6 ms·
Expansion joints are available since decades.
by iamgopal 9y ago
Expansion joints are available since decades.
- lisper 9y agoNot ones that will hold a vacuum.
- madamelic 9y agoI am not an engineer. Is it impossible to create one? If a tube is a vacuum, then the tube moves, I don't think that negates the vacuum or does expansion and contraction make a vacuum impossible? I wouldn't believe so.
- dx034 9y agoImpossible not. But expensive. And hyperloop is supposed to be cheaper than HSR.
- LeoPanthera 9y agoNot with that attitude.
- dclowd9901 9y agoYour comment may seem flippant, but honestly it seems like people are more eager to be right than aspirational these days.
- TeMPOraL 9y agoIt's not about being right, it's about pure attitude - "why this can't work" vs. "let's talk how can we make this work".
- dclowd9901 9y agoI don't think people are actually that defeatist. If it came to a difficult situation in their own lives, I bet they'd rise to the occasion, but they'd rather see others fail than succeed greater than they did.
- Robotbeat 9y agoDid you try googling? Here's a whole bunch: http://www.metraflex.com/metal-expansion-joints/ http://www.metraflex.com/metal-expansion-joints/
- lisper 9y agoLet 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.
- nkoren 9y agoThis 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.
- mrguyorama 9y agoHyperLoop does NOT run on an air cushion (remember, the entire tube is supposed to be nearly evacuated!), but instead floats on a maglev track. He's also missing another requirement: 5) The entire track, including any possible expansion components, valves, inspection hatches, etc etc etc have to be at least mildly tolerant to intentional or accidental damage. Running into a sudden wall of air at 700mph is a good way to destroy any passenger craft in the system.