# Evacuated Tube Transport shows us the future of travel



## CHamilton (Jun 18, 2012)

Evacuated Tube Transport shows us the future of travel



> A futuristic vacuum train could cut the travel time between the two cities by nearly 90%, or even take travelers from Washington D.C. to Beijing in just two hours — all of this done without ever touching the sky.
> 
> A company called ET3 is currently selling licenses for its Evacuated Tube Transport (ETT) system, which it claims is a safer, cheaper, greener and faster means of transportation. These futuristic “vactrains” are designed to travel through tunnels that have had all of the air sucked out of them to minimize friction, theoretically enabling the train to reach speeds of up to 4,000 miles per hour.
> 
> The concept of the modern vactrain was first introduced more than 100 years ago, when American engineer Robert Goddard drew up specs for a prototype in the 1910s while attending Clark University.


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## Shawn Ryu (Jun 18, 2012)




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## NY Penn (Jun 18, 2012)

What happened to the New York-London tunnel idea?


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## George Harris (Jun 18, 2012)

There were a couple of pneumatic pressure tube urban transit proposals somewhere around 1900 plus or minus. Proved not to be practical. They used leather seals for the most part. Amongst other things rats ate holes in the seals, so that leaks around the seals kept them from working problem. There was also the need fro airtight station and car doors. There were also evacuation problems when the cars failed to move.

I suspect as it is said, the devil is in the details.


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## Hotblack Desiato (Jun 19, 2012)

George Harris said:


> There were a couple of pneumatic pressure tube urban transit proposals somewhere around 1900 plus or minus. Proved not to be practical. They used leather seals for the most part. Amongst other things rats ate holes in the seals, so that leaks around the seals kept them from working problem.



Well, surely at least that problem must have been resolved in the last 100 or so years.


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## ehbowen (Jun 19, 2012)

Other issues I can think of....

Tunneling is about the most expensive kind of construction there is. George could probably give us some ballpark figures, but I can't imagine that the capital cost of a vacuum-tight tunnel from New York to Los Angeles would run much less than half a *trillion* dollars or so. And that's assuming that every Tom, Dick & Harry who owns property above the right of way won't ask for a million bucks for emotional distress and loss of property use. Exactly how much were you planning to charge for tickets?

How do you negotiate fault lines, especially undersea fault lines?

Do you _really_ want to travel in a cramped metal tube with no windows and no view? (Well, recalling my last trip on an airliner on a cloudy day...probably so!)


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## Anderson (Jun 19, 2012)

Just wondering for comparison, but how much would a new transcontinental highway or railroad cost?


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## George Harris (Jun 19, 2012)

What if something goes wrong? Evacuation (of people, that is not of the air.) Fire, stalled vehicle, mechanical failure of some sort, heart attack, hijack, etc., etc.


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## Aaron (Jun 19, 2012)

ehbowen said:


> Other issues I can think of....
> 
> Tunneling is about the most expensive kind of construction there is. George could probably give us some ballpark figures, but I can't imagine that the capital cost of a vacuum-tight tunnel from New York to Los Angeles would run much less than half a *trillion* dollars or so. And that's assuming that every Tom, Dick & Harry who owns property above the right of way won't ask for a million bucks for emotional distress and loss of property use. Exactly how much were you planning to charge for tickets?
> 
> ...


From looking at the company's website, it doesn't appear to be about tunneling underground, but rather tubes on some sort of elevated guideway. Think long straight water slides. Going across oceans would be a little more difficult, and I don't know whether it would be better to just run the tubes underwater and anchor to the sea floor, or if they actually envision raising them above the water and anchoring them to rigs or something.


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## Aaron (Jun 19, 2012)

Also, here are my favorite two pieces of information from the company's website (et3.com)

from http://www.et3.com/about.asp

"More than a dozen et3 licenses have been sold in China, and more than five dozen total in 5 different countries with indications of interest in several more."

and...

from http://www.et3.com/ett.asp

"By purchasing a life-time ETT license for just a hundred bucks..."


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## The Davy Crockett (Jun 20, 2012)

Aaron said:


> from http://www.et3.com/ett.asp
> 
> "By purchasing a life-time ETT license for just a hundred bucks..."


This sounds like companies that 'sell' naming rights' to stars... Link about 'buying' star names - from I*AU * :huh:


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## ehbowen (Jun 20, 2012)

Aaron said:


> From looking at the company's website, it doesn't appear to be about tunneling underground, but rather tubes on some sort of elevated guideway. Think long straight water slides. Going across oceans would be a little more difficult, and I don't know whether it would be better to just run the tubes underwater and anchor to the sea floor, or if they actually envision raising them above the water and anchoring them to rigs or something.


Elevated guideways, particularly vacuum-tight elevated guideways aligned for 4000 mph speeds, are not going to be a whole lot cheaper than tunnels.

Betcha a soda that for less than a tenth of what the first real application of the technology (say, New York to Chicago) would cost to implement, I could successfully develop a workable "Orient Express" spaceplane or Single-Stage-To-Orbit commercial rocket shuttle.


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## Green Maned Lion (Jun 20, 2012)

This can't be built, will never be built, and thank god for that.

Why? Because of the huge underestimation on the price at $500 billion. Yeah right. I wish. Why you ask? Lets talk numbers, concepts and physics. First of all, this kind of system would have to be branched, with one or two central routing points. Given the speeds involved- 2 hours Washington to Beijing would be on the order of 12,000 mph or something like that average- figure 20,000 mph max?- it is still a net saving of time, in all likelihood, to route a vehicle from Miami to New York via St. Louis, just as a for instance. So the items have to be switched. Given the inherent traffic this system would generate, and the relatively low speed a switch could operate (given the weight, which I will get into below), the vehicles operating on this system would have to carry large numbers of passengers- at least in the order of a Jumbo Jet. And it can't be too long- turns at these speeds get tight at radii that are invisible to the human eye.

Given that, the tubes would have to be, I would guess, about the 1.5 times the diameter of the Hudson River tunnels. And, at that diameter, they need to be thick enough to handle relatively explosive decompression, recompression, and the shock waves of a vehicle moving at 20,000 mph. So how thick do you think the walls of these tubes would need to be? A foot? Two feet? Solid steel. Concrete is simply too porous for this job. So we need a tube 30 feet in diameter, with walls 2' thick. Or a circumference of 30π, or 94.25 feet. The square volume of this metal, per foot of length, would be 188.5 cubic feet of steel. A cubic foot of steel weighs 489 lbs. So per foot of length, the steel in this alone would weigh, ahem, 92,000 lbs, or about 46 tons. So for a mile of this transit line, you'd be buying 283k tons of steel. At its current general price of $900 per ton, per mile of line you build, would cost you $254 million.

Keep in mind this is not construction, casting the steel, cost of moving it- dear god- assembly, land acquisition, or any other costs- just the bloody steel for the tubes themselves. The steel alone cost to build a line from Washington D.C. to Beijing, assuming a reasonable routing, taking 11,500 miles, is... dear kindly jesus, 2,929,050,000,000. That is, $2.93 trillion.

What do you think it would cost to create molds? Pour it? Transport it? Assemble it? Create the mounting columns? All that other stuff. I'd say to build this, just the one route, mind you, would cost an easy $15 trillion. Easy.

And what does it get us? Faster trip time? We have video conferencing- we don't even need the faster speed that bad.

I hate the following word- but for all intents and purposes, the project is not so much difficult, expensive, insane, or impractical so much as it is, in fact, impossible.


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## ehbowen (Jun 20, 2012)

Green Maned Lion said:


> This can't be built, will never be built, and thank god for that.
> 
> [...]
> 
> I hate the following word- but for all intents and purposes, the project is not so much difficult, expensive, insane, or impractical so much as it is, in fact, impossible.


I agree with everything you've said...except that last word. Remember Clarke's Three Laws:



> When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
> The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
> Any sufficiently advanced technology is indistinguishable from magic.


Also remember this proverb: "Do you want to make God laugh? Tell Him _your plans_...."


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## Aaron (Jun 21, 2012)

Green Maned Lion said:


> So we need a tube 30 feet in diameter, with walls 2' thick.


The plan as stated on their website is for small pods, each holding up to six passengers, which would only require a tube diameter of 5 feet. They're also assuming the possible use of something besides steel for the tubes. I'm not an engineer, so I can't speak to whether something like sealed concrete will hold vacuum enough for this application, but lets assume it can. That gives you a drastically different set of starting numbers for your equation. Funny thing is, though, after you plug in all the other numbers of what it would take to get this idea working, the conclusion is still the same! Sufficiently close to impossible that it might as well be called that.

Still, if I even saw any short distance proof of concept implementation of this idea in my lifetime, I'd think it was just about the coolest thing ever. Maybe something at DisneyWorld to replace the monorails?


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## rrdude (Jun 21, 2012)

"Derailing" at that speed, even the slower speed of 12,000 mph, could really mess up your day....

(I *know* there are no rails and it's in a vacuum tube, but just the *thought* of a _quick stop_ makes me queasy)

Scenery wouldn't be too hot either, I guess the scenery could be whatever you wanted to program onto the "Windows" (Flexible LCD screen, mounted on side of tubes, to look like a window, maybe even interstellar!)


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## Texan Eagle (Jun 21, 2012)

If someone has THAT much amount of money to spend, I'd rather like to see them spending it on inventing teleportation so that one does not have to endure many hours of travel inside pressurized tubes... or at least 3-D holograms


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## afigg (Jun 21, 2012)

rrdude said:


> "Derailing" at that speed, even the slower speed of 12,000 mph, could really mess up your day....
> 
> (I *know* there are no rails and it's in a vacuum tube, but just the *thought* of a _quick stop_ makes me queasy)


The tube would have to be made in sections. All it would take is a large enough kink in the tube from 2 sections that shifted but was not detected by the safety sensors in time to make for a rather abrupt squeeze. At 12,000 mph, it would not take much for the passenger car to be ripped apart. In a very short period of time. The good part for insurance cost considerations is that there would be minimal payouts for pain & suffering in the event of a fatal accident because the passengers would die very quickly. 

Does no one recall 2 TV Sci-Fi movies made in the early 1970s as pilots for TV series by Gene Roddenberry? Genesis II with Alex Cord and sort-of sequel Planet Earth with John Saxon? (I had to look these up on imdb.com for the titles and info). The premise of both was a 20th century man in suspended animation wakes up in the future after society has broken down into tribal communities (after a WW III I think). I saw the movies many years ago (late night cable maybe?) and if I recall, either one or both movies featured an abandoned vast underground tube transportation system with cars that The Hero used to transport himself from one society or fallen city to another. The tubes may have been evacuated as the small cars moved at high speed. I think the premise was that The Hero would use the tubes to move around to a different society, so if it became a TV series, then he could have a new adventure each week. One week or story arc for a society ruled by women (plot of the Genesis II movie). Next week, mutants! Then, primitive tribe!

The fantasy part, of course, is that a tube system like that would still be working after many years with no one to maintain it. There had be some hand-waving excuse on the power. B grade TV pilot movies at best as I recall.

Just goes to demonstrate that the idea of an evacuated high speed tube transportation system is hardly a new one. But is still an insanely impractical idea.


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## Anderson (Jun 21, 2012)

Well, lets be honest...there's a lot of handwaving that goes on in movies concerning railroad operations (and a lot of other things, but the railroad stuff tends to stand out for me...I won't lie, whenever I see a fictional train depicted, be it in a movie or in a book, I start making comparisons to analogous real life operations...I've seen some good depictions, some bad depictions, and some that depended on one's interpretation of the text).

There was actually a one-scene depiction of one an episode of Sliders that I recall (where you had an overcrowded world and the Golden Gate Bridge was replaced with something like this, with the NB tube on top and the SB tube below; the main difference is that it seemed to imply that they were using larger tubes akin to a full train instead).


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## CHamilton (Jul 13, 2012)

Ultra-efficient 4,000 mph vacuum-tube trains – why aren't they being built?



> Turns out there's a few serious roadblocks in the way.
> 
> Safety is no small concern when you're talking about speeds in excess of 4,000 mph (6,437 km/h). After all, we've all seen the wreckage that can be caused in a 60 mph (96 km/h) car crash. The kinds of tube tracks we're talking about here would have to stretch thousands of miles in order to reach their optimum level of benefit – that's thousands of miles of safety risks. What happens when an earthquake strikes and cracks the pressure seal or destroys the tube completely? A vehicle traveling 4,000 mph is going to eat up some serious distance in an emergency stop situation.


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## CHamilton (Jun 2, 2013)

Futuristic High-Speed Tube Travel Could Take You From New York to Los Angeles in 45 Minutes


> Traveling across the country or the world via any modern mode of transportation is a time-consuming affair. It can also be really annoying with the long lines, crying babies, armrest hogs, cramped space, etc. Would it not be the most awesome invention ever if some new type of transportation could cut that travel time significantly?
> 
> Get ready, because it may only be a few years from becoming a reality. A company called ET3 has plans in the works for the Evacuated Tube Transport, a high-speed transportation tube that uses magnetic levitation. The ETT can travel at speeds of up to 4,000 miles per hour, and each tube seats a maximum of six people and comes with a baggage compartment. How does it go so fast? It's airless and frictionless and could have you from New York to Los Angeles in 45 minutes, as opposed to the nearly five hours a direct flight would take. It could even have you depart from New York and be in Beijing in two hours.


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