Hyperloop One Raises $50M, Hires Former Uber CFO(bloomberg.com)
bloomberg.com
Hyperloop One Raises $50M, Hires Former Uber CFO
http://www.bloomberg.com/news/articles/2016-10-13/hyperloop-one-raises-50-million-hires-former-uber-cfo
202 comments
Or worse — billionaire trolling to try to subvert a state (CA) initiative.
Suggesting a faster, most likely more cost effective alternative to a notoriously overpriced state project = subversion? If that's the case then subversion is a good thing we should encourage because there's a serious lack of it happening these days.
Hey, you say that they're just doing high-speed rail in a tube. Do you have a source for that claim? I see lots of people saying it, but nothing from the company or journalistic sources to confirm that. And what's on their blog seems to contradict it:
https://hyperloop-one.com/blog/a-wheel-revolution-in-transpo...
This says that they are using passive magnetic levitation rather than air pressure, so it is a change from the original design, but not as drastic as you suggest.
https://hyperloop-one.com/blog/a-wheel-revolution-in-transpo...
This says that they are using passive magnetic levitation rather than air pressure, so it is a change from the original design, but not as drastic as you suggest.
tl;dr - it's a nice attempt but completely unfeasible as per below:
https://youtu.be/RNFesa01llk
https://m.reddit.com/r/Futurology/comments/4udgd2/the_hyperl...
https://youtu.be/RNFesa01llk
https://m.reddit.com/r/Futurology/comments/4udgd2/the_hyperl...
Most of the workable plans, such as the MIT prototype, are "maglev on a track in a vacuum tube", rather than the original Musk "flies at a 0.5 to 1.3 mm height on aerodynamic lift" plan. That low flying height would require a really smooth tube, with no millimeter-sized sags in the middle of tube sections. Not impossible, just expensive. The whole point of the Hyperloop system is that that the tube is supposed to be cheap.
Dubai Ports World might build a system between Abu Dhabi and Dubai. The route is flat and empty. and not too long. Dubai already has two monorail systems and a metro rail system, all beautiful and underutilized.[1] It may cost too much, but that probably won't be a problem.
A maglev doesn't need the tube below 200MPH or so. One way to build a useful system might be to run in a vacuum tube for long, straight runs, and switch to open track in congested areas. This would allow bringing the tracks much further into cities. Musk's original plan called for ending the LA-SF system in Fremont, near Tesla's plant.
[1] https://www.youtube.com/watch?v=615x7e8wXNU
Dubai Ports World might build a system between Abu Dhabi and Dubai. The route is flat and empty. and not too long. Dubai already has two monorail systems and a metro rail system, all beautiful and underutilized.[1] It may cost too much, but that probably won't be a problem.
A maglev doesn't need the tube below 200MPH or so. One way to build a useful system might be to run in a vacuum tube for long, straight runs, and switch to open track in congested areas. This would allow bringing the tracks much further into cities. Musk's original plan called for ending the LA-SF system in Fremont, near Tesla's plant.
[1] https://www.youtube.com/watch?v=615x7e8wXNU
The idea of creating a miles long pressure vessel "for cheap" always seemed to be the most insane part of the project. It is certainly technically possible to build a structure like that, but I have no idea how they plan to make it affordable.
That's a classic problem with monorail enthusiasts. Early drawings of proposed monorails used to show single lightweight elevated rails on thin pylons.[1] Pictures of successful operating monorails, such as Tokyo Haneda, show double tracks on heavy pylons.[2] Often there's an emergency walkway alongside.
(There are a surprising number of operating monorail systems in the world now. The US is way behind in this. The few in the US are airport systems or tourist attractions, but Japan and China, and now Brazil, have city-sized systems.)
(There are a surprising number of operating monorail systems in the world now. The US is way behind in this. The few in the US are airport systems or tourist attractions, but Japan and China, and now Brazil, have city-sized systems.)
> The US is way behind in this
I wouldn't worry about this - I've never ridden a monorail I liked. They always seem slower and much bumpier than a traditional track - see something like the Bangkok BTS SkyTrain for the type of system you really want.
I wouldn't worry about this - I've never ridden a monorail I liked. They always seem slower and much bumpier than a traditional track - see something like the Bangkok BTS SkyTrain for the type of system you really want.
It's not that low of a pressure, really. The pumps to keep it at a pressure, even with leakage accounted for, only need to be at the ends of the tube so it's fairly cheap.
I wonder how such a system would handle earthquakes and the like.
The tube might keep the train from flying off the tracks, but will possibly lose vaccuum. But maybe not. The trans-Alaska pipeline crosses the Denali fault, which is a big strike-slip fault similar to the San Andreas. The pipleline is on rail-mounted pylons that allow for several meters of lateral motion near the fault. The fault had a M 7.9 earthquake in 2002, and the pylons slid as intended, bending but not breaking the pipeline[1].
Now, I don't know that much about the Hyperloop design, but I imagine that the earthquake-induced deflection in the tube may render it unusable for some amount of time. However, the the example goes to show that somewhat similar infrastructure can be built to withstand large seismic events, as long as the faults are known about ahead of time (which is the case in southern California but not everywhere on earth).
[1]: http://pubs.usgs.gov/fs/2003/fs014-03/pipeline.html
Now, I don't know that much about the Hyperloop design, but I imagine that the earthquake-induced deflection in the tube may render it unusable for some amount of time. However, the the example goes to show that somewhat similar infrastructure can be built to withstand large seismic events, as long as the faults are known about ahead of time (which is the case in southern California but not everywhere on earth).
[1]: http://pubs.usgs.gov/fs/2003/fs014-03/pipeline.html
>rather than the original Musk "flies at a 0.5 to 1.3 mm height on aerodynamic lift" plan....
So what was that exactly? And where does that 0.5 to 1.3 mm height come from?
So what was that exactly? And where does that 0.5 to 1.3 mm height come from?
It's from section 4.1.4 of Musk's original paper. Air bearings are usually that thin, but at the proposed speeds, the inside tube surface can't have any irregularities.
[1] http://www.spacex.com/sites/spacex/files/hyperloop_alpha-201...
[1] http://www.spacex.com/sites/spacex/files/hyperloop_alpha-201...
It's almost as if PayPal founder Elon Musk doesn't necessarily always know best regarding manufacturing and vehicle dynamics.
He didnt found PayPal. He founded an early competitor to PayPal that merged with it, giving him huge equity in Paypal itself.
If you want to talk manufacturing and vehicle dynamics, he also founded Telsa, an electric vehicle company, and SpaceX, a Spaceship company. Anything about those two vehicle manufacturing companies that might lend you to believe he knows something about manufacturing and vehicle dynamics?
He undoutably doesn't have the concept fully sorted, but at least vilify the man for actual faults, not ones you want to make up.
If you want to talk manufacturing and vehicle dynamics, he also founded Telsa, an electric vehicle company, and SpaceX, a Spaceship company. Anything about those two vehicle manufacturing companies that might lend you to believe he knows something about manufacturing and vehicle dynamics?
He undoutably doesn't have the concept fully sorted, but at least vilify the man for actual faults, not ones you want to make up.
He's still not a mechanical or aerospace engineer. At least lionize him for actual qualities, not ones you project onto him.
So that's a really interesting statement...
He has an B.S. in physics and an
Honorary doctorate in Aerospace Engineering, and an Honorary doctorate of Engineering from Yale.
So I'm not sure what exactly it takes to count as an aerospace engineer, but it seems like he has both the bit of paper, and the employment history.
So I'm not sure what exactly it takes to count as an aerospace engineer, but it seems like he has both the bit of paper, and the employment history.
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Many SpaceX engineers helped him with the white paper he released. Steve Job's wasn't an engineer and he was fully capable of building a software/hardware company even after his engineer cofounder left.
Such a troll
> he also founded Telsa
Musk gave Series A funding to Tesla. Martin Eberhard and Marc Tarpenning founded Tesla.
At best, Musk bought Tesla really really early. But he wasn't one of the original founders.
> SpaceX
I'll give you that one. But Musk doesn't get Tesla in my eyes.
Musk gave Series A funding to Tesla. Martin Eberhard and Marc Tarpenning founded Tesla.
At best, Musk bought Tesla really really early. But he wasn't one of the original founders.
> SpaceX
I'll give you that one. But Musk doesn't get Tesla in my eyes.
In 2003, Musk did indeed gave Series A (as well as B and C) seven months after the company was incorporated. At the same time, in early 2004, he took up direct operational control of the company, and has stayed in that position since. The first Roadster arrived 4 years after he took over.
He has also been involved in an electric car (and battery) company, a solar energy company, and a space travel company. Much more recently.
>I still can't get past the feeling that this is another Moller Aircar type project. Something to string investors along forever while you bilk them out of money.
i wonder why such animosity toward Moller. His approach on the last incarnation of the car has some technical mistakes which made it a dead end, yet looking into his history and the overall history of VTOL i wonder how people may see that as a scam. It is pretty obvious today that we will have human carrying 8/12/16-copters in the next few years (we actually already have them as actually flying prototypes today) and that is pretty much where Moller was in 198x-199x just adjusting for the non-availability of modern hardware and electronics back then (so he went for complicated double-engine-same-shaft design with minimum of controlling electronics - the approach which doomed the last incarnation. I do fail to see a scam here.)
i wonder why such animosity toward Moller. His approach on the last incarnation of the car has some technical mistakes which made it a dead end, yet looking into his history and the overall history of VTOL i wonder how people may see that as a scam. It is pretty obvious today that we will have human carrying 8/12/16-copters in the next few years (we actually already have them as actually flying prototypes today) and that is pretty much where Moller was in 198x-199x just adjusting for the non-availability of modern hardware and electronics back then (so he went for complicated double-engine-same-shaft design with minimum of controlling electronics - the approach which doomed the last incarnation. I do fail to see a scam here.)
Moller makes the same claims over and over, and adjusts the proposed completion date on the web site year after year to be about three years in the future. (Long discussion of this on the Wikipedia talk page.) He's been in trouble with the SEC for overclaiming to investors. His product has been "real soon now" since the 1970s. Here's his 1974 brochure.[1] Full-scale production was to begin by the end of 1976.
Moller was trying to build a VTOL powered by Wankel engines. His company was trying to build Wankels with much better power to weight ratios than usual. As usual, this resulted in much reduced engine lifespan. (Classic tradeoff, as everybody in drag racing knows.) He's been able to build a vehicle that can get off the ground, and hover a bit, tethered from a crane, for 2-3 minutes.
Pure-thrust VTOL is quite possible with jet engines. The aircraft that do it, such as the Harrier and the F-35, are fighters, which are mostly engine anyway. It can be done, but not at low cost or high payload or high efficiency.
Jet engines remain expensive. Despite many attempts, small, cheap, reliable jet engines remain out of reach. Below 6-passenger bizjet size, reliable engines don't seem to get much cheaper. There are cheap high-powered small jet engines with model aircraft levels of reliability and a life of 100 hours or so. That's how the Flyboard Air does it.[2] Not being stupid, they always fly this over water at low altitudes.
[1] http://www.downside.com/scams/moller/ [2] https://www.youtube.com/watch?v=KEDrMriKsFM
Moller was trying to build a VTOL powered by Wankel engines. His company was trying to build Wankels with much better power to weight ratios than usual. As usual, this resulted in much reduced engine lifespan. (Classic tradeoff, as everybody in drag racing knows.) He's been able to build a vehicle that can get off the ground, and hover a bit, tethered from a crane, for 2-3 minutes.
Pure-thrust VTOL is quite possible with jet engines. The aircraft that do it, such as the Harrier and the F-35, are fighters, which are mostly engine anyway. It can be done, but not at low cost or high payload or high efficiency.
Jet engines remain expensive. Despite many attempts, small, cheap, reliable jet engines remain out of reach. Below 6-passenger bizjet size, reliable engines don't seem to get much cheaper. There are cheap high-powered small jet engines with model aircraft levels of reliability and a life of 100 hours or so. That's how the Flyboard Air does it.[2] Not being stupid, they always fly this over water at low altitudes.
[1] http://www.downside.com/scams/moller/ [2] https://www.youtube.com/watch?v=KEDrMriKsFM
> i wonder why such animosity toward Moller.
50+ years and $100m in R&D no viable prototypes might have something to do with it.
Maybe the approach was doomed from the start, but that didn't stop Moller from promising that you would be commuting to work by air in 10 years for decade after decade.
50+ years and $100m in R&D no viable prototypes might have something to do with it.
Maybe the approach was doomed from the start, but that didn't stop Moller from promising that you would be commuting to work by air in 10 years for decade after decade.
>50+ years and $100m in R&D
tell this to fusion guys :)
>no viable prototypes
i find this for example as looking very viable back at the time
https://www.youtube.com/watch?v=3MwxVAZuFOs
and actually if you add more props (possible with electric today not so much with gas engines back then) and much-much better control electronics you'll get the modern multi-copters :
volocopter prototype https://youtu.be/L75ESD9PBOw?t=97 and pre-production https://youtu.be/VAEy0NltoFQ?t=78
>Maybe the approach was doomed from the start, but that didn't stop Moller from promising that you would be commuting to work by air in 10 years for decade after decade.
only the last one, m400 was doomed as i mentioned above (and it wasn't actually that clear from the start, m400 was actually pretty logical and reasonable move forward - only after first tests one could see it clear). Put yourself at his place at any point in the history of his flying car development and those 10 years would look like a reasonable estimate. I personally actually say today that in 5 years we'll have the Volocopter likes flying around.
tell this to fusion guys :)
>no viable prototypes
i find this for example as looking very viable back at the time
https://www.youtube.com/watch?v=3MwxVAZuFOs
and actually if you add more props (possible with electric today not so much with gas engines back then) and much-much better control electronics you'll get the modern multi-copters :
volocopter prototype https://youtu.be/L75ESD9PBOw?t=97 and pre-production https://youtu.be/VAEy0NltoFQ?t=78
>Maybe the approach was doomed from the start, but that didn't stop Moller from promising that you would be commuting to work by air in 10 years for decade after decade.
only the last one, m400 was doomed as i mentioned above (and it wasn't actually that clear from the start, m400 was actually pretty logical and reasonable move forward - only after first tests one could see it clear). Put yourself at his place at any point in the history of his flying car development and those 10 years would look like a reasonable estimate. I personally actually say today that in 5 years we'll have the Volocopter likes flying around.
> >50+ years and $100m in R&D
> tell this to fusion guys :)
Drop the "50+ years" and tell it to every other SV startup these days... ;).
> tell this to fusion guys :)
Drop the "50+ years" and tell it to every other SV startup these days... ;).
The animosity may be more toward the impracticality of throwing huge volumes of fuel (generating untold pollution) at a rich man's problem.
I don't think so. Even if they were built the aircars would cost around half a million each. Nobody cares that much about the fuel burn on a product that only a few hundred people would ever own.
Plus, they would spend most of the time in the shop anyway. Moller's big idea was to design an engine that was cheap, lightweight, had a very high power to weight ratio, efficient, and extremely reliable. For some reason he has had trouble making an engine that ticks all of the boxes.
Plus, they would spend most of the time in the shop anyway. Moller's big idea was to design an engine that was cheap, lightweight, had a very high power to weight ratio, efficient, and extremely reliable. For some reason he has had trouble making an engine that ticks all of the boxes.
It seems to me like there's a fairly strong case for using them for transporting goods, at least. Much more durable than humans, tracks can be laid in places that would be far too risky to run humans through.
But what goods need to be moved so quickly? Autonomous vehicles are going to bring plenty of improvements to shipping and delivery, and are happening right now.
Reducing the time of shipping is a pretty common goal of many companies. It's not about need, it's about a clear improvement.
honestly, its the solar powered roadways for the technology oriented crowd. the science is beyond the majority of readers but who would want to admit they truly don't understand what they are supporting and look bad among peers who support it?
look, it might be technically possible but it in no means is viable. it does sound really cool though.
look, it might be technically possible but it in no means is viable. it does sound really cool though.
I'd like to think it's possible to make this work. However, I've lost faith in this group to make it happen based on the wackiness I've read so far.
https://www.wired.com/2016/08/hyperloop-one-lawsuit-bambroga...
https://www.wired.com/2016/08/hyperloop-one-lawsuit-bambroga...
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How about dropping the Hyperloop evacuated tube idea and replace it with something more achievable? How about a private roadway that is completely flat and only for specially-equipped electric cars? The cars are completely autonomous and communicate with neighboring cars and a central traffic controller. The cars can tailgate each other in complete safety at 200-250 mph allowing for extremely dense road usage (no 9 car lengths separations). And all the traffic will move at exactly the same super-high speed, carefully servoed.
People can just get in using their own privately-owned certified compliant electric cars. And then take a nap as the autonomous driving takes over for safe high-speed travel. No traffic jam slowdowns, no slowpokes in your lane. Road-embedded power can wirelessly beam energy so there is no need for refueling stations. Traffic control manages vehicles entering and leaving the roadway. Read the news or take a nap. SF-to-LA in 2hrs, and you arrive rested and with your car.
Not the hyperloop, but drastically cheaper and leveraging technology that's coming anyway. The novelty is drastically higher speeds, bumper to bumper driving, continuous fueling.
People can just get in using their own privately-owned certified compliant electric cars. And then take a nap as the autonomous driving takes over for safe high-speed travel. No traffic jam slowdowns, no slowpokes in your lane. Road-embedded power can wirelessly beam energy so there is no need for refueling stations. Traffic control manages vehicles entering and leaving the roadway. Read the news or take a nap. SF-to-LA in 2hrs, and you arrive rested and with your car.
Not the hyperloop, but drastically cheaper and leveraging technology that's coming anyway. The novelty is drastically higher speeds, bumper to bumper driving, continuous fueling.
Does Elon Musk still have anything to do with any of the Hyperloop companies?
50 million dollars is enough to build 100 feet of subway (in New York).
[deleted]
neat
The hyperloop - all the dangers of outer space, here on earth.
Or: if we can't get SpaceXplode into space, we'll get space down to earth
Or: if we can't get SpaceXplode into space, we'll get space down to earth
Am I the only one who gets confused by which hyperloop company is which?
What's the difference between the different players?
From what I can tell, Hyperloop One f/k/a Hyperloop Technologies [1] is a venture-backed company testing at an open-air track in Nevada. They are the ones raising $50MM. (They are also the ones playing the "everyone sues everyone" game.)
Hyperloop Transportation Technologies [2] is approaching the problem with crowdfunding and crowd collaboration. Their pictures are quite pretty.
[1] https://hyperloop-one.com
[2] http://hyperlooptransp.com
Hyperloop Transportation Technologies [2] is approaching the problem with crowdfunding and crowd collaboration. Their pictures are quite pretty.
[1] https://hyperloop-one.com
[2] http://hyperlooptransp.com
The technology isn't theirs either, or at least not the concept for it. The original idea was proposed years ago and named ETT or Evacuated Tube Transport by a company called ET3.
https://www.youtube.com/watch?v=92dK_yxaKvk
https://www.youtube.com/watch?v=92dK_yxaKvk
Hyperloop Tranportation hasn't had an update in nearly 2 years: http://hyperlooptransp.com/#!/updates
Which one has the test track next to SpaceX?
To make it more confusing: neither. It's SpaceX's track.
http://www.spacex.com/hyperloop
> "To support this competition, SpaceX is constructing a test track adjacent to our Hawthorne, California headquarters"
http://www.spacex.com/hyperloop
> "To support this competition, SpaceX is constructing a test track adjacent to our Hawthorne, California headquarters"
It's the one that's going to get built. By Dubai no less!
which one? hyperloopONE?
I'm happy for them, but I'm yet to hear for anybody to address the major challenges that many people have raised. The major one being - the sudden pressurization in any point and the consequent shockwave traveling at the speed of sound, exploding the tube, killing everything in its way.
Thunderf00t did a good job summarizing the problems:
https://m.youtube.com/watch?v=RNFesa01llk
Thunderf00t did a good job summarizing the problems:
https://m.youtube.com/watch?v=RNFesa01llk
I thought Thunderfoot's video has been pretty thoroughly debunked?
e.g. https://www.reddit.com/r/Futurology/comments/4udgd2/the_hype...
Also from Hyperloop One employees here:
https://www.reddit.com/r/IAmA/comments/4wck43/hi_were_mostly...
e.g. https://www.reddit.com/r/Futurology/comments/4udgd2/the_hype...
Also from Hyperloop One employees here:
https://www.reddit.com/r/IAmA/comments/4wck43/hi_were_mostly...
That doesn't seem like the main problem to me. The main problem is that the system as proposed by Musk, even taking all of the optimistic assumptions at face value, has a daily passenger capacity close to zero. The tube capacity is proposed to be less than 1000 passengers per hour. That doesn't even compare well with the capacity of a single lane of highway, and is orders of magnitude below what you get from a railroad.
> The tube capacity is proposed to be less than 1000 passengers per hour. That doesn't even compare well with the capacity of a single lane of highway
It takes 3 to 5 airplanes departing per hour to get near that capacity.
It takes 3 to 5 airplanes departing per hour to get near that capacity.
Major airports handle departures at the pace of 30-40 per hour.
Airport capacity is not the point.
The point is that each plane costs around 300 million. A single modern high-speed train costs less than 100 million, and has over 5 times the capacity of a single passenger plane.
The point is that each plane costs around 300 million. A single modern high-speed train costs less than 100 million, and has over 5 times the capacity of a single passenger plane.
Indeed . . . from the first announcement, I was intrigued by the concept and I truly hope it works out. HOWEVER, as proposed, it is no real competition with high speed rail. In fact, in my opinion, Musk missed the point of high speed rail entirely. It is less about getting from LA to SF quickly than it is about getting from Bakersfield to SF or from Fresno to LA. High speed rail links LA to SF as well as ALL POINTS IN BETWEEN. It creates a single economic corridor. Hyperloop on the other hand just links two points much the same way as air travel. This, coupled with the massive disparity in capacity that you pointed out, makes it ridiculous to compare Musk's hyperloop to high speed rail; it is more comparable to air travel.
Well, there could be a niche, upscale market for getting from SF to LA in 30 minutes, like people going for meetings and coming back on the same day. Other modes of transportation takes just too long for that kind of use case. I don't think this was ever thought of as a transportation option for people who commute to work every day because they can't afford to live in the center of those cities. Hyperloop, if it's ever built and works, will probably be the Concorde of ground transportation, in terms of market share and price. Although if we look at the outcome of Concorde, it may not make a lot of sense to follow that path.
Oh, I agree; there are use cases, but the original announcement billed it as a better alternative to high speed rail, and I just don't think it is in remotely the same category.
> High speed rail links LA to SF as well as ALL POINTS IN BETWEEN.
Except when you add the 'all points in between' it stops being high speed rail. The current CA 'bullet train' as planned is projected to be only marginally faster than standard rail over the majority of it's run - 80-100MPH.
Except when you add the 'all points in between' it stops being high speed rail. The current CA 'bullet train' as planned is projected to be only marginally faster than standard rail over the majority of it's run - 80-100MPH.
Accepting your statement at face value, that is still faster than driving and more convenient than the existing system which is, well, nothing. Standard rail, which does not currently exist on that route, would be even slower with the same stops. Los Angeles to Oakland on the Coast Starlight takes 11+ hours. [EDIT: Bakersfield to Oakland on the San Joaquins is about 6 hours. At 90 mph, high speed rail would cut that trip in half.]
Further, not every train has to stop at every station; there can be express trains.
Further, not every train has to stop at every station; there can be express trains.
Bakersfield to Oakland is a 4 hour drive by any reasonable measure, and it would be cheaper to boot.
The Cali bull*^% train isn't competing against rail - it's competing against cars and airplanes.
The Cali bull*^% train isn't competing against rail - it's competing against cars and airplanes.
German ICE trains don't run at full speed except in certain segments. At full speed, they get over 300kph!
Also, you're forgetting about express trains. With sidings and in-cab signals, you can have high speed rail that stop at ever stations and others that pass intermediary stations for morning/evening commuters.
Also, you're forgetting about express trains. With sidings and in-cab signals, you can have high speed rail that stop at ever stations and others that pass intermediary stations for morning/evening commuters.
No, I'm not forgetting them. Part of the lower speeds projected are due to shared rail, and noise/safety concerns traveling through populated areas.
I don't think the shockwave would explode the tube. The in-rushing air would be equalizing the pressure. It would have a deleterious effect on pods, however. I would equip the pods with airbags that could inflate and act as emergency brakes, which would also compartmentalize the tube. The emergency protocol would be to bring all cars to a stop, then inflate the airbags. If the shockwave is impinging on the car, the airbag would inflate immediately. Then each compartmentalized tube segment would be rescued, with access through emergency access points. (Which could also contain the mechanism that takes care of the thermal expansion problem.)
I don't think the shockwave would explode the tube. The in-rushing air would be equalizing the pressure.
Yes, the more I've thought about this, the more I agree. Moreover, I don't think the hypothetical shockwave would last all that long. As it moves down the tube, it has to drag an increasingly long column of air behind it, all of which is likely turbulent and definitely causing friction with the inside of the tube. This would slow and weaken the shock front considerably to the point that at some distance down the tube, the pressure would rise not suddenly, but slowly and evenly.
Yes, the more I've thought about this, the more I agree. Moreover, I don't think the hypothetical shockwave would last all that long. As it moves down the tube, it has to drag an increasingly long column of air behind it, all of which is likely turbulent and definitely causing friction with the inside of the tube. This would slow and weaken the shock front considerably to the point that at some distance down the tube, the pressure would rise not suddenly, but slowly and evenly.
Or the massive G forces on the passengers.
If you're going 650 Mph in an airplane and hit a bump (air pocket), the plane can bounce 5-10 feet. So the acceleration is spread over a long time / distance.
If you're going 650 Mph in a hyperloop and hit a bump, you have millimeters of room. So any minor bump is going to be a gigantic slam.
I've ridden TGVs in Europe. At 250 Km/h (~150 Mph), it's bumpy enough that I have a hard time doing anything other than stare out the window.
The hyperloop will be 4x faster than that. If it does work, I'd probably want a padded interior, and a face mask with attached vacuum aspirator for vomit...
If you're going 650 Mph in an airplane and hit a bump (air pocket), the plane can bounce 5-10 feet. So the acceleration is spread over a long time / distance.
If you're going 650 Mph in a hyperloop and hit a bump, you have millimeters of room. So any minor bump is going to be a gigantic slam.
I've ridden TGVs in Europe. At 250 Km/h (~150 Mph), it's bumpy enough that I have a hard time doing anything other than stare out the window.
The hyperloop will be 4x faster than that. If it does work, I'd probably want a padded interior, and a face mask with attached vacuum aspirator for vomit...
> I've ridden TGVs in Europe. At 250 Km/h (~150 Mph), it's bumpy enough that I have a hard time doing anything other than stare out the window.
This is the total opposite of my experience, I've ridden the TGV many times in France and I'm always amazed how smooth the ride is, without looking outside I wouldn't even notice I'm moving. It's actually a weird feeling to look outside as you see the landscape moving so fast.
This is the total opposite of my experience, I've ridden the TGV many times in France and I'm always amazed how smooth the ride is, without looking outside I wouldn't even notice I'm moving. It's actually a weird feeling to look outside as you see the landscape moving so fast.
Same experience for me- I took the Eurostar from London to Paris (and back) last summer and couldn't tell you if we were moving or stopped, if I closed my eyes.
I used to live in France, and would sometimes commute from the south to Paris for the day.
Sure, there are large stretches where it is straight and smooth. But when it's bumpy, it's really bumpy. In a way that a slow train just can't do.
Sure, there are large stretches where it is straight and smooth. But when it's bumpy, it's really bumpy. In a way that a slow train just can't do.
Which South? If it is via the Atlantic-side line, only the 200 km near Paris are a high-speed line, the rest is a classical line (on which the TGV rides).
I expect it's "really bumpy" on the non-high-speed tracks, the train would be extremely rigid all around and thus not absorb bumps from low-quality/low-speed tracks making imperfections much more noticeable. My experience seems to have been mostly on proper tracks/at speed, the ride is as smooth as can be in a wheeled vehicle.
I don't know what train you've ridden, but Spain's Ave goes 300 km/h and you don't even notice you're moving. And it definitely doesn't bump at all. You cannot notice constant speed but only speed changes (acceleration = force).
A better comparison might be the Transrapid Maglev in Shanghai. It goes 320km/h and it was incredibly smooth because it's levitating
> I've ridden TGVs in Europe. At 250 Km/h (~150 Mph), it's bumpy enough that I have a hard time doing anything other than stare out the window.
Uh? The only problem you may feel is the pressure in your ears when you are in a tunnel. But the ride feels much less bumpy than a regular train on a classical line.
Uh? The only problem you may feel is the pressure in your ears when you are in a tunnel. But the ride feels much less bumpy than a regular train on a classical line.
> So the acceleration is spread over a long time / distance
That's not how acceleration works. Maybe you mean force? Hyperloop cars are heavy enough that a small air pocket wouldn't be able to produce enough force to accelerate it substantially.
That's not how acceleration works. Maybe you mean force? Hyperloop cars are heavy enough that a small air pocket wouldn't be able to produce enough force to accelerate it substantially.
Perhaps it is encouraging then to see this first go of it be for transporting cargo rather than people.
..like the transporters in Star Trek :)
Just as aircraft (and I'm sure other pressure vessels) are designed to resist explosive decompression, I am sure any real hyperloop system would be as well. That is not to say that it could never happen, but with proper engineering (and maintenance), we can make it exceedingly unlikely.
I'm not talking about the pod depressurization, which is indeed analogous to the plane, but is a separate issue, and is actually much worse than the plane (planes don't fly in near-vacuum, and can descend very quickly).
I'm talking about the tube pressurization, which is much much worse.
I'm talking about the tube pressurization, which is much much worse.
So am I. You can still prevent explosive decompression in much the same way. If you provide reinforcing strapping for example, you prevent a minor puncture from turning into a massive tear and explosive decompression [EDIT: perhaps, I should say re-compression]. I.E. if air is leaking in relatively slowly, you will never get the violent pressure wave you are talking about.
That doesn't solve larger tears, like a terrorist shooting an RPG at it, or exploding something underneath, or flying a small plane into it. It's a very large target to secure compared to a plane.
Our current transportation system also doesn't solve terrorists planting bombs on rail lines or shooting RPGs at train cars or crashing planes into highway overpasses.
Not the same scale of destruction, not even close.
You might derail one train, if lucky, not every train on the track. We have defect detectors:
https://en.wikipedia.org/wiki/Defect_detector
Also trains, especially in the US, are much slower, and derailing one will probably kill a few passengers, but most will be fine. It's much more damaging to target bridges, which terrorists did:
https://en.wikipedia.org/wiki/Rafiganj_train_wreck (130 dead)
Crashing a plane into a highway overpass will do even less damage, because cars can stop very quickly when they see a problem.
You might derail one train, if lucky, not every train on the track. We have defect detectors:
https://en.wikipedia.org/wiki/Defect_detector
Also trains, especially in the US, are much slower, and derailing one will probably kill a few passengers, but most will be fine. It's much more damaging to target bridges, which terrorists did:
https://en.wikipedia.org/wiki/Rafiganj_train_wreck (130 dead)
Crashing a plane into a highway overpass will do even less damage, because cars can stop very quickly when they see a problem.
Fair enough. However, I think you are underestimating the size of explosion that it would take to seriously damage something like this. Engineers will definitely think about things like earthquakes and accidental (or intentional) collisions (such as a truck hitting a support pillar).
I also think you are overestimating the number of terrorists running around with RPGs.
EDIT: Of course, when all is said and done, the additional engineering requirements to make it safe may also make it economically unfeasible, in which case, your original point about the dangers would be essentially correct.
I also think you are overestimating the number of terrorists running around with RPGs.
EDIT: Of course, when all is said and done, the additional engineering requirements to make it safe may also make it economically unfeasible, in which case, your original point about the dangers would be essentially correct.
Unfortunately vacuum tubes are very vulnerable, they would have to be ridiculously overdesigned to take even a small explosion or a truck.
Terrorist with an RPG is just an example, it can be anything - a drone with C4, somebody throwing a long string of burning thermite, or just a gasoline canister set on fire.
Terrorist with an RPG is just an example, it can be anything - a drone with C4, somebody throwing a long string of burning thermite, or just a gasoline canister set on fire.
All of these things can cause the same loss of life on any current mass transportation system.
This reminds me of the people who were very vocal about automated cars needing to be perfect before they could replace human drivers. They seem to have quieted down as the technology gets closer to actual deployment. I suppose that will also be the case here if the hyperloop becomes reality.
This reminds me of the people who were very vocal about automated cars needing to be perfect before they could replace human drivers. They seem to have quieted down as the technology gets closer to actual deployment. I suppose that will also be the case here if the hyperloop becomes reality.
Not the same loss of life. A large rapture will propagate through the hole vacuum tube at the speed of sound, likely killing everyone, not just one pod.
Also it's a much easier target. Planes are only reachable to the terrorists during takeoffs/landings. And even then, it's not exactly easy to hit a plane moving at 300mph with an RPG/truck/drone.
The rest of your argument about automated cars is the classic example of straw man.
Also it's a much easier target. Planes are only reachable to the terrorists during takeoffs/landings. And even then, it's not exactly easy to hit a plane moving at 300mph with an RPG/truck/drone.
The rest of your argument about automated cars is the classic example of straw man.
You see, I didn't actually argue about automated cars, just noticed the similarity in the arguments.
And to address your original point in a horribly sarcastic way, if only someone had invented bulkhead technology...
And to address your original point in a horribly sarcastic way, if only someone had invented bulkhead technology...
Would building it underground largely solve these risks? We already build for natural disasters in mind- seems earthquakes would be the main issue in California, which structures claim to be "proofed" from.
The pressurization wouldn't be "explosive," there wouldn't be a pressure wave because a gradient of pressure would have to form between the atmosphere and the tube. Here's a playlist of videos rebutting this argument and many others:
https://www.youtube.com/playlist?list=PLSPi1JFx4_-Gz0Fm0qq2K...
https://www.youtube.com/playlist?list=PLSPi1JFx4_-Gz0Fm0qq2K...
You are correct in that it can be addressed, but I believe the issues people raise are that properly addressing everything makes the project to be (potentially) extraordinarily expensive.
Rebuttal playlist addressing all of his videos:
https://www.youtube.com/playlist?list=PLSPi1JFx4_-Gz0Fm0qq2K...
will hyperloop be the only martian transportation one day? imagine there being a grid of hyperloop to take all over the planet. it's also free of those pesky seas.
Hyperloop is much more feasible on Mars than on earth because you don't need to maintain a vacuum -- you've already got one. You don't even need a tube, just a U-shaped track.
I'm not sure that the ability to make a vacuum is our primary bottleneck to making a Hyperloop on Mars.
Let's hope we leave space in future Martian cities for public transportation infrastructure.
> You don't even need a tube, just a U-shaped track.
Thus making it a monorail, rather than a Hyperloop.
Thus making it a monorail, rather than a Hyperloop.
Well, you'd still be "flying" on a thin cushion of Martian atmosphere rather than riding directly on a rail. That makes a big difference.
What benefits does a U-shaped track have over traditionnal rails?
The reason the hyperloop is attractive is that it's effectively "flying" at low pressure, which is equivalent to flying at high altitude, which lets it operate effectively like a jet airplane. On Mars you can do the same thing in a U-shaped track because of the thin atmosphere. You would be "flying" on a very thin cushion of atmosphere between the vehicle and the track. That has much less friction than a rail, and so you can go much faster.
Musk's true hyperloop design isn't a train like the Hyperloop One company is proposing, but a sort of low-pressure ramjet hovercraft in a hose.
On Mars, you don't need the top half of the hose because it's already low-pressure, so the ramjet hovercraft could run in an open-air trough.
On Mars, you don't need the top half of the hose because it's already low-pressure, so the ramjet hovercraft could run in an open-air trough.
I think a simple train would be much cheaper and effective for Mars.
Yes, but those aren't disruptive.
Honestly though, this whole idea smells like technofuturism to me. High-speed trains are hard, and this is being sold as being easy and sexy and futuristic. However, if you do the math out, the capacity isn't nearly as good as modern trains - which is literally the entire point of a train. That means Hyperloops are sort of like making a really cheap airplane that doesn't fly. The whole world is not the web, and there are legitimately difficult problems out there, particularly in transportation.
The hype around the idea is absurd, and it sounds like at least 1 of the companies that took money to work on it was a scam.
Honestly though, this whole idea smells like technofuturism to me. High-speed trains are hard, and this is being sold as being easy and sexy and futuristic. However, if you do the math out, the capacity isn't nearly as good as modern trains - which is literally the entire point of a train. That means Hyperloops are sort of like making a really cheap airplane that doesn't fly. The whole world is not the web, and there are legitimately difficult problems out there, particularly in transportation.
The hype around the idea is absurd, and it sounds like at least 1 of the companies that took money to work on it was a scam.
Sure would be a lot easier/cheaper to maintain a near-vacuum when that is exactly what the atmosphere is!
Mars atmosphere is far from being near-vacuum. Also if you have to extract air, the difference between how much air you have to extract is pretty much irrelevant.
Ooh, how I wish I could buy put options on the Hyperloop. Because unless they solve the thermal expansion problem -- and there is no feasible solution on the horizon AFAICT -- they will fail.
I am assuming that you are talking about the thermal expansion of the tubes (ducts ?). A long time ago, the rails making up train tracks used to have gaps every few meters to accommodate thermal expansion (same problem). Modern rails in high speed train tracks are welded into one continuous bar that can be over a kilometer long. The trick is to stretch the rail just enough and then pin it down - kind of like a slightly stretched rubber band. That stretch can accommodate thermal expansion.
That's a good direction to pursue, but CWR (continuous welded rail) segments are only a few kilometers long at most. That, plus the fact that the cross-section of a rail is much less than the cross-section of a hyperloop tube, makes the tensile stress at the ends of the rail small enough that they can be managed by anchoring the ends of the rail to the rail bed.
The tensile stress at the ends of a hyperloop track would be orders of magnitude higher if you tried this approach. I haven't done the math, but I'd suspect you'd need an anchoring system comparable to what you see on large suspension bridge cables, if not more. Not only that, but I suspect you'd start to reach the limits of what steel can structurally sustain. With this solution, you've got a O(100km) long tube that is not only under vacuum but now also under enormous tension. Before this can be considered a viable solution someone needs to do the math on that, and AFAIK no one has.
So I still want my put options.
The tensile stress at the ends of a hyperloop track would be orders of magnitude higher if you tried this approach. I haven't done the math, but I'd suspect you'd need an anchoring system comparable to what you see on large suspension bridge cables, if not more. Not only that, but I suspect you'd start to reach the limits of what steel can structurally sustain. With this solution, you've got a O(100km) long tube that is not only under vacuum but now also under enormous tension. Before this can be considered a viable solution someone needs to do the math on that, and AFAIK no one has.
So I still want my put options.
Hmmyeah, but the result is so-so, it experiences a few troubles in the warmest days of the summer and trains (especially high-speed trains who both need perfect rails and put more strains on them) have to be speed-limited or in a few cases even cancelled.
Isn't space super-cold? I mean, if you pull air out of a tube, the stretched air absorbs calories (–or cools down, which is the principle of a fridge with other chemicals and a liquid/gas transition). So can this effect keep the metal cold?
Space isn't cold. It has very low temperature. These are not the same thing.
Because space has extremely low density thermal radiation doesn't really work very well... it's very hard for a vehicle in a vacuum to dump heat...there is no medium to receive the energy!
Because space has extremely low density thermal radiation doesn't really work very well... it's very hard for a vehicle in a vacuum to dump heat...there is no medium to receive the energy!
> Space isn't cold. It has very low temperature. These are not the same thing.
That's news to me. What do you think "cold" means if not a synonym for "low temperature"?
> Because space has extremely low density thermal radiation doesn't really work very well... it's very hard for a vehicle in a vacuum to dump heat...there is no medium to receive the energy!
No, that's completely wrong. It is very easy to radiate heat into space as long as your radiator is not pointed at the sun. What you can't do is convect heat away, which makes it hard to transfer heat from the hot part of a spacecraft to the cold part. But getting rid of the heat once you've transferred it to a radiator is really easy. In fact, some parts of a spacecraft need heaters to keep them warm if they don't get sun exposure.
That's news to me. What do you think "cold" means if not a synonym for "low temperature"?
> Because space has extremely low density thermal radiation doesn't really work very well... it's very hard for a vehicle in a vacuum to dump heat...there is no medium to receive the energy!
No, that's completely wrong. It is very easy to radiate heat into space as long as your radiator is not pointed at the sun. What you can't do is convect heat away, which makes it hard to transfer heat from the hot part of a spacecraft to the cold part. But getting rid of the heat once you've transferred it to a radiator is really easy. In fact, some parts of a spacecraft need heaters to keep them warm if they don't get sun exposure.
Not a good analogy. One of the main Hyperloop points it is to have near vaccum inside the tubes, which will reduce air resistance and allow faster speeds, otherwise it's just a train inside a tube. This means they must be totally sealed, so no gaps allowed.
So... you put in a flexible air tight seal in the tube. It will have to be modular anyway. Doesn't seem that challenging or cost prohibitive. A quick google turns up NASA projects that were looking into flexible airlock seals.
> near vacuum inside the tubes
This isn't true at all. The tube will still have air inside of it, you just need higher pressure behind the car than the air in front.
The cars themselves work a lot in the same way a cylindrical air hockey table would work.
This isn't true at all. The tube will still have air inside of it, you just need higher pressure behind the car than the air in front.
The cars themselves work a lot in the same way a cylindrical air hockey table would work.
The current hyperloop company has deviated substantially from Musk's design - now it's just narrow train in a semi-evacuated tunnel.
It won't be a complete vacuum though? I mean it doesn't have to be. Even removing 70% 80% of the air would greatly reduce drag. Plus don't they also need safety systems in case of issues so the tube segments can be locked and re-pressurized without damaging the train?
Drag reduction is, I think as important as decreasing the shock wave generated by breaking the local speed of sound. Partial vacuum does both. Not sure how to optimize for cost and reliability of construction vs max sped
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Not to mention all of the logistical problems with building and maintaining a low pressure tube.
People think high speed rail is expensive? Wait until you see how expensive Hyperloop is going to be per mile.
PS - And I haven't even touched on safety/evacuation problems with the concept. That quadupled the cost and size of the Eurotunnel for comparison, how can we assume it won't bloat the Hyperloop's size/cost/complexity?
People think high speed rail is expensive? Wait until you see how expensive Hyperloop is going to be per mile.
PS - And I haven't even touched on safety/evacuation problems with the concept. That quadupled the cost and size of the Eurotunnel for comparison, how can we assume it won't bloat the Hyperloop's size/cost/complexity?
And so it does? However you feel about the executives and history of Hyperloop, I think it's important that companies like this exist and try things like this.
You know what's expensive and was once unfeasible? Strapping thousands of tons of fuel to a rocket and launching it into space. And yet...
You know what's expensive and was once unfeasible? Strapping thousands of tons of fuel to a rocket and launching it into space. And yet...
> I think it's important that companies like this exist and try things like this.
They're not trying anything at this point, they've raised enough money for at most 5km worth of high-speed tracks (proper 350km/h graded tracks) and no rolling stock.
They're not trying anything at this point, they've raised enough money for at most 5km worth of high-speed tracks (proper 350km/h graded tracks) and no rolling stock.
What about R&D output? Even if the company goes broke, they / their research can be purchased and used in the future. They might only produce new materials that they sell the patents for upon going bankrupt. Their engineers and scientists will develop and learn, and move on to other firms if Hyperloop becomes insolvement, and take that knowledge with them.
But those problems can be solved. Maybe. Even if they're not, the research is important to tell us what does and doesn't work.
We build massive dams to stop rivers and invest billions into complex rockets that need to carefully control explosions in order to get people and cargo into space.
If one company can build a simple 10 ~ 20km tube between two major travel points in some country, it will be an invaluable proof of concept worth way more than the initial investment.
Just because something is hard doesn't me we shouldn't try.
We build massive dams to stop rivers and invest billions into complex rockets that need to carefully control explosions in order to get people and cargo into space.
If one company can build a simple 10 ~ 20km tube between two major travel points in some country, it will be an invaluable proof of concept worth way more than the initial investment.
Just because something is hard doesn't me we shouldn't try.
Any problem can be solved with unlimited funds. The question isn't if it is possible, it is how much good can be done with that same money elsewhere (opportunity cost).
For example, one mile of Hyperloop or five miles of conventional high speed rail? One mile of Hyperloop or two miles of Monorail? One mile of Hyperloop or investments into more efficient aircraft?
For example, one mile of Hyperloop or five miles of conventional high speed rail? One mile of Hyperloop or two miles of Monorail? One mile of Hyperloop or investments into more efficient aircraft?
That Musk sure is one big dummy!
That's a rather offensive thing to claim. He has actually accomplished a lot and pushed two or three industries forward.
Personally I don't think Musk is a "dummy" as you do, but I do feel sometimes his passion doesn't always address real world civil engineering limitations. The Hyperloop is technically very possible, thus isn't "dumb," it is just building it at scale (and addressing consumer safety, etc) that may be a challenge.
Personally I don't think Musk is a "dummy" as you do, but I do feel sometimes his passion doesn't always address real world civil engineering limitations. The Hyperloop is technically very possible, thus isn't "dumb," it is just building it at scale (and addressing consumer safety, etc) that may be a challenge.
I think GP was being sarcastic to the GGP's comment.
What's unsolvable about it? Every bridge I've ever been on has had a little gap for expansion. Just make a little gap every 5km, cover the outside with rubber that stretches across the two sides, boom, you are done. The cars float on a little air pressure cushion and don't normally use their wheels, so there wouldn't even be a bump.
The hyperloop tube needs to maintain a vacuum and be perfectly smooth on the inside, so traditional expansion joints won't work.
Could you have an outer tube with concrete and expansion joints, then a membrane on the inside that maintains smoothness but expands/contracts as the tube moves?
What would the membrane be made out of?
Remember, it's not enough to be smooth. You have to be:
1. Smooth (on the inside) and
2. Straight and
3. Strong (enough to bear the stress of having a multi-ton vehicle passing within a few millimeters at 700MPH) and
4. Long (300 miles at least) and
5. Airtight for that entire length, and
6. Cost-effective.
It is that combination of features that no one has ben able to even begin to tell a story about how they would make it work in the face of thermal expansion.
Remember, it's not enough to be smooth. You have to be:
1. Smooth (on the inside) and
2. Straight and
3. Strong (enough to bear the stress of having a multi-ton vehicle passing within a few millimeters at 700MPH) and
4. Long (300 miles at least) and
5. Airtight for that entire length, and
6. Cost-effective.
It is that combination of features that no one has ben able to even begin to tell a story about how they would make it work in the face of thermal expansion.
How do gas pipelines solve the thermal expansion problem?
By putting bends into the pipes.
https://www.quora.com/Why-do-oil-pipelines-have-so-many-seem...
But this obviously won't work for the hyperloop. It has to be straight.
https://www.quora.com/Why-do-oil-pipelines-have-so-many-seem...
But this obviously won't work for the hyperloop. It has to be straight.
Expansion joints or loops[0], and their thermal expansion problems are significantly lower since the source is environmental changes.
[0] http://i.stack.imgur.com/VhLi2.jpg
[0] http://i.stack.imgur.com/VhLi2.jpg
Oh, OK. Just have to do the same with the train :-)
Shouldn't this be a solved problem by NASA?
Space shuttles would have similar challenge (actually in reverse) - how to protect sealed air inside a closed cylinder from almost absolute vacuum outside in an environment where heat and cold are extreme; the cylinder being fabricated from overlapping conjoined pieces.
Space shuttles would have similar challenge (actually in reverse) - how to protect sealed air inside a closed cylinder from almost absolute vacuum outside in an environment where heat and cold are extreme; the cylinder being fabricated from overlapping conjoined pieces.
Some folks at NASA have spent some time analyzing the principles and technical challenges behind hyperloop (I know most of them for what it's worth):
https://scholar.google.com/scholar?cluster=45818300884035476...
https://scholar.google.com/scholar?cluster=45818300884035476...
Thanks for sharing. They seem to be convinced about the viability albeit concluding that it may need bigger diameter pipes and the speed would be little slower.
No alarms on thermal expansion, structural integrity etc.
No alarms on thermal expansion, structural integrity etc.
yeah, the analysis at that stage was focused more on the propulsion aspects of the system.
They did solve this: they have expansion regions at the stations (ends of the tube) and the tube is allowed to slide freely within it's supports.
Won't work. See http://www.leancrew.com/all-this/2013/08/hyperloop/ for a detailed analysis.
The funding round was led by DP World, which operates 77 marine terminals around the globe [1] and is interested in using hyperloops to move containers from marine terminals to inland ports.
[1] https://en.wikipedia.org/wiki/DP_World
[1] https://en.wikipedia.org/wiki/DP_World
Uber had a CFO? That's news to me
I think this needs to be brought to more people's attention, so I'm putting this in a top level comment:
Thunderf00t's video: https://m.youtube.com/watch?v=RNFesa01llk
Debunked: https://www.reddit.com/r/Futurology/comments/4udgd2/the_hype...
Also debunked: https://www.reddit.com/r/IAmA/comments/4wck43/hi_were_mostly...
Thunderf00t's video: https://m.youtube.com/watch?v=RNFesa01llk
Debunked: https://www.reddit.com/r/Futurology/comments/4udgd2/the_hype...
Also debunked: https://www.reddit.com/r/IAmA/comments/4wck43/hi_were_mostly...
I do not know a lot about the technology, but I remember reading that the hyperloop is not a full vacuum, just a lower pressure environment. That alone means all these videos are bunk themselves.
Thunderf00t's video got that same response quite a few times. He made an additional video that directly responds to common complaints about the first video: https://youtu.be/DDwe2M-LDZQ?t=238
I watched that video as well. He doesn't respond to more than a small fraction of the objections in the reddit thread.
Low pressure, vacuum, I doubt physics care (not a physicist), it's just a pressure differential, just a bigger or smaller one. So the effects would just be smaller.
Right, but using a true vacuum as your comparable for the construction of a partial vacuum is nonsensical. This structure has a differential closer to an airline, not a space shuttle. Airplanes can handle that pressure differential with a thin layer of aluminum. They can even have windows!
Thinking through this a little more. In basic terms, you just need a tunnel big enough combined with low enough pressure that at speed, the train has significantly less air to push out of the way. I'm sure it is some complex math, but someone who understands the math could figure it out.
Thinking through this a little more. In basic terms, you just need a tunnel big enough combined with low enough pressure that at speed, the train has significantly less air to push out of the way. I'm sure it is some complex math, but someone who understands the math could figure it out.
The air pressure 10 km above sea level is about 25 % of the air pressure at sea level, the Hyperloop paper says the air pressure in the tube will be 0.1 % of the air pressure at sea level. So the pressure is way closer to a perfect vacuum than to the air pressure outside of airplanes.
It's still a linear change. The tube needs to withstand 1 ATM of pressure, which isn't all that much in the grand scheme of things.
Withstanding one atmosphere is certainly not an unsurmountable challenge but given the dimensions and given that this thing is supposed to be cheap it is also certainly not a negligible issue. You also have to maintain the quality of the vacuum, possibly in presence of expansion joints, and you have to deal with the consequences of a loss of vacuum for whatever reasons.
Yes, the mechanical forces involved with a 0.75 ATM differential are very similar to a 1 ATM differential. But the same isn't true for leaks and residual gas because the difficulty isn't linear. Pushing a vacuum 0.1 ATM to 0.01 ATM is much harder than from 0.51 ATM to 0.501 ATM.
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Even a small pressure differential might be a huge boost. At least from what I've seen in my basic physics lab, you don't have to get anywhere near a vacuum or even what most people would call "low pressure" for it to make a significant difference.
Just running a tube between two cities of different elevation might allow for zero energy transport of small pods.
Just running a tube between two cities of different elevation might allow for zero energy transport of small pods.
^^I read this a lot on hyperloop forums and articles, but it doesn't really matter. What pressure constitutes a vacuum ? What pressure do you mean by low pressure?
Zero pressure(perfect vacuum) is impossible to do in life. So what these articles/videos mean by vacuum is sufficiently low pressure that can reduce drag and that is essentially impossible to do across a tube of any meaningful size.
Zero pressure(perfect vacuum) is impossible to do in life. So what these articles/videos mean by vacuum is sufficiently low pressure that can reduce drag and that is essentially impossible to do across a tube of any meaningful size.
Incorrect. It's not "essentially impossible" as it's very far from a vacuum, or even a near-vacuum. The Hyperloop paper explains why it doesn't require high cost to build the tube or maintain the vacuum within with only pumps at the two ends of the tube.
That concern is accounted for repeatedly in the debunking videos. It is not valid. Too much air pressure and the hyperloop is pointless. Too little air pressure and the hyperloop is impossible.
If your goal is low pressure, low cost, and high speed then build an airplane. No tracks required, no vacuum pumps required, no permitting required.
If your goal is low pressure, low cost, and high speed then build an airplane. No tracks required, no vacuum pumps required, no permitting required.
Pretty sure that building an aircraft requires a LOT of 'permitting' -- for instance, airworthiness certifications. And that's not just on the aircraft as a whole, but each individual aspect as well as the aircraft design itself.
No new permitting. The existing permitting process is well defined and understood.
Low pressure is only reached for a portion of the flight. In a relatively short trip like LA-SF, as Hyperloop was proposed to do, the plane spends quite a bit of its flight time climbing and descending: https://www.youtube.com/watch?v=J01iDyHq2p0
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I only made it to the 2nd third of Thunderf00t debunk, the vertical temperature gradient => buckling seems to ignore the plans to cover the pipe with solar panels.
The terminal length offset seems unrelated at first. It seems they have more options to handle this.
ps: I wonder if, even a public mode of transport fails, it could be interesting for objects; smaller diameter and less security issues.
The terminal length offset seems unrelated at first. It seems they have more options to handle this.
ps: I wonder if, even a public mode of transport fails, it could be interesting for objects; smaller diameter and less security issues.
Here's a playlist of video rebuttals to Thunderfoot's videos: https://www.youtube.com/playlist?list=PLSPi1JFx4_-Gz0Fm0qq2K...
Dubai Ports World invested in this? That's serious. They're owned by the government of Dubai.
Hyperloop was accepted into the Dubai government accelerator, which is a 3 month program specifically meant to match you up with a government department and sign a contract. The accelerator is overseen by the Sheik's son. There's a lot of money behind this program.
Consensys the blockchain company is in the accelerator as well as Sure Chill for cooling medicines, and an augmented reality for education startup, and potentially a concrete 3D printing company as well. There are allegedly 30 companies in the cohort although the list hasn't been made public.
I think the program has a huge amount of potential to rapidly scale up these technologies, I just hope that the companies are able to scale with the demand.
Consensys the blockchain company is in the accelerator as well as Sure Chill for cooling medicines, and an augmented reality for education startup, and potentially a concrete 3D printing company as well. There are allegedly 30 companies in the cohort although the list hasn't been made public.
I think the program has a huge amount of potential to rapidly scale up these technologies, I just hope that the companies are able to scale with the demand.
Why is that serious, considering the track record of Dubai investing in silly things ?
The things may be silly, but they still cost serious money. So Hyperloop appears to just gone from "unfunded wacky idea" to "funded wacky idea".
I'd like to see some venture capitalists put forth some big chunks of money on realistic infrastructure projects using boring, proven technologies. Sure, there's not much chance of ever getting any kind of return on it, but at the end of it, there's still a bridge, or an extra couple transit stops left over when you're done lighting money on fire.
Maybe something like imperial Roman conspicuous construction instead of conspicuous consumption.
Just for a change.
Maybe something like imperial Roman conspicuous construction instead of conspicuous consumption.
Just for a change.
I believe we have a presidential candidate quite well versed in conspicuous construction with negligible returns.
$50M is peanuts for this scale of a project and the engineering that will need to be done. Seems like this is likely only enough to get to a small scale POC.
I think it's a great start, but it's still super early to know if this can even work.
I think it's a great start, but it's still super early to know if this can even work.
50 million Dollars will buy you at least 200 man-year of clever people thinking about it, that should be more than enough to realize that this is not an (economically) viable endeavor and render building a prototype mood.
but it will also buy at least 50 'man-year' of clever people thinking about marketing it and how to continue to profit off of it regardless if it is feasible or not
I'm all for chasing ambitious goals, but America should probably demonstrate some modest capabilities in building and running high speed passenger trains before it disrupts that game. While Americans (and Dubai) chase this hyperloop boondoggle, Japan is rolling out 300kph+ trains from stern (Kyushu) to tip (Hokkaido) in the most inhospitable and earthquake-prone region in the world, with insane population densities in some places, across relatively vast waterways, and with almost zero delays in operating timetables.
Should America also have upgraded the mail system before telegraph lines were deployed? Should America have also made faster trains before building the interstate system?
Innovation and disruption are better than just incremental improvements to make some existing technology fit your bill.
Innovation and disruption are better than just incremental improvements to make some existing technology fit your bill.
Are you really arguing that 300km per hour trains that run on time and safely are equivalent to "telegraphs" while American passenger trains routinely fail to follow any schedule at all and have a bad habit of killing people? Not to mention that they don't serve large swaths of the country, including areas that need them
most.
>Should America also have upgraded the mail system before telegraph lines were deployed?
It is a bit different, you know. Investing in proven tech vs investing in vapourware..
It is a bit different, you know. Investing in proven tech vs investing in vapourware..
Honestly, I'm just glad that the project isn't dead after the recent kerfuffle. Hiring decent people may be a good way to get back on track and attract more investors.
I wonder if they've fixed the basic engineering errors from the first proposal: http://www.leancrew.com/all-this/2013/08/hyperloop/
> Neither of these is possible for the Hyperloop because the high speed of the capsule zooming along inside it means the pipe curves have to be very gentle. How, I wondered, is Musk going to solve the thermal expansion problem?
> The answer turned out to be simple: he didn’t. There’s some hand waving and, possibly, a complete misunderstanding of how thermal expansion acts, but no actual solution.
The rest of the article is a deep dive into the problems with the earlier Hyperloop proposal.
> Neither of these is possible for the Hyperloop because the high speed of the capsule zooming along inside it means the pipe curves have to be very gentle. How, I wondered, is Musk going to solve the thermal expansion problem?
> The answer turned out to be simple: he didn’t. There’s some hand waving and, possibly, a complete misunderstanding of how thermal expansion acts, but no actual solution.
The rest of the article is a deep dive into the problems with the earlier Hyperloop proposal.
That appears to be old. The official proposal by his engineers was released, where every criticism I've heard has been addressed. Here's a playlist of videos rebutting some common claims against the hyperloop: https://www.youtube.com/playlist?list=PLSPi1JFx4_-Gz0Fm0qq2K...
Interesting, thank you.
How resilient will the Hyperloop be against terrorist attacks?
It is situated above ground. This means the tubing is exposed to all and everyone. In other words, it is vulnerable to homemade explosives which can perhaps obstruct the path the vessel transverses. Sounds far-fetched, but the lengths extremists go to can not be undermined as we have learned time and time again throughout history.
I am interested in the security protocols more so than anything else.
It is situated above ground. This means the tubing is exposed to all and everyone. In other words, it is vulnerable to homemade explosives which can perhaps obstruct the path the vessel transverses. Sounds far-fetched, but the lengths extremists go to can not be undermined as we have learned time and time again throughout history.
I am interested in the security protocols more so than anything else.
This is a valid concern, but it's definitely not one that should impede efforts to construct one or prove its viability. For one, hyperloops have a lot of potential value for shipping. For another, most of the designs don't seem to involve a huge number of people in on point at once, and it wouldn't be hijackable in the way than an aircraft is. To be honest, the simplest form of transit to use in terms of ease of access combined with potential destruction is just a car or bus, right?
It's at least equally vulnerable as conventional rail, but more vulnerable than aircraft, which are usually out of reach of improvised weapons and are usually surrounded with some cursory security on the ground.
Hyperloop (and pretty much all "PRT") is a joke and whoever invested in this should be embarrassed. Just get it over with and build high-speed rail.
Hyperloop is not Personal Rapid Transport. And I don't think all PRT is a joke.
Is it your assertion that of the 200 countries in the world, none of them will ever, under any circumstances, create a self-driving car lane with higher speed limits?
Because that seems like a crazy assertion to me. It doesn't even take a country... One county could do it. And boom, Personal Rapid Transport is not a joke.
Is it your assertion that of the 200 countries in the world, none of them will ever, under any circumstances, create a self-driving car lane with higher speed limits?
Because that seems like a crazy assertion to me. It doesn't even take a country... One county could do it. And boom, Personal Rapid Transport is not a joke.
It's not a joke. It's a well engineered concept designed by engineers much more competent than you or I.
Well engineered? How so when the "engineering" to make this work does not exist. That some team might find solutions to this problems is pure gamble....
If you are talking about Elon Musk, he might have other incentives to put forward something like this. Note that we are living in an age when anything can be made popular or credible despite its worth....
If you are talking about Elon Musk, he might have other incentives to put forward something like this. Note that we are living in an age when anything can be made popular or credible despite its worth....
better yet, don't build any rail for passenger travel. let us instead engineer changes to our roadways to allow for self driving cars to occur sooner and safer. only a few countries in the world have more than 10% of passenger miles by rail.
heavy rail is just too damn expensive for what it provides and there are what, two non subsidized systems out there? plus hundreds of billions in backlogged maintenance to many rail systems, not even counting the rail car maintenance that has been put off.
heavy rail is just too damn expensive for what it provides and there are what, two non subsidized systems out there? plus hundreds of billions in backlogged maintenance to many rail systems, not even counting the rail car maintenance that has been put off.
Isn't rail inherently more energy efficient due to the rigid wheels even without the economies of multipassenger vehicles?
Rail is efficient due to the low slopes that are required by the steel-on-steel friction, required to accelerate/brake through the wheel/rail interaction.
And yes, the only mode of transportation that is cheaper than rail with regards to cost per tonnage is sea transport. In passanger transportation, it really depends on the distances and on the speed of transportation. People tend to pay a premium for point-to-point speed, and although airway transportation is unbeatable in that regard the time to get to the nearest airport and required to board end up adding a travel time penalty between 1 and 2 hour. This means that high-speed rail tends to be, by far, the best mode of transportation between destinations that are distanced up to around 400km.
And yes, the only mode of transportation that is cheaper than rail with regards to cost per tonnage is sea transport. In passanger transportation, it really depends on the distances and on the speed of transportation. People tend to pay a premium for point-to-point speed, and although airway transportation is unbeatable in that regard the time to get to the nearest airport and required to board end up adding a travel time penalty between 1 and 2 hour. This means that high-speed rail tends to be, by far, the best mode of transportation between destinations that are distanced up to around 400km.
More space efficient.
How many non-subsidized road systems can you name?
Off the top of my head, exactly one, the Dulles Greenway [1].
It's truly not a common occurrence.
[1] https://en.wikipedia.org/wiki/Virginia_State_Route_267#Dulle...
It's truly not a common occurrence.
[1] https://en.wikipedia.org/wiki/Virginia_State_Route_267#Dulle...
The proposals aren't even all that similar to the original Hyperloop proposal. Gone is the ducted fan setup and instead they're just building high speed rail in a tube. And the cost estimates still make no sense whatsoever. I will be frankly shocked if any of these companies ever lay anything more than a short test track somewhere.