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Flying Trains 115

Posted by emmett
from the better-than-maglev dept.
leb writes: "Engineers in Japan are developing trains that really do fly. Using the 'wing-in-ground' (WIG) effect, in which a high-pressure cushion of air forms underneath flying objects as they approach the ground, they believe they will be able to create trains that use only a quarter of the power required for magnetically levitated (maglev) trains. Read about it in this New Scientist article." This is rather nifty, but it isn't as cool as the flying train at the end of BTTF III. Put a flux capacitor on this baby, and we'll talk.
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Flying Trains

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  • by Anonymous Coward
    The Wing-in-ground effect states that you see an increase in velocity once you drop below one-half wingspan's altitude--the velocity gain is much, much higher as you get down to 1/4w, 1/8w, etc. Unfortunately, this velocity increase creates a drag increase proportional to the square of velocity (giving rise to a terminal forward velocity). Lift is proportional to velocity, so what you get is a "cruising altitude" for any given wing/engine combination. Assuming that pollution reduction is their goal, they're going to use small engines and big wings. The train will ride in a squared concrete trough (Why not a half-pipe cross-section allowing for smooth banked turns...?), so to increase altitude above 5-10 cm would require much larger wings and a much larger expenditure on concrete. Raising the track is much more economical. Imagine Chicago's "L" moving up around 250 mph, and you've got an idea of the utility of this thing. Cheaper than aircraft (all those precision parts, insurance, and failsafes, plus runways and airport crowds), and able to make the Boston->Atlanta route (stops in HArtford, NYC, Philly, DC, Baltimore, etc...) in record time for any multipassenger vehicle. --Jurph

  • This rules. When I was a kid I tried to build ground effect vehicles for toys- mostly, I tried to make a sort of wedge-thing that was more a ram-scoop than anything else. It's great to see this stuff becoming reality!

    I'm going to go play with 'X-Plane' [] (which is at least half a hardcore aerodynamic engineering sim) and design myself a ground-effect car. And see what sorts of terrain I can fly it over :) vroom, whoosh! I think it's sort of pointless to design in a non-ground-effect tail seeing as the thing is supposed to _not_ actually take off fully. I'm thinking in terms of three wings and flat plates for the sides, perhaps some form of drag rudder.

    I wonder if you could make the 'slots' for the Japanese train version in x-plane? It is sort of technically possible but would be absurdly hard to get the tolerances close enough...

  • Who'll be the first to make a ground-effect go-cart? *g* I was just thinking that the way to make a ground-effect car was to think 'dragster', with a big wing or wings in back and a _narrower_ wing as a canard up front to control pitch. Narrower meaning 'half the wingspan or less'. This would prevent the thing from taking off into the wild blue yonder because once you got high enough to get out of the canard's ground effect, it'd automatically bring the vehicle back down because the rear wings would still be lifting in ground effect. The result could look a _lot_ like a dragster, with the canard way out front to exert more pitch control.

    Anybody have a long steep hill, some bicycle wheels and aircraft spruce or aluminum tubing? No engine required! You just have to live near a big, _straight_ hill ;) oh, plus you'll have no brakes of any sort due to not even touching the ground, so busy streets would _not_ be the place to try this ;)

  • That's exactly the kind of ramscoop-thing I used to make as a kid! Wow- this slashdot article is a strong contender for my favorite slashdot article _ever_ :)
  • by rbf (2305)
    I want one of those flying train like in BTTF III. That'd be a lot of fun!

    rbf aka pulsar
  • "the tailwing doesn't create a whole lot of lift" Actually, the tailwing in a conventional aircraft produces negative lift (pushes down), which increases stability. You might visualize it as similar to drilling a hole while both pushing and pulling on a drill to avoid pushing the bit too far through when you get through, as brain surgeons do when drilling holes in skulls. Non-conventional planes, such as canard designs, often have no "tailwing" at all.

    "Flipping over backwards" is not typical of overloaded airplanes. The most common thing is to simply not be able to climb out of ground effect. This is most common in hotter, more humid, and higher altitude environments than the pilots are used to, as each of these factors reduces the density of the air; reducing the density of the air then reduces thrust and lift capacity at the same time.

    Taking off tail-heavy is very easy will make the aircraft difficult to control, and may cause a stall, particularly at low speed. However, it is more likely to cause a stall at approach to landing, as most aircraft store lots or all of their fuel in the wings, and as they use up fuel their center of gravity shifts slowly backwards. While the horizontal stabilizer ("tailwing") has sufficient effectiveness to prevent at stall at cruise speed, the airplane will be more likely to stall when it slows down for approach to landing, and will be hard to control in any case. Fortunately, certified aircraft generally have significant margin of error.

    Finally, I strongly doubt that the fat man you saw put your plane in danger. The crew will feel no compunction about asking folks to move around whenever there is a weight and balance problem; I've been on quite a few flights when this has happened. In this case, he might have been undercounted, but not completely ignored for W&B calculations. There is an "FAA standard passenger" that can be used for these calculations so that they do not have to ask you to stand on a scale, and at a minimum it is likely that he had been accounted in this manner. If they were very close to the W&B envelope, they would have known it and would likely have re-run their calculations.

    Folks interested in reading some of the best technical writing ever created and in learning more about the theory of flight should read Stick and Rudder by Wolfgang Langeweische. Only beware, as aviation is an addictive persuit, and you might get hooked. :-)

    PPSEL (Private Pilot, Single-Engine Land); Experimental Pulsar N456LT []

  • the TGV is a french "normal" train and its max speed is 515 km/h iirc, so "normal" train still have a long life! maglev or others exist for decades but are too expensive...
    BeDevId 15453
    Download BeOS R5 Lite [] free!
  • You didn't actually read the article, did you?. The Japanese have maglev trains as well. old news. If you had actually read the article, you would have noticed they mention that the whole point is to reduce energy consumption.
  • by maggard (5579) <> on Saturday March 11, 2000 @10:14AM (#1209790) Homepage Journal
    Lawrence Livermore's "Inductrack" seems much more feasible then winged trains. It fits onto current right-of-ways, no exotic technologies are required (no super magnets, etc.), and is quieter then existing vehicles. It's rails can be made of low-cost materials and the levitation system is conventional magnets in arrays. The levitation effect comes into play at speeds over 5 kph and improves up to 500 kph so a train simply rolls up to speed (a fast walk) and then glides from there. Best yet it's a passive effect inherent in the design - power failures don't cause the train to suddenly drop onto the rails (a problem with the Japanese and German designs.)


    "Inductrack" []

    Maglev: A New Approach, Scientific American (January 2000) - article not available online.

    "Track to the Future," [] Popular Mechanics (May 1998), pp. 68-70.

  • They are going to have a hell of a time with track security. If the train is cruising along at 500 km/h only 5 cm above the track, and kind of debris, either deliberately or accidentally placed there, is going to fuck up this train. At least with a diesel-electric locomotive on a typical passenger train, the vehicle is so massive that it can destroy most debris. This WIG train is going to have to be light.


  • by Jeffrey Baker (6191) on Saturday March 11, 2000 @09:09AM (#1209792)
    In North America, urban right-of-way would be trivial to acquire. Simply demolish the freeways.


  • You are close, but actually the Ground Effect (or "WiG" as these odd people are referring to it as) calculation depends only on the width of the lifting surface (wing) and its proximity to the ground. (and of course the amount of lift per square [your locally-preferred linear measurement here; cm, inch, lightyear, micron, etc.] needed to support the weight of the traincar.

    In this case, the wing simply needs to be wider than the designed flight altitude (Altitude measured from ground level, not sea level) to take effect of Ground Effect. It does not have anything to do with the total length of the train or traincar.

  • by KlomDark (6370) on Saturday March 11, 2000 @09:13AM (#1209794) Homepage Journal
    Who made up this "WIG" term? As long as I can remember, this has always been referred to as "Ground Effect".

    Essentially, this means that a wing, such as one on an airplane, gets double lift when the wing is as close, or closer, to the ground (vertically) as the wing is wide (horizontally). In other words, if a wing is 75 feet wide, and the plane is 75 feet or less from the ground, the wing will be able to generate twice the normal (above 75 feet) lifting force.

    This can create a lethal effect on overloaded or badly balanced (front to back) aircraft: The wings will generate double-lifting force while within the ground-effect zone, but as soon as the plane gets above the ground effect layer, the plane will flip over backwards and splatter all of the runway. Not a fun way to die. Always do those Weight-And-Balance calculations carefully!

    One time I was on a puddle-jumper (20 seater deal prop) going from Omaha to Minneapolis. We had gotten on the plane and were waiting to begin taxiing to the run way. The door was closed. Suddenly, they open it back on and let this digustingly fat man on the plane. He must have been 500 pounds or more. The only place he could sit was on a bench all the way at the back of the plane. (The back of the plane is the worst place for weight in the first place, the tailwing doesn't create a whole lot of lift) Since he was on so late, I doubt he made it into the W&B calcs. I love to fly, but this time I about got up and got off the plane. I stayed on and was pretty scared while we passed through the ground effect zone. There has to be a significant chance (at least 10%) that we could have flipped over. One person could have moved the wrong way, or something in the luggage compartment could have shifted and we would have been a textbook case of why obsessive-compulsive people should be kept away from both McDonalds and small airplanes! :)

  • In fact, several companies have expressed strong interest in taking the Inductrack idea to reality. Some include studying the idea for a magnetic rail track built up the side of a mountain to launch a rocket (the rocket when it leaves the track will be travelling 400 mph just when the main engine ignites), a method that drastically reduces the amount of rocket propellant needed to get a satellite into orbit. The reason is simple: rockets burn a large fraction of their propellents just getting to the speed of sound, and the Inductrack launcher elmininates this problem.

    Wouldn't it be strangely ironic that the first practical passenger train application of maglev comes in the USA of all things? Imagine a maglev train using Inductrack that can go from Chicago to Minneapolis-St. Paul in under 100 minutes.
  • In the UK most train cancellations and delays are caused by track problems and mechanical failures.
    In the UK, the rail network has been privatized in a scandalous way which funnelled the money that should normally be used for track and rolling-stock maintenance into the pockets of well-placed people.

    So, it is not surprising that the UK rail system is subject to delays, breakdowns, and extremely lethal accidents (sorry, we don't have money to fix that broken signal, we have to pay dividents, you know).

    The British Rail privatization is a showcase to the world of why thatcherism is a scourge, and a lesson that (fortunately) stopped dead similar projects worldwide.

    It is safe to say that thanks to the eye-opening experience of the british rail privatization, the people of England decided to kick out the little tory shopkeepers from the House of Parliament, and bring back commonsense to government (a State is NOT a business, and cannot be run as such).


  • by Pig Hogger (10379) <> on Saturday March 11, 2000 @08:20PM (#1209797) Homepage Journal

    Yawn... Old hat. Can't you slashdotters have a look at history? Otherwise, you'll be condemned at repeating it... badly.

    First, a brief word about ekranoplanes (a.k.a. Wing-In-Ground effect) []. Here is an actual picture [] of such a beast in flight (Gerry Anderson fans will be delighted by this one []). They have been around for almost 40 years, having been devellopped in the defunct Soviet Union . You may look at this page [] for historic information, as well as pictures of enormous ekranoplanes [] as well as the 400 ton Lun ICBM launcher [] . For those who worry about greenhouse gas emissions, there is also a pedal-powered WIG [] !!! Oh, yes, those craft are already covered by a Canadian regulation [], proof that they've been around long enough to rouse the attention of regulators...

    Now, about trains. Nothing really new, there either.

    In the 1960's, french engineer Jean Bertin [] (1917-1975) pursued the développement of his ill-fated Aérotrain [] , which, 30 years before the recently-canned german Transrapid maglev [], almost reached the realization stage (both in a commuter rail line [] betwen Paris and the western sububurb of Cergy, and a line between Lyon and Grenoble for the 1968 winter Olympic games). Bertin's Aérotrains ran on a single inverted T concrete rail, and used a cushion of air for sustentation. An early prototype, the Aérotrain expérimental 02 [] (which looks like it was inspired by this []), reached the speed of 400 km/h in 1966 and 422 km/h in 1969 (not an impressive achievement, since at that time, the rail speed record was achieved in 1955, when an ordinary locomotive pulling four totally normal cars reached the speed of 331 km/h on a perfectly standard railroad line). More pictures are available here [].

    Despite that, Jean Bertin built more prototypes, and a 20 km long rail line (which still runs accross the countryside [], completely abandoned) on which a much bigger "train" [], which ran not much faster []than today's TGV []s do (note that the record certificate is issued by the Fédération Aéronautique Internationale [] , and not the Union Internationale des Chemins de Fer [] ...).

    Bertin's Aérotrain technology almost got selected in place of the current TGV [], but at the last minute, State support was withdrawn from the Société Bertin. The Aérotrain (and any other newfangled guided transportation system such as maglevs [] and monorails [] - we're in the real world, here, not in Disneyland []) suffered most from gross incompatibility with existing rail lines (necessary to enter the core of cities) and an extremely heavy implementation of switches, which precludes their widespread use and thus reduces the flexibility of their rail networks.

    Jean Bertin never recovered from the shock of losing State support; he died a few months later, despite having built a prosperous engineering company [] which still thrives in high-technologies.

    Throughout the Aérotrain's history, the French National Railroads [] (SNCF)'s attitude was extremely interesting. Despite all the media hoopla that surrounded the Aérotrain and the political interest, it did not say anything at all. Not a single word either for or against the Aérotrain was uttered in official french railroad circles. But during that time, the SNCF worked hard at perfecting what is seen today as the epitome of high-speed travel technology, the TGV [].

    So, it is quite safe to say that this oldfangled flying "train" [] will certainly not fly very far, because the theorical speed limit of ground travel, the speed of sound, is within reach of conventionnal steel-wheel-on-steel-rail technology, which without much pain, ran at 515,3 km/h [] on May 18th 1990 (gee! Almost 10 years ago!!!).

    (What is the speed of sound at 20C at sea level anyway???)


  • Or, you could just put larger wings and bigger engines, and skip building all that incredibly expensive track/right of way.

    Oh wait, it's called an airplane, and it demonlished the passenger rail industry some time ago.

  • <i>So, it is quite safe to say that this oldfangled flying "train" will certainly not fly very far, because the theorical speed limit of ground travel, the speed of sound, is within reach of conventionnal steel-wheel-on-steel-rail technology</i>
    Absolute rubbish. Perhaps wheel-on-rail *can* reach that speed but the power dissipation due to friction would be substantial. The difference with both WIG and induction motor designs is that they promise to achieve such speeds with relatively little energy expenditure.
    It's inevitable that energy expenditure will become a major driving force in transportation technology in the century ahead. Because of diminishing fossil fuels. Because of restrictions on air pollution. And also because of noise levels (steel wheels on tracks are pretty loud) and the need to limit the production of waste heat in densely populated areas.
    In the UK most train cancellations and delays are caused by track problems and mechanical failures.
    These technologies are also attractive to train operators because removing the train's wheels( thus eliminating complexity and decreasing mechanical stresses on the track) would increase reliability and decrease ongoing maintenance costs.

    Consciousness is not what it thinks it is
    Thought exists only as an abstraction
  • Erm, I didn't know this was about politics!

    I agree that the way BR was privatised was a criminal waste of public assets for just the reasons you say. Mind you, if it had been handled better (if the public hadn't been robbed) separating rail infrastructure from train operations might have worked out. It might still work out, in the long term. Similar moves within the power industry (gas and electricity) have already brought benefits in terms of reduced prices to customers through competition.

    I look forward to seeing the British telco industry sliced up in a similar way (I doubt we'll see any significant reduction in call costs until that happens, notwithstanding recent announcements from BT, Altavista etc).

    I sympathise with your extreme dislike of Thatcherism; I was just as outspoken as you on that particular subject back when it still mattered. But since then I've become just as unimpressed with New Labour. We'll never see a sensible, moderate government in this country until (and if!) proportional representation is introduced. I want no more damn ideologues! Give me government by consensus - and I mean pluralism, *not* the tyranny of the majority that we have now.

    Consciousness is not what it thinks it is
    Thought exists only as an abstraction
  • I agree with you that trains can be noisy... if they used technology that is outdated by 40 years, as it is the case in the US. I took Caltrain [], in Silicon Valley, and from personal experience I can say that it is difficult to board when you carry luggage or you have difficulties in walking (high, steep stairs), it is slow, and it is quite noisy.

    However, there are some countries whose technology in the area is much more advanced than the American one, although the obstacles to modern trains in the US are more political than technological [].

    As explained in this Scientific American article [], it is possible to build trains that reach high speeds without making too much noise, using aerodynamics and a clever profile for the track. Small details, such as how to conduct power from the feeder cables to the locomotive, are important.

    The TGV has commercial speed around 300 km/h (180 mph). It departs from a city center at slow speed, revs up to cross the suburbs, departs from tracks shared with other trains and goes into some special track (with smooth curves). It then revs up to cruise speed. The reverse steps are taken at the end. Cities that high-speed tracks do not reach are not lost: the train simply goes at the speed of normal trains (100 mph for instance). On the latest generation of TGVs, the ride is extremely smooth: you barely feel any vibration.

    A run of a shortened stock TGV reached more than 500 km/h in an 1990 experiment. Engineers are working on increasing the commercial speed to 400 km/h.

    The idea is that trains run from city center to city center; no more clogged highways to reach airports dozens of miles outside of the city! A businessman going from Paris to Lyon takes the train a few metro stations from his office and arrives 2 hours later near the offices of his business partners.

  • You should perhaps consider what was done with the TGV in France. The TGV is an inter-city train. Its most used route is Paris Lyon (two biggest cities in France, 500 km apart). The TGV takes about 2 hours to do the trip. It goes into high speed (a little less than 300 km/h) in the countryside.

    The idea is that going to the airport in Paris (CDG or ORL), flying and coming back from the airport in Lyon takes a long time because of the urban commute times, check-in delays and airport congestion. The train stations are located in the middle of the cities; taking the train is just a matter of reaching the station (taxi, metro, bus, car...), punching the ticket and sitting down.

    The idea is therefore to use high-speed trains between cities several hundred miles away between which exists a lot a passenger traffic. Noise is not that a problem since high-speed is reached in the countryside; furthermore, I can tell you that TGVs are not that noisy (good aerodynamics).

  • Now instead of cars having to stop for trains, we'll see airplanes having to stop for trains.
  • This post actually motivated me to buy the BTTF trilogy AND play the Back to the Future Drinking Game! [] w00t w00t! BTW I'm completely trashed right now. yay!
  • If I Recall Correctly, such a thing already is in development, in Germany. With magnets, the train flies about 0.1 cm above the rails.

    That's a maglev train. As the article said, this new train doesn't use magnets - it's a totally different way of levetating (using ground effect).

    This train will ride between Berlin and another town, I think. It may eventually ride in other countries like the Netherlands too.

    Didn't the project get cancelled recently as being to expensive, and not compatitive with the ICE - the German high speed train?

    -- Abigail

  • Well this is only an intial design. I would think that if you take into consideration other design limitations you will end up with different perhaps beter designs. Your basic idea of WIG is correct. Turbulence under the wings, and the usual effect of Bernoulli's principle all effect to amplify the normal lift conditions caused by a wing. But your comment about size is wrong. In this case size doesn't entirely matter. Or more appropriately its not the only condition. If I remember correctly your lift is a function of speed, wing size, and wing efficency. So if my wing is effiecent, and I go fast enough I will get lift. Especially when that is multiplied by the ground effect. Ground effect does happen on normal airplanes generally when the airplane is 1/2 the wing length above the ground. Kinda nifty effect.

    Odd side note is that the train would have to have an upper limit on speed otherwise it would take off. Unless there was a top part to the track....
  • I wonder how loud those suckers are. As it is the current trains are loud enough.
  • *sniff*

    I feel I have done my duty. Thank you, and good night.

    The sun is going down, I say we follow it out of town- We've been here for far too long.
  • (re: the flying train in BTTF)

    Thats one thing that kinda pissed me off about Austin Powers 2. I mean, come on! Yeah, your time machine is this car, they were talking about meeting your past self (a la back to the future), and then theres no 88 mph, flux capacitor, OR flames coming out from the wheels?

    Sheesh. Some movies are just so unrealistic.

    The sun is going down, I say we follow it out of town- We've been here for far too long.

  • Silly me, I thought that was the Bernoulli effect.

  • It is not so much the EM feilds themselves, but the machinery used to generate them. (The superconductors have to be cooled somehow.) and just other general vibrations due to EM feilds being generated at such power. (Similar to the noise a transformer makes. There are no moving parts, but somehow it generates noise just the same.)
  • I don't know about the german ones, but the japanese ones do.
  • But if the idea is to replace maglevs then noice isn't that big of a problem. The magnets in a maglev put out a lot of noise as well, even when the train isn't around. The fans would probably be a blessing to the neighbors.
  • Here [] is the fix for that broken link.

  • The TGV tracks are VERY precisely aligned. in the US amtrak is struggling with the usual american tracks and experiencing trmendous wear and tear on the wheels of their new acela high speed services. Maglevs, inductatrack and WIGE based technologies dont have this problem.
  • by costas (38724) on Saturday March 11, 2000 @09:33AM (#1209817) Homepage
    Alright... let me start debunking:

    (a) the ground effect is a very well understood phenonomenon, much more so than MAGLEV. In fact, the Russians/Ukrainians have built massive WIG aircraft, that were probably gonna be used for rapid troop landings. A quick Google finds this page [].

    (b) WIG has nothing to do with turbulence. In effect when a wing is closer to the ground, the space between the underside of the wing and the ground acts as a nozzle, i.e. increases air pressure much more so than the wing can do by itself (roughly 2x). Increased air pressure => higher lift (although I am over simplifying here).

    (c) You don't have to have a large wingspan to take advantage of the ground effect. It just so happens, that when you fly slow, you can't produce as much difference in air pressure with a small wing, so you need a large one (again, I am over simplifying, but close enough). I.e. if you have lots of small wings, like these Japanese are trying to do, you're gonna get pretty much the same effect.

    (d) The pterodactyles did not use the WIG effect... I mean come on, do you ever see illustrations of pterodactyles soaring at 2' off the ground? ;-)...

    I personally think this is a very interesting idea. Maglev is cool and all, but this can work just as well. If I had to find a weak spot it would be the total cost of ownership (TCO) of these things versus a Maglev train... with a maglev, electromagnets may cost more at installation, but after that you're pretty much done spending. OTOH, aircraft (particulary aircraft *engines*) are notoriously expensive to maintain...

    engineers never lie; we just approximate the truth.
  • I was hoping someone would mention this tech - and here is an inventor trying to build the mass tran for the future - today.

    The core of his system relies on Inductrack - the rest seems off the shelf. Right now it is a "competing" alternative to the Transit 2000 Plan [] for Phoenix, Arizona - though I think neither will go over well with the voters.

    Does this inventor's implementation seem feasible?
  • Who needs maglev, when the French TGV, which use standard rails, go faster than 500 km/h and has been in use for years.

    Reminds me of the high-speed connexions : they all praised fiber-optics, but it is the cheap old copper cable that enables ADSL.
  • Maglevs, inductatrack and WIGE based technologies dont have this problem.

    Well I would say they have even more this problem, precision is at least as important for these systems than for regular tracks for high-speed train. Plus the cost of maglev per km is way higher than regular quality tracks.

    Although I must say maglev is cool :-)
  • Maglev will be much improved once superconductors reach the boiling point of nitrogen. I have in my posession a superconductor that works at the boiling point of liquid N. I used it in an eighth grade science fair. :) It's Y-Ba-Cu-O or something similar. -pod
  • by konstant (63560) on Saturday March 11, 2000 @09:44AM (#1209822)
    The W.I.G effect has been understood for a long time; this is a clever application of that effect across disciplines.

    This proves an interesting reminder of the fact that "innovation" - an overused term - is so much more than the ability to spawn new ideas fully formed from your brain. Some of the most brilliant advances we have seen and will see are the fortuitous combination of two seemingly unrelated facts or areas of study. That's real genius: the ability to see patterns where a less perceptive person might see none.

    I hope someone points to initiatives like this one the next time funding for pure science research is on the block. The quest for knowledge is almost never totally without payoffs.

    Yes! We are all individuals! I'm not!
  • Bah! Howdy Doody was doing this in the 50's! Does anyone ELSE remember his train? The one with the wings, and the ship's prow .. lessee, what else did it have? The first all-terrain vehicle, that's for sure!

    The Russkis have been "flying" a monstrous ground-effect vehicle for years over one of their huge lakes up Siberia-way. Never gets over 50 feet or so above the water, has jet turbines stuck on every possible horizontal surface (and a few vertical ones as well) .. but it works. Probably the largest "flying" object in the world. Yep, ground effect's neat, for sure. And being on rails, that'll take care of the pesky control problems most of these type vehicles have.
  • If I Recall Correctly, such a thing already is in development, in Germany. With magnets, the train flies about 0.1 cm above the rails. This train will ride between Berlin and another town, I think. It may eventually ride in other countries like the Netherlands too.
  • ISTR seeing a couple, but you'd have the problem of getting around/past ships, and I'm not sure if the turning radius for a ship @ 6 knots is compatible with a flying train at 80 mph (assuming they slow down for turns).

    But be that as it may, since Japan has so much costal water, and mountain ranges, I seriously doubt that the canals go where the trains want to go. If you need to move a boat along a costal area, you get a sea-faring barge or run close to the cost with a river/costal barge. Most of the canals, then, will be perpendicular to the coastline, while the trains will run parallel to it.

  • And that means you can't put it on pilons more than a few feet high, and even then, the ground beneath them needs to be even, and so you still have to control it.

  • by Doubting Thomas (72381) on Saturday March 11, 2000 @08:55AM (#1209827)
    They really, really, should look at designing a lifting-body train, instead of this monstrosity.
    Something you can use on existing track designs would be optimal. Instead of vertical wing sections, shorter diagonal sections should extend from the undercarriage.

    The train tracks and siderails in Japan look a lot like ours. They're too close together for one of these and another train to pass, and they frequently travel through urban areas, where the extra right of way is going to be a bitch to acquire.

  • I don't think will be a problem at all! Look at switches and crossovers on current tracks:
    • switches mechanically connect different sets of tracks.
    • crossovers provide non-mechanical places for tracks to cross.

    It's easy to imagine the WIG analogues. Since the vertical wings guide the trains by following the side rails of the tracks, implement WIG switches and crossovers like this:
    • switch: have movable side rails that either slide horizontally to connect one track to two or more (kind of like the chute on the back of a cement truck), or else raise and lower vertically to open or close certain paths
    • crossover: simply connect the tracks, and leave no walls where they intersect. Just like any road intersection. It will be a control task to ensure no two trains enter the intersection at the same time, but there's nothing new about that. Assuming the train is much long than it is wide, then it only has to be travelling fairly straight for the crossing to be no problem at all.

    There may be other issues (like widths of the tracks - but that issue hasn't stopped multi-lane highways from enter most urban areas; you just get creative in where you put them) but the switching and crossovers should be the same as currently tracks, just on a slightly larger scale.
  • by diggem (74763) on Saturday March 11, 2000 @08:55AM (#1209829) Homepage
    I ride a normal train at least once a week. There are always tracks criss-crossing one-another. I'm not sure how they plan to handle cross tracks or routing, for that matter. Unless they plan to build mondo amounts of tracks and over/underpasses with existing forms of transportation.. eventually Japan could be one big spaghetti jumble of railways. At least with a normal track/train you can do some routing between different tracks. Where's the savings if you need a single track for each route for each train? You spent your environmental savings building all those tracks. Not to mention how WIDE those tracks have to be to accomodate the train + wings.

  • The WIG effect is technology that has been around since the 1700's. All serious scientists now use the <b>R</b>ollers <b>O</b>n <b>G</b>round <b>A</b>nd <b>I</b>n the <b>N</b>ape of <b>E</b>arth effect, which uses ball bearings embedded into dirt to create a ride with 75% less friction, all in five days or your money back!

    void recursion (void)
    while(1) printf ("infinite loop");
    if (true) printf ("Stupid sig quote");
  • Is extrans to text suddenly not working?

    void recursion (void)
    while(1) printf ("infinite loop");
    if (true) printf ("Stupid sig quote");
  • Ooh. Wow. What won't they think of next. Putting pigs on conventional airplanes?


  • If this could be made practical on a smallish scale, this could make public transportation very appealing. Using less energy than maglev makes it more eco-friendly, and if it could somehow be made to work at an altitude higher than a car, it would enable public transportation to avoid traffic with ease. This is promising!


  • by dufke (82386)
    (The superconductors have to be cooled somehow.)

    Does the german maglev use superconductors? From what I figured, it doesn't use them, at least not in the track. But I'm not sure at all.

  • by dufke (82386)
    The magnets in a maglev put out a lot of noise as well, even when the train isn't around.

    What do you mean? Electromagnets generating noise? Uh, maybe electromagnetic noise, but I doubt you can hear that with your ears only...

    They may hum slightly due to vibrations, but nothing near a fan. The main cause of noise from Maglevs is shockwaves. Anything (ok ok, not spaceships :-) going at 500km/h or more is gonna generate a lot of noise. (Not to mention if it goes faster than sound. Booom.)

    And anyway, the track magnets are turned off when the train isn't there.

  • by Sirch (82595) on Saturday March 11, 2000 @08:49AM (#1209836) Homepage
    OK, the article stated that the prototype is 8.1 metres long. If I remember the last info I got on WIG, wouldn't a large WIG train actually have to have wings at least as wide as the train is long? I remember that the WIG effect is caused by turbulance from the high air pressure under the aerofoil being reflected by the ground. The only problem being that the wings have to be very wide. Look at the pterosaurs. They utilised the WIG effect as well as thermals to soar and glide. Their wingspan, however, was massive.

    I personally don't think that this idea will ever take off (forgive the pun). Maglev is a much better understood effect and is easily controlled - the WIG craft would have to take off. Surely there is a hell of a lot of chance that serious faults will occur during lift off? It will probably need a lot of work before being produced and used by civilians, and even then I don't believe that it will be as good as maglev. Maglev will be much improved once superconductors reach the boiling point of nitrogen.

    There, my (probably not-so-well-informed) two cents.

  • Ask yourself this question:

    If I have to live next to trait tracks, do I want a loud noise once an hour, or a really annoying buzz 24 hours a day, seven days a week, 52 weeks a year, or at least until the power goes out? I'd take the loud noise in a heartbeat. I'd take an apartment that wasn't near train tracks even sooner, but begger's can't be choosers.
  • Yes, a good train engine will crush a penny. However, a full soup can would derail the train, or at least give the engineer nightmares. If you say, put a chunk of rail on the line, a disaster will happen, It does not take as much as you may think to put the train off kilter; the wheels on the trucks are round, after all, and not designed to leave the flanges.

    So, either way, keeping the track clear is a bitch of a job :).
  • No fsckin thank you.

    Using less energy than maglev makes it more eco-friendly

    Bull. We have eco-friendly energy production methods and eco-friendly energy use methods. Stop throwing the problem under the rug. Change the most commonly used methods instead.
  • I take serious issue with your ignorant assumption that someone who is overweight is necessarily obsessive-compulsive.

    Making assumptions about someone's psyche based solely on their weight is among the most damaging and unfair judgements you can make. Discoveries concerning pre-diabetic chemical imbalances and other related advances in psychobiology and nutritional science show that inhibited reuptake of certain neurotransmitters and variations in the amount of sugar that is absorbed by different people is the *primary* factor in hunger-control mechanisms. These variations on brain chemistry -- NOT a lack of self-control or more serious neuroses -- are responsible for the eating habits of many, many overweight people. Their concomitant depression is, in my opinion, due in large part to the vitriolic treatment they receive from society as a whole and its members in particular.

    Don't get me wrong -- I have a number of hours logged in a Cessna 172, and also fully understand the discomfort obese people can on occasion cause their neighbors. But direct your anger at the airline for failing to take late (and potentially large) passengers into account, not at the poor individual who has to live his life apologizing for a chemical imbalance he inherited through no fault of his own.

  • All it takes to wreck a train is two kids and a 1.2m length of rail. []
  • If my calculations are correct, when this thing hits eighty-eight miles per hour, you're going to see some serious sh*t. - Doc Brown, BTTF I

    One can only hope these trains don't start sparking and going bezerk at eighty-eight miles per hour. Although it would be totally cool, it would still freak the bejeepers out of the passengers.

    [Rails]? Where we're going we don't need [rails]! - Doc Brown, [paraphrased]

    Also, did you know that BTTF IV and BTTF V are in planning. Too cool! I just hope they don't reck the awesomeness of the trilogy just to make money off of it. We'll have to wait and see. I hear its due to production after Jurrasic Park 3, so it'll be a few years from now.

  • the reaction someone has if they saw a train like this fly by and they weren't aware of it existing before. haha. Just imagine that. On another point, what's the point in this? We HAVE planes. Why trains? It's pointless from my point of view...
  • This looks like an exceptionally promising piece of technology but I question the viability of it in anything other than cross-country/continent use.
    This is obviously not something that is expected to help the daily communte, and would in fact be at a severe disadvantage in the metropolitan setting of any city. The noise of an object traveling in excess of 300KMpH at ground level is likely deafening and with most cities already having bylaws controlling when Aircraft may land or takeoff it is unlikely this may receive an exemption. Additionally it makes little sense to cross even the largest city with something like this since acceleration time to get up to cruise speed would reduce the benefit acrued.
    That cross-country/continent part would be interesting though. North America was built on the back of "The Train". Replacing the existing North American train routes with one of these babies would make the train once more a viable travel solution. Certainly less costly economically and environmentally - especially if this:
    He says the next step will be to reduce the speed at which the Aerotrain lifts off, so that the amount of time in contact with the track is kept to a minimum. That will cut friction and therefore overall energy consumption. The goal is to reduce pollution emissions to 36 grams of carbon dioxide per person per kilometre, compared with 122 grams for maglev trains.
    is a trend which continues. What I would like to see are some costs analysis, estimating what the full scale train would cost to build and to run. Not to mention how much the infrastructure upgrades would be..
  • hehehe just last night i was watching an anime film about a kid who flies around the universe in an old-school train. i thought it was completely looney, but now i'm beginning to wonder if flying trains might have some special place in the Japanese psyche... j/k

    ICQ: 49636524
  • That's a really cool way of measuring pollution - grams of CO2 per passenger per km - but does anyone have any comparison figures for other vehicles (other than maglev trains which were mentioned)

    Such as planes (large & small), your average family saloon, an SUV, a 50cc moped, etc...?

  • Article []
  • Well said.

    Maglev has the benefit of using the Maglev "mechanism" to both levitate the train and move it forward -- replacing the track, wheels and engine of a traditional train. The WIG effect is used to replace the track and wheels. Propellers driven by electric, diesel-electric or turbine engines are needed for thrust. And yes, they will be noisy. Spend a few minutes on the ramp at the local airport. Better yet, talk to someone who has heard that hovercraft that takes passengers and cars across the English Channel. It uses BIG propellers to drive it forward. Maglev would have none of this noise.

    One reason we are looking for an alternative to current wheel/track design has to do with the degree of precision required in designing, building and maintaining a track intended for use at very high speeds. Because Maglev (and WIG) are non-contact techniques, they can get by with looser specs for their "tracks".
  • As has been said in previous comments, the Wing In Ground effect is something that has actually been known about for some time. (The first evidence came from the Pilots of early Dornier flying boats.) I have found a site that deals with this effect, and the aircraft that have exploited it at:- o/edwin/html/index.htm []
  • the url doesn't work. this worked for me: here. []
  • To the naysayers, the WIG effect is well understood, and very energy efficient. It is also a very simple concept to implement - the problem is getting infrastructure constructed.

    In my first year of highschool I made a similar system - it was essentially the same design as in the picture, except with a R/C car with triling line to pull it along. On that scale it was trivial to make a model that would go about 2" off the ground.

    For a production model of this train you would expect it to ride about 1.5 - 2 feet above the tracks. Any closer and you have to spend too much time cleaning the track path to make it financially viable.

    The best solution would be to combine MagLev technology with the WIG train, have Maglev at stations, thus minimising time to get the train up to a high enough speed to use WIG. This keeps the costs of MagLev to a minimum, and the energy inefficiency of long time ground contact to a minimum.

    just my thoughts - one last thing, in a MagLev train, how do they shield everything from the fields? or i guess it wouldn't matter since its not oscillating....

    thats all folks

  • They could use this kind of train for high speed, high capacity, long distance express lines. This way, their only job would be to get from point A to point B, like a shuttle that just goes back and forth.

    I'd think that these are what they want to replace the bullet trains with.

  • I remember it as such too. Something on the discovery channel referring to the cold war era soviet union research - it was called Ground Effect. The Wing-In-Ground is somewhat of a misnomer, I think. When I read it, I thought "hmmm...are they carving a groove in the ground for the wings to be fitted into?"

    Hey, actually, if grooves ARE cut into the ground, and only the wings are in these "wing tracks", then they can construct the tracks with control over the shape to maximize the ground effect and at the same time, they don't have to worry about weather and air density having too much effect on the performance of the train.

    What if these tracks were tubular? And then the wings can be tubular as well, constructed so that it's like taking an airplane wing and curling it up into a tube. That way, the air pressure going through the middle of the tubular wing would be greater than the pressure outside of it, causing the tubular wing to be riding on a cushion of air that keeps the wing towards the middle of the tubular track. Of course, the shape would have to account for requiring more lift near the bottom due to gravity. Oh, the biggest problem is how to keep the wing attached to the train while trying to keep the track's air pressure high and stable.

  • One solution would be to get rid of the sidewings, and use magnetic switching and guidance. For Guidance vehicle has steel U-channel with permanent magnets, track has steel U-channel. they face each other to create a magnetic circuit. This provides steering force (~1/3 hold down) At switches substitute electromagnets in track for steel u-channel and power up the path you wish the vehicle to take. I do not believe that there are any major problems with either method (magnetic or aerodynamic) of guidance at rail crossings. (Aside from traffic conrol) Disadvantages: gap would have to be small 3-5cm. Advantages: No moving parts Short headway Any real system will be a hybrid. No maglev or magnetically propelled (via LIMs or LSMs)train moving at realistic speed can ignore aerodynamics, and why not make use of what you get for free? While magnetic guidance is not free, it is not expensive (being passive, except at switches) and solves other problems thus far not mentioned like train crossings (for cars and trucks).
  • I wonder if Japan has a canal system. As far as I understand it, the WIG effect can be used on water as well as land, so running them on canals wouldn't be a problem. Then its just a matter of getting rid of all those annoying barges, and finding a way around those lock gates.
  • i don't know much about the WIG effect besides what's stated in the article, but it would seem to me that if the train is going to create a cushion of air underneath it to ride on, then the weather would be something very important to consider. how would this be affected by rain/sleet/snow or high and low pressure systems, or high winds in general. if this technology came to fruition could we build and transcontinental line in the USA considering mountain ranges?
  • In my understanding, yes, but not dramatically/catastophrically. The biggest problem would be shearing from side to side due to winds. They appear to be using winglets to kee the plane aligned, but these would probably be insufficient, so guides of some sort would be neccessary. As for the actual lift from WIG, the effects would be pretty nominal, I would think. Not only does being that close to the ground mean easy vortex control and WIG, it means you get to fly in the ground's slipstream, i.e. in the (relatively) still air slowed by ground drag. There would have to be one *heck* of a tailwind & a straight track to actually cause the wing to stop lifting. If I understand the diagram, they're also building side walls (for the winglets to "push" on), and these will help break the wind. So, in short, winds will probably cause yaw problems, but not lift ones, this could be mitigated. However, only at a cost of efficiency. Most winds will be sufficiently slight, I would think. As for the rest of weather, I don't really know, but I'd imagine it'd roll off it. If I was feeling energetic, I would do the figures for WIG and ground slipstram, but I'm not. ;-)
  • by Quintus (147877)
    Pretty interesting. After a cursory skim of the article, the one thought which occurs to me is noise. They're talking about powering it with fans of some sort, which is all very well and quite energy efficient, but causes noise problems. Just look at one of its ground-cushion kin: the hovercraft. Anyone who has taken the hovercraft ferry from Dover->Calais (or, I presume, anywhere else), or even watched one whiz by from a ferry, will know that they arre notoriously loud. Turboprop Regional Aircraft face similar problems; It seems largely to be caused by propellor tips' vorices (selon a Bombardier); so perhaps turning them into ducted fans would help; Bombarider (I leave it to you to judge the technical merits of this blurb) [] use anti-noise/phase shift technology; The Beech(?) Starship simply placed the propellors well aft of the passanger compartment. In anycase, some serious engineeriing will probably have to go into this issue to make the service attractive to passangers. (A main competetive issue between regional jets vs turboprops is noise. Many travellers explicitly avoid TPs for this reason alone.)

    The comments about self powered tracks seem to suggest they might be looking into a hybrid maglev solution where some form of magnet propulsion could be used (or at least some form of track mounted propulsion) with ta wing providing lift to avoid friction.


  • Imagine one of thos zipping through the basement! Totally cool!! :-)

  • Actually it's not a problem, since these would be used most likely as a high speed long distance system, like the bullet trains. The bullet trains are already on a completely independent track system than the normal commuter trains anyway. And in most places they are built on raised tracks pretty high off the ground, so the width of the tracks doesn't matter too much.

    And despite the fact that they are trying to reduce the speed at which the train lifts off the tracks, I doubt anyone would want to use them for normal commuter service. Especially in Tokyo, where you reach the next station 1-2 minutes, doesn't seem too efficient as a replacement for the normal electric trains.

  • I agree that this doesn't seem like the best way to do things perhaps. But from an infrastructure point of view, if these trains are simply replacements for the shinkansen (the bullet trains), then I don't think it would be that much of a problem.

    The bullet trains for the most part are built entirely on raised tracks, so you wouldn't need extra right of way, you would just need to rebuild the track system that is already in place. Of course that is easy to say, but a lot of work to do. Especially if a wider railway is needed, I can imagine all of the existing tunnels would have to be widened considerably; not a fun prospect if you know how many tunnels shinkansen pass through in some parts of the country.

    But any non-conventional high speed rail will take lots of work to put in place...
  • And they are better than planes in lots of cases.

    Think about what you have to do to take a plane somewhere. You have to go to an airport, (not as many as train stations), sit on a cramped plane (especially if it's a short distance you are trying to go to, the plane will be tiny). Once you arrive, you are not very close to where you really want to go (once again, because not as many airports).

    For a high speed train, as far as boarding and getting off, it's almost like riding a normal train. There are lots more stations, so you often arrive much nearer to your final destination than you would in an airplane. In the end, with a high speed train I feel like I have just taken a trip across town, whereas if I take a plane, I actually feel as if I have really travelled a great distance!

    Add in the fact that you can run several high speed trains from point A to point B every hour, you start to see that for certain distances/destinations, trains are much better.

  • it uses "ground" effects, but does this necessarily mean the real ground? I think a flat surface is really what is required. The structure in place for the most part is more like a raised highway; long stretches of a relatively level, semi-enclosed concrete system upon which rails are placed. I can imagine that despite the effort it would require to install such a system, it is very do-able. (if you are familiar with the Japanese bullet train system, the highway system, and various other civil engineering projects, you would see why I think constructing kilometers of raised, specialized track over and through various terrain is not completely unreasonable)

    Of course, I don't want them taking the Toukaidou shinkansen offline to do this; that would be a pain!

  • TCO may be higher if they used aircraft engines, but my understanding of the article points to something more along the lines of an electric fan as the eventual form of propulsion. Electric fans are quite cheap to maintain, and with modern advances in low friction surfaces they could run 24/7 for quite some time before needing maintenance.
  • actually i can't think of any compelling reason why one couldn't use a combination of the ground effect and linear induction propulsion. something like a big coil on the track inducing an oscillating magnetic field on a carrier substrate (like aluminum) on the train. this would be virtually noiseless as well as virtually frictionless.
  • Uhh, the whole idea of it is that it uses the wig effect right? So, your post kinda insinuated that it would be flying over cars?

    I could just see that, train over a road at rush hour, flying along just fine over the normal cars, somehow adjusting for the natural bumps and curves in them, then WHAM an SUV is in the way.... or a semi or etc..

    I don't think using this technology is going to provide a way for freeform flying trains.. it needs to be close to a surface for the WIG effect to happen, and needs to have walls on either side so that it can steer. (be steered?)

    You want it higher than cars? Just have to build the track higher..

  • If all trains could fly,
    Why use a track? Let them roam,
    Returning when tired.
  • This type of technology has been tested for over 20 years ago. USSR, Kaspij Sea, Marine Troop Carrier (a big waterplane with small-altitude flying capability). Speeds - up to 500 km/hour, 500 men capacity. Making a train fly is just another way of reinventing a bike. Hehe. Japanese "inventors" in action...

"From there to here, from here to there, funny things are everywhere." -- Dr. Seuss