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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.

They'll just have a sensible warning for passengers, "Mind the vacuum ... mind the vacuum ..."

A 'Danger Vacuum' sign should be sufficient.

https://youtu.be/71ukAH6Ny80

You're right. I don't expect that they've thought about this at all.

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.

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.

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.

But a single terrorist bomb doesn't "break" the sky between Rome and Milan. Nor would it take out an entire train. This hyperloop thingy appears to combine the weakest aspects of both and once that fact is pointed out it will be targetted.

"...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".

There's better vacuum on the Moon! Something like this:-

https://catacombs.space1999.net/main/cguide/umtravel.html

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.

Like HS2, for example?

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? I mean, he makes electric cars.

Turns out we have enough people to do more than one thing at once.

https://www.bbc.co.uk/news/business-54841528

https://highviewpower.com/technology/#theprocess

In fact, maybe we could combine the compressed air energy storage with the hyperloop. What could go wrong? Drive the pods along like Augustus Gloop, but with high pressure air instead of liquid chocolate.

Taking away the Chocolate?!?!! You Monster!!!

Accelerating to 20,543,952 furlongs per day and then back down to 0 in 24,8548 chains is impressive.

but do they have self-deploying Bulgarian fun-bags in the event of an air leak leaging to rapid unscheduled decelleration?

A Hyperloop article without a mention of 'Paedo [Pedo - En-US] Guy'? Whatever next?

Say somebody had done 4 years of research to start up a new business that relied on people travelling inside a metal tube 12 km above the ground at 900 km/hr with an outside vacuum equivalent to 0.2 atmospheres, would you feel safe?

Was it designed by Boeing?

Now there’s your problem...

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!!!

The pictures on the BBC report showed a streamlined nose cone. If the tunnel is evacuated, why?

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.

Probably the pressure level in the tunnel will be high enough for the nosecone to make a difference.

"Evacuated" doesn't really mean much. Unless you get the pressure down to a few mB, then streamlining will be necessary.

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).