Why Ultra-Efficient 4,000 mph Vacuum-Tube Trains Aren't Being Built

cylonlover writes "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? This article looks into some of the problems."

Comments

Liability

[robinsonne]

Who wants to accept the liability if passengers/surrounding objects get turned into goo when a tiny defect causes the 4000 mph object to decelerate in a not-quite-so-planned manner?

Re:Liability

[geogob]

Airlines?

Re:Liability

[MozeeToby]

You're not any more dead than if your airliner falls out of the sky at 500 mph.

Safety is not the real problem. If you really put some research and development into it, you could probably get maglev down to $500,000 per km and probably a similar amount (if not more) for the vacuum tube (compare to $100 million per km right now). Then there's the cost of the trains, running the lines, maintaining vacuum ect. And for any run to make sense it's going to need to be thousands of km long, and every stop you make is going to defeat the purpose so direct lines between major cities are a must. A run from NY to LA would run you several billion dollars just to get started and several hundred million every year after that for maintenance and repair. So, the real question is: is there enough traffic between NY and LA (for example) to recuperate the cost of construction and operations. I highly, highly doubt the answer is yes.

Re:Liability

[ngg]

Won't be under an hour, unless we're pulling .2g or so.

More like 80-90 minutes.

Your point stands, however - it would make a bloody mint if it existed. If only from people who rode it just so they could say they did it....

I'm not sure I buy that: Round-trip flights between LA and New York can be had for under $300 and take 7-8 hours, including time at the airport. So what price premium is the public willing to pay to get there in 1/3 the time (assuming it takes some time to get on and off the train)? I have trouble believing the capital costs of a vacu-mag-lev passing through two mountain ranges is going to have a lower per-mile cost than the current California HSR (currently ~$100 billion for ~500 miles, or $200 million / mile).

Do you think you can really charge a big enough price premium to cover the extra capital and operating costs of such a thing? I think the Concorde has your answer.

Re:Simple

[NouberNou]

Trains are an economic disaster in the US, and it is not for any sort of engineering reason (you can look at pretty much any other industrialized modern country in the world and see that trains actually work out pretty damn well).

Re:The only answer for the USA

[Red Flayer]

Hah. I rode the train daily with Goldman Sachs guys who lived in houses I can barely *dream* of owning. The train was more convenient from Summit NJ to Manhattan than any other kind of transport, including helicopters (according to one of the guys, after his second paper-bag beer one Friday*). Apparently helicopter transport to NYC is a pain in the ass, because the helipads are not conveniently located -- either on the departing side or the arriving side.

*So every Friday, four GS guys who always sat in the same spot, would have beers on the train. One of the guys retired, and they need a fourth to occupy the seats -- they didn't want some random person sitting with them. They asked me to sit with them, it lasted about two months until circumstances made it better for me to commute by bus instead of train. These guys would pound a beer (or two) in Penn Station waiting for their train, then drink another one (or two) on the 40-minute train ride home... they jokingly said it was the ammunition they needed to deal with their wives for an entire weekend.

But I digress...

If you take the Morris & Essex express into Hoboken or NY, which skips all or almost all the stops in Essex county, you'd believe that it's only the *wealthy* who take trains.

Re:Simple

[TheRaven64]

First, airlocks used in space are used a few dozen times at most before being completely overhauled. The docking connector on a train like this would get more than that much use in a single day, probably in a single morning.

If you're thinking of airlocks, then you'd have to depressurise and repressurise the train at every station. If you actually mean a tube connected to equal pressures outside of the tube and inside the train, then you're assuming that the seal of something that can be attached and detached, can handle one side moving as the train bounces up and down slightly as people step on and off, and still will have zero leakage.