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


July 10, 2012

Terraspan's giant, 4,000 mph (6,437 km/h) vacuum tube train, which also doubles as a superconducting power line.

Terraspan's giant, 4,000 mph (6,437 km/h) vacuum tube train, which also doubles as a superconducting power line.

In the 1800s, when pneumatic tubes shot telegrams and small items all around buildings and sometimes small cities, the future of mass transit seemed clear: we'd be firing people around through these sealed tubes at high speeds. And it turns out we've got the technology to do that today – mag-lev rail lines remove all rolling friction from the energy equation for a train, and accelerating them through a vacuum tunnel can eliminate wind resistance to the point where it's theoretically possible to reach blistering speeds over 4,000 mph (6,437 km/h) using a fraction of the energy an airliner uses – and recapturing a lot of that energy upon deceleration. Ultra-fast, high efficiency ground transport is technologically within reach – so why isn't anybody building it?

The next frontier of speed

Vacuum tube-based transport has a lot of things going for it. Speed, for one. Anyone who has spent time on a fast motorcycle knows that even without any wind, the air itself is a brutally powerful force working against your engine as you get up above 125 mph (200 km/h). In fact, air resistance is the number one problem to combat as speeds increase. Airliners have to fly 40,000 feet up in the air to take advantage of the reduced drag you get when the air thins out a bit. And even with this advantage, they still can't cruise much faster than 570 mph (917 km/h) without being horribly inefficient.

Take air resistance and rolling resistance away by operating in a vacuum and magnetically levitating your vehicle, and you're eliminating the biggest two hurdles to achieving extremely high speeds. And once you reach your top speed, you simply stop accelerating, apply no further energy, and coast. You lose very little speed until you reach your destination, at which point you can slow your vehicle down electromagnetically and recapture almost all the energy you put in to speed it up.

Theoretically, with the right length of vacuum tube set up, you could zoom all the way around the world in a matter of hours, nearly ten times faster than today's airliners. Operating in a vacuum, these vehicles would make almost no sound, even as they smashed through the sound barrier, because there'd be no air for them to create sonic vibrations in. With no actual points of contact or friction with the track or tube, there would be virtually no energy lost to heat dissipation.

The vacuum-tube revolutionaries

There are no shortage of people and groups pushing for widespread adoption of vacuum tube technology as a superfast travel option – after all, with the demise of the Concorde supersonic airliner, mass global transit speeds have remained stagnant since the 1960s. Sending an e-mail from London to Beijing might be instantaneous, but the rest of the world still feels like a long way away if you have to physically travel around it.

We recently wrote about the ET3 consortium, a licensing organization that owns a number of patents in the evacuated tube transport space, Acabion's vacuum tube streamliners, and the gigantic Startram space elevator project, which would make use of the low energy requirements of the vacuum tube maglev idea to cheaply propel various objects into orbit.

Another contender with an interesting take on the technology is Terraspan, a group that wants to combine superfast transport with the creation of a new intracontinental power grid that can make much more efficient use of the cycles of power creation and usage across a large country like the United States.

Here's the plan – for step one, Terraspan would like to build a backbone network of underground vacuum tube train tunnels linking eastern Canada to western Mexico through the United States. Embedded in the train tunnel network would be a series of thick, superconducting energy cables that would form the heart of the first true continental power grid.

The benefits of a long-distance power grid are simple – you can take the energy produced by solar and wind producers in the arid central areas of America, and make it available to much more densely populated and power-hungry areas on the eastern and western coasts. You could also make more efficient use of power creation and usage cycles – energy that's created in California at off-peak times can be sent across the grid to be used in peak hour in New York.

So here's a plan that wraps up super-fast, ultra-efficient, convenient transport with smart energy usage and a tangible boost for renewable power creation schemes. Let's go, right?

The case for the negative

Of course, if it was that simple, we'd already be blasting around the Earth at orbital speeds like they were predicting in the 1800s. 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.

What's more, there's really very little precedent to show exactly what happens when a populated carriage goes from ultra high speed in a vacuum to being struck with regular air pressure. Terraspan's website details a plan to shape the trains with a sort of air wing to bring them down gently in the case of pressurization, but one can easily imagine that being battered to death at the top of the tunnel would be just as bad as crashing to your doom at the bottom of it. How can you hope to control a 4,000 mph airfoil within a tiny tube when the air pressure onset is sudden and unexpected?

The thing about maintaining a total vacuum is that one hole in your structure compromises the vacuum almost immediately. And it's not hard to dream up a dozen situations, whether natural disasters, man-made errors in judgement or acts of war or terrorism that could easily crack or break a structure like this.

Then again, let's say these safety issues can be adequately addressed. Perhaps the more pressing obstacle – at least for the time being – is a purely economical one. Mag-lev train lines themselves are exorbitantly expensive: Japan's Linimo HSST, a low-speed suburban mag-lev line, cost around US$100 million per kilometer (0.62 miles) to build. And while China hopes to get away with only US$18 million per kilometer when it extends its high speed Shanghai demonstration line, neither of these trains require air-tight tunnels.

Add to this the hidden cost of maintaining the vacuum (presumably by constantly pumping air particles out of thousands upon thousands of miles of vacuum tube) and you're left with a very costly proposition. And that's not to mention land acquisition – which could prove tough, as these machines move so fast that their turning radius is gigantic and route choices will be limited.

So where is vacuum-tube transport likely to go in the next few decades? It's hard to say – although it seems extremely unlikely that a cash-strapped United States or European Union member would be willing to pony up and lead the way.

Note: edited for correct physics - thanks guys, you can always rely on Gizmag commenters to keep our facts straight!

About the Author
Loz Blain Loz has been one of Gizmag's most versatile contributors since 2007. Joining the team as a motorcycle specialist, he has since covered everything from medical and military technology to aeronautics, music gear and historical artefacts. Since 2010 he's branched out into photography, video and audio production, and he remains the only Gizmag contributor willing to put his name to a sex toy review. A singer by night, he's often on the road with his a cappella band Suade. All articles by Loz Blain

BRAVO! Well Said Loz Blain!

Alastair Carnegie

I see a lot of good comments today here. However no one seemed to notice one bit of detail. Why a train ? Why not smaller "personal" elements that would require much less energy and diameter to speed through ? Of course braking and traffic management of each individual cell would be a real safety issue, but hey, they would all be automated. On the plus side, if an incident were to happen, the amount of cargo (or worse, people) trapped, injured or dead would be significantly lower since we wouldn't be having a train to stop/calculate damage to but just a smaller pod weighing... let's say 1 ton, therefore much easier to stop.

The tunnels needed in that case would also cost MUCH less money to build and maintain while they would also be more practical to build (imagine only having to occupy 3m in diameter instead of 20 or more). They could also be build above the ground as digging for such a small tube would be impractical and the extra earth around it could require stronger tunnel walls because of higher underground pressure.

Another thing that everyone seems to forget is the fact that the train is marketed as 4000mph but it doesn't necessarily have to be so. I personally would consider it a marvel of modern engineering if such a project would be put in practice at speeds of only 1000mph, thus requiring much shorter breaking distances and energy consumption levels would definitely sink.

Regarding emergency breaking systems, I'm sure that a manual switch between "break" and "accelerate" at localized management stations (every 100miles along the lines) would suffice in case of most emergencies. There is of course always the possibility of war or terrorism, as stated above, but let's be honest, how many of you have considered what would happen in case of war or terrorism on a 8 lane highway at rush hours ?!!?!? We can't let fear of new technologies govern our lives, that's what the Catholic church did during the middle ages, and look where that got us !

Stefan Padureanu

Where do I start......

It's useless unless it goes coast to coast. Distance between LA and NY is around 2400 miles. Sealing all that....good luck.

If you were going to do it. Why not two narrow diameter tubes, instead of one huge honking one. Look at the SST and the Concorde. Narrow hull. That way, even if you could lower the atmosphere by an appreciable degree it wouldn't need to be a vacuum. Which brings me to my next point. Carrying atmosphere for the passengers.

And no one has built a maglev of any appreciable distance. I'd make it a highspeed corridor on a narrow lifting body and call it good. At least that isn't a pipe dream. No pun intended.


High speeds in tubes are best attained by very long trains of tiny frontal surface area vehicles not much larger than a single person. High speeds would mean that serving meals and bathroom breaks on a train would be unnecessary, thus no isles would be necessary. Stations would have very long boarding platforms into parking lots with cabs ready and waiting, pre-positioned. A break at a station for a meal would mean a stop of you and your aero-car. IV nourishment, catheters, and anesthesia could move masses of people more efficiently over interplanetary distances. Tickets would be purchased online so stations would no longer be needed. Having everyone lie down head to foot boarding the train would maximize speed and minimize supporting infrastructure. Small diameter pipes are easier to design than large ones. Similarly light weight bridges could be used instead of massive expensive structures. Yes we could do it, but why?


Even if it was the perfect ride, @ 4000mph, what would that break neck momentum do to the human body? Does this thing also generate its own gravitational field? If so, it belongs in a discoid aircraft in space, not a tunnel under the ground.

Randolph Directo

I would put my money on a normal-air-pressure solution, running along or above highways, electric powered, fully-automated, modular and regulated to allow for easy and flexible shuttle cargo and passenger traffic with thinner infrastructures and lighter vehicles.

Monster projects are nice to admire on paper but not very practical. The ROI on this thing will be horrible unless we're talking about a mid-Europe/mid-US to Beijing sort of investment, where there's tons (pun intended :) of cargo traffic.

PS. I work for a rail company ;)

Τριαντάφυλλος Καραγιάννης

Not to mention....what happens if the train loses cabin pressure? You gonna put everyone in a pressure suit to prevent the passengers from boiling in zero atmosphere?


Good balanced overview. They will never get the construction costs back: twin 50m bore tunnels over 1000's of kilometres? And keeping a vacuum in that volume? good luck to that.

So much wasted volume, why not go for more conventional train dimensions? it's not as if you're constrained in train-length. ET3 is too far the other way for my liking, too claustrophobic. And superconducting power distribution? maybe, but you won't get the energy back either from this project.


Would be nice to have more info on how they would generate the vacuum, and what quality would be required/maintained. Could a design be developed whereby high level vacuum on has to be maintained around & ahead of the train, easing off once the train has passed? Another thought, and possibly daft - but if you can't maintain a vacuum, how about increasing the air speed in the tube? If the tube was circular, could air speed be pushed up to 500mph+ to offset any drag at the same speed? Trains could enter & exit the main 'loop' via separate connectors so that the air speed wasn't an issue when stopping at the destination.


Look,to all the naysayers.. they don't HAVE to go 4000 MPH.. the point of the article, is the same as all the 'popular mechanics' magazines of the 1950's that asked "if we have the capability of 100 miles per gallon engines, why aren't we building them?" or are you too young to remember those issues.. Oh the pain of age...;-(

Doc Rock

it would be far cheaper and easier to build spaceplanes that fly above the atmosphere.


Removing wind resistance takes away a huge constant loss, but the energy needed for acceleration to high speeds is not affected, and not trivial. Kinetic energy increases as the square of speed, so an earthquake or other surprise could turn the train into a big explosion. @JPAR - the total skin friction in a tube is far greater than that on a train, unless the trains are extremely close together.

Bob Stuart

whoa! all we need is a tube that goes around the globe and a ride in the centrifuge for 10 min and we will have our brains descend to our you know what... and have an over easy fried brains sunny side up with a garnish of popped out eyeballs. Don't we already have that? what fun.

Mukul Rawat

4,00 mph are almost 1,800 meters per second. If we accelerate at 1G we need three minutes to reach that. Let's assume a mass of 440 lbs (200 kg) per person including luggage and vehicle then our vac train would need some 480,000 hp per person at target speed. If we allow for a longer acceleration time we could reduce this to, lessay 100,000 hp per person. If a vehicle has 500 seats we would need 50,000,000 hp. I think this it's a demanding task to supply such power and engines / motors will probably rather heavy.

Oh, and 4,000 mph at earth surface reduces your weight by 5% due to centrifugal forces when travelling on a great circle around earth. Tracks different from great circles require more narrow turns leading to higher centrifugal acceleration.

Thomas Bremer

There's no profit in efficency so obviously it won't happen.


Quote: TogetherInParis " serving meals and bathroom breaks on a train would be unnecessary"

There's a statement from someone who apparently doesn't have kids.


Well that´s a good question but poses many more questions and technoligical problems. A much simpler question is why don´t we see diesel planes. True they would be slower but sooo much more efficinet and cheaper to maintain. A jet engine gives a tremendous amount power to weiight ratio but are real fuel guzzlers and very expensive to maintian. The Germans flew many transport planes in WW2 with Diesel engines at a time when the Diesel engine was still in its infancy and had a really poor power to weight ratio. BUT they are ideally suited as a Diesel is at its best as a stationary engine and that´s basically what a plane engine is: once in the air the RPM does not change. OK we would give up speed and maybe by quite a margin, but who would not like to travel give up a few hours to save a bundle.


I have been working on this design for 20 years.

First you have to eliminate acceleration and deceleration for the system to work.

Therefor a continuous speed is maintained in the main transport train. The best solution is to have two tubes encircling the earth one for east bound travel the other west bound travel.

Passenger access to these trains traveling at a constant 4000 mph is accomplished by separate local circulating tube trains stop at a station, pick up passengers, accelerate to match the speed of the main transport train, dock with the main train to allow passenger loading and unloading, and then detach decelerate and return to the station and stop.

Several east bound and west bound train units travel in the same tube to provide timely schedules. It takes the first train 8 hours to circle the world but if you want hourly trains you need 24 units traveling in the east tube and 24 trains in the west tube. So you get up in the morning in New York, get on the west train and get off in LA 40 minutes later. At the end of the day in LA you get on the east bound train and get off in New York 40 minutes later.

Chances are the acceleration and deceleration time will be as much as the travel time.

Problems not yet solved are the vacuum locks or an alternative technology to overcome the air resistance in the tube. A continuous train without spaces would solve this but the CAPEX would be astounding, (i.e. two 24,000 mile long trains) but no waiting.


The title "ultra efficient" is a bit misleading : the energy needed to dig the tunnels, to carry out excavation work and to build the tube infrastructure, plus the energy needed to constantly vacuum these tubes will surpass by far the energy of supersonic flight like the Concorde ! This project will never see the light of day.


alaskaken, what happens in an airliner if there is a loss of cabin pressure? Loss of vacuum in a confined space would be like a meteor hitting earth's atmosphere. You could suck the air out in front of the train, and use atmospheric press behind the train to help push it along.


Because nobody wants mass Build a city longitudinally with each of its elements (residential, comerical, parks and recs, and industrial) along single boulevards. That way you drive down one road to get home, go to work, go to school or go shopping. You put the residential elements at both ends with industrial in the center. No more traffic lights, no more accidents and no more commuting 70 miles to work. You eliminate traffic and fatal accidents, while saving energy.


@Bill.Smith.Sa Sir I admire your enthusiasm and the fact that you've spent a lot of time working on this project but I would caution you to not let yourself get carried away by an idealistic 4000mph global train system. Coupling a smaller train with the main one at those speeds poses huge security and engineering issues, while the costs of running the 48 trains alone would never be resource efficient (unless maybe we finally develop fision until then).

@Thomas Bremer I din't wish to sound like a smartass but I'm pretty sure those calculations don't actually depict the truth. Please be so kind as to explain first how you would require 480k bhp / person, which conditions, what length and size of train, how many passengers or cargo.

Stefan Padureanu

Faster and faster. Faster cars, faster planes, faster trains. I often wonder what the point is of all the massive investment in research and infrastructure to achieve this when it is all ultimately wasted by then spending 10-15 minutes in a queue at a rest stop waiting for a coffee, having to arrive two hours in advance for a flight and waiting in line at border control for hours to get into the USA or UK.

There was a great comment on the radio here in the UK when the 13 billion pound project to extend the Hi Speed Eurostar line from Dover to London was being discussed. the project was going to shave half an hour off the journey time. An old lady rang in and suggested "couldn't they all just get up half an hour earlier?". There was a stunned silence from the politicians and train techies on the show, then, one by one, they all had to admit that that, yeah, she had a point.

Doug MacLeod

Lets go right to basics - the tube only needs to be 0.5m in diameter..... basically you get put into a hypnotic sleep (or drug induced sleep) prior to being put into a horizontal coffin like capsule - then you are 'shot' to your destination whereupon you wake up with no memory of the journey.


When we think about a high speed train, we should realize that today, trains mostly transport cargo, not people. This one fact takes a lot of the problems out of the picture.

We would need two tubes, one for each direction. They could be built from steel pipes. I don't think the idea is far fetched at all.

Weasel Squeezil

@Stefan - Indeed. Smaller pods seem more practical. If you could model it after the cardiovascular system you would have more options and safety, With branches of systems, you could merge into different corridors. Use a vacuum pull / push mechanism to provide moments of startup and stop for two tubes going in different direction. Wrap the cell pods in bumpers and you would bounce off your neighbors. An automated computer system would pull your pod out of the main line based on your destination.


We have lost our way as a species. We need to get back to gentler times when things could wait.

The Spanish have a lovely word: 'mañana'. It is supposed to mean 'tomorrow', but in practice it means 'not now'. When you learn the difference, you will understand one of life's greatest secrets. We don't need to rush here, there and everywhere. Chill out, enjoy the journey, you might even wish it took longer not shorter.

Mel Tisdale

Infrastructure isn't about near or medium term profit. Look at the highway system. Look at our space 'system', people like to give it a hard time as a money waster, but NASA tech has made every GPS and telecommunication technology possible that we use today. Cost-wise this would be a great place to put money INSTEAD of the drug war, or endless 'security' upgrades against imagined shadow enemies.

There are several digging projects using boring machines in the US today, like the recently completed sewer project in Portland,or. So the digging technology is available.

Little known is the fact that in several of these projects the 150 million dollar boring machine is abandoned in a suicide tunnel after the project is completed. This was done with several of the boring machines in Europe. Just purchase one of these machines at a discount and continue digging.

Often times high speed rail requires the purchase of very high cost right of ways through private land. This adds massively to the cost. Eminent domain isn't used nearly as much nowadays as it was in the past, due to the risk of lawsuits. Tunneling bypasses this expense since many states dont include underground rights with land ownership.

If your building a tunnel deep underground/underwater, it is necessarily airtight. Its very hard to poke a small hole in such a structure. The only place this would be a real worry is near stations. We have a number of technologies that can quickly reseal tubes, especially when they use negative pressure. We've had resealing fuel tanks on airplanes since WWII, for 1 quick and vaguely related example.


What would work here is to sell the idea. You need to convince people that it is fun to ride a train or something. Years back on early visit to the DW, I rode the Mono rail and thought it was great fun. I still do today though it could be updated...Make the journey interesting yet speedy and people will want to use it. They don't like to be told it is more efficient (though it may be) they don't want to be told it is good for the environment (though it may be). You want to create a feeling of traveling and adventure. This will get people interested. The method you use wouldn't be this massive tube system but something closer to the monorail system. Something modern (even if it doesn't look that way) Make the trip more exciting and people will want it.


northrop grumman had a tethered ekronoplane as a possible alternative to quick surface travel. it was called TTWIG-TRACK TETHERED WING IN GROUND EFFECT

hummer boy

Don't know about Terraspan however, sounds similar to Aqua=Terra T.W.I.N.S. (Trans-Web Infrastructure Network System) projects ( that propose a sub-surface transport system on land and sea and does not require taxpayer moneys, however, does require government participation and cooperation.

Aqua=Terra Planetary Holdings, LLC

I like the idea but in practical terms it's waaaay tooo complicated! It would be a thousand times easier and more cost effective to simply use the same tubes to launch vehicles into space, or close enough to have to use very little fuel to escape earth's atmosphere and enter a ballistic trajectory. Breaking is done by the air and the fuselage and you just have to land. Safer than a catastrophic puncture anywhere in the system too. Cheers!

Alfredo Balmaseda

I think the Transporter will be invented before this becomes a reality :-)


Just wondering why you couldn't put 'check valves' in the vacuum tunnels at regular points and let the trains themselves pump the air out of the system...

Larry Hooten

This idea would be great for cargo and mail, smaller tube, if it fails you pick up the mail,6 ft diameter would work great

Edward Marchand

The response is truly wonderful! So much interest!

For those concerned the Space Station travels at 17,500 mph and so do the people inside- no problem. Its acceleration not speed that counts. Terraspan accelerates much, much slower then a rocket about the speed of the moving sidewalk at the airport.

Since Mr. Blain has chosen to pan terraspan, and most of the comments line up with him. That Gizmag made no effort to fact check or even contact terraspan is sad.

I can assure you this is true for its I that would have seen the enquiry for the last few weeks. Perhaps he tried and it was broken I'll check.

First terraspan is primarily a power distribution system with a complex HVDC and superconducting backbone, described simply because the complexity of the actual triple back-up installation and maintenance design is both way too technical and complex as one would and should expect from a many hundred kilovolt DC distribution grid. It will be built out from each coast and immediately begin doing its job of delivering power long before it hooks up across country or delivers freight followed (after proving its safety thereby) by passengers.

Second terraspan will store power in its carriages or cars. Terraspan is not really a train but a collection of independent cars. It can store terrawatts of power that is instantly available to the grid.

Finally terraspan is a transport system for freight and people. Any concern about the ability of the carriage design to self decelerate in a complete power failure IN WHICH THE EMERGENCY ESCAPE TUBES WILL BE AUTOMATICALLY OPENED TO THE SURFACE AIR will be thoroughly tested and debugged before the first carriage carries the first passenger.

There are many, many more interesting and powerful elements to the terraspan design to make it cost effective and profitable to implement today. Here are two:

Most of the length of terraspan will be in prefab "pipes" just like giant water or gas pipes laid in DITCHES not bored tunnels at orders of magnitude less cost. Note in both water and gas pipes the pressures held in are 10 TIMES HIGHER then the atmospheric pressure trying to come into the terraspan vacuum. Yet these pipes criss cross all the continents of the world (except Antartica).

More then 7% of all power made in the US alone is lost to long distance distribution losses, further another 3% is lost in maintaining baseline power generation that is unneeded. This is many billions of dollars per year. The opportunity exists for terraspan to substantially save this "lost" power and more across most of North America as the first serious buried high reliability transcontinental HVDC power grid (superconducting is a DC grid and some and eventual all of the backbone will have a superconducting component when the price/performance/per delivered kilowatt makes sense). Terraspan will work through fires, floods, hurricanes, tornadoes and even tsunamis.


Well, it might work OK on the moon. Down here, it fails the back of the envelope calculation.

Captain Obvious

The tunneling problem is huge...look how long the Chunnel took, and it was merely boring chalk. I suggest we shelve this idea for now and focus all of our efforts on interstellar transport. Once we solve that one, we can bring back some Hortas and build a network of these tunnel trains with almost no tribble at all.


Dear Loz Blain,

Accelerating an object from 3000-3050 mph takes 40x as much energy as accelerating the same object from 50-100 mph. (Look at the change in kinetic energy which is proportional to velocity squared) It will take the same force to produce the same acceleration, but power increases proportionally with velocity and acceleration.


Jason Cuadra

WHAT GREAT INFORMED AND CONSTRUCTIVE COMMENTS ON THIS ISSUE! Now that I've buttered you all up (though the compliment is sincere)... I'm no ace physicist or engineer, but there are a few additional points I can bring to this party: 1-The folks who brought you our present societal structure - ecocidal, criminally predatory and unequal, overweeningly oppressive and 1%-centric - have little interest in sharing their carefully constructed honey pot (think Pooh Bear sitting on that tree branch in a flood) with any of us hoi-polloi until it no longer matters. As we have seen, those who are foolish enough to threaten their hold on such ill-gotten gains get the 4-step treatment leading to the would-be usurper's (or her/his invention) removal as said threat. Call them Illuminati, Committee of 300, CFR, whatever, it is they who must be gotten out of the path to progress before any ideas, such as this one, will ever see the light of day. Planetary economic meltdown may be the only way to awaken enough of humanity to oust these bastards from their perches. It is the one thing they fear. 2-If the above gents (aside from a royal, or two) gain control of this tech, or any other, one of two things will happen: 1) if a profit can be made, the neessary funds will speed it to a store near you, asap; 2) if no, or insufficient, profit is to be made (anything provided gratis by Mother Nature, for example), said "advance" will be denied humanity by any and all means deemed necessary (and I do mean "any'). 3-For a primer on how calculatingly successful this infinitesimal group of (alleged) humans has been in prosceuting their agenda, go to the Suppressed Inventions section of, or read a book by that title by Jonathan Eisen. There's much, much more, but that will get you started. 4-Finally, there is no need to build a network of underground tunnels as it already exists under the good, old U.S of A. Mais, no, say you. Oui, oui, say I. Try this link and see what you think (ask not for whom these tunnels were built - you won't like the answer).


Remember, just because you're paranoid doesn't mean somebody isn't after you.

After reading this great mag for 2+ years, I'm finally making a comment. But, then, I finally had something worth saying. Cheers, NjW




"How can you hope to control a 4,000 mph airfoil within a tiny tube when the air pressure onset is sudden and unexpected?"


There is an extensive body of work concerning airfoils in tubes. A body designed to be stable in an atmosphere based solely on its shape and relationship to the tube walls is stable. It's stability is related to and will be will be familiar to pilots as the "ground effect".

Despite Mr. Blains concern such a shape cannot be "surprised" nor does it ever "expect" anything. Except in the emergency the shape moves in vacuum and has only a safety and perhaps style function.

The terraspan Safety Airfoil is truly Fail Safe and independent of power, or human intervention.

After the carriage comes to a safe rest the tube is filled with air and safe for the passengers to traverse to emergency exits.


You don't want "trains", you want individual carriages. Imagine: you arrive at a station at any time day or night, tell a computer terminal how many in your party and your destination, a correct size carriage quickly arrives, and off you go, arriving at your destination in two hours or less, no matter where in the continent it is. You don't need 4000 mph carriages for that. For short runs, a couple hundred mph is adequate. You could have private carriages that would follow you wherever you go above ground.

Most of the energy that is put in to accelerate the carriage is recovered when you slow it down.

The tubes have evacuation pumps every hundred feet or so. If air starts entering, the pumps fire up and keep the vacuum to manageable levels.

We need to start by building an east-west freight line.

Randolph Lee

I desperately hope that vacuum tunnel train is never built because only a fascist government could put the resources together to build it. ...................................................................................................

re; mystixa

About your number 3.

Would you buy a car for a daily driver that has all ready been driven for its design life? ....................................................................................................

re; freesense

Do you really believe that glass is enough denser than solid rock that you could build a tunnel that way? Have you ever seen the effect of tossing an ice cube into a hot deep fryer? On average it takes to 18-35MJ (5,000 to 9,700 watt-hours) produce 1 kilogram of glass and glass weighs about 2.58 kg per liter. How much energy would it cost per linear meter of a tunnel with a 3 meter bore by melting?


The biggest issues are safety and maintaining the vacuum in the tube. Here is the solution to both.

Build a space elevator at one end. Run another tube up the accelerator cable into the vacuum of space so instead of using huge pumps do depressurize the tube, simply open up the 'valve' and let the air flow out into the vacuum of space. This "valve" could stay perpetually open while the tube is in use, this way in case of a leak the air would rush through the tube up the elevator shaft into space preventing a Quick Amassing of air in the tube itself, giving the train time for an emergency stop. Than the "valve" can be closed so that the tube fills with air until the people are rescued and the crack is fixed. Most cracks would be smaller than the elevator vacuum tube(diameter wise) so that would make it impossible for a sudden build up of atmosphere in the tube. This is in addition to not having to artificially pump air out so the next greatest cost, (to building it)-keeping the vacuum perfect, would be eliminated.

AnOld BlackMarble

Amtrak already requires subsidies for every passenger and it runs sub 100 mph. Think what subsidy this might cost? I can take a Mega-bus for about 1/6th the cost of Amtrak. Private enterprise works, kids.

Yes, let's use up the remaining supply of rare earth magnets. And let's use up the remaining supply of copper And spend Trillions more of our kid's money.

As an engineer it is nice to keep in mind (non-train) applications for this idea. But it is obvious decentralization, market forces, and incremental change produces better results for society than large political programs such as these.

Think about Darwinian evolution (decentralized, market forces, and incremental changes) next time.


About your number 3. Would you buy a car for a daily driver that has all ready been driven for its design life?

Certainly. Look at the mars rovers.. look at the entire used car market, look at the B-52.

Thats one of the major failrures of the modern US economy.. we look first to the newest, most high tech, most technological solutions to even the simplest problems. That immediately drives cost up and causes many projects to not even be started.

Corollary to that question.. do you automatically dispose of all things simply because they have reached their design life? What if you have followed maintenance procedures in such a way that that life could be extended by experienced operators?

(from the i-45 project page) estimates of boring machine costs 6 lane tunnel - 160 million per mile (from 5 yard tunnel through solid rock - roughly 48 million per mile.

(numbers from cost for a laid pipeline, ~$100k per inch/mile

so for an equivalent 5 yard pipe- roughly $18,000,000 per mile. (flat surface and assuming a linear cost per size)

So a combination of methods would likely have to be engineered. Sometimes going over rock might be better, sometimes going over mountains like the rockies might not be practical, or perhaps old train tunnels could be repurposed.

Its time to look at how to get things done, and solve the engineering problems needed to get there, not find reasons they cant and stop there. Thats how great things get done.


What about a pneumatic train? A circular design, having the air help propel from behind and move forward in front a mag-lev train in a closed air tunnel? Seems like that would prevent resistance similar to a vacuum but wouldn't be as dangerous if there is an air leak. Have a way to route air pressure around a train while it stops if there are other moving cars in the same system.

Jake Welches

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

No it doesn't. Energy goes with the square of speed (kinetic energy = mv^2), so it takes just over 40 times as much energy.

Plz to fix.

Confused Vorlon

Feasible: absolutely. Necessary: no. Worthwhile: Maybe. Interesting: Incredibly!

@Thomas Bremer The horsepower is calculated this way: V0 = 0 m/2 Vf = 1800 m/s a = 4.5 m/s^2


8,025,000,000 (8 billion) tons gets shipped globally and 75% of that is between 20 countries or so.

Connecting them all with maglev vacuum cargo trains would cost around 100 billion USD for construction cost.

10,000 miles x $10 Million p/mile cost = 100 Billion USD.

Now if you charged just $0.5 for super fast cargo delivery (from china to Europe within 2/3 hours) the market could be around 4 Trillion USD.

Averaging out for $0.03 shipping commodity prices and $2/$3 consumer freight.

Spend around a 100 Billion (chump change if Oil companies start an Alliance together).

ROI of over 4000% within a year of operating. Profitable? Even at 5% of the global shipping market it is still around a 200% ROI at 200 Billion USD.

With these return rates, every major city can be linked to the maglev network.

Abdi Mahamud

Does it have to be propelled by maglev tech? Only the levitation bit is needed. And they should also rethink the size of the vessel. It should be less expensive and easier to design in a smaller scale. Makes sense, industrially speaking. Smaller is easier to design, produce, and construct, in general. And the speed, does it have to be as close as possible to the theoretical? I would be happy with airliner speed. Besides, we wouldn't have to be 1 or 2 hours earlier at the port (I think).

Nitrozzy Seven

How about you flood the tube and supercavitate the train?


Hey Loz,

There's an error regarding the energy to accelerate 50mph at different speeds because energy is not linear with speed, it's proportional to the square of the speed.

Energy = 1/2 mv², so

50->100 = 1/2 m(7500) 3000->3050 = 1/2 m(302500) (units are a little funky due to mph)

but the ratio, as someone else said, is 40:1

Daven Hughes

Well, it sounds like there are some very smart people working on this idea. On paper, in math, engineering, physics, and design. The only thing I could add, would be that there is no place, on this earth, that I need to reach that quickly.

Our pioneers often camped within sight of their last night's camp.

So, factor this into your calculations. I don't need this.


The primary resin for building an evacuated tunnel transportation system (vacuum tube) is to reduce drag and reduce the energy required per mile traveled. Increases in speed are a very desirable by product of drag reduction. In the 1960s, it became technically possible to build supersonic airliners. Europe, the US and the Soviet Union all started programs to build them, but only the English - French Concord saw regular passenger service. It was a technical success, but an economic failure simply because supersonic air travel requires to much energy to be practical.

The energy losses to air drag (and the cost per mile) are primarily proportional to the pressure of the gas being traveled through. Reducing the pressure in the vacuum tube to 1/100 atmospheric pressure will cut the air drag on a vehicle by a factor of 100. The power required to propel a vehicle 300 mph sea level pressure will allow travel at 3000 mph at 1/100 atmosphere pressure and reduce the energy required per mile by a factor of ten. Reducing the pressure to 1/10,000 of an atmosphere will reduce the energy per mile to 1/100 that of the 300 mph vehicle. Further reductions in pressure and energy savings are probably not needed, but vacuum systems are easily able to reduce pressures by an additional factor of 10,000.

Air drag never goes to zero and magnetic hysteresis losses will be significant. Because the number of vehicles traveling in the system will be high, heating of the residual gas in the tube will be significant and perhaps a limiting factor in system capacity. A cooling system will be needed to keep the temperature inside the tunnel down to a reasonable level not much over 100 F.

It turns out that the least expensive place to build the tube is in the ocean as a submerged floating tunnel. It will be far faster to construct per mile than a tube either above ground or buried. It is conceivable that a transatlantic tube could be constructed in as little as 3 years. This rapid construction time improves the affordability dramatically as the time from the start of the project until revenue is produced is reasonable. However a basic land side system will need to be in place before starting the transatlantic tube so a large passenger capacity will be available on the land side when the transatlantic tube starts service.

In the US, the Washington - New York - Boston Amtrak service area is the logical initial landslide US coverage area. Constructing this part of the system will likely take at least 10 years and probably much longer. The land side system can be constructed in short sections that can be accommodated by conventional financing.

The economics of the system look reasonable. In all other transportation systems, energy is the primary cost driver. The cost per passenger mile in a vacuum tube system appears to mostly covering the interest cost of construction financing. However, maintenance and then vacuum pumping could easily become cost drivers. The energy used in a transatlantic trip probably would be about 1/10 that of air travel. If the total of all other costs can be kept close to the cost of energy the system would replace air travel. A top speed of 3600 mph will produce transatlantic trip times under 1 hour, Washington to New York less than 10 min and Washington to Boston less than 15 min.

For a transatlantic tube to be feasible, the marginal cost per trip will need to be much less than air travel, and the system would need to have the capacity to handle all the transatlantic traffic. Transatlantic air traffic is the order of thousands of planes per day with several hundred passengers per aircraft. When the large numbers of passengers is taken into account, it is clear that each vehicle will need to be sized for 50 to 200 passengers and have the ability to be assembled in trains of 10s to hundreds of cars. These trains will not need to be physically connected to each other, only travel in a closely space group.

A significant factor in designing the system is the very long distances required for acceleration and deceleration. With acceleration rates of around 1/2 G, 200 miles are required to accelerate to maximum speed and then stop. This is the distance from Washington to New York. When vehicles start and stop at different locations along the tube scheduling becomes a nightmare. Vehicles traveling the longest distance are moving so much faster than others only a few vehicles can be using the tube at one time or they will collide. This severely limits the capacity of the system. To illustrate the problem, if a vehicle in New York starts for Europe just as one form Washington passes at full speed, the two trains will be 100 miles apart while crossing the atlantic. This means only about 30 vehicles could be in the tube at one time, but up to 1,000 vehicles are needed at once to handle the passenger volume. To circumvent this problem, acceleration / deceleration tubes will need to parallel the mainline tubes and incorporate high speed merging and switching tubes. These secondary tubes will need to extend at least 75 miles from stations.

Dominic From NASA

Just like California is building a train to no-where, this is a tunnel to no-where. Get real folks, a boon-doggle. plain and simple. Take the money, go to Las Vegas and play the craps table, better odds of getting anything back.

S Michael

re; mystixa

Mars rovers are built to operate on a very limited energy budget so they have very good bearings.

It is more cost effective to buy a new car and hold onto it for 10 Years than it is to pay for the constant stream of repairs that come with a car used beyond design life car.

When the B-52s were modified into the G/H models they were Zero lifed (Everything that wears out was replaced) and the existing fleet has since spent most of their time on the ground. So despite having many years of existence they are young aircraft.

I keep things until they fall apart, or are totaled but it is standard operating procedure to stop doing preventive maintenance on equipment that you are going to abandon. If you want to buy used boring machines make sure that you make the deal early enough that they get full maintenance right up to the change of ownership.

A Boeing 787-9 costs about $227,800,000. How many miles of tunnel will that buy, and how much will it cost to reroute it?


re; funglestrumpet 'Mañana' is a symptom of knowing that extra effort will not result in extra reward.

re; AnOld BlackMarble Why would putting the air in a large tube make it lighter than the air outside the tube.

re; Dominic From NASA Stop spreading the lie! The Concord earned a profit for most of its service life despite its poor design.


We all know...time is humming along. With Virtual Reality and High Resolution Screens, there will be no need for us to sling our meatsacks across the surface of the earth...period. We can meet and greet each other on the Web. This high speed rail idea is nice, however, when you consider "material goods". "Material goods" do not need to be protected from acceleration forces, or the lack of air. The best design would keep air in the tunnels, because it would be cheaper. Still, you want to have the Maglev portion of the design to be definitely included. The skin of your "aircraft" would have "microturbine" generators on it to capture the "friction" of the air...this way you don't need a "vacuum" tunnel. Make it small, make it cheap. Make it a way to transfer material goods. If you can get that done first, then look at transferring human bodies. Personally, I would much rather meet my European friends on a "virtual reality" port than to spend ridiculous money to get my "meat puppet" to Europe.

Thomas Matthews
It doesn't have to be that safe. Look at cars. They kill 40,000 people a year in the States alone - and yet not using one is considered very odd. It doesn't have to go at max speed. If it even went the same speeds as planes today but could maintain more efficiency with regards to energy expenditure - its price points would eventually drop. It doesn't have to carry passengers. If cargo can be moved faster and more effeciently, that may provide profit incentive. djanossy

The pneumatic idea seems better. Increase pressure behind the train, reduce it in front. No resistance; the train is always "chasing" the partial vacuum.

But Sub-orbital flight is faster and easier and cheaper at low volumes. It will come first.

Brian Hall

Thomas Matthews; The "microturbines" don't "capture" the turbulence they increase it. And increase drag requiring more energy to overcome it than is "recovered". A guaranteed loser idea. Themodynamics: there ain't no such thing as free energy.

Brian Hall

Vacuum transport is simple. the physics and materials can be calculated. if they can make a 100km line in Japan or a 200km line like London to Paris, they should prototype it. If a very good design specification comes up, that costs 500 million or 1 billion, probably some rich country will want to do a prototype. but it sounds like a vacuum cleaner. it needs a flashy name.

you can quantify all the costs and performances to withing about 50 percent.

Lol build a giant superconducting cable from mexico to canada? no one has done that before, it costs billions right? supercooled etc, we dont have that technology yet.

Antony Stewart

This principle was tried about 150 years ago. Search : 'brunel atmospheric railway' for further info. the train ran in the normal way but the motive force came via a vacuum tube.


Have a look at

This is a very similar project (linear motors, partial vacuum), which has been somewhat close to reality.

Although theoretically feasible, this kind of project faces an economical problem, as it is far from being an industrial, ready-to-sell-and-built product. Swissmetro aims at speeds of 500 kmh, but still requires the whole industrial process and know-how to be developed, which is a enormous task, that only a group of wealthy countries can afford over a long period of time.

At the same time you have high speed surface trains (like Alstom's TGV) reaching commercial speeds of 320 kmh+ with prototypes approaching 600 kmh. And yet this is a product (industrially viable, with proven economical model) and not just a concept or project.

So 4000 mph just seems to be pure futuristic anticipation. Theory is one thing, industrial application is another.


ok theres so many comments that im not sure if anyones said this or not but, why does it have to be 4000mph?? saying that maintaining that speed is near impossible due to the risks involved (at that speed) so therefore the whole entire concept is nearly impossible is like saying that because one cant swim at the bottom of the ocean that one cant swim in a river... how about first aiming for a more 'conservative' 1000mph..?? still twice the speed of a jet liner and alot safer and i think more attainable.. and at "slower" speeds like that it could be conceived for a commute from say NY - Denver - LA, Vancouver - Calgary - Torronto, Melbourne - Adelaide - Perth, London - Paris - Berlin - Rome, etc ... it would take not a country to fit the bill for the infrastructure but a collaboration between nations in the same way as has happened with Fibre Optic cables... but once the infrastructure is there then as the trips are so short you wouldnt need say 20 flights to one destination a day, so not as many trains needed = less maintenance, and its energy efficient right? so it would take a while but eventually the costs would pay for themselves. Next question is the huge energy needed to power the thing.. If you increase the spark points in a spinning electric motor you can make it self sustaining, you put energy in to start it but as the motor spins it receives more energy & creates more friction producing more energy till the energy produced by the spinning runs itself, the energy to power Tube Mag-Levs could be produced like that.... So over all i think its a long way off, but in the same way that "alternative energy" is a long way off from just being regular energy... i think alot of it, alot of technology innovation in nearly everything is hindred by those who make HUGE profits from old technology controlled by them, from where i see it, most of the "alternatives" are readily available, they just need to be harnessed better, whereas regular energy sources require huge projects or certain individuals to source it for us, creating huge revenue either way.. the same is for health too.. lets face it, Cancer & other illnesses are extremely profitable, as is the research to try to "solve" the problem... in the same way, the reason i think why Tube Mag-levs & such other energy efficient public transport is so far off is because the normal old dead technology of fossil fueled transport is so much more profitable for a long time yet... Its just the usual power & profit for a selected few getting in the way of human advancement, power & profit for a few, the same reason why most high technology research is on Weapons, Bio Tech & Pharmacology.. with comparatively hardly any on efficient energy or human happiness or "alternative energy sources" or the environment or the real underlying causes of illness etc... Its mostly the current societal/ecconomic structure getting in the way of this energy efficient high speed transport being a reality...

Dan Harveyy

While this is fascinating to ponder. I think the negatives outweigh the practicality. Why not build a normal Mag-lev train that produces it's own vacuum in our atmosphere? Remember the reports of Russian stealth aircraft that created a sort of ionized plazma around the aircraft? Or the Supersonic submarines that blasted along in a bubble? Something like that. Heck, I would settle for ANY type of Hi-speed train for regional travel in the US. I am currently trying to travel from Cleveland, OH to Nashville, TN and there are no direct flights. It will take me about 6 hours total travel time to get there. I can drive it in 8 hrs. That is ridiculous.

Jonathan Hatfield

Why not be content with a partial vacuum and utilise a jet powered "vacuum cleaner" as the train?


Love this Mag. This article about super trains as struck a chord here. I live in Western Canada, close to Calgary. This is a huge raw materials hub in the world which has just barely scratched the surface. It is expected that in the next dozen years that the bulk of it's resources will grow by a factor of ten. Roads are over taxed now. I live close to the railway line that services the area which is a page out of the 1970's diesel DC electric propulsion, with an added turn of the century inverter technology. This system is so antiquated for our needs it is laughable. If there was a place on earth right now that technology of this sort had merit it would be here. I do not think 4000 MPH hour is necessary, but a wider based tubular path covered with solar collecting sheets and wind turbines along the route that merit such treatment should not only bring some of my world into the 21st century, it will offer benefits to the environment and industry that are hard to calculate. If there was a loading depot that 18 wheelers could drive onto a rail car and be at it's destination quicker than driving and at slightly lower than fuel cost fee, who would not take advantage of such a work horse. To me the answer is simple. Where does all the confusion come from? You do not need to tell me, though.


There's a better way to deal with wind resistance. Just get the wind going at your same speed. Forget the magnetic levitation, just put it on wheels, or on a track, and push air through the tube at 500 MpH. You can generate the hurricane wherever you have a good source of kinetic energy, if you like. The tube doesn't have to be air-tight, or even powered. It just needs to hold in the wind. Now it's cheap. Stations would be places where the diameter of the tube becomes larger, and the train can dock outside of the main wind flow. When it's in the tube, it can put up little mini "sails" to help it keep up with the wind better. Much safer, cheaper, and not quite as fast. But actually doable.

Eric Wadsworth

There is no reason to believe that trains are safer than airplanes that can take evasive action when error places them on a collision course assuming the pilots are trusted enough to be allowed to deviate from the planed route.

Also trains lack flexibility in getting around a clogged corridor.


Why aren't they being built? Well, let's see, for an example, In Boston Mass., A tunnel was dug to faciliate traffic and airport access. Budget? $4 billion. Final cost? $14 billion. Final, final cost after financiers got a hold of it?$24 BILLION. THAT'S WHY! To top it off, As California continues o sink under an insurmountable debt load, the legislature voted to go ahead with a High Speed Rail initiative. Incredible, ain't it? Like buying a Porsche Cayenne the day after you find out your pay has been cut 70% and foreclosure is imminent. This is why you're not supposed to smoke dope after getting elected.


Is it necessary for the size of the 'carriages' to reflect the carriage size of a normal train. Bearing in mind that it's primarily for saving time in the transport of people, the carriages could be made a lot smaller in diameter, the minimum being maybe three feet or a metre for single file seating, with a more acceptable size being for two abreast seating.

There is then a cost benefit in terms of tunnelling (much smaller tunnels) unless it is not feasible to build a tunnel in which workers cannot stand up. An added cost benefit is the reduction of weight per unit length, which determines the levitation power needed. The train can be as long as needed and the cost of extra platform length (either one long platform or split the train across several shorter ones) is minor compared to tunnel costs.

There are safety issues in tunnels where people cannot move around to rescue others but a larger (but less complex) service tunnel could be built between two single direction carriage tunnels.

Sharon Fishwick

Let's get real about this idea. Forget about full sized trains. Forget about 4000 mph. Forget about round the world.

Instead, imagine a 1.5m (5ft) diameter pod perhaps 6m (20ft) long (think executive jet fuselage) able to accommodate 10 people, running on a maglev track inside a 1.8m (6ft) pipeline. Imagine a pair of these pipelines, one above the other, with interconnecting framework to form a rigid girder able to span a good distance between supports. Now let's build the supports and string this track between NY - Washington ( or NY - Boston; LA -SF; London - Edinburgh; choose your own pair of cities). At each end we need 16 Km (10miles) of linear motor, but in between we'll be coasting.

So, we're at the station in NY. We've just climbed aboard our pod, the doors have been closed and the cabin pressurised. The pod has been slid into an airlock at the beginning of the tunnel, the airlock has been evacuated and the inner doors opened. We're ready to go. The linear motor cuts in and we accelerate down the tube. Our acceleration is controlled at 5m/s/s (1/2g, like a sportscar) Exactly 80 seconds later we reach the end of the motor track at a speed of 400m/s (895mph, mach1.175). From here until 16 kilometers before we arrive in Washington we'll be coasting. There is no friction from the track and in the near perfect vacuum of the tube there's no air resistance either. The only thing that will slow us down is climbing over any hills, though speed lost going up will be regained coming down the other side.

About 14 minutes later we reach the beginning of the Washington linear motor and start to decelerate. And 80 seconds after that we glide to a halt at the Washington terminus. Out through the airlock, equalise the cabin pressure and climb out of the pod. NY to Washington in just under 17 minutes and not airport to airport but centre to centre. Using the same system, LA to San Francisco would take approximately 26 minutes and London - Edinburgh 30 minutes.

OK, safety. Sending pods at 20 second intervals would result in a separation at cruising speed of 8km (5mi.). A smart system would enable every pod to know the status of all the others and, in an emergency, pods would be able to be braked to a stop in 4km (2g deceleration). Thus a catastrophe could be limited to just one pod.

Assuming 10 seater pods at 20 second intervals the capacity would be 1800 passengers per hour each way, though I can see no reason why the pods couldn't be considerably larger, though this would add to the power required during acceleration. Note that if we can keep the weight of the pod to 1500kg then the power required over the 80 second acceleration phase would average to just over 2000bhp.

Quite apart from the speed, it seems to me that the greatest advantage of this system lies in the ability to recover most of the energy used in accelerating the pods during the deceleration. Imagine - a high speed mass transit system that uses minimal energy.

It will happen.


Most people don't understand that pushing air out of the way is the primary cost driver for transportation near the surface of the earth. Reducing air drag is the fundamental way to reduce the cost and energy required. Trying to use air to support or propel the vehicle is not compatible with reducing cost per mile or increasing speed.

Orbital - sub orbital methods of transport from point to point on the surface are made impossible by the extreme energy demands of rocket flight. Much of the flight is high mach number atmospheric flight with very high drag levels. Most of this flight is at speeds higher than the 3 to 4 thousand mph envisioned for vacuum tube systems. Ballistic flight over ranges of even a few hundred miles requires vertical climes of 50 to 100 miles and speed approaching orbit velocity of 17,500 mph. Currently space launch systems cost around $10,000 per pound of payload. Even the most hopelessly optimistic speculation of launch cost reductions still place the cost at around $100 per pound. This would give ticket prices greater than $10,000 per passenger, clearly much more expensive then aircraft.

To make a vacuum tube system cost competitive it must have a very high passenger mile capacity and be heavily used due to the high cost of the infrastructure. One person compared the price of one aircraft to the cost per mile of track and tunnel system. This is not a valid comparison. The completed system would replace thousands of aircraft and last for hundreds of years. The North America - Europe passenger market has the greatest potential to be economically justified. To be economically justified it must out compete aircraft by making the marginal cost per passenger much less than can be done with aircraft so all the traffic will shift to the vacuum tube system. Top speeds in the 3 to 4 thousand mph range provide transatlantic trip times of less than 1 hour. Reducing drag sufficiently to make these speeds possible will also provide ticket prices 1/10 of cost of air fair.

While for inter-city travel of less then 1000 miles, these high speeds are not necessary if the system only used for inter-city travel. But when the system will mix inter-city travel with inter-continental travel, all vehicles in the system will need to have the same speed capabilities. Halving the maximum speed from 3,600 mph to 1,800 mph will only increase trip time from Washington to New York form 10 to 15min and Washington - Boston from 15 to 25 min, but iit would create huge problems for the transatlantic traffic.

The system will fundamentally change the way people live. It will become routine to live several hundred miles form the place one works. Changing jobs from one city to another will not require changing were one lives. If the system were developed to cover much of North America people living near the middle of the continent could work anywhere on the continent with reasonable commute times and cost similar to what many now have for travel in and out of urban centers. Not only would daily travel change, it would be routine to go to Europe for the day to attend a meeting or go shopping and still eat both breakfast and dinner at home.

I made a mistake in my earlier posting. Air drag changes as the cube of speed, thus increasing the speed of a vehicle by a factor of 10 requires a reduction of air pressure by a factor 1000. The corresponding reduction in cost per mile is 1/10. To reduce cost by a factor of 100 required a reduction in pressure of 1,000,000. Vacuum systems can easily reduce the pressure by another factor of 1 million.

re; Slowburn I never said that the Concord did not make an operational profit. As an aircraft development and manufacturing program is was an economic failure because the development cost was never recovered. The "sale" price of the aircraft represented only the serial production cost per aircraft without any contribution to the development cost. If the program had been an economic success, there would have been many more aircraft produced and probably operated by more then the two state airlines of the governments that paid the development costs. The operational profitability was only possible because there was enough but a still limited number of passengers that were willing to pay very high ticket prices for an exclusive prestige product. Economic success also implies that the service is available to large numbers of people and the Concord was not. The Concord was a masterful technological achievement. If it's economics had not been so fragile, the vulnerability it had to tire failures would have been addressed much earlier when the near misses occurred.

The Concord program was successful as government policy. It retuned commercial jet aircraft production to Europe in the form of Airbus Industries.

Dominic From NASA

First of all the capital costs put this thing in Dreamworld. While airlines have their inefficiencies, they have great flexibility. With trains you can only go where the tracks take you. Aircraft can go just about anywhere.

In a vacuum with virtually no drag, the power to hold speed would be fairly modest. Tho at high speed there may eddy current drag. 4,000mph is way more than is needed. Development costs skyrocket. So 1,500mph may be more practical.

How would breathing air/cabin pressure be obtained? The tube is evacuated, so what is the source for pressurization? In an aircraft if there is a pressure problem, the a/c can descend to a breathable level. Not so with this. What if you need to get the passengers totally out of the train due to a fire? Pressure loss? No oxygen mask is going to save you.


re; Dominic From NASA

I agree the concord program was a disaster of miss management. Even if there was a market for the number of SSTs they expected to sell they would not have sold enough to justify opening 2 assembly lines.

It was also government action that destroyed commercial aircraft production in Europe even if De Havilland Comets falling out of the sky didn't help the industry.


re; ChgoSTrider

Airlines do not seal they vent huge volumes of air when pressurized, for maintaining a vacuum in the tunnel the train must be as near to perfectly sealed as humanly possible and since the trips are of such short duration the trapped air will provide enough air provided there is a coat closet worth of air per passenger. But if this lunatic device is ever built they will probably provide CO2 scrubbers, a small feed of fresh oxygen, dehumidification, and cooling for passenger comfort.


This debate is spookily like the debates worldwide about energy production and global warming. In that debate the answer to most of the problem is greater efficiency and less waste, but everyone concentrates on new sources of energy. For better transport speeds the answer is the same. Stop wasting our time at airports with fantasy security threats etc. and the overall journey time drops without new investment.

Think about it like this: say you fly 300 miles in 1 hour. Your speed is 300 miles per hour. But if you had to spend two hours in check-in and security, then another hour in baggage reclaim and passport control, you have been "travelling" for 4 hours so your speed is actually only 75 miles per hour.

Each time you make a journey divide the distance by how long it really takes, door to door and see how frighteningly slow and what terrible value travel can be. It soon becomes obvious that sorting out mundane airport delays is much more cost effective than mega-investments like vacuum tube maglev trains!

Doug MacLeod

I can easily envisage a nationwide system of magleg, linear motor, T-pillar hanging monorail trains that travel 200 to 300mph for passengers and freight (the latter on a separate system using standard containers). However, all you folks dreaming about this 4,000mph tube train can go ahead and build it if you can find 10 or 20 trillion dollars lying around somewhere in this bankrupt nation, but I'M not going to be riding in it, thank you very much.


Maybe we could genetically engineer ourselves to be not so keen on transportation? Would save lots of money.


So were supposed to rely on vacuum pumps to keep the tube depressurized or else the train would be ripped to shreds before it could slow down if a section of tube became pressurized? You mean like how we so successfully relied on pumps to cool off the Fukushima reactors?

The risk might be worth it if there was a way to slow down or stop in a reasonable amount of time, emergency sensors could deactivate the train if they detect something like an earthquake, but at these speeds by the time a sensor goes off it's too late.

Still, it might not be any more of a risk than hurling yourself into mid-air in a glorified beer can.

Brandon Humphries

It's wonderful that all these great ideas for changes and improvements to the terraspan plan are emerging!

We thank Gizmag for listing all their objections so everyone had a chance to address and put forward cogent arguments regarding each one. Not a single objection has gone unmatched!! GREAT JOB EVERYONE!

See the site and please sign-up and add your input!

Youtube to see the video we volunteers put together.


Also about the Concord. It burnt about 25% less fuel per mile at its supersonic cruising speed than it did at its subsonic cruising speed.

re; ridelo

Until we see and hear something live and in person we are only trusting that it is not something that was faked up to fool us.

re; Brandon Humphries

The pumps at Fukushima reactors? you mean the pumps that served reliably for forty years and had to have a record earthquake followed by as record tsunami interrupter their power supply to make them quit?


I've never seen the public question the air supply and leaks (of the air) in submarines and spacecraft such as the space station. The short trip times make supplying air fairly simple for normal operations. Resupply of compressed oxygen can occur frequently, but long term life support in emergencies is a little more difficult. If liquid oxygen is used, a very large amount can be stored in a small volume. Because gaseous oxygen will be required in the cabin continuously, the normal boil off from the emergency liquid oxygen supply will be enough for operational requirements. The liquid oxygen could be refilled at every stop. Several days worth of liquid oxygen could easily be stored onboard.

If memory serves, I think there have been only two unplanned de-pressurization events in the history of space flight, and both were in the soviet program. Late in the life of the soviet space station Mir, a progress resupply ship had a failure of the automatic docking system causing the progress ship to strike one of the stations modules on its side. I don't think the exact location of the resulting leak was ever identified but I remember there were a number of cooling system pipes that penetrated the hull in that area.

The crew immediately knew there was leak from a hissing sound and the reducing pressure in the station caused discomfort in their ears. The effected module had a pressure hatch that could be closed but there were a number of power cables that had to be disconnected going through the open hatch. The crew disconnected the cables then closed and sealed the hatch. The important thing is it was obvious there was a leak and there was time to do something about it. The cars for a vacuum tube system can be divided into 2 or three sections with pressure bulkheads, if there was a leak the people could be moved into an unaffected section and close the hatch.

I was a passenger on an airliner that had pressurization system failure while operating near an airport. I think we were at 2 or 3 thousand feet when the outflow valve opened. The outflow valve is designed to quickly equalize the cabin pressure to the local barometric pressure when on the ground so the doors can be opened. The cabin pressure equalized in a fraction of second making a loud bang and discomfort in the ears. The captain told the passengers what happened and added the flight crew didn't like it either.

The other incident was during reentry of a capsule in the 1970s.(?) The soviet design had a small valve used to equalize pressure after the capsule was on the ground similar to the outflow valve on airliners but much slower. I think it opened automatically. I never heard why but the valve opened at very high altitude after the period of reentry heating. It was an accident that could have been easily dealt with, the pressure loss could have been stopped literally by putting a finger tip over the end of small tube. But the crew was either unable to find the source of the leak or was not able to get to the tube. This was a great blow to moral in the soviet space program as this had been an otherwise flawless flight and the ground crew was unaware of anything being wrong until opening the hatch of the capsule and finding the 3 crew members dead.

In submarines leaks are much more dangerous. When the sub is at depth, the pressure outside the sub is so high that water comes in at very high speed, killing the crew in seconds. This kind of failure is extremely rare.

The possibility of fire can be dealt with. The Apollo 1 fire took place because there was an attitude that nothing can be done about fire in a pure oxygen environment so absolutely no precautions were taken. These cars will operate with at most normal oxygen levels of 20%. The oxygen level can be reduced from normal to between 10% to 15% with no impact on the passengers. At full atmospheric pressure, these oxygen levels are the equivalent to normal air at the 8,000 Ft altitude air liners prove to the passengers. However, the reduced oxygen percentage makes fire in normal materials nearly impossible. Matches will not light! By carefully selecting materials for the car that do not support combustion and do not produce toxic gasses even if heated to high temperatures fire and smoke simply cannot happen. Buy putting luggage in a separate sealed compartment even highly flammable materials brought onboard by passengers should not cause injury to passengers.

Fire outside of the car is prevented by the vacuum itself. No air, no oxygen, no fire. However, electrical arcing in the vacuum environment is a real hazard. Remember radios and TVs that used vacuum tubes for the electronics? Under certain condition electricity flows freely through a vacuum. Once an arc starts in a vacuum, it tends to be self promoting and can cause substantial damage. Using electrical protection systems similar to ground fault interruption circuit breakers can remove power form sections of track where a problem has developed. At speed, the levitation system can be designed to support the vehicle for miles without external power.

Both space and the deep ocean are much more demanding environments than would be encountered in a vacuum tube system. The pressure differential is the same as in space, but there no requirement to build light weight structures. Submarines are less sensitive to weight, but weight still must be considered. The car for a vacuum tube system can be built with multiple pressure hulls each capable of holding the pressure. I would propose using a 4 hull design. This would meet the strictest interoperation of maned spaceflight safety standards of being able to handle 3 failures without causing harm. In conjunction with pressure bulkheads between passenger cabins, 4 failures of pressure seals can be accommodated. As there is no resin to have any hull penetrations, other then the passenger door, the possibility of a leak developing is extremely small.

Even the passenger door can be made redundant. The compartment next to the access door can be a cargo (luggage) compartment, that is separated by a pressure bulkhead and pressure door from the passenger cabins. Having a separate luggage compartment at both ends of the car will provide crush space in the event of a low speed collision and protection against foreign object penetration into the passenger cabin in the event of debris strike at high speed.

I just did a back of the envelope calculation of the capital cost per passenger for the trans-atlantic tube. The two cost drivers for overland maglev trains is the cost of the materials for the levitation and propulsion system built into the track and the cost of construction of the rail bed. The vacuum tube system cost would be very similar to meglev trains and the additional cost of concrete to enclose the tube would be small compared with the track and other construction costs. In the transatlantic tube, the construction cost would actually be less than an over land system because the tube would be floating and suspended in the water. Using the relatively high figure of the Japanese cost per mile of $100 million per kilometer, the cost of capital per passenger is in the range of $10 to $20, a very reasonable sum. Construction cost of high-speed rail in Japan is very high as Japan is a mountainous country were there are expensive problems to solve.

The completed high traffic sections of the tube system will need to have 4 or more parallel tubes. Multiple tubes are required to provide flexibility for maintenance and high peak capacities to accommodate the unavoidable bottle necks, The cost of the track is the largest single cost component, concrete is cheap, provisions to add additional tracks can be efficiently built in during initial construction but only one or two tracks initially installed. Each segment of the system can begin operations with only one or two tracks with additional tracks added as needed and funded by the revenue being collected by the tracks in operation.

Concern over the system diameter should not be over emphasized. Making a small rail-bed or tunnel is nearly as expensive as making one twice as big, but the diameter of the system is made twice as big the capacity increases 4 times. It has been pointed out that freight will be an important part of the system, it is important to have the capacity to handle the excepted norms of freight sizes, IE it should accommodate standard size shipping containers. Shipping containers are approximately the shape of public transportation busses. Accommodating container freight may not increase the size of the system from what is need for passengers.

Dominic From NASA

Brandon: to specifically answer your "questions."

To achieve vacuums greater than about 1/1000 atmosphere the pumps need to be closely spaced, so the loss of any one or a few would make little difference in the pressure in that section of the tube. After the tube had been under vacuum for a few weeks or months, it could be operated for several days or even weeks with no pumping what so ever. The only effect would be a slow increase in drag and eventually slower operation. The vacuum pumps that are used to produce the needed level of vacuum are not mechanical, they have no moving parts and are thus very reliable. One type, called cryo pumps use cryogenic liquified gasses, like liquid nitrogen, and simply freeze the gasses they pump to the inside of the pump. Another type called ion pumps, ionize the pumped gasses then ram then into a metal plate using electric fields. The ionized gas become imbedded in the metal plate.

The trains themselves will produce a significant pumping effect. This effect could be so large that few pumps will be needed except at stations. This effect will need to be carefully studied not only to get the correct mix of pump types and numbers, the optimum relative size of the trains and tube will be affected as well.

I like to use 3600 mph as the max speed because 3600 mph is exactly 1 mile per sec and makes calculations easy enough to be done in my head. 1 mile per second is 5280 feet per sec. For emergencies stopping at 16G is an acceleration rate of approximately 582 feet per sec per sec. and would produce a complete stop in 10 sec. 16 G's is to high and could produce fatalities in seated restrained healthy people. 8 Gs is more reasonable but would still cause g lock in 100% of people who do not have advance preparations. 8 G's would take 20 sec and require 10 miles to stop. Only trains that were close to the location of an emergency condition would need to take this drastic action.

If people don't like staying in their seats with their seat belts on, a sudden 5 second burst of 2 G acceleration at the beginning of each trip would make believers of them. If the use of an unsettling effect to change peoples behavior seems out of the ordinary, I was scanned once in a MRI machine that had the platform the patents laid on shake and bump as the patent was being moved into the scanner. The MRI scanner made an assortment of strange buzzing and clanking sounds while operating that made the patents become frightened thinking something was wrong with the machine. The clunky table made them think the thing was just cheep and noisy and not a problem.

Because the tube system will need to be built with clearance on all sides outside of vacuum the envelope to enable precise alignment for passenger comfort, this automatically provides space and a suspension system that can accommodate the ground motion during an earthquake and static displacements afterwords. The tube system can be designed to survive nearly any strength of earthquake without sustaining damage that would cause a crash. Because very large earthquakes take palace over time scales of 30 sec or more, the trains would be able to stop before a large quake had ended. Also, if a train is within a mile or two of the strongest shaking the safety system can be designed to allow the train to leave the area of strongest shaking before stoping. Remember, the trains are magnetically suspended and do not touch the track, there also will be a mechanical suspension system on both the train and the track that will absorb the quakes movements. The ride might be ruff, but not damaging.

Dominic From NASA

Why create a vacuum in air? Just fill the tube with water. Then produce super cavitation.

Joseph Kevin

re; Dominic From NASA And then a wall of air or water hits the stopped trains.


Reduce friction, first, identify best speeds, can have reduced pressure, not vacuum, be practical.

Dawar Saify


Vacuum required for terraspan is not the "hard" vacuum of a physics experiment such as that at CERN where the LHC is said to have recorded the presence of the Higgs boson, but rather the vacuum of near space where Mach 10 Ram Jets scavenge what little atmosphere remains. Planes like the Black Bird (or its modern equivalent) fly nearby at 70,000 feet.

Essentially the vacuum is functionally adequate for high speed travel when there is less then 1% of sea level air pressure left in a tube system.

Despite what some have said here this level of vacuum a so called "rough" or poor vacuum is relatively easy and low cost to obtain and maintain. The carriages and some special pump carriages can actually push most of the air out using the maglev drive to move a line of carriages with their dynamic seals extended through the tubes section by section.

The system can seal off any section and connect it to air or pump it down to "rough" vacuum while other parts of the system remain evacuated and ready.


The only safe way to run this system is to design it to tolerate being slowed down by air friction in case of a breach.

This concept would be less exciting but far more practical at speeds in the 1,000 mile per hour range. You wouldn't need quite the level of vacuum and if the tube pressurized your biggest problem would be mechanical forces rather than heat.

The big problem at hypersonic speeds is heat from friction. Everything gets exponentially harder and more expensive once the level of air friction can quickly fatigue, melt or ignite metal. Our supersonic vehicles are assembled from titanium and aluminum parts. Our hypersonic vehicles are cast in one continuous form out of exotic ceramics.

A supersonic train that burns less energy than a jumbo jet would be pretty awesome and nobody has to get cooked.

Timothy Rohde


Let me first complement Mr. Rohde, he is absolutely right the actual operational speeds are the choice of the operators with their upper limits being ultimately defined by distance, allowed acceleration, actual air pressure, and the design limits of the maglev or near zero rolling resistance carriage support system. No lower limit of course but the upper limit is probably in the 5000 to 7000 mph range with certain areas of very long straight runs permitting somewhat higher top speeds.

The energy to accelerate to a given speed depends very much on the mass being accelerated if there are no losses associated with speed and in particular non-linear losses like air resistance or magnetic field hysteresis.

The goal for terraspan is a massive carriage made from the very best material for such construction which is steel. Cheap and easily fabricated compared to extreme demands of airplane technology steel carriages in motion store enormous amounts of energy which are available to be returned to the grid during deceleration. Carriages circulating in the system can transfer energy to other carriages or take up or put out energy to the grid incrementally without any major change in velocity.

Carriage Material is STEEL

Terraspan is thus robust, using low cost but proven material. As Mr. Rhode points out ablative material can be used to dissipate re-entry from space, and such materials could certainly be considered for terraspan but most of the heating effects occur above 5000 mph with space vehicles returning to Earth at 17,500 mph or faster. We can choose operational speeds that serve passengers better then any airline today at pennies on the dollar even at speeds nearer to 1000 mph then 4000 mph.

Average Speed is 2800 mph

Terraspan travels by accelerating slowly up to top speed (we have used 4000 mph as a proposed top speed) coasting at the top speed for a time and then decelerating. Terraspan's initial and arrival speed is less then a normal train because it intentionally is meant to have very low acceleration much lower then subways or trains.

With a top speed of 4000 mph on the run from the East Coast to the West Coast of the U.S. the average speed would be closer to 2800 mph with substantial slow portions at the beginning and end of the trip. It is noteworthy that the earthquake watch areas are at the beginning and end of this journey and present the greatest known threat to some sort of breach or substantial leak to the terraspan tube system.

Power Loss

The other major problem for terraspan as a transport system is power loss. In systems power loss a carriage suspended maglev is now going to be released and will no longer be either accelerated or decelerated. Using limited power backup air is actually brought into the tubes through emergency tunnels to the surface. Carriages not brought safely to stop are now air braked and their sacrificial braking pads are used to bring the carriages still in motion to a complete stop.


No one is building it because it would be impossible. Where on earth does the ground stay put? It is always moving by expanding and contracting. The straight tunnel will be crooked in a few months. Then what would happen in an earth quake? Good luck with this idea.


@agnar150 Good point about the earth constantly shifting, and the likelyhood of alignment changes. Earth shifting is primarily due to tidal forces that apply differently to different density and stiffness soils and rock. This is why ET3 infrastructure alignment is adjustable. At higher speeds (to 4000mph), the alignment adjustment must be automated. Most ET3 infrastructure will be above ground and operate at 200 to 600mph and only need manual adjustment (unless crossing active faults). For underground use (required at higher speeds), the two 1.5m diameter tubes will be placed in a single 4m tunnel to allow room for alignment adjustment and service.

Other systems with tubes in direct contact to the earth (such as "SwissMetro") must use much greater maglev gaps (at much higher cost) to accommodate alignment shifting, and then only a small range of miss-alignment is possible.

Daryl Oster

I feel that 3D printing will go a long way to helping with the cost and time for deployment. I also like the ET3 design as it seems to be building smaller tubes, which one would hope would be less likely to cause as many problems as a larger single tube...

Isaac Rowntree

For vaccum tube transit we really do not even need the supeconductor zero friction thing... you make a slick tube with just the right seal, lubricated right and that sucker (no pun intended) will just fly though it's tube! Make to tubes from reinforced concrete in factories all over the place and just keep slappin em together right down the middle of already existing interstate highways, and railways ...Coils wound around tube sections make for both solenoid drive for vaccum pistons (could be independent of passenger plugs) and inductive brakes (which of course double as generators) I say make em small diameter, just lots and lots of plugs with a few folks in each ...that way #1 not as many casualties in "accidents" THOUSANDS of miles of difficult to protect system makes it irresistable to terror guys) I think these are the keys to getting it going and then later incorporate BIG version ..maybe. I love the idea of a destination coordination central computer routing people like mail where diverter sections flip at just the right time for a split second and swooosh flies my passenger plug out of the main tube and into a deceleration spur line where it merges with the next final destination cab (unmanned of course) where my GPS routing address has me home for supper right on time.

Doug Chaney

Instead of evacuating the air inside the tube couldn't similar results in reducing air resistance be achieved by moving the air inside the tube so long as the tube is a continuous ring? The train would act like a carrier like you see at drive-up banks. The air behind would push while the air in front would pull.


Or replace the air with a lower density gas such as helium...?


" A much simpler question is why don´t we see diesel planes. True they would be slower but sooo much more efficient and cheaper to maintain"

No matter what speed you travel it takes some energy to resist gravity. If you travel slower, you resist gravity for longer. If you have heavier engines you also add to energy spent to resist gravity.

Both eat into diesel plane efficiencies, in end not worth it right now.

"reducing air resistance be achieved by moving the air inside the tube" Just as friction when train moves through air, there is friction when air moves through pipe.

David Kay

For you physicists.... pretty cool... for you imaginative peeps, wrap your brains around this mother load!

Melody Sellner

Again and again, I see the same idiotic mistake: if you are operating the transport device in a vacuum, YOU DON'T NEED TRAINS! The biggest benefit of a train is the the first car breaks the air and the rest ride in the first car's slipstream. But with no air, you could have individual cars. Imagine: you log into the station's information system, reserve a car for the number of people in your party, and provide a destination and departure time. You show up at the station, log on, and within a minute or less, your car pulls up at the station ready to take you and your party to your destination. Changes in schedule or route are trivial.

By the way, we don't need them to go 4,000 MPH. 1000 MPH would be more than enough for most purposes. Sure, if you are going to go to Europe, 4000 MPH would be great, but let's start with short lines going at relatively lower speeds. If I could get from San Francisco to Truckee in 20 minutes, that would be huge, and all that would take would be about 500 MPH. I could get to New York in 3 hours at 1000 MPH, and that would, again, be huge!

Let's start with a freight line that goes from SF to Kansas City to New York. We'd save thousands of gallons a day of diesel and jet fuel.

Randolph Lee

@JBar, not longitudinal but oval shaped should the cities be built, with 5, 10 or 20 miles in diameter, with agricultural and recreational space in the center. Normal trains could run along the outer walls of the city connecting several building blocks and moving walkways from building to building. No need of cars, buses or elevated tube transport systems. Normal maglev trains to connect between cities.

Rolf Graf

Spontaneous pressurization of the tube is fun. You're just one big flying railgun projectile (okay your air drag is proportionally far 'less' due to the front shape) that's going to heat up to extreme temperatures. I imagine the front half requiring significant heat shielding in that event.

Instead of seeing people first, I'd like to see these tubes being built for transporting materials first. Sometime in my lifetime perhaps. That would up for some interesting initial 'crash' testing.

Fretting Freddy the Ferret pressing the Fret

translate and read the same... its an article on how engineering students made a prototype of vacuum tube train

Mohammed Ranoob

No one ever mentioned plasma windows, a nifty highspeed way to create vacuum airlocks, and to put up emergency forcefield like walls to hold in or out atmosphere. Yes it takes lots of electricity to create and hold, but the system has plenty of power for just that. I built a model of this exact idea for my eighth grade science project 25 years ago.


There is a use for this vacuum tube technology that hasn't been explored - namely as fire evacuation from tall buildings. At the moment vacuum tube technology is only being used in the UK to send money / messages within old departments stores but why not have it for dropping people from the top floor downwards, on the outside of the building? Zip wires could also be used to get people across to lower buildings as could helipads as obligatory rescue devices. Using parachutes as someone has suggested shouldn't be discounted either but fire engines? Impractical as they can only reach up so far and cannot get above flames if in the centre of the building.

Tony Sandy

To all those who say this wouldn't be useful because we "don't need to go that fast," consider this: how far from work could you live if we had no cars or public transit? Preferably within a mile, maybe three. Now you can easily live much further than that. Suppose you and your spouse each work in NYC, and you can't afford to live in the city. You could live in New Jersey with a 45 minute commute in a 200,000 dollar house and spend perhaps 20,000 dollars a year on the house and 3400 dollars on 24 monthly passes on NJ transit. Or, with a 4000 mph train, you could live hundreds of miles away from NYC, live in a 100,000 dollar house with low property taxes, spend 10,000 dollars per year on your house, and still have a 45 minute commute to work. Even if the transit now costs 500 dollars per person per month, you are still saving money over living in NJ.

4,000 mph transport doesn't make sense to make a trip you would now make at the frequency you now make it only because you define whether a place is worth going partly by how long it takes to get there, and it it's close at 40mph you don't need to go faster - but with faster transport, the places you can go to expand - you could many live hundreds of miles from your office and still make two trips a day.


I personally believe there is a future and a necessity for this idea today. But take a smaller step, for the present, by setting aside the idea of moving people. Use the ' Vacuum Tube System' ("VTS") to ship materials or containers.

Think about this. The majority of shipments from companies like UPS and FedEx are less than 150 lbs and 28" x 28" x 28". Also, most truck loads are made up of small sized, individual 'packages' and quite a number of materials, such as liquids, foods, etc. can be sorted and placed in a 'POD' that would ship in the VTS.

Envision major transportation connections like between Boston to NewYork to Washington, or San Francisco to Los Angeles to San Diego.

If we were to build the VTS for transporting 'PODS' filled with materials (whatever you place in the POD) between these connections, it would lessen traffic issues throughout the US.

A shipment POD, lets say the size a typical pallet of Mushroom Soup could easily transport from Los Angeles to New York in a matter of hours.

Almost every highway has a large center strip that could be used to build and place the VTS so right of way may not be an issue, because the VTS could be engineered to go up, over around any road way.

Economically this is feasible. We charge and pay for the goods that are shipped today we would also do the same for items shipped Via VTS, with all the taxes and costs included. it would quickly become less expensive to ship via VTS than any other method I use today.

New jobs and a whole new industry will be created to build and maintain the 'PODS' used to ship certain items, just as there is for building trains and containers.

I envision the Vacuum Tube System "VTS" to be computer controlled so that once a 'POD' was inserted into the VTS it would then be routed to the closest destination, off loaded to a local DELIVERY HUB and transported by low emission transportation. This would also create jobs, but instead of long haul trucking of goods, drivers would most likely only have to make short runs, within a few miles of a HUB.

Some of the HUBS may well terminate in places that have a concentrated interest like a large mall / shopping center where multiple customers would use the VTS for daily (even hourly) deliveries.

I believe that the Vacuum Tube System is a realistic idea that is due.

I would like to offer a challenge to anyone or any business or university or student who reads about the VTS to add your thoughts and as your own ideas.

Here is the challenge. If you are willing to contribute your own expertise, such as Engineering, Financial, Environmental, Educational, experiences to the challenge of the VTS as outlined , I think our collective inputs could actually build this system on paper. Collectively we can build this into something so compelling that it will command the attention of those that can actually build a test platform for this concept.

Think of the jobs VTS will generate, in design, engineering, manufacturing and a host of other opportunities. Think of how this will be from an environmental standpoint.

Just as the ' containers' that are used to transport items via ships changed the seagoing community, I believe we have the need and the knowledge to build VTS today.

Lets share our good thoughts and build this model using our knowledge to change our world.


Ssfd541 you are quite right! And your suggestion is exactly the plan for Terraspan as of today.

First distribute power using the HVDC backbone. Note that we no longer are calling for electrical power distribution by Superconductor (except in special and limited places). The vacuum isolated 900,000 volt DC conductors forming the backbone array require no cooling and are advantageously located in a clean vacuum environment.

Second begin the transport of freight and the testing all systems including the power out and loss of vacuum conditions until all independent reviewers agree that the system is safe and reliable.

Third, with the fully vetted system, begin the transport of passengers.


This idea is the same as building a flying vapor cargo ship. Will never work. Unless instead of building it here you do it in space where you already have vacuum. What you need is: Suborbital + capable spaceplanes flying the monkey to vacuum. After a coca cola and banana board service, you transfer the monkey to a space "train" and well, maybe you dont even need rails overthere since apparently things seems to fly pretty steady overthere.


Bananas Monkeys Aeroplane capable of flying to vacuum (Richard Bransom knows a bit) And you fix something up there to spin the passengers, then you land the monkey back using another spaceplane, or a new reentry system (not 50,s stuff please). Look at the park rides: monkey 1 rides, cart 2 will pick monkey 3. Very simple. WARNING: Never eat bananas under the high G loads of your experience.


By the your blood won't boil in the vacuum - you are a self contained system. A vacuum will result in you passing but not instant death.

A NASA test pilot passed out in vacuum testing with no ill effects. Why not magnetic attraction rather than repulsion since it already has circumferential tube around it.


accident caused in such speed can kill all

Arul Raj

Everyone is fussing on how to decrease the air pressure in the tunnels. First, determine how much pressure needs to be removed to create the optimum speed. 2 go to the nearest mountain to the tunnel and run a pipe to the top. If necessary run more than one pipe to the top. The difference in atmospheric pressure will do the rest. Anyone who has ever seen the effect of running a pipe down into a deep lake to relieve the CO2 in the lake will be able to testify to the flow of pressure. As to the loss of the cabin pressure... We have been flying in pressurized cabins for years...get a life.

Clifford Schneider

Maybe a 100% vacuum would be problematic, but I guesstimate that large vacuum jets could counter the lost pressure while the maglev is in super speed. sounds good to me!

Or use forward flow and backward flow air jets that are flush angled tubes entering the tunnel ends, sucking at the destination end of the tunnel while air jets push air from behind the maglev at the beginning, also some jets in the middle sections, and then just switch current direction when the maglev goes the opposite way. The max speed may not be as good using air flow but it would probably do half the 4k. It would be very dangerous for people at the ends of the tunnel with that kind of air movement, maybe similar to a shop vac hose sucking up a gummy bear... bye bye...

Dayday Omega

What's the rush? We can communicate instantly online and teleconference. If we want to travel, why not enjoy the ride at a safe, slow pace on luxury liners and airships?


Right now a vacuum tunnel is simply impossible. Howzabout we start with a fast train, say, like LA to Vegas at 200 mph. Do THAT and then we'll talk about scifi stuff. You could build a low pressure (i.e. not a vacuum) zone around our notional 200 mph train and we can go from there. EVERY bullet train loses money so let's make sure our fast train can actually make a profit. It's hard to compete with airplanes which need no road/track maintenance.


Flowing air through the tube to match the train speed doesn't save energy. Skin friction of the high speed air on hundreds of miles of tube consumes more energy than a conventional HS train going through the atmosphere.

Tony Morris

I would rather Jerry Brown spend the 80-100 Billion on this, then His crazy train to nowhere. I would be nice for people In NYC to zip to Malibu for time on the beach. But I think what will make this train is carrying freight. NY to California in a few Hrs vs truck or rail over 5+ days.

Matthew Jacobs

Vac-tube mag-lev trains + fast (passenger service, and light express freight) + compact + benign (no exhaust, sonic boom, environmental impact) + high capacity with short headway

Objections regarding cost, must first answer the question : “Who has the power to create money and its trade value?”

[In American law, Congress has no power to create money. It can coin money (stamp bullion) or borrow money. If it did have the power to create money, why would it need to borrow it?]

Frankly, no “issued money” has any direct correlation with the supply of human labor, and the output of that labor multiplied by tools, machinery and automation. So arguments about “cost” are irrelevant. Those who control the money supply and its trade value are the ones in control.


Cost of transferring people maybe not profitable than transferring goods at a shorter time. I will do this for UPS if I have money, imagine fresh seafood in the mountains, last minute contract from the other continent, at the minute manufacturing..

Nova Sy

I have addressed all the concerns. I sent these to Elon Musk's Hyperloop team at SpaceX. I was ignored. However, I sent my proposed HYPERTUBE system to a major corporation I cannot name at this time. That is because THEY are listening...

Robert Fallin

Even if all of these complex problems are solved, it is an origin destination device and cannot have stops in between. Not everyone that wants to use the system lives right at the start of the system and where they are going is right at the terminus of the system. Ground or air transportation will be required at both ends. Lets say they drive, which takes from a short time to hours in congested traffic. Time to park the car and go through the terminal (like an airport unless we solve that problem ) get their turn of a few at the time and enter the system and go very fast to the end of the system. If people want to go to other destinations, lots more tubes have to be built or you have to be able to switch directions to other branch tubes at very high speeds. Otherwise at the end of the line the person has to go to another mode of travel. When you add up all of the time it takes for a person to get from their starting point to the start of the system, Change modes of travel, maybe get to another airport, get through it's terminal and all that hassle and fly or drive to their final destination. If they fly they have to rent a car, go to the rental car and drive to their final destination, The time saved for even the longest distance in North America, is a tiny part of the trip from the the person's starting point to their final destination.

After all that, you will have to forgive me if I got it a little mixed up but you can see what I mean. If an automated ground dual mode system forming trains and separate from all other traffic where there would be no congestion and moving at 200 miles an hour, you might make it almost half way or more from NY to LA faster than flying with all the same problems mentioned above.


I've got an idea for energy efficiency.

There would be four air tight doors within the tunnel.

One each at the very ends of the track.

One each at a certain distance in from the ends.

At the end of each tunnel there is a gradual downward slope.

Between the two innermost doors there is a constant vaccum.

Between the innermost doors and the outermost doors there is sometimes vacuum and sometimes no vacuum.

What would happen is the train would enter the outermost door which would close behind it, once it is closed the air would begin to be sucked out of the outermost section (between the outer and inner doors). The train would pick up momentum on a downward slope. By the time the train reached the innermost doors there will be a vacuum in the outer section, as it approached the innermost door it would open and close behind the train - maintaining the vacuum of the inner section. As it reached the other end of the tunnel the inner door on that side would open and close behind the train and because of the slope the train would begin to slow down, once at a certain speed a chain - like on a roller coaste -r would pull the train the remaining way to the the top. The outer door would open allowing the air to enter the outer section but only to where the inner door is - which is closed.

It would still need some type of motor to maintain speed but most of the heavy work accelerating would be done by gravity. Without air resistance and a steep enough slope, I imagine it could reach fairly high speeds. The inner tunnel - once it had vacuum should require little energy to maintain that vacuum. Deceleration would occur on the upward slope and hopefully allow the train to reach near the top of other side. The train would not have to deal with smashing into a sudden atmosphere at supersonic speeds either.

Nicky Hansard

I forgot to mention in my previous comment that between the outer doors the air could be allowed in near the inner door. As the air rushes in, it could help push the train up the slope and only when it had reached the outer door does it open.

Nicky Hansard

Rather than a vacuum why not use a rotating ring of air? like constantly rotating air which would create a high velocity potential. So rather than operating IN a vacuum, the trains would operating in a high and low pressure zone similar to how weather works, or how a planet moves through the universe... by shifting high and low potential.

Andrew Keim
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