Test tube babies: Virgin Hyperloop pops pair of staffers in a pod, shoots them along 500m vacuum tunnel Virgin Hyperboleloop was cock-a-hoop over the weekend after blasting a pair of employees along its Las Vegas test tube. "Blast" might be an exaggeration since the duo only reached 172kmph (107mph) on their 15-second, 500-metre journey. A far cry from the 670mph (1078kph) to which the company lays claim – although with only …
At 28 people per vehicle it still just doesn't seem a practical method of mass transport, and that's just getting people in and out of the vehicles in a timely fashion. When you add in having to seal and pressurise the vehicle, seal and depressurise the tube, and then get the vehicle from the station onto the main track and up to speed without getting a 670mph rear-ending by another vehicle, I don't see how the throughput could be any more than a joke.
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There'll be a short section of tube that opens to the air like a tube train station. I will work like an spaceship airlock. Then maybe plenty of sub sections that can each be isolated if there's a problem, the locks open and close automatically if a train approaches.
I can't believe your comment - how do you think railways manage to avoid collisions? Ok it fails sometimes but not often.
Getting 28 pods in and out is easy to automate - look at the food industry programmes on TV, e.g. Ocado warehouses, where everything is on automated lines.
I see a number of carriages on a number of platforms each with an airlock - you airlock carriage 1 and send it off, meanwhile you load and airlock carriage 2 and send it off etc. so there's one tunnel and lots of embark/disembark points on the terminal platform. That would maximise the tunnel use, minimise the differential pressure stress on each vehicle as they can take longer to pressurise/depressurise each airlock. One tunnel and one platform at each end would just be crackers. The only real issue is how far apart you want to run the carriages - close makes more money but distance increases safety.
The only real issue is how far apart you want to run the carriages - close makes more money but distance increases safety.
Well that's the difficulty. For 28-person pods, to get anywhere close to a useful Pax-per-Hour (~15,000pph being a good average for metros and commuter rail) requires them to be launching a pod every 3-6 seconds. Obviously with multiple platforms/airlocks (which they intend to have), that is doable from an engineering standpoint. But that's a lot of pods tailgating very close if one pod has some sort of critical failure.
And a huge potential for leaks. I do wonder whether using air to push rather than pull would not be a better idea - you'd stop things banging into each other and the likelihood of killing a pod full of passengers is a seal goes on a journey and sucks all he air out.
I have a lot of doubts about how many real use cases there are that will justify the great expense of a system like this. But in current rail transit systems multiple cars follow each other at zero distance. And yes, if there is a catastrophic failure in in one car, the cars following it are prone to suffer serious damage and possibly fatalities and/or major injuries as well. Doesn't seem to bother users much.
I suppose that objectively hyperloop is no more complex than air travel. But air travel scales fairly smoothly to small and infrequent payloads. For example moving people and goods around the Arctic. Hyperloop can't do that today. And not any time soon?
But in current rail transit systems multiple cars follow each other at zero distance.
Mechanically connected and using the same braking and traction control system. Yes, derailments are ugly, but also rare.
The idea of independent pods travelling at very small separations and relying on a digital coupling to prevent collisions rather than a mechanical coupling is a wholly different matter.
I suppose that objectively hyperloop is no more complex than air travel.
Air travel requires a costly engineered tube around the passengers. Hyperloop requires a costly engineered tube along the entire length of the journey as well.
Consider how expensive railways are to build and operate, where the fixed mechanical infrastructure is a strip of level ground with pair of metal bars placed a few feet apart.
Even so, railway accidents are not unknown, although fortunately none has ever resulted in a 10 tonne per square metre explosive repressurisation pulse travelling supersonically along the entire route of the track.
I don't think this is intended for commuter rail or metros - it's intended for medium range travel between urban centres that's not practical or economic for short haul air transport, such as Boston-New York. On a European scale, it might cover TGV-style distances like Paris-Amsterdam or even a next-gen Channel Tunnel.
The equivilent air pressure is 200.000ft (61Km) altitude, so the transit tubes will be holding a near vacuum. Air pressure at sea level is 10 tonnes per sqr metre, the tube appears to have a diameter of 4 metres, that's about 120 tonnes of pressure difference, I can only see this working with a series of pressure step down sections between station & the main transit tube.
The number of airlocks needed to to work as you describe (for carriage through flow) will require quite a rigorous (& expensive) safety maintenance regime.
I can't see any real technical challenges to doing this, but the economics are borderline at best. Building the tubes & infrastructure under cities will cost tens of billions, Crossrail currently being built across London in the UK is costing about £19Bn for 73 miles of rail (only 13 of that is tunnel) and that will operate ordinary full size trains at a mere 90mph.
I can't see any real technical challenges to doing this, but the economics are borderline at best.
It depends where you want the tunnel. Problems include cutter wear in hard rock, jamming and steering problems in difficult ground, water inrush, fractured and faulted zones, high in-situ stresses, gas pockets, existing services etc.
Other problems include how it is going to deal with sudden large air leaks (i.e. explosive repressurisation)? How are underground sections of tube going to be replaced after construction if they become damaged? Where relevant, how are you going to maintain tube integrity during a major earthquake? etc.
> how do you think railways manage to avoid collisions?
By leaving a gap of 2-4 minutes between each train - enough distance to stop safely if there's a problem ahead.
The claimed top speed of Hyperloop is 1078kph (= 300 m/s). Even if you strapped people in so tightly that in emergency they could decelerate at 1G, it would take 30 seconds to stop, during which time they will cover 4.5km.
The logistics work out far better if you think of this as competing with short-range flights, rather than trains.
Don't think of this as something where you show up, buy a 20 quid ticket, wait for the next one, stamp the ticket and board to get somewhere 100 km away in 15 minutes. While that would be cool, I too don't see it as feasible.
However: think of this as something where you book a few days in advance, paying 200 quid, show up at the time printed on the ticket, board and get somewhere 500 km away in an hour. *That* can work. The logistics around hyperloop are significant, but they are nothing next to taking an airplane. If they had something like this between, I dunno, Rome and Milan, it would be packed all the time and the air route would pretty much vanish overnight.
This still seems very complicated and inefficient compared to Japanese bullet trains, which are vastly simpler and cheaper to build. Admittedly they only do 300 km/h, but that is enough to be faster than planes for distances like Milan-Rome, since you remove the trips to/from airport and the waiting time at the airport. For trips under 1000 km, high-speed trains are already competitive with flying, while being far easier to build and use than the hyper loop: As you said, you buy a ticket and wait for the next one. There might be a small range around 1000 km of distance where the hyper loop is fast enough to beat the simplicity of trains and simple enough to beat the speed of flying, but it's very niche and hardly seems worth the trouble.
I agree mostly. The speed advantage of hyperloop over best high speed rail would seem to matter only over really long distances -- Los Angeles to Chicago. And its doubtful there is enough long distance travel anywhere on the planet for the economics of hyperloop to work. Note that the US and Canada where high speed rail might seem reasonable have about 50 km total of not especially fast HSR. If HSR doesn't work in economically North America, how is hyperloop which surely costs more going to succeed?
The problem isn't technology (probably). It's economics.
"...just doesn't seem a practical method of mass transport"
This is my thinking too, at least for Earth. Now putting one of these on Mars... There's surely a future in this if humans survive long enough, I just hope these people are around when that time comes to laugh at the "haters".
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Well yes, Hyperloop was only ever a side-line for Musk. Notice how he's not spending any of his own money on it.
The reason for Boring Company developing narrow-diameter electric-powered TBMs is to develop a small, lighter TBM that can be launched to Mars and dig tunnels there (habitation, storage, solar radiation shelter, eventually to connect colonies).
If you can develop material-reuse (convert spoil into new tunnel liners), then tunnelling offers limitless living space compared with a surface colony. But you can't sensibly launch conventional TBMs to space - too big, too heavy, too complicated and they run on diesel. Conversely many of the smaller/micro TBM designs are oriented towards pipe-jacking, which may also be impractical on Mars where you won't have pipe-section to jack behind the TBM.
Musk's Boring Company TBM also has a brick-factory on the back, which seems like an obvious step towards a liner-factory.
Boring Company's Earth-bound projects are just a paycheck, much like SpaceX's NASA and commercial launches are a paycheck to develop their Mars rocket.
In the UK, the new Crossrail trains are around 200m in length which can accommodate 1,500 passengers (With provision to extend to 240m). One of the reasons for that is that longer trains are more efficient than shorter trains. On urban/metro type services, the length of time to bring a train to a stop, allow passengers on & off and get back up to speed again is the limiting factor for the frequency of trains.
You missed all the issues with maintaining a several hundred mile long vacuum chamber.
People need to stop wasting money on vacuum trains. They're massively more expensive and difficult to engineer than the mag-levs that are already prohibitively expensive to implement. Just build yourself a conventional high-speed rail system to start before trying to jump to the insane price point of something like this*.
*If this was actually practically possible, which no one has proven.
*If this was actually practically possible, which no one has proven.
Isn't proving it is possible, what they're doing?
I wouldn't get too hung on the economics. Given how Musk wants to go to Mars, this looks more like convenient local test bed for something intended for Mars.
that was sunk went into the hyperloop being invested into research on how to efficiently store energy.
It's nice and all fun, when billionaires waste invest their money into their playthings, however, with hyperloop Elon got other, non-billionaire people to invest money into one of his ideas.
You do realize that, if you rank people by how much they contribute to energy storage research, either in absolute value or as a proportion of their wealth, Musk has got to be at or very near to the top, right?
As a proportion of their personal wealth people, the people at the very top of the list for contribution to energy storage research are various underpaid and overworked PhD students and independent entrepreneurs etc with a minuscule or zero research budget which they have to top up out of their own money whilst working a 100 hour week on their project.
i.e. People who don't have much money, but everything they do have all goes on their research.
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" Imagine all the money ... that was sunk went into the hyperloop being invested into research on how to efficiently store energy."
I think that if you look into it, you will find that vast sums are being invested in energy storage research by the US, the EU,China and others-- vastly more than on hyperloop. There's money to be made there and lots of people trying to get a cut of the pie. It's a tough problem -- or rather, a tough complex of problems. I don't think lack of funding is what is limiting the rate of progress in solving those problems.
No, I don't mean the faults with the design or operation.
I mean the tectonic faults that this thing would have to cross! Could you imaging approaching one of these at speed just as that lets go?
Not sure if it would be brown trouser time or red smear time!!!
> would being in a 200+ mph train be any better?
The Japanese Shinkansen has shown it is possible, if you want to: Japan does have an awful lot of active faults and resulting earthquakes, and yet in its 50(ish) years of service the Shinkansen never had an accident (AFAIK).
All right, it only does 200mph, but I guess that's enough for most people. Especially since for the passengers it's just a nice, comfortable train like any other.
(Didn't downvote you BTW)
The Shinkansen has experienced one earthquake-related accident. In 2004, in Niigata Prefecture, a Series 200 Shinkansen suffered a derailment of 8 out of the 10 carriages comprising the train. The train was pretty damn close to the epicenter, but the emergency systems functioned as intended. No injuries or deaths, though the train itself was scrapped as a consequence.
> No injuries or deaths, though the train itself was scrapped as a consequence
I think that's a fair price to pay for keeping all passengers safe.
It proves the Shinkansen can deliver on its promises of safety (for common levels of disaster obviously, we're not speaking about some freakish earthquake ripping the island apart).
The pictures on the BBC report showed a streamlined nose cone. If the tunnel is evacuated, why?
Probably the same reason why there's a thriving market for spoilers on cars. But at least with those, you can easily measure the downforce added by just weighing them.
But the hype for the Hypeloop seems to be morphing from vacuum tunnels to low pressure, so the nose cone may make more sense.. As would having a 5-10km tube so the PR folks can market something a bit more impressive than a touch over 100mph.
Correct. Most vehicles, even 'sporty' ones, produce some lift at speed. Anything more than a couple of fat blokes' worth of downforce puts more load on the tyres, increases steering effort, changes suspension geometry and all sorts of undesirable things, unless the vehicle as a whole has been designed around this.
A device designed to add downforce is a wing. Spoilers are not meant to produce downforce (although they can as a by-product of their operation). They literally spoil the airflow coming off a surface in some way to reduce drag - e.g. preventing it going under the floor at the front, or presenting a shallower transition over the roof to the rear.
Because the tunnel isn't a perfect vacuum. That would take far too much energy to maintain, while vastly increasing the costs and engineering challenges. Still some air in there. Not enough to breathe, no way, but still enough to get in the way. Aerodynamics still applies.
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Doing a very quick back of the envelope calculation and assuming constant acceleration, the entire journey took about 20 seconds (10 seconds acceleration, 10 seconds deceleration). Acceleration was about 0,5g the entire time.
If you need a sickbag after a 20 second ride, then something would have been VERY wrong...
Yeh, but there's hills in the USA that will "throw" your stomach in half a second and people sometimes throw up from those... of course they weren't in a perfectly straight tube (which makes me wonder how much of a parabolic turn one of these can take). I know 0% about any of this, but I can't help to think that the design would benefit from a thick "rubber" skirt/gasket around the entire module to allow for some deviance when things get bumpy, of course that design is for more of a suck or blow (but youporn might have some helpful data for this).
I'm always reminded of the Brunel's atmospheric railway.
I seem to vaguely remember reading about a train that used air pressure difference in a tunnel, similar to Hyperloop but at much lower speeds back in Victorian times. IIRC it sucked air at one end to draw the carriage along, which had big rubber seals that moved along the tunnel walls. I've no idea if that was just a concept or if any form of test line was ever built though. It may be that it was an earl;y idea that that never got built but led to the atmospheric railway.
Yes, thanks, that was it.
IIRC, it was in a magazine in the late 70s or early 80s called Speed and Power. Primarily about cars, planes etc related to the title, but ran other historical (and often weird) transport stuff and short SF stories too. It introduced me to Clark and Asimov amongst others.
I could see such being true for a final product, where a lower acceleration could be applied for a longer time. But here...
They went 395 meters (or possibly metres) in 15 seconds. Average speed is about 26 m/s, so peak speed is 52 m/s. (This assumes you accelerate halfway, then decelerate the other half, resulting in a consistent acceleration. Anything else will require a higher peak acceleration somewhere along the path.)
Anyway. To reach 52 m/s in 7.5 seconds, we're talking about roughly 7 m/s^2 acceleration, or about 70% of earth gravity. At startup, you'd suddenly feel an acceleration of sqrt(1^2 + .7^2) = about 1.2 gravities, and the direction of "down" would shift by atan(.7) = 35 degrees from vertical. After 7.5 seconds of that, it'll switch around (so that the direction of "down" will swerve back through the vertical to 35 degrees the other way, a change of 70 degrees total), still at 1.2 gravities. You definitely want to be sitting through all this, and I suspect you want to have not eaten much recently. Or at least want the person sitting next to you not to have eaten much recently. Or both.
I assume the acceleration was changed a little more smoothly than this (i.e., the "jerk" -- the time derivative of the acceleration -- was kept to a more reasonable level). Which would mean more acceleration. I don't see how you'd make this a stomach-settling experience.
I just cannot see how this is going to be useful. The cost of building and operating is just fantasy (although the same could be said of HS2).
For short distances the time spent at each end outweighs the advantage. For something like London to Edinburgh it will be competing with air travel, not train and the construction costs are just horrific. Air has to be better and is certainly less destructive in land use. The green credentials are dubious as well. I have no idea how it compares to air travel but just maintaining the vacuum is horrendous in energy, green or otherwise.
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