Core77

ET3 Transportation Concept Promises NYC to LA in 45 Minutes

By Rain Noe - April 24, 2012

in Cars

Breathlessly billed as "Space Travel on Earth," a transportation concept from Evacuated Tube Transport Technologies, or ET3, would reportedly be able to whisk passengers from New York to L.A. in 45 minutes. The science sounds a little breezy, but the idea is that a long, airtight tube is constructed between point A and point B. The tube has the air sucked out of it, creating a vacuum, and a cylindrical "car" carrying six passengers is then propelled via maglev at speeds up to 4,000 miles per hour.

ET3 claims we would not arrive all flat-faced, but would somehow experience just 1G of atmospheric pressure during the ride. On the green front, they say much of the energy expended to accelerate the capsule would be recovered during the braking process. Then there are the outright incredible claims:Speed in initial ET3 systems is 600km/h (370 mph) for in state trips, and will be developed to 6,500 km/h (4,000 mph) for international travel that will allow passenger or cargo travel from New York to Beijing in 2 hours. ET3 is networked like freeways, except the capsules are automatically routed from origin to destination.

ET3 capsules weigh only 183 kg (400 lbs), yet like an automobile, can carry up to six people or 367 kg (800 lbs) of cargo. Compared to high speed rail, ET3 needs only 1/20th the material to build because the vehicles are so light. With automated passive switching, a pair of ET3 tubes can exceed the capacity of a 32 lane freeway. ET3 can be built for 1/10th the cost of High Speed Rail, or 1/4th the cost of a freeway.

Fly the friendly tubes

Fly the friendly tubes

o

Favorite This
Q
12

Comment

Comments

Craig Borysowich

10 years ago

Z

Z

Reply

A lot of good questions here already - but my big concern is how does it stop and still only have an impact of 1G on the riders?
!Report as spam
Rob

11 years ago

Z

Z

Reply

Of course it was only 150 or so years ago that people thought the human heart would stop at 60 mph! I think the concept with a simpler propulsion system at reduced speeds would be a giant step forward. Also this would be a great design for bicycle lanes with the top of the tube open or closed depending on the weather!
!Report as spam
Darrell

12 years ago

Z

Z

Reply

This system will be way to dangerous at those speeds. Think of the G forces just from a roll coaster ride. That tube would have to be almost perfectly straight, no up, down or side ways turning at those high speeds. How will they cross the oceans? ha ha no ways reasonable. Air travel is by far the best high speed travel. Future engines for air travel will allow for faster speeds, like maybe Star Trek type engines.
!Report as spam
Stephe

12 years ago

Z

Z

Reply

Made of Rearden Steel you say?

Who is John Galt?
!Report as spam
patrick andrews

12 years ago

Z

Z

Reply

http://iotd.patrickandrews.com/2010/06/14/1307-orbitube/
Interesting that even negative commenters are keen to see it happening! No need for maglev...rails would work fine.

("1g of atmospheric pressure" shows you need a technical proof reader).
!Report as spam
Matt Carson

12 years ago

Z

Z

Reply

Is there a proof of concept somewhere?
!Report as spam
Pierce Nichols

12 years ago

Z

Z

Reply

What I think they've left out are the safety systems and the power required to maintain the vacuum. A tube 3m in diameter running from NYC to LA has a surface area of 38,000 square meters. Over that kind of surface area, the leak rates through welds and through the body of the metal itself will be significant. Plus it's going to have a ton of seals and other elements that will leak as well, and the pump down required of each car as it goes into the system.

Safety is a huge concern with this. At those speeds and accelerations, starting or stopping will eat up about 100 miles. And there's the question of what happens if the tube breaks, through malice or misadventure. Air will flow into the tube, and rapidly form a shock wave moving down the tube at the speed of sound. That shock wave will shred one of the proposed cars, even if it's stopped. Some system of emergency doors and other fail-safes will be required in order to prevent everyone in the tunnel from being killed in the event of a tube break. I think you'd also have to bury the tube over most of the run, in order to prevent things like air crashed and truck accidents from breaking it, which just kicked your cost up a bunch.

Then there's the question of starting and stopping. Stopping one of these cars from full speed will take about 160 km. If we assume that the separation between sequential cars should be equal to the stopping distance, that implies that you can only have 25 cars in a NY-LA tube at one time. If each car carries six people, that implies a capacity for one tube of approximately 220 passengers per hour, or 12 mt of cargo per hour. That's equivalent to a 737 load of passengers, or half a truckload of freight. You might be able to link groups of cars together in order to increase capacity, but that would be another safety issue in and of itself.

I think their deployment cost estimates are likely optimistic by a factor of four or five due to the need to bury and harden the tube. The development costs would be very, very high, due to the massive safety challenges.

In conclusion -- massively cool concept that I want to see happen. Probably doable, but space elevator levels of challenging.
!Report as spam
Scott B

12 years ago

Z

Z

Reply

The concept is hardly new to anyone who's ever been to a drive through bank, but the details presented here are ludicrous. 1/4 the cost of asphalt highway? 400lb cars? Complete nonsense.
!Report as spam
Dan Lewis

12 years ago

Z

Z

Reply

A 140 year old concept. The Beach Pneumatic Transit -- 1869, New York City.

http://en.wikipedia.org/wiki/Beach_Pneumatic_Transit
!Report as spam
Ken J

12 years ago

Z

Z

Reply

The cryogenics only have to be maintained on-board the capsule and depending on the design of the magnet cryo-chamber, it could be made reasonably efficient. Think a 10 kW or so (13hp) to maintain temperature (that's a generous wag from some of my past cryogenic experience albeit much smaller scale than a mag-lev train!).
!Report as spam
Scott

12 years ago

Z

Z

Reply

I really like the concept but while I think security in air-travel is a joke, security on a system like this would be a definite requirement, and not just at the beginning and end of the journey.

A terrorist, or incompetent motorist, or anything else, which was able to blow a hole or otherwise damage the tube would be instantly catastrophic for a lot of people I imagine. And while there's some chance of recovery from an airline emergency, 4000mph into a hole or other object would mean instant obliteration for the passengers. Something to consider.
!Report as spam
Tom Mc

12 years ago

Z

Z

Reply

Great concept!

A few questions:
How does the energy/heat expended evacuating the system of air, stack up to conventional propulsion?
How does one verify the integrity of the tubing, as a catastrophic accident will result at 4000km/hr?
MagLev requires liquid helium and lots of power, what is the energy input of those two components compared to conventional propulsion?
How will the system cross tectonic plates without affecting alignment of the tubing? Oceans?

Who will repair and maintain this system? Who will be in charge of safety (don't say the government)?

I think it's a great idea. Build a line from Long Beach to Chicago for cargo only and let's prove it out.

!Report as spam