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Transportation Science Technology

The Race To Create a Hyperloop Heats Up (wsj.com) 172

An anonymous reader writes: When Elon Musk unveiled his idea for the "Hyperloop" transportation system based on capsules zipping through depressurized tubes, much was made about the enormous technical challenges the system would face in development. However, that didn't stop a number of companies and organizations from starting to work on it. Several companies are pushing the development work hard, and it's shaping up like a race to a workable prototype. University teams are only increasing their efforts as well. "The Illinois team enters the SpaceX contest with a strong competitive edge. This is its fourth Hyperloop design project, the first dating to fall 2013, and the Hyperloop is now a part of the MechSE curriculum. The team has assembled an interdisciplinary network of faculty from aeronautical engineering, thermal dynamics, mechanical engineering, electronic engineering and software, and two of the team members have interned at SpaceX."
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The Race To Create a Hyperloop Heats Up

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  • by trout007 ( 975317 ) on Wednesday December 02, 2015 @11:39AM (#51041275)

    "The pod has been pressurized to minimize the G forces effects on a passenger."

    Really? How is that little trick performed?

    • I believe this is an extremely roundabout and misguided way of describing the pod maintaining a constant pressure so there's no "ear popping" and other silly effects connected with changes of altitude.

    • How is that little trick performed?

      Duh: having a cushion of air inside the capsule would obviously reduce G-forces; think about how a shock absorber works.

      (Alright, kid but I wonder how many right-brained, artistic types [washingtonpost.com] would have been taken-in by my simple "logic?" *grin*)

      • (Alright, kid but I wonder how many right-brained, artistic types [washingtonpost.com] would have been taken-in by my simple "logic?" *grin*)

        Much of the public and a good portion of government officials (those officials who aren't pushing the "hyperloop" boondoggle solely for purely cynical political, ideological, and/or cronyism reasons).

        Strat

    • I'm pretty sure the pod is pressurized so they can breathe.
    • by hey! ( 33014 ) on Wednesday December 02, 2015 @02:47PM (#51043157) Homepage Journal

      "The pod has been pressurized to minimize the G forces effects on a passenger."

      Really? How is that little trick performed?

      Simple: they depolarize the tachyon flow to the defector dish. It's almost like you've never even seen an episode.

      • "The pod has been pressurized to minimize the G forces effects on a passenger."

        Really? How is that little trick performed?

        Simple: they depolarize the tachyon flow to the defector dish. It's almost like you've never even seen an episode.

        They could just reverse the neutron flow.

    • "The pod has been pressurized to minimize the G forces effects on a passenger."

      Really? How is that little trick performed?

      It's the principle of buoyancy; at higher pressures air is more dense and therefore you appear to weigh less. So at double atmospheric pressure you'd appear to weigh about 50-100 grams less. That, and you'd have an easier time breathing and more oxygen in your blood.

  • by goombah99 ( 560566 ) on Wednesday December 02, 2015 @11:50AM (#51041353)

    they should bury it so it can be a straight line tube cutting into the earth's curvature. Then you can just "fall" from Los Angeles to SF with no propulsion needed. The theoretical transit time, ignoring the friction, is 43 minutes. the energy you need to supply is to overcome the friction. Since gravity will be both accelerating this and decelerating this there's no need for a complex propulsion system, decelleration system with energy reclamation. Less to go wrong, and less abrupt acceleration of the passengers, and probably greater safety.
    Of course the hard part of this is you have to tunnel underground to make a straight line cutting in to the earth. Since LA to SF is about 400 miles along the surface and the earth's circumference is about 25000 miles this means arc length is about 0.016 radians. thus 25000/2/pi*(1-cos(0.016/2)) = 0.127 miles.
    so the center of this would be roughly 1/8th of a mile buried or 672 feet at the deepest point (ignoring the mountains). This doesn't seem radically crazy as a depth for boring a hole.

    • No can do. Lava too shallow.

      10-15km deep will hardly make a difference and we can't really go much deeper without ridiculous amount of work on thermal isolation.

      Plus tectonics will really rain all over the parade unless it's built as a flexible maglev in a way oversized tunnel.

    • by Scottingham ( 2036128 ) on Wednesday December 02, 2015 @12:22PM (#51041609)

      Then you can just "fall" from Los Angeles to SF with no propulsion needed.

      I've found that if you use the word 'just' when describing anything related to engineering it's WAY more complex than you think it is, and usually impossible.

    • by DrXym ( 126579 )
      And as an added bonus people come out the other side roasted to perfection.
      • Okay, so it's not a good idea for people. It sounds like it's perfect for cross-country pizza delivery. It cooks while it's on the way!

    • by Rei ( 128717 )

      One of the main points of Hyperloop is to *save* money. You don't save money by tunneling from LA to SF.

    • by Software ( 179033 ) on Wednesday December 02, 2015 @12:51PM (#51041921) Homepage Journal
      You're talking about a project that's 10 times longer than the Channel Tunnel, which took 6 years and cost £13 billion in today's dollars. Of course, there's no English Channel overhead, so you can make boreholes overhead and pull out the rock that way instead of hauling it along the length of the tunnel. But on the other hand, you don't have the advantage of being able to choose the tunnels' path to get favorable geology - given the higher speeds, you're pretty much stuck with going through whatever rock is in your way.

      Plus, a straight line tube is not going to accelerate rapidly enough to get you there in 43 minutes. Are you assuming that you're going to be accelerating at 9.81 m/s^2? I think you'd be closer to 0.3 m/s^2.

    • by mjr167 ( 2477430 )

      Except the earth isn't a sphere. It's an oblate spheroid that is better modeled as an ellipsoid. This matters. A lot. The radius at the poles is significantly less then the radius at the equator.

      And the rocky mountains are pretty damn big. So are the Appalachians (when you talk about tunneling under them). You can't just hand wave them away.

    • Since LA to SF is about 400 miles along the surface and the earth's circumference is about 25000 miles this means arc length is about 0.016 radians. thus 25000/2/pi*(1-cos(0.016/2)) = 0.127 miles. so the center of this would be roughly 1/8th of a mile buried or 672 feet at the deepest point

      Now imagine a gradient 200 units long, which slopes down for 1/8th of a unit. What rate of acceleration do you imagine a craft sliding with no friction down that gradient will have? And with friction? Now do you see the need for propulsion?

    • Assuming you can do it for an ultra-cheap $60M/mile [tunneltalk.com], that's a total construction cost of $24 billion dollars for just the tunnel itself. That's roughly 5 times the estimated ~$4.85 billion cost for pylons, tunnels, and land rights that you would need for an over-land route. (Musk estimated $7.5 billion for the project as a whole, though commentators say he's being optimistic.)
  • by Thud457 ( 234763 ) on Wednesday December 02, 2015 @11:56AM (#51041389) Homepage Journal

    boy, painting this fence is really fun.

  • by nimbius ( 983462 ) on Wednesday December 02, 2015 @11:56AM (#51041397) Homepage
    1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs. others cant be bothered to even consider a greyhound to the next state, let alone a train, and once they arrive the local public transit infrastructure based on their destination is either so poor as to be unusable or nonexistent through legislative fiat.

    2. We cant keep up. our bridges, roads, highways and railroads are crumbling further into the dirt each year, and neither body of legislation seems capable of passing meaningful funding. the hyperloop would surely face the same fate as a majority invested government project that eventually turned into public private, then abandoned once the payout wasnt suitable for corporations, and finally maintained at about a quarter of its original capacity.

    3. the initial projection for this works project (and, it would be a works project) is six billion dollars. America cant manage to keep its government running for more than 2 years at a time in this foul year of our lord 2015. It wont fund education, its states wont fund healthcare, and its been cutting federal public transit funding for 35 years. the only way a hyperloop is getting built is if it somehow includes a rider to invade a neighbouring country.

    the only real reason companies even thought of doing work with the hyperloop is to do what companies do: suckle at the taxpayer teat. You start by investing in a renewable effort, secure grants and loans, develop a few proof of concept ideas, sell out to a capital management firm, and then declare bankruptcy.
    • by SharpFang ( 651121 ) on Wednesday December 02, 2015 @12:23PM (#51041621) Homepage Journal

      What percentage of Americans consider flying with commercial airlines to be the mark of poverty?

      Hyperloop isn't a replacement for buses or city cars. It's a replacement for airplanes. Supersonic travel with high initial but low unit cost - airplanes are very wasteful because they need to use a lot of energy just to prevent falling. Hyperloop train, once running, keeps running with only minimal friction losses and can recuperate most of energy used on acceleration during braking.

      It actually drives a lot of funds towards science/education. But yeah, the initial investment is huge. I mean, something like, 6% the amount any of the wars USA started!

      • by bigpat ( 158134 )

        Hyperloop isn't a replacement for buses or city cars. It's a replacement for airplanes. Supersonic travel with high initial but low unit cost - airplanes are very wasteful because they need to use a lot of energy just to prevent falling. Hyperloop train, once running, keeps running with only minimal friction losses and can recuperate most of energy used on acceleration during braking.

        That still needs to be proven out, but yes it could be theoretically more efficient and therefore less expensive than air travel.

      • airplanes are very wasteful because they need to use a lot of energy just to prevent falling.

        It's not as if airplane engines are on the bottom providing upward thrust. Air pressure + speed keeps them aloft. The hyperloop does theoretically help the wind resistance slowing problem though.

    • the problem is not that it is seen as a sign of poverty, it's that the trains don't go where people need them to go. most jobs are far from the stations so it doesn't make sense to take the train. instead of sitting in traffic you would have to drive to a park and ride, pay money for parking, take the train and then a bus or whatever to your job instead of simply driving all the way. this is around NYC as well. taking the train into manhattan isn't that big a deal, it's taking the train outside of NYC if y
      • by Ichijo ( 607641 )

        most jobs are far from the stations

        Is that true where employers aren't forced by cities to overbuild their parking lots? Or where freeways pay for themselves 100% from gas taxes and other user fees instead of less than half [uspirg.org]?

        Or is the fact that "most jobs are far from the stations" a result of the kind of Big Government authoritarianism favored by the right?

    • 1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs. others cant be bothered to even consider a greyhound to the next state, let alone a train, and once they arrive the local public transit infrastructure based on their destination is either so poor as to be unusable or nonexistent through legislative fiat.

      Have you ever taken a Greyhound, or even investigated a ride on one? They're ridiculously impractical; that's w

      • I will say however that your lack of confidence in the American government (at every level) is very rational. It does seem that our government would just bungle any kind of transportation technology, Hyperloop, SkyTran, etc. I guess that's why SkyTran is first being built in Tel Aviv, Israel. Maybe after it's deployed across Europe and parts of Asia and finally it's the norm in places like El Salvador, we can get it here in the US.

        • There's actually some things that the US Government gets right with transportation.

          The freight rail system in the US is the envy of Europe. We move billions of tons of cargo untold miles incredibly efficiently, over massive mountain ranges. Air travel, for all the annoyances it creates through security theater and companies that want to siphon every last nickel from your wallet for checked bags and seats that aren't akin to torture, is more affordable then ever, with traffic control and airports that are

        • Just so you (or maybe not you, but others) know, the USA lower 48, would span from UK to Israel if overlayed on a map. People not in the USA, having never been here, have no idea how big it actually is. They love to tell us, how we should be, comparing us to little Scandinavian Countries with Monolithic cultures. I can assure you that Miami Florida is nothing like Seattle Washington, or Casper Wyoming, or Boston Massachusetts or Phoenix Arizona or Chicago Illinois or Memphis Tennessee ....

          The only thing tha

          • The only thing that is intriguing about Hyperlink is that it is capable of providing personalized transportation with High Speed.

            SkyTran can do the exact same thing, only on a much smaller scale (like being able to transport you a few miles that way, station-to-station, with stations all over the place in a grid, not a line). However, it's not that fast: maybe 100mph in-city max, and up to 150mph for longer routes. That's a lot faster than a car of course (esp. considering the lack of congestion, stops, e

          • by dave420 ( 699308 )

            The EU is larger than the US and still manages to get decent public transport. And "monolithic culture"? Are you kidding? That would have nothing to do with anything, if it ever existed, which it doesn't. You are trying to find excuses for shitty policies and a lack of basic infrastructure the rest of the developed world seems to have figured out decades ago. "SJW"? Get a fucking grip - you are embarrassing yourself. You sound like a bitter, unloved old person.

      • Don't forget that most mass transit projects end up being pork for property developers and public employee unions, and aren't actually designed to be cost-efficient or efficient from a passenger-miles traveled perspective. Projects usually go over-budget, and no attention is ever paid to operating costs after the thing is built, causing transit agencies to cut services elsewhere to keep it running, because the fare box doesn't even come close to paying for operations.

        Urban Streetcar projects in the 1990s w

    • And yet there are transportation modes that continue working fantastically, because the advantages far outweigh the costs and horseshit. People don't have issues with air travel, even though the experience is as close to public transit as you can get - you go to a big government paid-for terminal called an 'airport' where you get in a big metal tube filled with strangers, where you then sit for a non-trivial amount of time until it gets to another government paid-for terminal. Then you pack up your shit a

    • 1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs.

      Aren't airlines public transport? I thought Americans loved them.

  • Musk's idea?! (Score:2, Informative)

    by Anonymous Coward

    Larry Niven's book World Out of Time has a "hyperloop" system in it. And I can't help but think other SF writers may have come up with something similar before that.

    The notion that Musk came up with this 'idea' is ludicrous.

    • by Matheus ( 586080 )

      Not to mention Futurama!! :)

    • Larry Niven's book World Out of Time has a "hyperloop" system in it. And I can't help but think other SF writers may have come up with something similar before that.

      The sci-fi writer isn't obliged to demonstrate that his system is technically feasible or economically viable.

      In film and video "instant" transportation by tunnel or teleportation makes for fast transitions between scenes and is dirt cheap to animate.

      • by Altus ( 1034 )

        Musk has done neither. He isn't even directly involved with the people who are actually trying to see if this is technologically and economically viable. This is an old idea. It almost certainly could work but the engineering and economics are the hard part and musk has had nothing to do with those.

    • by Rei ( 128717 )

      What's ludicrous is that you're commenting about the topic without even realizing what Hyperloop is.

      Sci-Fi (Niven, Heinlein, Clarke, Bradbury, and countless others) love vactrains. Hyperloop is not a vactrain. It wouldn't even work in a vacuum. It's an extreme version of a ground-effect aircraft - at pressures as if it were at extreme altitudes, and very small ground effect clearances. Unlike with a vactrain, the tube does not hold a hard vacuum - while pressure is greatly reduced, it still has more than

    • Larry Niven's book World Out of Time has a "hyperloop" system in it. And I can't help but think other SF writers may have come up with something similar before that.

      The notion that Musk came up with this 'idea' is ludicrous.

      Musical analogy: Musk did not compose the vactrain [wikipedia.org], he merely arranged it under the name "hyperloop."

  • Why would Elon Musk open-source an idea this valuable, while also leaving the door open to step in himself?

    Because the idea has been in the public domain for decades, including the whole depressurized tubes bit, maglev, and electric propulsion via external coils.

    For now Elon Musk, it seems, is calling his invention home to see what it’s become.

    Not his invention ...

    • by Rei ( 128717 )

      The fact that you think that Hyperloop is a maglev vactrain shows how you shouldn't talk about a topic of which you don't even know the most basic aspects.

      • I never said it was a "vactrain." Also, you don't want any physical contact with the walls, and the best way to do that (and supply boost at the beginning and regenerative braking at the end) is with electromagnetic fields. All this is more than a half-century old.
        • by Rei ( 128717 )

          But that is not what Hyperloop does. Hyperloop is not maglev, and for good reason - maglev is expensive. Hyperloop capsules are close ground-effect vehicles, relying on air bearing skis at high speed (at low speed they settle onto wheels).

          Show me a single - single - example in history from before Hyperloop Alpha - of a design involving evacuated but not vacuum tubes containing an effective ground-effect aircraft with battery-powered compressors to shunt the sparse air behind them, but propulsion coming fro

  • by SharpFang ( 651121 ) on Wednesday December 02, 2015 @12:15PM (#51041521) Homepage Journal

    Imagine a section of tube going splitting away from the main network. It has an airlock shortly after the split, then gently curves up a tunnel through a mountain, and exits at a rather steep angle upwards. Then there's a quick-acting airlock at the opening.

    A special train is loaded - a rocket adapted to travel through these tubes. It speeds up to the regular Mach 1 in the "civilian" section of the tunnel, then goes down the branch and gains another 2-3 Mach. The airlock at the end opens right before the rocket reaches it, then the hyperloop propulsion module drops on a parachute while the rocket ignites its engines. We've just shaved off first 1.5km/s out of the required 9 or so needed to reach orbit - and with the tyranny of rocket equation, that's quite a bit of savings!

    • by frnic ( 98517 ) on Wednesday December 02, 2015 @12:49PM (#51041905)

      Thew airlock would need to be long enough so that the pressure could be normalized before the outer door is opened, while the rocket is traveling at Mach 3. Probably in the neighborhood of a mile or two if you pressurized the airlock in one second.

      Constant/repetitive cycling of the pressure would certainly be very stressful to the structure.

    • We've just shaved off first 1.5km/s out of the required 9 or so needed to reach orbit - and with the tyranny of rocket equation, that's quite a bit of savings!

      No you haven't. The Earth's surface is not in a vacuum. The initial launch of a rocket is just spent climbing out of the atmosphere . The Space Shuttle traveled at a constant, subsonic velocity (slower than a commercial airplane) until it reached 10 km, above most of the atmosphere, before it started to accelerate and acquire its actual launch velocity.

    • by Rei ( 128717 ) on Wednesday December 02, 2015 @01:10PM (#51042167) Homepage

      You plan to have a capsule emerge from a near vacuum at several times the speed of sound straight into atmospheric pressures? That's going to be like hitting a brick wall. "Opening an airlock" will send in a shockwave down the tube to meet the capsule. And then to boot, its lift surfaces, designed for providing lift in a near-vacuum, are suddenly going to be facing huge amounts of air.

      It's actually better to have hypersonic (relative to atmospheric air) projectiles moving through vacuums or near vacuums literally break through whatever "airlock" is sealing off the end (this is done in several types of hypersonic guns) - it's better to hit a literal (as thin as possible) wall than to hit the shock of air flooding into a near vacuum.

      There is no such thing as a "hyperloop propulsion module". Hyperloop capsules are not self-propelled.

      Note that you can't reach "mach anything" greater than 1 in such a tube relative to the internal gases. But you can increase the speed of sound several times over by using sparse hydrogen and/or very hot gases in the tube instead of sparse atmospheric air.

    • A lot of the energy of a space launch is spent getting above atmospheric thickness - this is why launches are vertical on the ground, and then perform a "gravity turn" after getting above 10km. Getting out of the atmosphere is fairly easy - they proved that with the X-25 rocket plane and the initial Mercury launches. It takes a whole shitload more energy to stay up there, because you need horizontal velocity, which you're not going to get in the scheme you suggest.

      Also, instantly transitioning from less t

      • by ceoyoyo ( 59147 )

        Gravity turns are not performed after getting above 10 km. Reality isn't KSP, and those things in KSP aren't gravity turns anyway. Gravity turns usually begin as soon as possible after launch (some rockets actually launch at a slight angle). The idea is that gravity will naturally bend your trajectory over into a curve and aerodynamic pressure will keep you pointed along that trajectory. Gravity turns are also called "zero-lift turns."

        The space shuttle initiated it's turn quite early on, despite having

    • You might be interested in the Launch Loop [wikipedia.org].

  • Go to a bank at the drive- in teller station and you have proof of concept immediately. They only need to use a vacuum but the air removed from the front of the carrier could easily be pumped in behind the carrier and a bit more added as well if speed or distance requires the added boost. There is no question that it works the only question is the expense balanced against the benefits.
    • by Rei ( 128717 )

      Hyperloop is not a pneumatic tube system. And pneumatic tube systems unfortunately don't scale well.

  • Literally (Score:5, Funny)

    by bravecanadian ( 638315 ) on Wednesday December 02, 2015 @12:38PM (#51041791)

    a pipe dream..

  • I'm probably being Toronto, Canada centric but when I look at the number of 18 wheelers travelling between Windsor, Toronto and Montreal (520 miles a bit longer than LA to San Francisco) I would think that a hyperloop with the 401 highway, eliminating big rigs, would make a lot of sense in terms of reduced traffic, wear on the road and truck/driver costs.

    According to http://www.thetruckersreport.c... [thetruckersreport.com] it costs $1.38 USD/mile and let's assume that each truck is carrying 100,000 lbs of cargo. Along with that,

    • I'm probably being Toronto, Canada

      Can I be Peculiar, Missouri?

    • by Rei ( 128717 )

      I'm sure there are lots of people running the numbers for various routes. The LA/SF route was chosen to introduce the concept in the Hyperloop Alpha document, but it's hardly the only route possibility (personally I think they should have started with a LA/Las Vegas proposal so as not to earn the ire of the HSR people and the "but you won't stop at my town on the way" people, but anyway...)

      If you want to roughly estimate tube costs in your area, your best comparison would be not roads or rails, but large oi

    • Add in the savings for the state with regards to road wear from semi trucks. Those can become tax incentives and other benefits to get it built that can reduce that 5 year ROI (for all parties excepting truck drivers, they would be reduced in number and transitioned to end-point work).

      Great idea, by the way.

      • How would the use of light rapid transit (hyperloop) reduce wear and tear on roads from heavy trucks? Heavy trucks are not normally used for bulk people transport.
        • The parent specifically mentioned 18 wheelers, which are probably non-person cargo (I hope so, otherwise it would be terrible).

    • by ceoyoyo ( 59147 )

      Existing trains are even cheaper. The reason they use trucks is because the trucks can do local delivery.

  • Alon Levy, transit expert (particularly about costs of construction,) has this recent update [wordpress.com] about the proposal. His earlier analysis [wordpress.com] brought up a number of concerns about cost and how it would actually work. Basically, at the speeds that are claimed, the required gentleness of the curves means expensive construction. Or just going fast and cheap and thus having barfing passengers.

    • by Rei ( 128717 )

      Apparently this "transit expert" is following up to his humorously bad** G-forces post by commenting on the G-forces on a deliberately small test track, as if that's relevant to what actual passengers on actual public tracks would experience. And his complaint is about a vertical 0,2g? Seriously? That's the vertical G-force of a passenger jet taking a 30 degree bank. Oh my god, we're all going to die.

      Also, I'd like to see his credentials on the topic of pipeline construction. Because we're not talking a

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