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Hyperloop One Becomes ‘Virgin Hyperloop One’

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Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#91

Post by ravenstine »

batrat wrote: post #16

I see so many negative comments about this, but in my opinion everything has to start somewhere. It doesn't matter how crazy and impossible it looks, it will be done eventually (and we have plenty of examples). Maybe we will not teleport in 2 seconds across the globe or this project will die, who knows if we don't try. A little bit of optimism doesn't hurt. Just saying. And for Virgin, it's not my money, if they want…

My instinct tells me negative comments aren't actually coming from the direction of "stupid idea! can't be done!". This isn't to say there aren't significant engineering roadblocks to the Hyperloop, but I don't think that's the root of the negativity.

People are pointing out the glaring flaws in the Hyperloop idea, not because they can't or won't believe that crazy ideas are possible, but in reaction to the media's reaction to Elon Musk's PR. Surely I'm not the only one who wants to upchuck every time that Musk makes a claim and the media drools all over whatever he says. It even goes beyond the media itself but how the public reacts to how the media reports Musk. Otherwise smart people I've met have likened Musk to a modern day Edison, or even Tesla. Musk's companies have achieved great things, but he has more in common with Barnum than famous inventors.

Testing impossible ideas is wonderful. Musk's PR being inflated by the media, creating an audience of believer sycophants, is a different story and I really don't mind people blowing holes in the Hyperloop theory if the newsprint-spewing public isn't going to get that from technology reporters. I'd bet Hyperloop critics actually like the idea at one level or another, and hate to see such ideas looked at with pollyanna eyes.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#92

Post by losteric »

lisper wrote: post #53
DiThi wrote: post #45

Earlier quoted context omitted.

This point is clearly addressed in the paper: The ends of the tube can slide 300 meters next to the station, and the tube is not firmly attached to the pylons but can move to accommodate the expansion.

No. The paper gets this badly wrong. It looks only at the incremental thermal expansion between pylons, and neglects the fact that in a sealed tube the thermal expansion will be cumulative. "These would absorb the small length changes between pylons due to thermal changes, as well as long form subtle height changes." [emphasis added] The cumulative expansion is dealt with in a single sentence: "A telescoping tube, si…

I'm not this kind of engineer, but couldn't the pylon problem be addressed by a sliding rail mechanism between the pylon and the sealed tube? Or replicating the station mechanism at each pylon? Maybe I just don't see the problem you're pointing out.

edit: in retrospect, I can clearly see the problem with expanding shaped tracks.

What happens to a long S-shaped track? Think about expanding each segment of the top curve... the turn radius increases and as does the length of the turn. How do you support a tube that can get longer, move outwards along the curve, and change angles at various points? S is just an example, it seems to be a problem with any number of turns (including 1)...

I suppose one option is to simply put it underground to stabilize ambient heat input, and use heat extractors to manage heat generated by the train. If the system shuts down, there might be some thermal contraction but that's easier to manage (it's OK for track segments to separate when trains aren't running - just warm them up before operation)

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#93

Post by QAPereo »

simias wrote: post #90
batrat wrote: post #16

I see so many negative comments about this, but in my opinion everything has to start somewhere. It doesn't matter how crazy and impossible it looks, it will be done eventually (and we have plenty of examples). Maybe we will not teleport in 2 seconds across the globe or this project will die, who knows if we don't try. A little bit of optimism doesn't hurt. Just saying. And for Virgin, it's not my money, if they want…

Your types of comment annoy me more than harsh criticism frankly, at least criticism can be constructive, your comment is just fluff. I mean, let's apply your logic to its logical conclusion: we should never criticize anything, ever, on the off chance it could end up working and then people would look back on our comments and call us silly. On that note I'm just starting a gofundme to create my own interplanetary tra…

I only wish that HN was similarly skeptical about near-term Mars colonization. For a group of largely smart, educated people, too many are willing to suspend disbelief for a sufficiently charismatic person, or out of desperation.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#94

Post by biznickman »

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 bad decision (like creating an airline company). Public perception is the name of the game at this stage, not just feasibility. From that perspective, Hyperloop One has effectively done one of the only strategic moves remaining at this point that ensures it has any chance of persuading a government to select them as a preferred vendor (or continue doing so).

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#95

Post by cowsandmilk »

Gustomaximus wrote: post #44
batrat wrote: post #16

I see so many negative comments about this, but in my opinion everything has to start somewhere. It doesn't matter how crazy and impossible it looks, it will be done eventually (and we have plenty of examples). Maybe we will not teleport in 2 seconds across the globe or this project will die, who knows if we don't try. A little bit of optimism doesn't hurt. Just saying. And for Virgin, it's not my money, if they want…

So much this. Especially when people chime in with some minor detail means it will fail because clearly 'must not have thought of it' if they didnt mention in some 400 word press release. Its like Elon going into trucking and people saying the range isn't sufficient. The guy is pretty darn smart. I'm confident he understands trucking range and has some solutions, and simply isn't discussing it for secrecy and/or succ…

> if they didnt mention in some 400 word press release.

There's a lot of in depth criticism of hyperloop based on Elon's 57 page paper. It is hardly a case of gut reactions to 400 word press releases.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#96

Post by nkoren »

lisper wrote: post #64
Robotbeat wrote: post #51

Earlier quoted context omitted.

Did you try googling? Here's a whole bunch: http://www.metraflex.com/metal-expansion-joints/

Let me be more precise: not ones that 1) will hold a vacuum and 2) are available in the 3+ meter diameter that the hyperloop requires and 3) provides the smooth inside surface that the hyperloop requires and 4) are economically viable.

This kind of Hyperloop criticism is commonplace, but strikes me as intellectually lazy. Did you read Robotbeat's link? Particularly with respect to to the MNLC Bellows Expansion Joint.

> 1) will hold a vacuum

Plain wrong.

> 2) are available in the 3+ meter diameter that the hyperloop requires

This is a simple manufacturing problem, although calling a "problem" seems like an overstatement. Obviously not everything to build a Hyperloop is wholly off the shelf. If there is some reason why this can't be built in larger diameters, then that's certainly not obvious.

> 3) provides the smooth inside surface that the hyperloop requires

The Hyperloop runs on an air cushion. It's a hovercraft. Millimeter-scale bellows ought not to be a problem.

> 4) are economically viable

And here, you could be entirely correct, and is why I'm not yet a Hyperloop true believer. I'm not wholly convinced that this kind of machinery can be economical over its whole life-cycle in its intended service environment. But proving that this is the case requires more than glib, hand-wavy assumptions. You need to run the numbers. I have yet to see any Hyperloop critic do that in a remotely convincing fashion, whereas there are many Hyperloop engineers who most assuredly are running numbers. Maybe those calculations are wrong, but the only way to refute them is with better calculations. Anything else is just dogma.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#97

Post by johnking »

LaikaF wrote: post #55
felipelemos wrote: post #49

Earlier quoted context omitted.

Care to elaborate?

Thunderf00t has a good video on the problems with it. https://www.youtube.com/watch?v=RNFesa01llk He has some other good videos (solar roadways) but tends to spend to much time bashing creationists.

Thanks for the video reccomendation, super interesting.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#98

Post by alexanderstears »

lisper wrote: post #54
Gustomaximus wrote: post #48

Earlier quoted context omitted.

I dont know if this an elephant in the room. I'm guessing engineers have thought about this and just not discussed it publicly. They have some pretty smart guys. Also to nitpick, from "the ends of a viable hyperloop track will have to move hundreds of meters" - this doesn't have to be true. There can be absorption points along the track. Overlaps. Or maybe they tunnel the entire way where its cooler. Or wrap the tunn…

> There can be absorption points along the track Sure, but these have to hold a vacuum. No one has figured out a way to do that.

Except for the people who invented the accordion and bellows.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#99

Post by jandrese »

warent wrote: post #73
Analemma_ wrote: post #21

Earlier quoted context omitted.

When Musk first said that an LA SF Hyperloop could be built for 1/8th the cost of the equivalent HSR, I chuckled and then waited for the punchline, which still hasn’t arrived. It’s a cool idea and I do want to see more prototypes and feasibility studies, but people need to get off the hype train (no pun intended) and be realistic about the cost.

To be fair, if Elon worked in the project for 40 - 80 hours a week, he probably could get a team to accomplish it at 1/8th the cost or lower. Consider he did this with rockets, getting them to under 1/10th the cost

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.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#100

Post by jandrese »

Gustomaximus wrote: post #48
lisper wrote: post #10

All of the Hyperloop development efforts are ignoring the elephant in the room: thermal expansion. If you do the math, the ends of a viable hyperloop track will have to move hundreds of meters [1]. No one has yet advanced even a viable idea for how to deal with that, let alone an actual design. Until that happens, the Hyperloop is vaporware. [1] It's a trivial calculation. The thermal expansion coefficient of steel i…

I dont know if this an elephant in the room. I'm guessing engineers have thought about this and just not discussed it publicly. They have some pretty smart guys. Also to nitpick, from "the ends of a viable hyperloop track will have to move hundreds of meters" - this doesn't have to be true. There can be absorption points along the track. Overlaps. Or maybe they tunnel the entire way where its cooler. Or wrap the tunn…

Wouldn't they just put accordion joints on the junction at every pylon? It's not like the tube is going to be built as one gigantic piece. It has to be assembled from parts.
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