Rumor: High-speed tube travel concept in the works

[Little Star]

Photo courtesy of ET3. A Colorado company has developed a concept for high-speed tube travel, that could allow passengers to complete an LA to New York trip in 45 minutes.

Is it really possible to travel between New York and LA in under an hour? An engineer in Colorado believes he has developed the future of travel.

TRUE: Prototypes for tube travel are complete; company searching for a test site

Imagine traveling from New York to Los Angeles in less time than it takes to get through those annoying airport security lines. Well, a company called ET3 out of Longmont, Colo., has developed a concept for the Evacuated Tube Transport, an airless, frictionless tube that can propel vehicles up to 4,000 miles per hour, effectively moving you from Los Angeles to New York in 45 minutes, all for the low, low cost of $100.

http://news.msn.com/rumors/rumor-high-speed-tube-travel-concept-in-the-works

I wish I were younger because some day this type travel might be possible.

[BlueStreak]

1. Test site? Can we just put some chipmunks

in those tubes they use at the bank drive-through?

[Savannahmann]

82. Well, they have pnumatic elevators.

I guess if you hit the button wrong, you could end up at the bank, would that work?

I kind of like the idea, you can suck an old person to the second floor, or even the third floor. That's awesome.

[Major Nikon]

2. Seems like a larger version of this...

[nebenaube]

5. hmm...

an early network...

[backscatter712]

32. Sort of. The point is to eliminate air drag.

The train itself would most likely be maglev, like China's high-speed trains.

The difference is that the maglev train would be riding in a loooong tube that's had all the air pumped out, so the train has no air resistance. That's what enables it to zoom along at 4,000mph.

My impression is that it's physically plausible, but insanely expensive. The tubes would have to be nearly curve-free. So you've got a route to dig between Chicago and LA? Over the Midwest Plains, it's probably not too hard. Once you hit the Rocky Mountains? You can't switchback up over the mountains or ride through canyons and valleys and mountain passes. Any curve is Bad at 4,000mph. If anything's in the way, you've got to get it out of the way. Which means lots of tunnels. And lots of expense.

[Major Nikon]

35. I've ridden on the Maglev

Even that is little more than a proof of concept. It was kinda cool to hear everyone scream as the other train went by.

[backscatter712]

37. Which one? China and Japan have built them, and they carry millions of live passengers.

Maglev's a well-understood technology.

The trick is the evacuated tube. Keeping a tube pumped free of air for thousands of miles is a technological challenge.

If it's working correctly, you get to go ZOOM at 4,000 MPH. If there's a leak, well, remember what happened to the Columbia?

[Major Nikon]

45. The Shanghai Maglev

[zappaman]

39. but you could conceiveably only have a few bends, not curves...

and just stop for a few minutes.
One line from A to B, passengers get on/off B and then turn to C, etc...

[backscatter712]

42. I'm not a physicist, so I'm not familiar with the math...

But my impression is that when you're going 4,000 mph, to keep the trip comfortable, rather than having to scrape the passengers off the floor of the train with a spatula, we'll be talking about tube-tracks with turns with a radius of 100 miles, or even more.

[Rocky888]

3. Wishful thinking

Oil Barron's will never allow this technology to manifest and become reality in the USA.

[kristopher]

4. Elon Musk (Tesla, Solar City) is involved

He has an announcement of some sort planned for Jun 21.

[bananas]

49. I don't think Elon Musk is involved in this.

Soon has talked about something he calls a hyperloop,
But he said it's not an evacuated tube http://en.m.wikipedia.org/wiki/Hyperloop

[kristopher]

70. Thanks.

The timing and the similarity of goals fooled me.

[BlueStreak]

6. I'm not impressed with that cabin size

That makes me wonder whether these people are looney tunes. That is so small that many people will have trouble with claustrophobia, and there is no room for a bathroom, or even any ability to stand up and move around at all. Maybe that would work for a 20-minute segment, but I can't see this ever being acceptable for a 2-hour trip.

They refer to it as "space travel on earth", which seems an apt description for their design paradigm. They think passengers will be happy to cram themselves into a little capsule, like astronauts? I don't.

Considering they whole concept revolves around an international standard for the "roadway" (ie tube network), one would think that they would choose a form factor that would actually be palatable to people. For example, if it were 8 feet in diameter and could have capsules at least 25 feet long, you could have a lavatory and an aisle between two seats where a person could stand up.

[MattBaggins]

24. What if they made all the seats commodes?

[BlueStreak]

30. Complimentary Depends [tm]

[defacto7]

26. Maybe you could get off at Denver, 15 minutes?

Or maybe you could take a bus; have you ever seen those lavs? OK, making them comfortable is good but I don't think most people would be that picky for a ride like that. Such luxuries could triple the cost or make it not happen at all. Anyway, I'm sure there will be room for improvement after it's successful for 10 years of so.

[BlueStreak]

31. My point is that once you lock in the 5 foot diameter thing

you are pretty much stuck with it. Even 7 foot diameter would give enough room for a small aisle between seats

[backscatter712]

34. We cram ourselves into similarly sized craft when we go on road trips.

How many times have you gotten in your car and driven on 2+ hour trips, or trips that were far longer?

That strikes me as no big deal.

[BlueStreak]

46. You can't pull off at the next exit to take a pee break

I guess maybe you could if you had booked the entire capsule.

[Ter]

89. Go before you start the trip

Who can't hold it in for 45 minutes?

[Codeine]

56. I make two/three-hour drives all the time.

I've never needed to stop and go to the restroom or walk around in that time. I think most folks could manage.

[BlueStreak]

58. Seriously? Never?

You are very fortunate.

[Codeine]

79. I just go before I leave.

Who pees every two hours?

[BlueStreak]

80. Well, a lot of people do, unfortunately.

And sometimes people have lunch that doesn't agree with them. Some people have circulation problems in their legs that require standing every half hour or so. Some people are diabetic, and would prefer not to do their blood tests and injections in plain sight. Some people are claustrophobic in such a tight space.

If this system were actually available, I'd try to plan my life such that I could utilize the system. But I'm just saying that a larger form factor -- an expansion of only 2-3 feet in diameter, could make a huge difference. I doubt that the laws of physics are forcing such a small diameter. It seems really foolish to limit it to that size arbitrarily, because once you start building you can't easily change the dimensions.

But there are more basic issues with this concept that don't seem to be very well thought out. It is not a proposal I can take seriously.

[RC]

77. Then you have, at best, about 3 minutes to find a can when you get out at the end of the trip.

[kristopher]

71. Looks as large as the cabin on some commuter planes.

And those often have 2 hour flights.

[olddots]

7. How long ago did the Wright brothers get off the ground ?

I teleport from L.A. to NYC daily and it takes no time at all .

[Mr. David]

8. Woo!

Sign me up!

$75 from Denver to New York via tube! Whattadeal!

My wife can visit every week if she chooses to

[DavidDvorkin]

9. 4,000 miles per hour inside a close-fitting tube

What could possibly go wrong?

[formercia]

10. Perhaps it's how the Tube is lubricated

based on a predictable failure rate.

[caraher]

16. It's supposed to be a maglev system - no lubrication needed.

But it is true that hitting anything remotely substantial at that speed... well, the best part is that the passengers probably won't suffer much.

[DavidDvorkin]

21. It will be evacuated

So there will be the issue of keeping the air out.

[BlueStreak]

62. 4,000 miles per hour IN A VACUUM. What could possibly go wrong?

Actually, I believe that reasonable safeguards could be built to maintain cabin pressurization. That's essentially the same process as flying at 40,000 feet.

The real issue, as indicated on this thread, is the vulnerability of these tubes to sabotage, natural events, or just random failures that could result in sudden loss of vacuum. What happens when you are traveling at 4000 MPH and then suddenly hit a wall of air? Hint: it ain't pretty. There would be no need to send these capsules to the crusher for recycling. That 20 foot of cabin would instantly become about 18 inches long.

[William769]

11. Interesting.

Thanks.

[Logical]

12. Isn't breaking the sound barrier an issue? Concord was trouble prone for ever. n-t

[pediatricmedic]

14. No sound barrier to break, no air to transmit sound, no air friction to create heat

Really a nice idea if they can work out the engineering of keeping the tube in constant vacuum and the passenger pod from touching the sides.

[Logical]

22. OK, sorry. So tube it a vacuum? Wow. Seems hard to maintain that also. n-t

[defacto7]

27. What's that movie....

In space, no one can hear you scream! Or something like that....

[pediatricmedic]

33. Can we skip that design feature please

Face hugging, acid spitting aliens would make the ride somewhat tedious. Not to mention they would likely be employed by the TSA.

[longship]

38. I am sick of these mother fucking face sucking aliens on my mother fucking tube train!

[RC]

78. Let's see... A pressurized capsule inside of a vacuum tube. Hmmm...

Has anyone worked out how to get the passengers in and out of that contraption, without leaking too much air into the outer tube? And how much energy will it take to maintain that vacuum, end to end?

[backscatter712]

36. As long as the tube was sufficiently pumped free of air...

That won't be a problem.

Aircraft have to deal with air drag. All the air will be pumped out of this train tube, and the train itself will be a maglev train riding on a magnetic field. Zero friction.

[Logical]

13. Then saying "It is a series of tubes" would make sense. n-t

[Shankapotomus]

15. This would be great to ship

more than people if it ever comes to fruition. With all the trucks shipping products around the country, this might help drastically reduce fossil fuel emissions. I can see small scale applications for this principle, as well: Suburbs connected to a central marketplace and drop-off facility which sends shipments to each location via tube. No cars needed for local pick up or delivery. No emissions.

[caraher]

17. The plan is to start with cargo

Though really, the high speed matters most for people. Most goods don't get health problems from sitting too long on an airplane...

[Shankapotomus]

19. I don't know how they'll get around

the no bathroom issue either. Unless they sit them on one.

[caraher]

25. Actually, they have a plan

Their idea is that if it's an "emergency" you can interrupt your trip. The plan is that you never have to go more than 15 minutes without an opportunity to stop.

[alittlelark]

18. ....it's eternity in there....

"Longer than you think, Dad! It's longer than you think!"

(Steven King - 'The Jaunt')

[hunter]

20. I like my Low-Speed Concept better.

First of all it's not powered by fossil fuels. There are solar panels alongside the right-of-way, geothermal power plants, various kinds of load balancing schemes, etc.

It goes maybe 35 mph but it never stops. Boarding and exiting is by special shuttle cars that run along side and then return to the station.

The main train is like a rolling hotel, with restaurants, movies, bars, wifi, and other entertainment. Or you can just look out the window if you like.

It's a world where nobody is ever in a hurry but the air ambulances.

Want to cross an ocean? You board a great sailing ship that is as comfortable as the train.

There's no hurry ever for anything but life-or-death emergencies, and those are rare. Two month annual vacations are the norm, with a year off every decade or so. Good work is easy to find anywhere you go.

[MattBaggins]

23. What does "in the works mean"?

Written on the back of a napkin after a four day binge?

[kentauros]

66. Considering that this idea has been around quite literally for decades

in science fiction novels, it could mean more like they are doing a bit more than writing fiction about it

[defacto7]

28. Anyone calculated the G forces of having to make quick pee stop?

So you accelerate to 4000 MPH for half the distance then you have to decelerate to 0.. unless of course you have to stop in Denver at the last minute. Splat.

[Gravitycollapse]

29. Decelerating from 4000 mph to 0 mph in 60 seconds would generate 3.04 Gs

So...yeah no rapid stops unless you want a lot of people to pass out / suffer injury.

[backscatter712]

40. Worst case accident scenario.

You're riding on the tube train, zooming from LA to New York at 4,000 miles per hour. That's faster than a mile a second. Faster than the SR-71. Almost as fast as the X-15.

And the SR-71 and X-15 were designed to fly in the extremely thin air at 100,000 feet+ of altitude. You're in a tube down on the ground. Pumped free of air to make 4,000 mph possible.

Now imagine that all of the sudden, maybe because a backhoe was digging in the wrong spot, or terrorists were up to no good, there was an explosive pressurization of the tube about 5 miles ahead. Something big enough to let the air pressure by the leak be close to outside pressure.

If it can happen to Keystone XL, it can happen to the tube train.

Your train's going over a mile a second. There's no time to stop or divert. You reach that leak five miles ahead in 5...4...3...2...1...

The result will be something like the accident that destroyed the Space Shuttle Columbia. You'll slam into a wall of air at 4,000 miles per hour. That air will superheat and incinerate your train in a matter of seconds. Your train will become a ground-hugging, tube-riding meteor.

They'll be giving your remains to your next of kin in an ashtray.

[defacto7]

47. and the last moments of a passenger may sound something like

"...the subject is contextualised into a neotextual deconstruction that includes truth as a whole. However, the primary theme of Hubbard’s critique of postdialectic textual theory is..."

"Excuse me, did you say Hubbard?"

"I'm sorry, I didn't say anything."

"But I distinctly heard you say Hubbard."

"No, actually I was admiring the Baily's beads effect of the sun..."

And the two passengers, silently engaged, were deeply immersed in the ecstasy of their new 4th dimensional world that had little resemblance to New York.

[Egalitarian Thug]

50. What are the odds of surviving a catastrophic failure in a jet? n/t

[Orrex]

41. But nature abhors a vacuum.

I remember seeing a film in school in the mid 80s about speculative technological marvels, among them a coast-to-coast super-pneumatique like this one. We all laughed about it.


Hmm...

[MindPilot]

43. That thing will have to be made of unobtainium

The cabin will have to have a self-contained fail-safe life support system. And it will go through a pressurization cycle every 15 minutes or so. There are some serious technical challenges there.

Seems like a large-scale hi-speed subway might be more viable.

[backscatter712]

44. I think it can be done, just that it'll be expensive.

Airliners do a similar trick all the time - they go through repeated cycles of going from about 1 atm of pressure on the ground at an airport to about 0.2 atm at 35,000 feet or so. And they have to keep the cabin full of air sufficiently pressurized as to be breathable. And they have to do it over and over and over, causing stress and flexing of the airframe.

It's doable, and even doable at a light-enough weight to fly. I don't think that the train vehicle itself will be very hard to put together. It's the tube-tracks & the infrastructure required to keep them pumped free of air. You cannot have leaks of consequence. Leaks are Bad. You have to do this for thousands of miles. And the tracks have to be almost perfectly laser-straight, with only gradual curves with a turn radius of 100+ miles, with no bumps. That will be hard.

[n2doc]

55. Yep. It would be the #1 terrorist target in the US

Plus, has anyone thought this through: we can't even get high speed rail from LA to SF because of all the costs and other issues involved. Even Elon Musk doesn't have 1/10 of a % of the money needed to construct this. None of these folks do.

[oldgrowth]

51. good old ted stevens would have loved this story sure miss him. nt

[geckosfeet]

52. 10 times faster than flying for 10 times less cost?

If it sounds too good to be true,,,,,

Evacuating (even a partial vacuum which it would most certainly be) a tube 4000 miles long would be a chore.

Interesting idea though. Maybe some kind of huge fan system, partially powered by air displaced by the train to create negative pressure in the tube around the train.

[Earth_First]

53. Imagining traveling from the hospital to your home...

...and not have to worry about bankruptcy.

I'm no luddite, however if were going to focus on improvements to society, how about we focus on our general well-being first so that we have a healthy populace that can be around to enjoy future technological advances...

[HiPointDem]

54. i don't see the point of going from new york to los angeles in 45 minutes anymore. why the rush?

[caraher]

61. The appeal for me is that it could be far more energy efficient

If you can pump the air out of the tube for a lot less energy cost than it takes to keep pushing air out of the way for the duration of a trip, and you don't have to spend energy moving (and lifting) fuel, this can result in great energy savings over flying or high-speed rail.

I do think the construction challenges are greater than these people suggest (though at this stage I'd expect them to downplay that; you'd hate to scare off investors!). And the system would be vulnerable to all kinds of disruptions including terrorist attack, though I think the human damage that could be done is much less than attacking airliners (you can't fly one of these into a building, and each unit is so small that you're not going to kill a lot of people in a single attack; but if the system were heavily-used disruptions could be economically costly).

[itsrobert]

72. So Justin Bieber could tape Letterman and Leno on the same day

n/t

[GobBluth]

83. You must not have 3 kids

I travel to MN from FL about once a year. It's 4 hours by plane and at least 2 days (usually 3) by car. My kids are actually pretty good, but still, 4 hours by plane or 2 days will make any kid go crazy. All 3 get that horrible ear pain in the plane. The other problem is cost. Almost $2000 for a family of 5 to fly to MN from FL (usually). We are skipping that annual trip this year, as we need a new roof. Which sucks for us, my parents (who live in MN), my brother and new niece, aunts, uncles, etc.

I'm usually not in a hurry, but for vacation, we only get so much time off. Many Americans only have so much time (if they are lucky) for vacations. That extra day in the care each way can mean seeing Great Grandma or not. Would rather spend as much as time as possible with the people I need to see.

I would KILL to get to MN cheaply in under 3 hours. It's that last hour by plane that is hell for some reason. So far we have been fortunate to not annoy other passengers (I think).

[HiPointDem]

87. i started riding trains alone, with my sibs, when i was about 7, 2.5 hour trip we did regularly

to see our parent. we loved it. seats were comfortable, you could walk to the end of the train & look out the back, the bathrooms were huge and had chairs, and there was a dining car where we got to order.

try going slower, but on the train. being able to get up and move makes a huge difference.

[GobBluth]

88. hee, I checked out a train from Tampa to Minneapolis. shoot, it's like 15 hours.

I'd love to be able to take my time. We are pretty fortunate, I don't work and Mr. Gob gets plenty of vacation. This wasn't always the case though. We could maybe take 7 days, and to spend 4 of them driving (total) really would eat into the time I could see my family in MN. That also limited all my husband's vacation time to driving up to see my family. Thankfully we have much more time. Maybe when the youngest gets a little older we will take a train up there. He would love it!

[madrchsod]

57. i like this concept....

http://www.google.com/imgres?start=87&sa=X&rlz=1C1CHFX_en&biw=1280&bih=610&tbm=isch&tbnid=AsTHo7toziKxLM:&imgrefurl=http://blog.modernmechanix.com/issue/%3Fpubname%3DPopularScience%26pubdate%3D7-1934&docid=8nUs7qnL4FaWBM&imgurl=&w=2528&h=3414&ei=d4iwUeWZI8TtygHCyIHYBg&zoom=1&ved=1t:3588,r:1,s:100,i &iact=rc&dur=867&page=4&tbnh=186&tbnw=146&ndsp=31&tx=63&ty=78

[HereSince1628]

59. I think I saw this in a 1964 Popular Mechanix... n/t

[BlueStreak]

63. I'm still waiting for the airplane-car that mag has been predicting for 60 years

As if having 1,000,000 cars buzzing around the sky is our future.

At least this rhino tube thing would have some possibility of managing the traffic a little.

[Bluenorthwest]

60. First NYC subway was pneumatic tube style

The City's first subway opened back in 1870, a short underground tunnel under Broadway that stretched 312 feet (95 m) from Warren Street to Murray Street near City Hall. Constructed by inventor Alfred Ely Beach, the editor of Scientific American, the subway was driven by pneumatic power. An eight-foot (2.4 m) long car that could carry 18 passengers was blown through the tunnel by a 100 horsepower (74.5 kW) fan; the blower was reversed to create a partial vacuum and suck the car back through the tunnel. Although Beach received a charter to extend the line from the Battery to Columbus Circle, the Panic of 1873 and innovations in electric traction motors left the pneumatic subway as a short-lived public demonstration project. Nonetheless, Beach's pneumatic subway helped to demonstrate the practicality of constructing an underground railroad in Manhattan.
http://www.ascemetsection.org/content/view/332/865/

[eppur_se_muova]

75. Beach Pneumatic Transit ... GMTA ....

I about to post this link:

http://sometimes-interesting.com/2012/05/19/the-first-attempted-new-york-subway-beach-pneumatic-transit/

[One_Life_To_Give]

64. Something like this I think

Gene Roddenberry, Genesis II

[Orrex]

65. I can't decide whether this idea sucks or blows.

[sir pball]

68. Having worked with Ultra-High-Vacuum systems before, this is impossible with current technology.

It's an endless game of whack-a-mole keeping four cubic feet evacuated; a 5-foot diameter, 3500 mile long tube has a volume of 362,853,952 cubic feet.

The vac requirements themselves might not be as stringent as in the lab, but even holding even 100x the pressure is categorically impossible with today's technology. Less a pumping issue and more a container issue - once we can extrude a seamless multilayered five-foot graphene tube for the whole 3500 miles there MIGHT be a chance of making it work, but even then I wouldn't trust it. A single failure of any part of the vac system and we all get a graphic demonstration of how dense air can be at 4000mph..

[kentauros]

69. My one question is: Why is it above ground?

At 4000 mph, it's not like you'll be able to discern much of the scenery. Everything will just be a big blur. Yeah, you'll get sunlight (when it runs during the day) but there are many reasons why having it above ground isn't the best method of placement.

First off, people are stupid. Put them behind the wheel of anything, give them even a not-so-obvious target and they'll find a way to run into it. Or, as with railroads, they'll find a way of getting hit. Yes, I know this is not open-air. Just that at-grade RR crossings are always in danger of being an accident site due to the stupidity of people. If we ever have high-speed rail, I do hope the builders realize there can simply never be any at-grade crossings of any kind.

Burying a tube-system like this is the best way to go (not to mention that you'll have to do some kind of long tunnel-boring to get across the Rockies and other mountain ranges.) If you're worried about sabotage, you've already eliminated the ones that can only think in terms of the easy ways, like shooting it, or running a dump-truck into it. Plus, once it's buried, you can further protect it in low-tech ways, such as a half-shell of thick steel over the top half, or even just a two-lane concrete road overhead and along its easement.

That's another thing this would have to use: a dedicated easement, separate from existing roads and highways. Think of your average power right-of-way, usually at least two hundred feet wide, both for safety and future upgrades. An easement that size could also have high-speed rail for those that would like to actually see the scenery.

[itsrobert]

73. At that speed, you take a path around the rockies

NY to Dallas, TX, Phoenix, AZ to LA. You won't lose much time.

[kentauros]

74. You're still going to have hilly grade to navigate.

Someone here mentioned that you won't have turns, you'll have bends, and those based on at least 100-mile radii. Hills are here and gone often in less than one mile before the next one starts. You can't build at grade in that kind of terrain if you can't make hilly bends. Roads and (low-speed) rail don't have such restrictions. So, it would likely have to be drilled its entire length due to this major problem.

As I recall from all those science fiction stories from many decades ago, every single one of them had done this very thing: drilled the entire length to ensure extremely shallow curves and to avoid mountain ranges and other above ground obstacles. You're going to have to avoid cities, too, other than starting and ending, so you drill under them as well.

There are relatively few areas of the entire continent that would be flat enough to have this above ground. Everything else has "wrinkles" and would not be conducive to building this at grade.

http://en.wikipedia.org/wiki/File:North_america_terrain_2003_map.jpg

[BlueStreak]

81. To put this in some perspective

Forget the 4000 MPH nonsense. Let's say they are "just" trying to do 1000 MPH. That means you are covering 4 miles every 15 seconds. What is barely noticeable at 60 MPH is going to feel like a roller coaster ride at 1000 MPH.

And if you start to lose your lunch, there is no lavatory. You are strapped into your seat for the duration.

Going across Kansas, you could build this straight enough, but we're talking a major engineering challenge to make the tubs straight enough to not make everybody sick.

As far a s the view, there wouldn't be any. These are enclosed concrete tubes. The "windows" shown in the graphics, I think, are video panels, so there could be a simulation of what the outside world looks like.

Now think of what it would take to build it straight enough to handle 4000 MPH. This is over a mile every second.

[kentauros]

84. I don't disagree at all.

You just added some good examples of what would happen without grading in basically a straight line I thought it was apparent to most, but I guess I was wrong. People need examples.

Now, one example we could use, just for slower, "terrestrial" speeds is how the Autobahn is designed. No matter where you go on it, no grade is steeper than 4 degrees! They will stretch out any overpass to achieve that tiny grade. And it's all because there are production cars out there that can go 250+ miles per hour. Going at that speed, any grade higher than four degrees is going to do similar things to your body as you laid out for this tube-system. Not to mention the fact that people would lose control of their vehicles far more often if the roadway wasn't built for higher speeds like that.

[BlueStreak]

85. And we are talking potentially 16 times that fast

In theory, this is "just" an engineering problem. In practice, it is probably something like 10,000 times more complex than building the Hoover Dam.

The fact that the advocates just gloss over these obvious issues tells me that this is not a serious proposition.

With telecommunication, there really isn't such a great need for this super-fast transport from New York to Beijing. High speed rail, on the other hand, serves a very real need using proven technology.

There are loads of trains running in China today at over 200 MPH and 5 years ago the French demonstrated a train running 350 MPH:

That French demo was a peak speed, and I don't know about the economics of trying to run that fast, as wind resistance tends to be exponential. But lets say that 300 MPH is a plausible speed. That is only 50% more than the technology in widespread use and well short of the demonstrated speed. That makes LA to San Fran just a little over an hour door to door if there are no stops, and this would be traveling in great comfort. There just would be no practical advantage of this silly tube idea at that distance.

LA to Chicago would be about 7 hours door to door, which is very comparable to air travel when you consider all the hassles and delays built into air travel. And again, the comfort level would be magnitudes greater than air travel. Practically speaking the tube might cut the door-to-door time in half if all those engineering issues could be overcome. So maybe there is a case for the tube at these distances and beyond.

[kentauros]

86. Personally, I'd rather see the same engineering go into building the Space Elevator.

Maybe they'll do something like that once they capture an asteroid as a counter-weight.

The other nice thing about high-speed rail is that there are plenty of potential customers due to a fear of flying. While I don't have that problem, I think their fears are justified to some extent. Plus, rail travel is even safer than air travel. High-speed rail rights-of-way would also be restricted access, i.e., no at-grade crossings whatsoever. Or, I would hope that would be how they'd design the routes. Otherwise, I'd be wary of their safety, too.

[eppur_se_muova]

76. 4000 miles of vacuum ? Unlikely.

Other systems involve pumping air from in front of the train to in back -- this is how most pneumatic systems work -- use the air, don't fight it. The cost/benefit ratio of removing that last little bit of friction probably doesn't stand close inspection.