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Hyperloop

spacex.com

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Re: Hyperloop

#211

Post by thedufer »

potatolicious wrote: post #139
r00fus wrote: post #82

Earlier quoted context omitted.

What happens currently on a high-speed rail system? I suppose there's a lavatory in the HSR (e.g.: France's TGV).

Currently you get up and go to the bathroom at the end of the car. I've only had time to skim the full PDF, but there's something about experiencing 0.5g of acceleration - unsure if that is a constant or if that is simply right at the very beginning. If you're going to experience 0.5g of acceleration over a prolonged period, letting passengers get up and move about is going to be a bad idea. It also doesn't look like…

> until you think about it as 50% of your body weight tacked on

That's not how vectors work. It's only 11% extra weight. If its reasonably smooth, that's easy walking.

Re: Hyperloop

#212

Post by digikata »

hyperbovine wrote: post #110
druiid wrote: post #74

Earlier quoted context omitted.

Not really. It's a valid welding http://en.wikipedia.org/wiki/Orbital_welding ), but I imagine it might be quite a task to scale it up to pipes as large as would be needed for this project.

For some reason Elon Musk is extremely enamored of welding technology. I remember seeing a page on an old version of the SpaceX site containing a high-level overview of the Falcon 9, where they went out of the way to mention how great circumferential friction stir welding is compared to whatever NASA used to do. And here he is bragging about it being the large stir welded thing ever created: http://www.nasaspacefligh…

Makes sense, most of the volume in a rocket is a tube structure. I imagine that SpaceX has spent a lot of time evaluating ways to precisely and cost-effectively build tubes...

Re: Hyperloop

#213

Post by nsxwolf »

axus wrote: post #176
mortenjorck wrote: post #160

Earlier quoted context omitted.

I'm not claustrophobic, but this image ever so slightly terrified me: http://i.imgur.com/lGD9bUP.png I have to wonder, would making the capsule the size of a small subway car completely destroy the economics of it?

It's also scary that the passengers would suffocate if the life support system failed.

BYOO (Bring Your Own Oxygen)

Re: Hyperloop

#214

Post by greedo »

toble wrote: post #186
sbashyal wrote: post #157

Earlier quoted context omitted.

Not for the first 30 minutes - which in this case is the entire trip.

I think one advantage of air travel is it's distracting. Busy flight attendants, announcements from pilots, plane moving to the runway, taking off... so there's less reason to concentrate on the lack of space while stuck in the seat.

I'm sure the seatbacks would all have some net connected display for movies or actual computing.

Re: Hyperloop

#215

Post by evan_ »

marshray wrote: post #203
ciex wrote: post #153

Earlier quoted context omitted.

How do you get out of there in case of fire? If the doors open like that I don't think it would work while inside the tube wouldn't it?

Well, there's a low grade vacuum outside so you probably don't want to. It's a failure of the onboard steam tanks that scares me. ("The steam is stored onboard until reaching the station. Water and steam tanks are changed automatically at each stop") I don't want to think about what the result of that would look like for the cleanup crew. Eeeewww.

It's a big self-contained pod, they'd just pull it off the line and bury the whole thing.

Re: Hyperloop

#216

Post by spikels »

[deleted] wrote: post #66
aresant wrote: post #32

"In the case of the Hyperloop, Musk started focusing on public transportation after he grew disenchanted with the plans for California’s high-speed rail system." And who says that big government stifles entrepreneurial innovation? If ALL Musk does with the Hyperloop announcement is shed more light on the potential debacle that is to be our $70b+ high-speed rail in California, we owe him a debt of gratitude. PS - Dire…

[deleted]

If the California high speed rail project is completed (or even makes progress) it will likely stifle any similar projects for decades. Competing against government projects is hard enough because the goverment has the incentive (from voters, contractors, workers, unions) to "succeed" regardless of costs and has access to vast resources thru taxation as well as control of the rules of the game (laws, regulation). Project with high fixed cost such as this would be impossible because of the huge financial risks. Once the government establishes its presence it will either be uneconomic (Amtrak) or illegal (US Post Office) to compete.

Re: Hyperloop

#217

Post by hristov »

ansible wrote: post #182
acadien wrote: post #80

Earlier quoted context omitted.

But that's at a pressure of 100Pa (1/1000 atm). How much power does it take to maintain a vacuum of 1/1000atm in a tube hundreds of miles long? It seems this point is skipped over in the whitepaper, so perhaps its negligible. Edit: yes I was referring to the power to sustain a vacuum in a leaky system, of course no power is required to maintain a vacuum in a perfectly sealed system :)

How much power does it take to maintain a vacuum of 1/1000atm in a tube hundreds of miles long? It doesn't require any power, if there are no leaks. The power required will be determined by the amount of leakage that is considered tolerable to the system.

But there will be leaks. He himself said there would be leaks and he would use commercial pumps to continuously keep the vacuum.

Re: Hyperloop

#218

Post by adventureartist »

lmg643 wrote: post #180
aresant wrote: post #32

"In the case of the Hyperloop, Musk started focusing on public transportation after he grew disenchanted with the plans for California’s high-speed rail system." And who says that big government stifles entrepreneurial innovation? If ALL Musk does with the Hyperloop announcement is shed more light on the potential debacle that is to be our $70b+ high-speed rail in California, we owe him a debt of gratitude. PS - Dire…

Interesting point that big government provoked the advancement of the hyperloop idea - counterintuitive idea, and clearly yes. but any idea like this will need government cooperation. The real test of big government will be how they respond to the hyperloop. magic response: "of course we may be wrong, we'll look into this immediately." and then they decide to build it. likely answer: praise, perhaps even an evaluatio…

I wouldn't be so fast to make that declaration. Elon Musk, Tesla, and SpaceX are pretty influential players right now, and I don't think anyone reading this white paper are anything less than wide eyed at the possibility that the future of travel is written right here and we could build it, for cheaper than the current slow expensive system.

Influential people and money people and politicians are all going to read this and say Sounds great. Elon Musk? I'm listening. 7 Billion? Go on. And scientists are going to chime in, and universities, and people always forget the global reactions. Momentum.

I'm going to keep my faith that this idea has legs.

Re: Hyperloop

#219

Post by enraged_camel »

goodcanadian wrote: post #188

I am intrigued, but not overwhelmed. Many of his reasons why his hyperloop is superior to high speed rail are not specific to the hyperloop. For example, you can put railway tracks up on pylons, too, with very little impact on the ground. It is common to do this in urban areas, but it is rarely done in rural areas because it is flat out cheaper to put it on the ground. I don't believe that an experimental tube is goi…

>>However, the answer, to my mind, is to do it properly rather than propose a wild experiment with hand-wavy arguments as to why it would be politically easier to do. Do you really think the special interests that are making HSR so difficult and expensive would say, "Oh, do whatever you like with your tube."?

Even when done properly, HSR has most of the limitations stated by Musk. And while it is possible that special interest groups would make the construction of Hyperloop more difficult than it is, I don't think that's an argument against giving it a try.

Re: Hyperloop

#220

Post by typon »

cma wrote: post #193
aaronmarks wrote: post #75

Earlier quoted context omitted.

From the report: "...with capsules departing as often as every 30 seconds from each terminal and carrying 28 people each. This gives a total of 7.4 million people each way that can be transported each year on Hyperloop."

Eventually hits up against this problem: http://books.google.com/books?id=DenWKRgqzWMC&pg=PA67&lpg=PA...

Wow...this is one of those rare intuitive insights that make you think "I'm not as smart as I thought"
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