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Hyperloop

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Re: Hyperloop

#921

Post by alexeisadeski3 »

jfoster wrote: post #744
alexeisadeski3 wrote: post #695

Earlier quoted context omitted.

As opposed to aircraft sitting on the tarmac, which are not subject to such problems?

Aircraft sitting on the tarmac doesn't have to take off if it has been shot at. In the process of taking off could be more of a problem, I suppose. On the other hand, at least airports are a relatively small area to keep secure.

Presumably the Hyperloop isn't actually in danger when shot at. The cars just slow down when depressurization occurs. Thought I read that somehow.

I responded to concern over the Hyperloop shutting down for hours whilst the damage is repaired.

And, if someone fired a few pot shots into a taxing A380 at LAX, I have to imagine that the whole place would be shut down for a few hours.

Re: Hyperloop

#922

Post by nickik »

lotu wrote: post #867
simias wrote: post #783

Earlier quoted context omitted.

Because you can't crash a train into a skyscraper. I don't know if that's a good reason, but that's the reason.

The problem (as I'm sure many others have stated before) is that airport security doesn't really solve the problem of being able to crash a plane into a skyscraper. However, reinforced cockpit doors, armed pilots, and a belief that a hijacker will use a plane to commit suicide instead of as hostage do effectively solve this problem.

Thats how I see it. Also if the goverment crebily commits to a 'we will shut you down policy'.

Of course in the contract you have to agree that its ok with you that if the plane does get hijacked its ok with you to shut it down.

Re: Hyperloop

#923

Post by FrojoS »

jarek wrote: post #899
FrojoS wrote: post #894

Earlier quoted context omitted.

As others have pointed out, 6bn is about the cost of the Bay Bridge extension or, if you prefer, six Instagrams or other retarded "tech" startups. This is not aimed at you, but when I started reading Hacker News I was amazed how excited, interesting and smart people were on this site. But now Im starting to get tired of this 'valley think'. Greetings from Switzerland where mind blowing infrastructure projects are sti…

In case it wasn't clear, I was voicing my doubt that any company would actually build such a line for $6B claimed by Musk, not an opinion that it was unduly expensive.

Infrastructure projects like this a usually not financed by companies. The I-5 wasn't either.

Re: Hyperloop

#924

Post by rottyguy »

A few thoughts:

1) We don't have to hit the ball out of the park on our first time out. I'd be happy to see a hyperloop prototype from, say, Manhattan to JFK built.

2) Which countries might "race" to get something like this sorted out (which may compel a more world-wide movement)? China? Spain? Japan?

Re: Hyperloop

#925

Post by tinco »

mattermill wrote: post #847
tinco wrote: post #438

Earlier quoted context omitted.

Bill Gates has more important things to spend his money on than moving rich americans from somewhere in America to somewhere else in America.

What about a $40 round trip ticket implies that those of us in LA County or the Bay Area are rich?

There's a difference between having 40 dollars, and having 40 dollars to spare :)

Re: Hyperloop

#926

Post by tinco »

acqq wrote: post #920
acqq wrote: post #771

Earlier quoted context omitted.

Thanks for writing! I can also imagine that when there's one very long tube there's going to be a lot of the length change with the temperature, ideally one wouldn't want to have any hard joints at all to allow the individual pieces to extend and shrink. One hundreds of miles long welded tube does sound potentially problematic.

The biggest problem seems to be that Musk's costs don't include most of the costs actually included in High Speed Rail proposal that allow you to actually travel between SF and LA and not SF minus bay (they omitted that cost) and Sylmar (where you've still got over an hour to go on the Antelope Valley Metrolink Line to reach the LA city ): http://stopandmove.blogspot.fr/2013/08/hyperloop-proposal-ba... It seems that…

You can't stand up in a car either. In any case the ride is going to get you to qualified medical personnel within half an hour :)

Re: Hyperloop

#927

Post by willyt »

krschultz wrote: post #459

This is very serious first proposal. As a professional mechanical engineer I have worked on high quality steel tubes (nuclear submarines) before. The immediate thing that sticks out to me in this proposal are the tight mechanical tolerances that have to be maintained. Talking about tens of thousandths of an inch tolerances on a 10' diameter tube is not to be dismissed lightly. That is going to be tough to maintain -…

Back of the envelope, SI units.

13 × 10^-6 thermal expansion coefficient of steel

45 - -40 max temp difference

570k length of tube in meters

line1 × line2 × line3 = 629m (~1890') of thermal expansion over a 570 km tube.

Did I read it right that they will take out all that expansion at the ends? To get that down to say 30m between pylons you have to have about 30 expansion joints. Can they go full speed through an expansion joint?

Re: Hyperloop

#928

Post by rtkwe »

tinco wrote: post #926
acqq wrote: post #920

Earlier quoted context omitted.

The biggest problem seems to be that Musk's costs don't include most of the costs actually included in High Speed Rail proposal that allow you to actually travel between SF and LA and not SF minus bay (they omitted that cost) and Sylmar (where you've still got over an hour to go on the Antelope Valley Metrolink Line to reach the LA city ): http://stopandmove.blogspot.fr/2013/08/hyperloop-proposal-ba... It seems that…

You can't stand up in a car either. In any case the ride is going to get you to qualified medical personnel within half an hour :)

You're in control of your car though so if you need to you can stop and get out to deal with any bodily functions or sickness. You can't do that in this train. There's a lot to be said for the effect of just having the option even if you don't exercise it. Control is very comforting to people.

Re: Hyperloop

#929

Post by crdoconnor »

lmm wrote: post #728
jarek wrote: post #591

Earlier quoted context omitted.

Sounds vaguely like maglev a couple of decades ago. It too was a neat idea on paper.

I take it you've never travelled between Shanghai and its airport?

That was a test. They were planning on building it all the way from Shanghai to Beijing but the cost was too high.

Re: Hyperloop

#930

Post by mhandley »

mhandley wrote: post #736
adventured wrote: post #649

Earlier quoted context omitted.

This system would seem very weak to criminals / terrorists / whatever firing bullets at it. It would be exceptionally difficult to track where the shot/s came from, and it would cause serious pressure problems.

Even if the pressure problems could be countered, a bullet hole is likely to leave a pretty ragged profile on the inside of the steel tube. The specification calls for the air bearing skis to ride 0.5 to 1.3mm off the tunnel wall. They'd need to be pretty robust to take hitting the ragged edge of a bullet hole at 700mph.

I wonder - could you line the high-speed part of the tube with half an inch of soft wax or something similar? Then any dents or imperfections caused by bullets would rapidly be smoothed out again, and the damage to the skis would be minimized by vaporizing the wax you hit.
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