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Hyperloop

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Re: Hyperloop

#321

Post by mpyne »

Osmium wrote: post #199

Reading the entire PDF is highly recommended; it contains a surprising amount of answers already (including many to comments below). I think, if anything, safety aspects haven't been sufficiently explored in the pdf. I'm quite happy to believe it's safer than other modes of transport, but I wouldn't be too quick to overstate it. Also, if anyone can explain what "Tubes located on pylons would limit access to the criti…

Indeed, I started getting giddy when he was discussing how to get the best power factor from the stator of the linear induction motor. It's obvious there's been a lot of thought put into this.

On the other hand even with a recommendation to use something similar to TSA doing something similar to airport security, his response plan to a terrorist attac--, er, a "human related incident" is basically to say that the system will have redundant power and vacuum pumps.

I suppose this isn't his area of expertise and so it's better to say little, but this is the kind of thing people are going to worry about before they board a small tube hurtling at 700 mph while 100 feet above the ground.

For instance, does a HRI impact his plan for rapidly handling luggage pods at all? Just one thing to think about...

Re: Hyperloop

#322

Post by zevyoura »

jcromartie wrote: post #232
mercurial wrote: post #138

I was thinking that a well-timed explosive charge on a support pylon would make for a nice mess, but I suppose it's not any easier to secure a conventional railway.

The distance between the pylons is small enough that adjacent pylons may be redundant. It's also a massive steel tube which would be pretty strong in itself compared to rails (or roads).

The tube itself also isn't bearing nearly the same load as a train track.

Re: Hyperloop

#323

Post by delsarto »

GigabyteCoin wrote: post #257

I thought it was just a few days ago that elon musk said that he "wished he had never mentioned the hyperloop as he doesn't have enough time to work on it" [sic]. When I heard the news about this announcement on the radio today, I thought that my local news station was just a week behind the times as usual. Apparently they were not?

Just FYI, [sic] is used when you're quoting something with a mistake and you wish to indicate that mistake is in the source document, and not added unintentionally.

Re: Hyperloop

#324

Post by checker »

dkrich wrote: post #231

The main reason why air travel continues to be the most practical, cost-effective means of high-speed transport is that the politics involved in connecting two points with a transit system are enough to make you lose faith in humanity. Take for instance, the DC metro system. There is an expansion underway to extend the system west to Dulles Airport, about 30 miles or so from downtown DC. A huge project, no doubt, but…

I'm not saying that fighting won't bog a hyperloop down, but the Silver Line fighting was largely due to who was going to pay for it. You had Federal funds, VA state, each VA county, Dulles, and Metro all with their fingers in the pie. This hyperloop only has one state and a few stops, and it looks to be much cheaper than the HSR so it should be an easier pill to swallow.

They both have right-of-way issues, but what land-based project doesn't?

Re: Hyperloop

#325

Post by tptacek »

slacka wrote: post #290
tptacek wrote: post #76

Earlier quoted context omitted.

That's an argument in favor of a useful HSR system. But politics have resulted California's HSR system being deliberately pessimized; it may do more harm than good to the HSR cause, right?

“The man who moved a mountain was the one who began carrying away small stones.” -Chinese Proverb I've lived in China for over 3 years, and spend countless hours riding the HSR system. HSR combines the speed of a plane, with the cost and convenience of a regular bus. Traveling through the countryside of China at 380km/h made me feel like I was in the future. Coming home and seeing the the sad state of our infrastruct…

Again, the problem isn't that HSR is a bad idea.

Re: Hyperloop

#326

Post by HCIdivision17 »

acadien wrote: post #80
revelation wrote: post #44

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) Mind blown.

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 :)

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 would backwash at 1/10000 atmo (though it would take a while to get from 1 hPa to 0.1 hPa, many multiples of the time it to to get from 100 hPa to 1 hPa).

Edit: fixed units (0.001hPa is still leaky for base pressures but a completely different thing from 0.001atm).

Re: Hyperloop

#327

Post by pxtang »

mcintyre1994 wrote: post #301
ewoodrich wrote: post #275

Earlier quoted context omitted.

It was approved by a ballot measure, so in this case it may be the "idiocy" (or will) of the voter. http://ballotpedia.org/wiki/index.php/California_Proposition...

I'm not from the area, so I don't know how such a ballot works but for voters who didn't have Musk-level engineering knowledge, was the choice the status quo of not fast trains and spending on fast trains?

IIRC, the choice was between no trains and a train. I think a lot of people voted for it so they had a cheaper alternative than planes and a less time/effort intensive alternative than driving.

Re: Hyperloop

#328

Post by coldtea »

untog wrote: post #142
raldi wrote: post #132

Earlier quoted context omitted.

Doesn't look any more cramped than the back seat of a car.

...which is pretty cramped.

Really? As a European I don't find the backseats of most American cars cramped at all.

Plus, with a car you'd have a 7-8 hour journey to look into.

And with an (equally cramped if not worse) plane you'll have more traval time than in this scheme, if you include waiting to depart, the lengthy procedures at the airport and getting to the airport in the first place.

Re: Hyperloop

#329

Post by DannyBee »

hristov wrote: post #223
pjungwir wrote: post #47

The key advantages of a tube vs. a railway track are that it can be built above the ground on pylons and it can be built in prefabricated sections that are dropped in place and joined with an orbital seam welder. Did anyone else read this and imagine laser beams fired by satellites?

I do not get this part. These are not advantages of tube v railway track, because a railway track can also be built above ground and can also be build from prefabbed sections. In fact I would think that building a railway track would be much cheaper than building an airtight tube.

Railway track built above ground has to support weight of the cars, which seems significantly higher ....

Re: Hyperloop

#330

Post by abruzzi »

stcredzero wrote: post #196
axus wrote: post #176

Earlier quoted context omitted.

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

No different than planes.

Except that planes have (supposedly) trained staff that can go around and make sure everyone is getting oxygen. These pods are automated and would most likely have no staff on board.
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