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Hyperloop One Becomes ‘Virgin Hyperloop One’

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Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#11

Post by The_Double »

sschueller wrote: post #3

When are we going to address the elephants in the room? Just the tube alone: - largest pressure vessel in the world. How do you keep it at near vacuum? - Thermal expansion over such a large distance, especially if the top of the tube is warmer than the bottom. - Safety, how does an evacuation look like if the tubes are sealed?. There are many more. Some how I feel like this is a "pipe" dream. Lots of marketing, very…

I haven't done any work on hyperloops. But expansion seems to be a problem already solved by industry a long time ago: https://en.wikipedia.org/wiki/Metal_expansion_joint

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#12

Post by wlesieutre »

Filligree wrote: post #5
sschueller wrote: post #3

When are we going to address the elephants in the room? Just the tube alone: - largest pressure vessel in the world. How do you keep it at near vacuum? - Thermal expansion over such a large distance, especially if the top of the tube is warmer than the bottom. - Safety, how does an evacuation look like if the tubes are sealed?. There are many more. Some how I feel like this is a "pipe" dream. Lots of marketing, very…

The pressure tube doesn't need to be at near-vacuum. By the drag equation, air resistance is proportional to pressure; merely cutting pressure by 90% would reduce air resistance by the same amount, and that's trivial with perfectly ordinary pumps. Serious vacuum pumps are not required. This is not to say that keeping it airtight won't still be a major engineering problem, it just isn't as near-impossible as near-vacu…

Doesn't the Hyperloop concept rely on not having a perfect vacuum? It's supposed to suck in air on the front and blow it out the bottom as an air cushion. Without the air cushion you just have "maglev in a vacuum" instead.

I'm sure that's also a fast mode of travel, but like you said, the vacuum part of it takes a lot of money.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#13

Post by iamgopal »

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…

Expansion joints are available since decades.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#14

Post by bmh_ca »

Faaak wrote: post #6
sschueller wrote: post #3

When are we going to address the elephants in the room? Just the tube alone: - largest pressure vessel in the world. How do you keep it at near vacuum? - Thermal expansion over such a large distance, especially if the top of the tube is warmer than the bottom. - Safety, how does an evacuation look like if the tubes are sealed?. There are many more. Some how I feel like this is a "pipe" dream. Lots of marketing, very…

The CERN LHC tube is a 27km circle of vacuum and near-zero temperature, and they don't seem to have a problem with that (granted, they had some but it's solved now). Frankly, yes, there may be issues, but I'm confident that the Human race will be able to overcome those.

I love how you've capitalized "Human", as if to say there were some other race competing to complete the Hyperloop. :)

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#15

Post by dmix »

sschueller wrote: post #3

When are we going to address the elephants in the room? Just the tube alone: - largest pressure vessel in the world. How do you keep it at near vacuum? - Thermal expansion over such a large distance, especially if the top of the tube is warmer than the bottom. - Safety, how does an evacuation look like if the tubes are sealed?. There are many more. Some how I feel like this is a "pipe" dream. Lots of marketing, very…

> Lots of marketing, very little engineering.

It started as a technical whitepaper, not a marketing campaign, and multiple companies are building experimental models. I don't think this critique is accurate or fair. There have been far worse vapourware and hype-only concepts that haven't gotten close to hyperloop's tangible progress.

No tech can be perfected from the planning stage either, it takes talent, money, and time - and you can't get those things without a bit of hype, the key is keeping it balanced.

Regardless the concept seemed feasible enough to some very smart people and people with money to spend, where they see it's worth the R&D.

I don't really see what the big risk or downside here of exploring this? Considering the rewards could be very high if it does work and otherwise there has been little innovation in transportation in 50yrs, it's not like there are some obvious alternatives are being neglected.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#16

Post by batrat »

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 to invest in a black hole sure they can.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#17

Post by lisper »

iamgopal wrote: post #13
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…

Expansion joints are available since decades.

Not ones that will hold a vacuum.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#18

Post by dmoy »

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 am curious, does an expansion joint not help here? Is it impossible to make an expansion joint that deals with the kinds of pressure involved?

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#20

Post by iamgopal »

ginko wrote: post #9
Faaak wrote: post #6

Earlier quoted context omitted.

The CERN LHC tube is a 27km circle of vacuum and near-zero temperature, and they don't seem to have a problem with that (granted, they had some but it's solved now). Frankly, yes, there may be issues, but I'm confident that the Human race will be able to overcome those.

The LHC's vacuum pipes are 6.3 cm in diameter..

What, really? What's with all those mega photos we see everywhere ?
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