Ask Slashdot: What Would Happen If a Hyperloop Train Failed?

dryriver writes: I've been following Elon Musk's Hyperloop initiative with great interest. The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary. I'm glad that somebody is trying to innovate in the area of land travel. My question though: When conventional trains going at much slower speeds derail or crash, the result is often serious injuries or deaths. What happens if something goes wrong with a 700 MPH Hyperloop train/pod or with part of the track? Would a Hyperloop accident at that speed even be survivable?

Comments

Even More Simple

[ranton]

We don't know what will happen because it hasn't been engineered and built yet. Determining how it handles various types of failures will certainly be part of the engineering process. Worst case scenario is everyone dies, which isn't much different than a plane crash. But just like with a plane, plenty of fail safes will be there to allow for managed failures. Most catastrophic failures will probably just cause the train to come to a gradual halt.

Re:Even More Simple

[Ami Ganguli]

A containment failure doesn't need to implode - it can just leak. Depends on the materials and the details of the design. And if it leaks, then everything slows down and stops.

I can't imagine they'd build this thing without any sort of safe failure mode.

Re:Even More Simple

[bws111]

There is not 'a lot more pressure' outside than inside. IF they managed to create a perfect vacuum, the pressure difference would be about 15PSI. There are tons of materials that can handle that puny pressure difference. For comparison, natural gas is pumped through pipelines at about 250PSI. A leak does not cause a catastophic failure of the pipeline.

Re:Even More Simple

[MightyYar]

Tanker cars are designed to keep the contents inside, not contain a vacuum. The forces are literally the opposite of what was designed. You might as well claim that the pyramids are a poor design because they'd fly apart if turned on their side.

Re:Even More Simple

[jeremyp]

What do you mean by a containment failure? The tube is going to have a near vacuum in it so it has to be built to withstand a pressure difference of only one atmosphere. That's like a submarine diving to 10 metres. I think we can manage that.

I think it's much more likely that the tube will develop a leak. When a train traveling at 700 mph hits the air, it's going to slow down, probably quite rapidly. I couldn't begin to tell you how that will pan out. It may be that it is not a big deal because there probably won't be a wall of air so much as a pressure gradient.

Re:Even More Simple

[sdinfoserv]

I don't buy it. The average cruising speed of a jet is (c) 525 miles per hour. Plane crashes are not survivable when the plane is going at cruising speed. Survival happens then the plan lands ungracefully at a landing speed, or (c) 150mph. Forced landings ie:, a plane hits something and is forced to turn around, or an in flight failure forces a landing. This is when survival happens.
Assuming a hyperloop cruses at 700 mph or 25% faster, the notion of survive ability of virtually any crash, regardless of how the system is engineered, is ludicrous

Re:Soft failure possible too

[DaHat]

Hatch doors... which would be separate failure points along the way for the pressure difference to be changed.

Assume perfect seals and no malicious or accidental misuse of even a single hatch door. A tech team is sent out to to assist the passengers in getting out. You can't just open the hatch, you've 14.7 lbs of pressure per square inch trying to keep that door closed, assuming it swings out. Now you've got to pressurize either the entire system (so largely shutting it down), or the particular leg you are on. How long does this take? Now how long does it take to undo these steps?

Short of a 9/11, when there is an airplane crash, even an entire airport (or state) is shut down due to weather, the rest of the system keeps going.

This also aside from all of the issues related to thermal expansion & contraction of the materials, making the sealing even more difficult.

Re:Plane crashes are seldom fatal

[networkBoy]

The mortality rate for national newsworthy and international newsworthy airplane accidents is near 100%, hence the cognitive disconnect.

Please think, even if just for a moment.

[SuperKendall]

Air fills the vacuum at the speed of sound.

Yes, exactly. Sound is not all that fast (six seconds to travel just a mile), mostly the pod would be so remote from the source of the leak it would have plenty of time to slow down to a reasonable speed before substantial pressure reached it. Also if we are talking about small leak its not like it would INSTANTLY be a huge volume of air in front of the pod, it would be a gradual loss of vacuum and therefore simply not the "wall of air" you are scare-mongering about.

And of course, the leak would have to occur in front of a moving pod instead of behind it to even be that much of a potential danger...

A wall of air hitting you at that speed would likely kill you.

Not at 70MPH instead of 700MPH, you blithering retard.

Also I've not seen any arguments for why emergency vacuum pumps placed along the tube would help eliminate the danger from common leaks? But you didn't even think that far you were just like YABBER YABBER YABBER FLOOM DOOM!! *throws hands in air and waves frantically like muppet on acid*

Sabotage

[emil]

Perhaps a more salient question is sabotage.

Explosive charges attached to the tube that detonated five seconds before the arrival of a pod would likely kill everyone on board.