ect. And for any run to make sense it's going to need to be thousands of km long, and every stop you make is going to defeat the purpose so direct lines between major cities are a must. 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.

      • Re:Liability (Score:5, Insightful)

        by pthisis (27352) on Wednesday July 11, 2012 @05:19PM (#40620501) Homepage Journal

        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, Informative)

          by CrimsonAvenger (580665) on Wednesday July 11, 2012 @07:18PM (#40622463)

          but they're peanuts compared to how profitable a NY-to-LA in under an hour route

          Won't be under an hour, unless we're pulling .2g or so.

          More like 80-90 minutes.

          Your point stands, however - it would make a bloody mint if it existed. If only from people who rode it just so they could say they did it....

          • Re:Liability (Score:5, Interesting)

            by ngg (193578) on Thursday July 12, 2012 @12:59AM (#40624797) Homepage

            Won't be under an hour, unless we're pulling .2g or so.

            More like 80-90 minutes.

            Your point stands, however - it would make a bloody mint if it existed. If only from people who rode it just so they could say they did it....

            I'm not sure I buy that: Round-trip flights between LA and New York can be had for under $300 and take 7-8 hours, including time at the airport. So what price premium is the public willing to pay to get there in 1/3 the time (assuming it takes some time to get on and off the train)? I have trouble believing the capital costs of a vacu-mag-lev passing through two mountain ranges is going to have a lower per-mile cost than the current California HSR (currently ~$100 billion for ~500 miles, or $200 million / mile).

            Do you think you can really charge a big enough price premium to cover the extra capital and operating costs of such a thing? I think the Concorde has your answer.

        • Re:Liability (Score:4, Informative)

          by dontclapthrowmoney (1534613) on Wednesday July 11, 2012 @07:40PM (#40622721)

          Plus, if it was more convenient and also faster than air travel, more people would use it. One hour from LA to NY would take about the same time as my regular commute into work from the suburbs into the city (a distance of roughly 25 kilometres, in traffic).

    • by icebike (68054) *

      First there was never any realistic suggestion of 4000mph, I think he made it up as a premise to write his fluff article.
      The story is about as thin on science or facts as your typical comic book.

      If you could achieve 400mph that would be sufficient. Nobody has seriously suggested 4000mph land based travel.

      400mph tube trains would allow you to have fixed stations supplying the propulsive power, and the mag-lev or air-suspension engineering can easily handle any defects that would affect the ride at that spe

      • Re:Liability (Score:4, Informative)

        by garyebickford (222422) <gar37bic AT gmail DOT com> on Wednesday July 11, 2012 @07:28PM (#40622603)

        The problem we have in the US with high speed trains is our rail system is beat to crap by freight trains, meaning our trains can't go very fast. Other countries tend to use new and separate facilities for passenger and freight. Even Amtrak is starting to gear up for high speed rail [inhabitat.com], but it is dependent on private railroads for track. But laying new track, or improving existing track is far cheaper than building tubes all over the country.

        Yet another example of how politics can ruin anything. In order to get the law creating Amtrak through, the politicians agreed to allow the railroads to continue to prioritize their profitable freight over Amtrak. Amtrak trains, except in a few cases, get the lowest priority of anything on the track. And Amtrak has no ability to improve track so their trains can go faster. In many areas they are restricted to 20 MPH due to track conditions, hills, urban conflict, etc.

        The right way to do it would have been to nationalize the railbeds (buy them from the railroads) and let the railroads, now stripped to their essential function, compete on service and price. This could have been done back when the railroads were all going bankrupt. Now it's too late. Governments are reasonably good at maintaining infrastructure, businesses are generally better at service, so it would have been a productive arrangement, similar to both airlines vs. airports and trucks vs. highways.

  • by ackthpt (218170) on Wednesday July 11, 2012 @04:52PM (#40619993) Homepage Journal

    Perhaps it could work, but the technology and mechanics would have to be pretty darn reliable or people would arrive as pâté

    We're having a dickens of a time getting our Bullet Train going in California, which has finally been green-lighted to sell bonds and collect some federal funding.

  • Maybe because... (Score:5, Informative)

    by Anonymous Coward on Wednesday July 11, 2012 @04:55PM (#40620031)

    When the British did it [wikipedia.org] they had hella mechanical problems. The smallest glitch with a seal and suddenly your trains aren't moving nearly as fast anymore. You'd have to build two tunnels: the vacuum tunnel for the train, and then a slightly larger outer tunnel that allows for service and leak detection.

    • by Teun (17872)
      Not exactly comparable right?

      The British pneumatic system was somewhat comparable to the steam slings used to launch aircraft on carriers and was inherently leaky.
      And that's aside from the crude technology available 1-1/2 centuries ago.

      As a matter of fact there is no comparison.

    • by kheldan (1460303) on Wednesday July 11, 2012 @06:05PM (#40621345) Journal
      Never mind leaky tunnels, what about leaky cars? I can see the headline now:
      Mach 10 Train Arrives At Station, All Passengers Dead From Exposure To Vacuum
    • Re:Maybe because... (Score:4, Informative)

      by gutnor (872759) on Wednesday July 11, 2012 @07:21PM (#40622515)
      Thanks for the info, but really 150 years old tech ? 150 years ago aluminium was more expensive than gold, now take a look at your kitchen foil roll and the 6 pack in the fridge.

      To put that in perspective, the first notable "flying machine" was invented 50 years after that. Yet we managed to put a man on the moon 69 years after, and 100 years after the sky is filled with airplane carrying passenger with safety record that rival all the other type of transportation.

  • by Hentes (2461350) on Wednesday July 11, 2012 @05:00PM (#40620125)

    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.

  • by n5vb (587569) on Wednesday July 11, 2012 @05:01PM (#40620135)

    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. Oh, and handling the exterior pressure loading without risk of accidental implosion would be nice. ;)

    The other problem which is less trivial than it might seem is how to get people and cargo (and possibly vehicles) onto and off of these trains without breaking the vacuum .. really big airlocks at the stations maybe? .. and how to evacuate one of these safely in case of an emergency on the main line ..

    • by khallow (566160) on Wednesday July 11, 2012 @09:04PM (#40623495)

      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.

  • kinetic energy (Score:4, Insightful)

    by joostje (126457) on Wednesday July 11, 2012 @05:02PM (#40620153)

    it takes more or less the same amount of energy to accelerate from 3,000 to 3,050 mph (4,828 to 4,908 km/h) as it takes to get from 50 to 100 mph (80 to 161 km/h)

    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.

  • by fustakrakich (1673220) on Wednesday July 11, 2012 @05:02PM (#40620165) Journal

    They do have a warmer more 'natural' sound

  • by geogob (569250) on Wednesday July 11, 2012 @05:09PM (#40620301)

    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.

    • More important, you go that fast below ground on an isolated track and you've probably beaten out air travel as a better infrastructure option considering logistics and payloads.

  • by foobsr (693224) on Wednesday July 11, 2012 @05:10PM (#40620311) Homepage Journal

    Probably its time that /. posts links to Wikipedia entries to be at least a little more informative.

    If one would have looked up Wp, one could have found this, quote: "Vactrains have occasionally appeared in science fiction novels, including the works of Arthur C. Clarke (Rescue Party, 1946), Ray Bradbury (Fahrenheit 451, 1950), Peter F. Hamilton (The Night's Dawn Trilogy), Joe Haldeman (in his novel Buying Time), Larry Niven (A World Out of Time), Robert A. Heinlein (Friday), Jerry Yulsman (Elleander Morning), and Jasper Fforde (the Thursday Next novels). Flash Gordon (1947) and the movie Logan's Run (1976) featured similar high-speed transport trains. The Space: 1999 TV series, featured a Lunar Vactrain. 23rd century San Francisco has one stretching across the Golden Gate Bridge in Star Trek: The Motion Picture (1979). Earlier Gene Roddenberry television productions, Genesis II and Planet Earth, featured such transport systems.".

    CC.

  • by Cassini2 (956052) on Wednesday July 11, 2012 @05:24PM (#40620585)

    The reason the vacuum systems went out of favor was the massive associated fire risk. At first, it doesn't seem obvious why a vacuum system would have a fire risk, as in theory the vacuum should extinguish the fire. However, this doesn't work in practice.

    What actually happens is the fire starts outside the vacuum system, where it has access to air. The fire then causes this air to expand. The logical place to expand is straight into the nearest low or negative pressure environment around, which is the vacuum system. In no time at all, the vacuum transportation system spreads the fire between floors - and disaster ensues.

    Vacuum transportation systems used to be popular in multilevel buildings of large companies. Then one by one they caught fire. Eventually, the fire codes understood the significance of plenums and air return systems in spreading fires. Now any kind of vacuum, plenum, or return air space that stretches between floors has special safety devices inside it. They are extremely dangerous spaces if fires occur.

    Additionally, vacuum systems were never used to transport people, because if air integrity on the capsule fails, then everyone suffocates.

  • by Animats (122034) on Wednesday July 11, 2012 @05:42PM (#40620935) Homepage

    There's been enthusiasm for underground tunnels in science fiction since at least the 1920s. Tunnels, though, are hard to build. Read a few issues of "Tunnels and Tunneling" to get a sense of the problems.

    Solid ground isn't really that solid. Tunnel projects encounter sand, silt, water, oil, natural gas, shale, coal, and salt. Each requires different techniques, and most can't support an open in space in them. Tunneling often involves building a structure able to hold the tunnel bore open. Support rings, props, rock bolts, shotcrete, and steel are used when necessary. A single long tunnel job may encounter all of those.

    As a construction project, a tunnel has a major logistical problem - most of the work is at the cutting face. So there's not much parallelism. Major tunnels are bored from both ends. In some cases, shafts are dug to intermediate points to allow advancing from multiple locations.

    That option is possible on land, but slow and expensive for deep tunnels. It was used for the 57km Gotthard Base Tunnel, and required digging two access shafts around a kilometer long. That job took 14 years of tunneling.

    Underwater tunnel projects are usually limited to working from both ends. In a few cases, existing islands, or even artificial ones, have been used to gain access points. The Tokyo Bay Aqua-Line has an artificial island.

    Large tunnel projects today seem to run about US$0.2bn to $1bn/kilometer. It's much more expensive in urban areas or earthquake-prone areas. Hard rock tunnel projects are slow, but not overly expensive. Tunnels in difficult ground get very expensive.

  • It's a no-go (Score:4, Interesting)

    by downhole (831621) on Wednesday July 11, 2012 @06:13PM (#40621519) Homepage Journal

    I thought of the idea a while back, and I'm sure plenty of other people have too. It's really cool in a way, but I doubt it would ever be practical. The main problems I thought of:

    Cost. It would have to be ungodly expensive by any measure, both to build and to operate. Could there ever be enough people willing to pay enough money to get, say, from NY to LA, faster than anything else to justify it? And it isn't very flexible either compared to air travel. If some other part of, say, NY, gets much more popular, then you can just build a new airport and reroute flights as needed. If you're using these giant vacuum tubes, you'd have to re-drill half of the run.

    How tough it is to keep the tube in vacuum? We don't have any good way to estimate that now. Might need several high-grade vacuum pumps per mile that draw lots of power. It's pretty single-point-of-failure too - any significant air leak anywhere on the entire run, and any trains going fast enough to make such a system worth the trouble would probably be completely destroyed. It isn't just an air-resistance problem - unless the tube is much, much bigger than the train, then all of that air would be forced through the relatively small area between the train and the tube, thus much higher pressure spikes that would probably compromise any structure, and once you get the first crack, the whole thing will disintegrate real quick under the 6k MPH winds, leaving everything and everyone in the train as a stain on the walls over the course of a few hundred miles.

    Handling sounds tough too. Like loading, unloading, servicing, turning them around, etc. You'd need lots of really good pressure seals that will stand up to many thousands of cycles with passengers doing all sorts of wacky things to them, and lots of elaborate procedures carefully followed. Getting trains into pressure for service (or do we have service techs in space suits?), loading and unloading passengers and cargo though some kind of airlock/jetbridge thing. Make a mistake anywhere, and you either pressurize the tube, destroying any trains travelling in it at the time, or suffocate all of the passengers in a train. Hope you never have a train break down in the middle of the line either.

  • Swissmetro (Score:4, Informative)

    by jcdr (178250) on Wednesday July 11, 2012 @07:12PM (#40622367)

    A concept like this has be studied since 1970 in Switzerland. The subject was more warm in the early 1990, with an idea of real experimentation, but cooled down when faced the complexity of the project and his hazardous profitability. There is still some trace of it on the web:

    http://en.wikipedia.org/wiki/Swissmetro

    http://www.swissmetro.ch/en/home

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