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Hyperloop

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Re: Hyperloop

#601

Post by platz »

robomartin wrote: post #572

None of this is to say that Hyperloop is a bad idea. The idea sounds very interesting and I'd rather spend sixty billion building a Hyperloop --even if it fails-- than the ridiculous California high speed rail project. Cost is probably off by an order of magnitude, if not more. Why? Unions and other groups. Building anything in this country costs massively more (and takes significantly longer) than one could imagine…

I think I'm going to have to go over michaelochurch's article again on unions and bloc voting power, which are very relevant to these ideas:

http://michaelochurch.wordpress.com/2013/08/01/statistics-co...

Re: Hyperloop

#602

Post by arrrg »

gsnedders wrote: post #455
arrrg wrote: post #170

Earlier quoted context omitted.

Fast trains are just fast trains. Inside there isn’t much special about them compared to slower ones, except that they are usually more comfortable (softer and adjustable seats, definitely wider, at least in first class, better and more tables, more storage space for luggage, electrical outlets, sometimes crappy WiFi, a crappy restaurant, relatively roomy bathrooms that don’t even look that bad). Also, they actually…

In general, most of those things vary massively between classes of trains, and there's no simple low-speed/high-speed distinction. Seat width varies massively between body shell designs, softness often depends on how long since the last refurbishment more than anything else, number of tables and luggage space are often based on the target market for the class, electrical outlets are more and more common (even on comm…

Dude. What are you on about?

At least in Germany WiFi sucks and is not available everywhere – and even if it is you have to be lucky and actually be in a train that supports it. In general seats are most definitely more comfortable in longer distance trains. Yeah, you can find a seat that’s less comfortable in a long distance train than in a regional train, sure, but that’s hardly the point, is it?!

And electrical outlets are getting more common, sure, but the vast majority of German regional trains does not have them and you can only be certain that there will one in a high speed train.

Re: Hyperloop

#603

Post by krasin »

macinjosh wrote: post #127

For all of you whose panties get wet at the sound of Elon Musk's name Hyperloop is essentially just Aérotrain in a tube: https://en.wikipedia.org/wiki/A%C3%A9rotrain This guy isn't really a genius, he's just rich.

430 km/h (Aerotrain) vs 1200 km/h (Hyperloop) is a big deal. That is possible with the tube design. Aerotrain operated on the "free air" and that was the reason to lose the competition with TGV.

Re: Hyperloop

#604

Post by Retric »

dredmorbius wrote: post #563
wavesounds wrote: post #501

Earlier quoted context omitted.

Not to be nitpicky but if you haven't driven the I-5 theres substantial room between each direction of the freeway so I don't think it will actually be above traffic if that's your concern.

At 700+ MPH you'll need more than 100' of freeway median to contain potential incident fallout.

Depends on how strong the tunnel is. Assuming your taking 3/4 atmospheric difference your starting at ~11 pounds per square inch add in a 3-5x safety factor and that tunnel would be one tough son of a bitch.

Not to mention it's got to be really close to a strait track so your more dealing with scraping forces than a direct strike.

Re: Hyperloop

#605

Post by uptown »

krasin wrote: post #595
uptown wrote: post #228

Really interesting proposal. How do you maintain the tube when something needs repair? You need to shut the whole system down, don't you?

Fair question. I would build 3 tubes instead of 2. That would help with repairs as well as with handling asymmetry in demand (for example, if more people want SFO->LA in mornings and LA->SFO in evenings)

I was thinking the same thing. Eat the up-front build costs, but assure yourself a persistently-functional loop. Probably the type of thing best determined as part of the review-process, and not listed a requirement in the technical draft.

Re: Hyperloop

#606

Post by HCIdivision17 »

Balgair wrote: post #413
HCIdivision17 wrote: post #326

Earlier quoted context omitted.

To me, a 1/1000 atmosphere vacuum system IS a really leaky machine :) Anecdotally, the machine I used to work on would gleefully chew on that for hours idling while we scrambled to find the hiss on the system. It made an awesome sound when it ground into the atmospheric pressure on initial pumpdown, but at about 1/100 atmo it got bored (mere minutes), and without additional high speed stages the mechanical pumps woul…

I used to work with a system of about 1m^3, 2 little mechanical pumps would get you to 10E-6 atm or so. A turbo pump got you down to 10E-9 or there abouts. The door on the thing was about 2.5 feet in diameter, with a big ol' O-ring that would get twisted and tangled all the time (we broke it once, gorilla glue worked just fine to fix it). I also second the great sound they made. It was like 2 very angry horses going…

To geek out for just a moment on the topic: we had two fix-a-flat substances that required two engineers to agree to use (mostly as a joke interlock - someone had to stop management from slathering it on everything). One was basically putty that you could smoosh over a leaky o-ring (clamp and all); with some work you could seal anything for a few days, but it made an awful mess and it was darn near guaranteed to destroy base pressures later. The other was a vial of clear stuff that was disturbingly like super glue, which would seal any micro leaks like a charm and would hold for a couple pumpdowns. At least, consistently until forgotten.

The machine was so big that it was easy to forget where it was, which o-ring had the clear super glue on it (after a few weeks it was covered in plant filth anyhow, the tags were lost, and too many of the seals had sharpie Xs on them to trust anyhow). It was MASH's meatball surgery, but with low energy plasma physics instead.

I ab-so-freaking-lutely guarantee they will use gorilla glue on the Hyperloop once leak failures become boring and routine. Or super glue. Or giant sheets of Kapton.

Re: Hyperloop

#607

Post by Anechoic »

yk wrote: post #530
Anechoic wrote: post #224

Earlier quoted context omitted.

I don't believe that an experimental tube is going to be somehow magically cheaper and easier to route and build than train tracks. 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."? These are extremely important issues that advocates seem to be glossing over. Putting the guideway on pylons doesn't magically eliminate land is…

> one important reason I have to deal with is that the speed of shear waves through soil is only on the order of a couple of hundred miles per hour. Perhaps a stupid question, but the shock wave forms because the trains is moving continuously over the ground? So if you put the entire thing on stilts, there would be one wave formed at t0, x0 when the train reaches pylon 0 and the next wave would be at t1, x1 etc. So t…

Yes, rather than a line-source, you have multiple incoherent point sources, but those point sources are being excited along a line at a rate faster than the shear wave speed. So yes, it somewhat different, but also similar.

A test segment would go a long way to determining if/how much of a problem this might be in a hyperloop system.

Re: Hyperloop

#608

Post by enraged_camel »

anko wrote: post #577
iamjustin wrote: post #507

Earlier quoted context omitted.

We shouldn't expect him to demonstrate his idea?

I think tesla motors releasing an affordable car would benefit the world a lot more than the hyperloop. But it's nice that he is presenting the idea so the world can do their own analysis and even implement it before he has the chance.

>>I think tesla motors releasing an affordable car would benefit the world a lot more than the hyperloop.

Specifically, an affordable Tesla car could benefit the entire world, whereas the Hyperloop would (at least initially) only benefit people living in LA and SF.

Re: Hyperloop

#609

Post by gizmo686 »

kamjam wrote: post #583
Maxious wrote: post #570

Earlier quoted context omitted.

Too late: http://www.seattlepi.com/technology/businessinsider/article/... > If you don't want to be searched at the train station, you have the freedom to not ride the train.

I wonder what the security checkpoints would be like on the HyperLoop if it ever got built? They are saying capsules could depart 30 seconds apart. Imagine is there was an attack in on of them, with several others travelling at high speed just behind. http://www.bbc.co.uk/news/world-us-canada-23677205 I'm sure there some contingency has been thought of, unfortunately it's just the world we live in these days :(

Forget about an attack. The system would need to be robust against simple malfunctions which could also result in a massive pile-up.

Re: Hyperloop

#610

Post by kamjam »

Did anybody ever see Discovery Channel's Extreme Engineering episode about a possible high speed train from London, UK to NYC, USA?

http://www.smartplanet.com/blog/intelligent-energy/new-york-...

http://www.youtube.com/watch?v=frYWTrEfPRs

This reminds me a lot of that, but without the vacuum tunnel... there was a proposal in 1960's apparently... so no so new after all.

http://en.wikipedia.org/wiki/Transatlantic_tunnel

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