Vaccuum Trains

8/10/2019 Vaccuum Trains

1/4

Ultra-efficient 4,000 mph vacuum-tubetrains why aren't they being built?ByLoz Blain

July 10, 2012

120 Comments

Terraspan's giant, 4,000 mph (6,437 km/h) vacuum tube train, which also doubles as asuperconducting 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
http://www.gizmag.com/author/loz-blain/http://www.gizmag.com/author/loz-blain/http://www.gizmag.com/author/loz-blain/http://www.gizmag.com/terraspan-vacuum-tube-train-supersonic-ultra-fast/23267/terraspan-vacuum-tube-train-supersonic-ultra-fast#commentshttp://www.gizmag.com/terraspan-vacuum-tube-train-supersonic-ultra-fast/23267/terraspan-vacuum-tube-train-supersonic-ultra-fast#commentshttp://www.gizmag.com/terraspan-vacuum-tube-train-supersonic-ultra-fast/23267/pictureshttp://www.gizmag.com/terraspan-vacuum-tube-train-supersonic-ultra-fast/23267/terraspan-vacuum-tube-train-supersonic-ultra-fast#commentshttp://www.gizmag.com/author/loz-blain/


2/4

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 magneticallylevitating 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 heatdissipation.

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 theET3 consortium,a licensing organization that owns a number of

patents in the evacuated tube transport space,Acabion's vacuum tube streamliners,and the

giganticStartram 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 isTerraspan,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 ofunderground 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
http://www.gizmag.com/et3-vacuum-maglev-train/21833/http://www.gizmag.com/et3-vacuum-maglev-train/21833/http://www.gizmag.com/et3-vacuum-maglev-train/21833/http://www.gizmag.com/acabion-streamliner-future-tube-transport-system/17735/http://www.gizmag.com/acabion-streamliner-future-tube-transport-system/17735/http://www.gizmag.com/acabion-streamliner-future-tube-transport-system/17735/http://www.gizmag.com/startram-maglev-to-leo/21700/http://www.gizmag.com/startram-maglev-to-leo/21700/http://www.gizmag.com/startram-maglev-to-leo/21700/http://www.terraspan.org/http://www.terraspan.org/http://www.terraspan.org/http://www.terraspan.org/http://www.gizmag.com/startram-maglev-to-leo/21700/http://www.gizmag.com/acabion-streamliner-future-tube-transport-system/17735/http://www.gizmag.com/et3-vacuum-maglev-train/21833/


3/4

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.


4/4

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.

Documents

Vaccuum Trains