Masks would be of no use. Usefull consciousness is several seconds. Decompression sickness (bends) would be possible from exposure to 150,000 feet altitude.
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Hyperloop
- Thread starter gg_got_a_tesla
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- Hyperloop Transportation
It depends on how fast the leak is. If the compressor can keep up enough to maintain the air pressure at least to the equivalent of 50k feet, the masks would work for some time although it wouldn't be a great experience to say the least. That's why the planning is to open the tube to the outside if there's a really massive pressurization failure.
Your comment "almost like a commercial spacecraft" is right on the money. There are so many potential small things that could lead to major catastrophe. I think that is what makes Elon's disclosure so interesting. Coming from anyone else I would either think "This guy has no real world experience, even if he could do it technically, it would be impossible financially", or "Great idea, but too technically challenging". What's appealing in my perspective is the success of SpaceX (not without failure on first 3 attempts) has taught Elon and his team the challenges of such a creating a potential ground-based spacecraft, and his business savvy makes it seem like it would actually be do-able (by the right people).
On a side note, please keep the technical conversation going. That was the purpose of the disclosure.
:smile:
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Norbert
TSLA will win
Although for long-distance airplanes the pressure difference is smaller, they also must avoid leaks to some degree. But that doesn't seem to be a big problem. At least i can't remember hearing anything in that direction. The pods should be well protected within the tube, as long as the tube doesn't get damaged. Which in turn seems unlikely but not impossible. I suppose the tubes would have something like a vibration detection system (maybe like a car alarm).
A fellow I know used to have a private plane that was pressurized. He had an intermittent leak problem somewhere and had a heck of a time getting it resolved. I do believe you have to avoid leaks to a fairly significant degree...
Exactly right. They explicitly say that for minor leaks they would use reserve air, the masks are for more significant leaks, and that full scale depressurization of a capsule would cause the entire tube to be pressurized.
Norbert
TSLA will win
For the hyperloop pods, it would of course be a major design priority. It does seem to me that airplanes, in general, succeed with that.
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For your convenience, here is the (current) part of the proposal addressing this:
Rapid decompression is definitely one thing that would keep me up at night if I were designing the Hyperloop. I've been through the Air Force physiological training course a couple of times, where they give you a day of classroom sessions on hypoxia and disorientation/vertigo, then take you up to 25,000' in the altitude chamber (it doesn't move, they just pump some of the air out) and have you remove your oxygen mask for a few minutes. Very educational, and vital training for pilots who routinely fly at high altitudes. One factoid I remember is that blood boils above 60,000' (that can't be good!), even if you're mask-breathing 100% oxygen under positive pressure: so unless you're wearing a full-body pressure suit like SR-71 pilots and astronauts do, you won't survive a rapid decompression event in a Hyperloop capsule unless there's a way to quickly re-pressurize the tube it's running in.
Since issuing, fitting and wearing pressure suits just isn't going to fly in a rapid transit scenario, this leads to a host of design considerations---as the alpha design hints at---and sleepless nights for the designers. If non-destructive, rapid re-pressurization of the tube (or a portion of it, at least) is a design requirement, that begs the question of what happens to the system after a tube re-pressurization: how long does it take to recover and restart operations, assuming nothing worse than a decompression event in a single capsule?
You know, if I were a young engineer, full of piss and vinegar, this is the sort of problem I'd love to sink my teeth into. I hope a whole bunch of bright young people get a chance to burn the midnight oil turning out a full-blown design: this sort of opportunity comes along only once in a blue moon.
Since issuing, fitting and wearing pressure suits just isn't going to fly in a rapid transit scenario, this leads to a host of design considerations---as the alpha design hints at---and sleepless nights for the designers. If non-destructive, rapid re-pressurization of the tube (or a portion of it, at least) is a design requirement, that begs the question of what happens to the system after a tube re-pressurization: how long does it take to recover and restart operations, assuming nothing worse than a decompression event in a single capsule?
You know, if I were a young engineer, full of piss and vinegar, this is the sort of problem I'd love to sink my teeth into. I hope a whole bunch of bright young people get a chance to burn the midnight oil turning out a full-blown design: this sort of opportunity comes along only once in a blue moon.
Norbert
TSLA will win
Of course, from SpaceX comes the experience with the Dragon capsule, which is mostly pressurized (IIRC).
I guess the pods will have an inner capsule separate from the compressor/air-bearing system. So the main task will probably be the doors. Or?
(Plus air exchange with the compressed-air system.)
I guess the pods will have an inner capsule separate from the compressor/air-bearing system. So the main task will probably be the doors. Or?
(Plus air exchange with the compressed-air system.)
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"The aerodynamic power requirements at 700 mph (1,130 kph) is around only
134 hp (100 kW) with a drag force of only 72 lbf (320 N)" - Hyper Loop Document
The 100kw is the amount of power lost to friction and slows the pod down, that's why 100 kw is needed to keep it at the constant speed of 700 mph. So the pod will generate 50 kwh/180 MJ of heat over a 30 min trip, some of this will heat the pipeline, the air and some will heat the pod so not all of the heat will warm the pod. This gives us the upper limit of the needed cooling of the pod, the pipeline will radiate away its heat.
For reference one gallon of gasoline holds 33.4 kwh /120 MJ of thermal energy.
134 hp (100 kW) with a drag force of only 72 lbf (320 N)" - Hyper Loop Document
The 100kw is the amount of power lost to friction and slows the pod down, that's why 100 kw is needed to keep it at the constant speed of 700 mph. So the pod will generate 50 kwh/180 MJ of heat over a 30 min trip, some of this will heat the pipeline, the air and some will heat the pod so not all of the heat will warm the pod. This gives us the upper limit of the needed cooling of the pod, the pipeline will radiate away its heat.
For reference one gallon of gasoline holds 33.4 kwh /120 MJ of thermal energy.
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I agree. Yes, eBay completely and utterly screwed up when they bought Paypal. I would be loads bitter too were I in his shoes. Heck, I'm bitter anyways
Paypal would have by now replaced credit cards. Instead of merchants being charged 3% to accept a credit card, they would be charged something a lot lower. Person to person transfers of money would be easy, free and simple. I could go on and on, but suffice it to say that Paypal could have done it all with regard to banking, billing, payment and credit. Instead eBay uses it as a captive method of buying and selling auction items. Big sigh. You know, I mentioned to my MBA wife how Elon should just start a VC fund and start funding all these great companies he no doubt has ideas for (Hyperloop being just one idea). Her comment back was that it wasn't that easy. Unless you are actually running the company, you don't get the right information about what is going on, and the CEO you hired will likely be making mistakes left and right. Being a CEO of a startup is amazingly hard work, being the CEO of TWO startups, in probably two of the hardest industries to have a startup in (cars? rockets?) is just insane. Hats off to you, Elon, there are damn few people on this earth who can accomplish what you have done.
I would SO be willing to pay for some of that experiment. They could do a whole season on it.
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1. Beg the stewardess to go to the restroom.
2. If #1 fails, wet the seat.
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Heh. Well played. You win this round.
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And/or the experts are patiently wading through the subject matter before speaking publicly.
Norbert
TSLA will win
Except he doesn't seem to have anything to steal that's actually his to begin with.
And except he omits mentioning that Elon acknowledges prior work:
And except he thinks the hyperloop uses a maglev train (which it doesn't).
And except he claims that Elon's proposal even has the exact same price ("6.8 billion"), when actually it is different ("less than 6 billion" for one version, and 7.5 billion for the other version, supporting cars/cargo).
And except he omits mentioning that Elon acknowledges prior work:
And except he thinks the hyperloop uses a maglev train (which it doesn't).
And except he claims that Elon's proposal even has the exact same price ("6.8 billion"), when actually it is different ("less than 6 billion" for one version, and 7.5 billion for the other version, supporting cars/cargo).
Not to derail the conversation here, but does anyone know of any external sites that have interesting hyperloop discussions?
I've been able to find these two:
Hyperloop | Hacker News - 900 comments
Elon Musk has unveiled new details about the hyperloop, a new (super fast) form of transportation. : technology - thousands of comments, you can argue how much of reddit's conversation is interesting...
I've been able to find these two:
Hyperloop | Hacker News - 900 comments
Elon Musk has unveiled new details about the hyperloop, a new (super fast) form of transportation. : technology - thousands of comments, you can argue how much of reddit's conversation is interesting...
Any thoughts on what a demonstration project would look like?
My two cents:
- Not required to carry passangers, nor solar panels
- Should probably have a tube of full diamater (i.e. 7'4")
- Should reach the max velocity (760mph), and maybe coast for a mile or so
- Should maybe have curves of (close to) the minimum bending capacity, to test the banking in the curves and measure actual g-forces (centripetal)
The length of such a thing would depend greatly on the applicable acceleration/deceleration. Assuming 1g, you would need approx. 8.5 miles. At 2g you need approx. 5 miles. At 3g you need approx. 3.5 miles.
Generally assuming prototype has triple cost of full scale (this may be underestimating things) and using the Alpha design figures, the budget would be:
- 2x vehicle: 3 * 2 * MUSD1.35 = MUSD 8
- 5 miles of tube = 3 * 5 * MUSD 650/350 = MUSD 28
- pylons for 5 miles of tube = 3 * 5 * MUSD 2550/350 = MUSD 109
- propulsion (1 unit, compared to 10 in full scale): MUSD 140/10 = MUSD 14
- 5 miles of solar panels and batteries (3 * 5* MUSD 210/350) = MUSD 9
- Station and vacuum pumps (MUSD 260 for full scale): MUSD 10?
Total: MUSD 178
I think it would make no sense to put the prototype on pylons. Probably it could be put on simple concrete foundations. That could bring the "pylons" cost down by 90% or something. In that case we get a figure south of MUSD 100.
My two cents:
- Not required to carry passangers, nor solar panels
- Should probably have a tube of full diamater (i.e. 7'4")
- Should reach the max velocity (760mph), and maybe coast for a mile or so
- Should maybe have curves of (close to) the minimum bending capacity, to test the banking in the curves and measure actual g-forces (centripetal)
The length of such a thing would depend greatly on the applicable acceleration/deceleration. Assuming 1g, you would need approx. 8.5 miles. At 2g you need approx. 5 miles. At 3g you need approx. 3.5 miles.
Generally assuming prototype has triple cost of full scale (this may be underestimating things) and using the Alpha design figures, the budget would be:
- 2x vehicle: 3 * 2 * MUSD1.35 = MUSD 8
- 5 miles of tube = 3 * 5 * MUSD 650/350 = MUSD 28
- pylons for 5 miles of tube = 3 * 5 * MUSD 2550/350 = MUSD 109
- propulsion (1 unit, compared to 10 in full scale): MUSD 140/10 = MUSD 14
- 5 miles of solar panels and batteries (3 * 5* MUSD 210/350) = MUSD 9
- Station and vacuum pumps (MUSD 260 for full scale): MUSD 10?
Total: MUSD 178
I think it would make no sense to put the prototype on pylons. Probably it could be put on simple concrete foundations. That could bring the "pylons" cost down by 90% or something. In that case we get a figure south of MUSD 100.
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