I don't particularly defend feasibility of Hyperloop, but did want to point out that your comment sounded awfully like when people were ridiculing the idea of human flight, landing on the moon etc... Finding engineering solutions to what looked as "impossible" challenges were some of the best feats of humanity so far.
If you put it above ground, you are a few short bullets from killing everyone in the loop. Hitting a wall of air in a vacuum at hundreds of miles per hour is going to be like hitting a brick wall. Ask any reentering spacecraft.
The same problem exists underground, the weakest points being the stations themselves which can be bombed.
A failure in the system itself (even just a power outage or malfunctioning equipment) would mean people suffocate inside after a matter of minutes.
So, sure, it is possible to create it, but it is impossible to make any sort of safety guarantees. In other words, literally any other mode of transport would be safer, including a hydrogen-filled dirigible.
So, sure, the concept itself might be possible, but an engineer doesn't concern themselves with possible. That is for scientists. An engineer considers what is realistic AND possible, because that is an engineer’s job: to make the possible real. This cannot be real; literally no regulator would ever sign off on it.
> So, sure, it is possible to create it, but it is impossible to make any sort of safety guarantees.
Right, because cars and planes and trains and boats and bicycles and footpaths and airships all famously have 100% perfect safety track records, right?
They have mitigations. If a plane breaks down, it can glide. If a regular vehicle breaks down, it can be moved off. If a train breaks down, people can just get off the train. On a hyperloop, where are they going to go when surrounded by a vacuum? What about whatever is behind them also waiting?
There are no mitigations and the only option is death. Maybe you can repressurize the tubes ... assuming there is power to do so ... to evacuate people. This is the main issue, there is no air outside your vehicle. If a window breaks (see: airplanes where this happens every so often) everyone inside is dead. No discussions, no second chances.
That's the problem. The main problem and you can't engineer around it. There are no emergency procedures because if you have an emergency, you are dead; and there will be emergencies.
There are mitigations though. Assuming you have sensors in every segment, you could detect the vacuum ahead deteriorating and brake.
Equally, if the train stopped in an emergency, the valves around it could fail safe to open and let the atmosphere back in. The train has to be pressurised anyway so a small delay there isn’t unreasonable
Sure. I'll play. I assume those sensors are always powered and never malfunction and so, now the train is stopped in a vacuum. What now? How do we get the people out, and all the trains behind them now also stopping. If the tracks are below ground, where is the nearest valve that can open? Given some parameters to chatgpt, because I can't be bothered to do the math myself, it takes ~5 minutes to fill a 500m section with air. So, that assumes a 500m sealable section with an independent valve. So, there would need to be some kind of system that can seal a section on power loss or breach, without a train running into in-progess.... so, 500m sections are too small. The sections need to be ~5km which would take nearly an hour to fill with air that won't kill you instantly. So, if there were structural integrity issues with the train, everyone is guaranteed to die. If there is a critical power loss, hope that it can scrub the CO2 out of the air for at least an hour without power. If there is a breach, hope that it isn't in your section or is at least 3 sections away.
Killing everyone in the train because someone gets in a fight and fires a gun is pretty much a non-starter. That's the real problem you got to solve. It's not like a plane where someone can fire a gun in nearly any direction without consequence to the plane, firing a gun in literally any direction on a hyperloop would mean certain death for everyone on board.
It's in a vacuum, it's not like you can drop oxygen masks. In a vacuum, your blood boils and your eyeballs are sucked out. It's a pretty shitty way to go, but you'll lose consciousness before the worst of it.
Huh? In what world is a hyperloop going maybe 700mph comparable to a spacecraft reentering from orbit at 17,000mph? Also, maybe there's something I'm missing but spacecraft can and do renter from orbit intact, thus proving that this problem is solvable even when the forces at play are orders of magnitude greater. Apply your safety argument to passenger airliners or even ordinary trains and you'll see that they are also "impossible to make safety guarantees" for.
> In what world is a hyperloop going maybe 700mph comparable to a spacecraft reentering from orbit at 17,000mph?
In that case, the air can just "go around" the space craft. Try pushing down a syringe with the end capped. Bet you can't do it. Now imagine that at 700 mph; you will get a lot of heat and destruction. No heat shielding will save you.
> Apply your safety argument to passenger airliners or even ordinary trains and you'll see that they are also "impossible to make safety guarantees" for.