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Hyperloop One Becomes ‘Virgin Hyperloop One’

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Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#391

Post by mercutio2 »

jankotek wrote: post #203
daemin wrote: post #165

Just as a thought experiment, could the promotion of these "hyperloop" projects be a clever political ploy to misdirect/divert attention and prevent a viable high speed rail network from being built? Elon's main business is electric cars and (one of) Branson's is airlines. So a reasonable competitor to both is fast and cheap(er) public transport along a major travel corridor in the USA. This means that by promoting t…

There is some public support for high speed trains? Hyperloop at least started a discussion. Once it fails, there might be some actual public support.

There is tons of support for high speed rail. California's voters passed a bond initiative to fund one stage of it. Whether voters would vote to raise taxes to fully fund it is another question, but voting for $9 billion in bonds cannot be interpreted as anything other than public support for high speed rail.

Just because there are significant interests that oppose high speed rail at every turn doesn't mean there isn't public support.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#392

Post by phinnaeus »

baldfat wrote: post #267
nradov wrote: post #226

Earlier quoted context omitted.

That's barely faster than driving, once you account for the time spent moving between your origin/destination and the train station as well as transferring luggage.

In the near age of driverless cars I think this might be its biggest demise. If cars are automated people wouldn't need a train. It will be cheaper and less confining to a schedule and to a destination. I think air travel for short to medium flights will fall off. By the time I leave my house and get to someplace that is 8 hours by car it would take 5 hours to check in and check out and you still need to rent a car.

Autonomous vehicles do not obviate grade-separated transit options. Even if we imagine a road network populated only by highly efficient and inter-connected autonomous vehicles, the increased capacity allowed in such a situation will only create more demand, which will scale up traffic problems.

Now, other than traffic, I agree. When deciding whether to drive somewhere or take the train, my second factor is whether or not I feel like actually driving a car. That answer is usually no, so I'm very excited about driverless cars.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#393

Post by schiffern »

JumpCrisscross wrote: post #357
schiffern wrote: post #337

Earlier quoted context omitted.

> No--they've just punted the "hard" stuff to the end. Citation needed. The link provided gives no support. I would be interested in seeing your calculations on the thermal side. An ANSYS multiphysics simulation (the software SpaceX uses) would show the problem, no? SpaceX has already built and used a mile-long, 11' diameter vacuum tube in Southern California, which would seem to put this matter to rest (the proof is…

> An ANSYS multiphysics simulation (the software SpaceX uses) would show the problem, no? Yes. But SpaceX != Hyperloop One. > SpaceX has already built and used a mile-long, 11' diameter vacuum tube in Southern California, which would seem to put this matter to rest (the proof is in the pudding, after all) I'll go ahead and predict that the strength of that tube will have materially decreased after 1 year in the eleme…

>I'll go ahead and predict that the strength of that tube will have materially decreased after 1 year in the elements.

With steel, the real question is not the weakening from Year 0 -> Year 1, but from Year 4 -> Year 5. After an initial period of weakening the strength of steel levels off.[1]

Anyways, another user pointed out that a cheap foam layer can reduce the daily flexing to arbitrarily low amounts, and give an arbitrarily amount of time for the tube temperature to equalize circumferentially.[2] Cheaper than either a temperature equalizing water jacket or an underground tunnel. I know you disagree in that other thread, but I now consider this problem solved.

[1] https://en.wikipedia.org/wiki/Fatigue_limit

[2] https://news.ycombinator.com/item?id=15460535

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#394

Post by hwillis »

BRAlNlAC wrote: post #387
sbierwagen wrote: post #330

Earlier quoted context omitted.

> "Regenerative cooling" is a rocket term. It came to mind because I used to be an aerospace engineer. There's no requirement in the definition of regenerative cooling for the coolant to be dumped. ? Regenerative cooling in rocketry uses propellant. Propellant is always dumped overboard, because it's propellant. Please show me a rocket that uses closed loop cooling of the rocket nozzle. > Filtering and then compressi…

>However, maintaining the air dryers and replacing the filters sounds like it wouldn't be any cheaper than conventional phase-change cooling, and having to build custom vacuum/compressor pumps for the hyperloop project is going to be more expensive than buying COTS vacuum pumps. Just want to point out a facet of such a project that you probably haven't considered. The EPA puts strict requirements on the operators of…

Heat tubes use distilled water as a refrigerant and do not use pumps

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#395

Post by hwillis »

JumpCrisscross wrote: post #353
schiffern wrote: post #345

Earlier quoted context omitted.

>At that point why not just bury it? Because foam is cheaper? A nice K.I.S.S. solution. Having seemingly solved this thermal expansion problem "in the same category of problems separating us from a space elevator," I'll be expecting The Fountains of Paradise to come true soon. ;)

> We seem to have solved this thermal expansion problem I guess I'll have to telegraph my buddies in Hawthorne and at NASA :). Joking aside, no, foam doesn't solve the problem. You'll still have flexing. This is one of the limits on how long you can have a launch tank on the pad. Imperceptibly small flexing, but of the kind that weakens every metal we know.

> Imperceptibly small flexing, but of the kind that weakens every metal we know.

This isn't a rocket. The tube wall is inch thick steel. It would rust into nothingness centuries before it would crack from distortion.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#396

Post by totalZero »

jaredhansen wrote: post #185
daemin wrote: post #165

Just as a thought experiment, could the promotion of these "hyperloop" projects be a clever political ploy to misdirect/divert attention and prevent a viable high speed rail network from being built? Elon's main business is electric cars and (one of) Branson's is airlines. So a reasonable competitor to both is fast and cheap(er) public transport along a major travel corridor in the USA. This means that by promoting t…

Of all the problems facing construction of "viable high speed rail" in the US (they already exist in many other places), I don't think Hyperloop competition is among ... the top 50. Practically anything could be "a clever political ploy", but where's the evidence for this? Any in the absence of such evidence, why speculate? Just as a thought experiment, could HN user daemin's comments be part of a clever ploy to inve…

It's not competition from Hyperloop that's in consideration. It's the diversion and absorption of public demand and political capital. If people think Hyperloop is in the works, they are less likely to ask for high speed rail. And politicians are less likely to become banner carriers for high speed rail in such a situation.

Not taking a side here, but it doesn't seem useful make fun of the parent comment for what, on its face, seems to me as a pretty apt comment.

These two gentlemen stand to gain from the failure of mass long distance transit. So, why are they spearheading any kind of Hyperloop project? It's a valid question, and the suggestion about their motive is not farfetched for a couple of successful business magnates.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#397

Post by alphaalpha101 »

biznickman wrote: post #94

The viability of Hyperloop One should not be the focus in the context of this article. That's not what this is about at all. It's that Hyperloop One needed Richard Branson on board because Elon Musk is creating his own competitor now. This is an incredibly smart move to ensure the survivability of the business from a publicity perspective. Branson has a history of doing things that people thought impossible or just a…

The viability of hyperloop is nil. It doesn't exist. It is literally physically impossible for it to be viable.

I think it's on-topic whenever hyperloop is on-topic.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#398

Post by alphaalpha101 »

imron wrote: post #170
jandrese wrote: post #99

Earlier quoted context omitted.

With rockets he was competing with fat and lazy government contractors for the most part. The hyperloop will be competing with already cutthroat airlines, the goddamn personal automobile, and, ...well, a fat and lazy passenger train company. IMHO he'll be well over 1/10 the cost before he finishes the thousands of land deals he would need for this, even if he somehow got permission to build it over the highway.

> even if he somehow got permission to build it over the highway. Hence the boring company.

Which won't do anything, because you can't magically make tunnelling cheap

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#399

Post by rohit2412 »

Brakenshire wrote: post #188
jaredhansen wrote: post #185

Earlier quoted context omitted.

Of all the problems facing construction of "viable high speed rail" in the US (they already exist in many other places), I don't think Hyperloop competition is among ... the top 50. Practically anything could be "a clever political ploy", but where's the evidence for this? Any in the absence of such evidence, why speculate? Just as a thought experiment, could HN user daemin's comments be part of a clever ploy to inve…

We're just building a new major high speed line in the UK, and you'd be surprised how often you hear people say that it shouldn't be built because the technology will be superseded by the hyperloop, or autonomous cars, or whichever. It's one of the major talking points, even if it isn't one of the major blocks.

Same here in India. People oppose hsr train as a waste of money in favor of centuries old infrastructure. The same people also believe that if we should move to a new technology, it should be hyperloop, rejecting maglev on the way. They either want current infrastructure to be maintained, or pie in the sky dreams.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#400

Post by imron »

alphaalpha101 wrote: post #398
imron wrote: post #170

Earlier quoted context omitted.

> even if he somehow got permission to build it over the highway. Hence the boring company.

Which won't do anything, because you can't magically make tunnelling cheap

You can't do it magically, but you can do it by improving the technology - see for example SpaceX.
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