[Jeroen]

Originally Posted by Cessna182

If there is a leak somewhere, will it not force outside air into the tube and destabilize the fast moving object? I was thinking simplistically about what would happen if an airplane suffers a leakage while flying at a high altitude- maybe through a window or door failure. The pressurized air would escape violently and objects/passengers might be sucked out too, because of the lower pressure outside the aircraft at those heights.

In case of the hyperloop, is the possibility of a vacuum leak similar to this situation in reverse? The pressure difference between the inside and outside of the tube is going to be far higher in this case.

There are two different kinds of leak. The cabin or the tube in which the cabin moves.

If there is a leak on the tube air would rush in. So the vacuum in front or behind the cabin would decrease. Either way that would result in the cabin slowing down due to increase in drag (essentially air resistance builds as vacuum degrades.

Unless a massive hole opens up (catastrophic failure) right where the cabin passes I don’t see any real problem.

If there is a leak in the cabin, air would rush out into the tube, similar to what happens on a plane. Similar to a plane oxygen masks will deploy.

Catastrophic failures of airplane hulls and windows, are extremely rare, despite many many movies showing it! There have been a few cases where people got sucked out. But it is extremely rare and I don’t think it has happened in the last 10 years at all, if not longer ago.

Jeroen

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[arijitkanrar]

I was thinking of the leakage scenarios.

In the Hyperloop implementation, the capsule/pod is magnetically levitated, propelled using linear induction motors in a depressurized tube to provide minimal air resistance on the pod as it 'flies' through the tube.

If a leakage happens in the pod itself, the passengers will be provided oxygen masks and the tube will be re-pressurized to keep passengers safe (similar to how pilots bring an aircraft down to below 10000ft when there is a cabin depressurization but can be done much faster and safer). Thereafter the pod can continue but the system will use more power since there is no vacuum in the tube anymore.

A catastrophic failure of the pod itself is unlikely since it looks to be designed like a pressure vessel. Its no different from a catastrophic failure of an aircraft fuselage with similar consequences.

Coming to the tube.
If a small leakage happens in the tube, the vacuum would decrease in the tube thus providing more resistance and slowing the pod down. Very minimal impact.

If a massive leakage happens in the tube, I think the safety systems would detect the leakage when a pod is still kilometers away (depending on the speed) and bring the pod to a stop safely.
Also the tube must be designed in a way that there is no catastrophic failure (implosion). May be the tubes would be designed with some kind of relief joints which would fail first and prevent a catastrophic failure by equalizing the pressure between the inside and the atmosphere.

Other ways catastrophic failures can happen are through external forces. For e.g. a projectile hits the tube. I think this is no different to a projectile hitting a moving train and the results would be equally disastrous.

About people getting stuck in a vacuum tube. Well I think if the pod stops for some reason, the best thing would be to stay in the pod and wait till help arrives. Safety crews should certainly be able to pressurize the tunnel and reach the pod using access hatches at regular intervals just how modern day tunnels have access hatches.

So it doesn't look like this is technology is any more unsafe than any currently available technology.
On the other hand the benefits are huge. Aircraft like speed with train like ease of access with low power consumption.
The major consumer of power in this system is keeping the tube under vacuum. The pod will require very minimal power as the system only needs to energize the part of the track where the pod currently is.

I have to say I'm excited about this!

[Samarth 619]

In my opinion, we have enough scientific knowledge and research, to make this concept a commercial success. Problem is, faraway implementation. Implementation in a place like India or Pakistan where clearly multiple compromises may happen in terms of standards for whatever reasons.

There's a non zero probability of death in everything you do, including staying at home. Even bungee jumping has a 1:5,00,000 possibility of death. I would definitely like a close to zero probability situation, but it can be known only after it commercialises.


Clearly, tube leakage is not supposed to cause much of a problem, but what about hyper speeds like 800 kmph or so?
We're talking concentrated air suddenly hitting a very lightweight capsule (because of magnetic levitation) at 800 kmph.


Someone above said that if the capsule itself leaks, then the inhabitants need to use masks and that's it. I beg to differ. Situation might be very different.
Their eardrums will fall out due to air inside our body. Bleeding will happen from multiple places in our body, the most sensitive areas like eyes, nose first. Vomiting will happen. It will be intolerable.
This has happened in aircrafts already so I'm not exaggerating.

Please note that aircraft flies in a low pressure zone (lower than that on a mountain tip), but still not zero pressure. This capsule will be passing through zero pressure.

One solution is, when you detect it, you open valves to make the tube itself to outer environment and release the vaccum to save the inhabitants from death. Other way is to have multiple layers of safety in the capsule.

But if we've handled space travel, I'm sure with the right research and implementation, it will be a success. The fear you're facing right now, was there, even when people took their first flights in older days. It goes away eventually.

Concept has potential in my opinion... I'm more scared of Indian implementation and corruption than the original concept itself.

[Jeroen]

For those of us with a sceptical disposition on this hyperloop have a look at this article: Your worst doomsday scenario for this adventure has just gotten a whole lot worse

https://interestingengineering.com/b...y-of-hyperloop

For those with a bit more enlightened and upbeat disposition and outlook on life, physics and engineering in particular, see how many mistakes and errors you can find.

Enjoy!

Jeroen

[srini1785]

I need to read up more to understand this principle but it takes a lot of energy to evacuate a volume of space. How long the test tracks were , i am not sure , but when you think in terms of Mumbai - Pune , Bangalore - Chennai that's 350 odd Kms of tube. Energy efficiency is what i had in mind.

Overall i think this has more potential for india than any other nation. Simply because its a closed loop and if they don't allow a stray cattle/dog/man/elephant on either end of the high speed track, we can easily see Bangalore Chennai in 30 mins.

[lalgudi]

Saw that and this tweet thread

https://twitter.com/AstroKatie/statu...640940041?s=20

Have attached a screenshot of what the critics had to say. I believe in the case of public transportation in the US, they do have a point.




There was also another highly scathing criticism that i read on this -
https://defector.com/virgin-hyperloo...gh-speed-rail/


Then yesterday night, i read this - https://interestingengineering.com/s...s-over-621-mph

Probably there is a lot we have to answer before the technology matures and questions around its cost efficiency also need to be looked at

[dragracer567]

Originally Posted by Sebring

Wow. This stuff is awesome. The UAE was considering this for travel between Dubai-Abu Dhabi and we got to see some prototypes that time. I'm astounded how some visionaries get these 'fantasy' projects off the ground. Hope it sees light of day!

Given the financial situation of the UAE right now, I really doubt we will be seeing hyperloop in the UAE anytime soon even if the tech is introduced! It would probably make more sense to build a more traditional railway (maybe highspeed) connecting the various Emirates and neighbouring countries like Oman. Also, Dubai desperately needs more metro lines while Abu Dhabi still doesn't have a metro line (planned 10 years ago). The days of the UAE doing impossible infrastructure projects are over!

Coming back to hyperloop, it is indeed an interesting technology but I believe the bigger issue is the passenger-carrying capacity of individual pods! I think a bullet train (or a typical passenger aircraft for that matter) has a much higher carrying capacity making them much more feasible for large scale transportation (albeit slower). Might be viable for cargo but again we've to keep in mind that the infrastructure on land has to built and maintained unlike for an aircraft where we only need airports in the origin and the destination. It is an interesting space though, let's see how it evolves!

[xway]

I hope someday it makes to India where even bullet trains have not yet seen light of day and max speed of fastest rajdhanis and durontos is hardly 100 miles/hour.

Atleast such technology will stop all rail roko andolans and track blocking dharnas. What happens to squatters in vaccum, maybe shit will hit the roof.

[V.Narayan]

Interesting concept from an engineering and physics point of view. But how practical and economical is this to transport masses of passengers? Let alone the risk of an implosion of the pathway tube, the cost of construction and maintenance is likely to be horrendous. Imagine the effort and cost of maintaining this tube against air pressure in its 20th year of operations. A real life comparison would be a submarine. The pressures involved may be different but the concepts are identical. Once every 5 years in its long refit the entire pressure hull of a submarine, every square centimetre of it, on both sides of the mettal, is examined under X-ray for microscopic cracks that could implode at pressure underwater. A pressure hull is only 40 to 80 metres long. Imagine doing that for 200 kms!

Speed as a virtue in passenger transportation has value up to a point. After that diminishing returns set in as we have discovered with air travel. Building better, safer and faster trains that get you half way into the city using improved versions of existing infrastructure is a way better solution to our transport needs.

Once a train starts running at an average speed of say 250 kmph between two cities it starts to get to the point where for most people the additional saving of time matters less and less. This is so especially for distances below 500 kms. Because the passengers counts his door to door time and not just station to station or airport to airport. Also for many that extra hour of companionship or solitude in the train has a value of its own.

[volkman10]

Virgin Hyperloop and Bangalore airport plan feasibility study for high-speed corridors.

Virgin Hyperloop, the category leader in hyperloop technology, and Bangalore International Airport Ltd (BIAL), operator of the Kempegowda International Airport, Bengaluru (KIAB/ BLR Airport),recently signed a first-of-its-kind Memorandum of Understanding to conduct a feasibility study for a proposed hyperloop corridor from BLR Airport.

The pre-feasibility study, which focuses on technical, economic and route feasibility, is expected to be completed in 2 phases of six months each. With speeds of up to 1,080kph, hyperloop could transport thousands of passengers per hour from BLR Airport to the city centre in under 10 minutes

Travellers could streamline their multimodal trip with seamless check in and security – for both their hyperloop as well as air travel – at centrally-located hyperloop portals.

Link

[Samarth 619]

Originally Posted by lalgudi

Saw that and this tweet thread

From what I've read in the links above, I think its far too dangerous to have implemented in a vacuum form. Any one mistake will result in almost certain deaths.

Why not instead of vaccum, we make air inside the tube travel at 800-1000 kmph?
Wouldn't that be far easy and many many times more safer... ?
The storm flowing inside the tube will help the capsule gain high speeds easily, if both go in the same direction... Big industrial fans can help achieve this much air speed.
Of course, I'm not into science, so I may happily be corrected if I'm wrong somewhere.

And since its not vaccum, the pressure of the air would be same as outside. Even if there's an emergency, most likely a simple red button pressed with send a signal to stop the air flow to both ends of the tube...

Only one disadvantage exists in my limited understanding, and it is the massive amount of air flow and due to that, the energy needed. But compared to maintaining a vacuum (!), it can't be much worse, right?

I think its a wise idea to drop the entire vacuum concept for now. Its too dangerous. Either ways, its a concept that must go back to the drawing board for it to be an overall success.

[Zen2001]

Have they factored in the risk of deceleration injury to the intra cranial, intra thoracic and intra abdominal organs and the effect that these speeds have on the velocity of normal blood circulation?
Would be similar to coming to a near halt from a speed of 700kph in a second, should something go wrong.
It's all good to have completely " healthy" and "normal" humans for the test conditions - what would happen if someone with an arterial stent, carotid/cerebral aneurysm, DVT etc were to travel in it?

[Lazy Driver]

Originally Posted by Dieseltuned

Imagine yourself strapped to a seat inside a capsule which is placed inside a pressurised tube and hurtling at almost mach 1.

"Imagine yourself strapped to a seat inside a metal tube, traveling at a speed of over 500 km/hours, that too thousands of feet above the earth! What if the engine stops working or what if lightning strikes?"

Change is inevitable, innovation is inevitable! It is time that the world solves for fast & efficient on-ground transportation & basis what things look like right now, Hyperloop is a pretty solid answer!

[Gansan]

If this will be as fast as a maglev system, then why not just lay a maglev track and run a maglev train on it? It will be much simpler (relatively) to create and operate than a vaccum tube hundreds of kilometers long.

[Jeroen]

Originally Posted by Zen2001

It's all good to have completely " healthy" and "normal" humans for the test conditions - what would happen if someone with an arterial stent, carotid/cerebral aneurysm, DVT etc were to travel in it?

Nothing would happen as they would find themselves in a pressurised cabin, feeling similar accelerations as on an airplane in similar comfort.

If folks with these conditions can fly on commercial jets, there is no reason they can’t travel on this hyperloop I imagine.

And as with aircrafts, if anything goes catastrophically wrong, most likely all aboard will die.

Jeroen