[TylerE]

Yes, if you have no ventilation.

If you're above ground you'd just pop an emergency hatch in the tube.

You can't do that underground.

I'd also point out that a hyperloop tunnel is a much worse place to be stuck in than a normal tunnel.

In a normal tunnel there is room to walk alongside the tracks.

In a hyperloop tunnel there is virtually no room between the car and tunnel - maybe an inch or two, tops.

[jengleton]

You might not want to pop the emergency hatch when you're surrounded by vacuum.

[TylerE]

Hatch in the tube, not the car.

[liability]

Heh, look up "vacuum cannon" on youtube. The tunnel would need to be slowly depressurized, otherwise anything in it would turn into a bullet when the atmosphere rushes in.

This also applies to any sort of failure that compromises the vacuum. A dipshit with a rifle could kill anybody in the system in a fraction of a second. Burying the tubes is probably the only way to avoid this, but thankfully the whole thing is vaporware anyway.

[aeternum]

You don't need a full vaccum. Even half an atmosphere would greatly reduce air resistance and allow for 4x the velocity in 1 atm.

Humans can survive (uncomfortably) at .5 atm and you eliminate the vacuum cannon problem simply by putting pressurization valves periodically throughout the tube.

[godtoldmetodoit]

The tube is vacuum, you'd need an airlock not just a simple hatch, no? How do passengers get from car to airlock without a suit?

[chrisco255]

Hyperloop is not a full vacuum, only partial vacuum if I'm not mistaken. I don't know what kind of difference that would make on pressure but I assume that means that the tubes are not air tight and actually breathe.

[ClumsyPilot]

Hyper-loop requires 99.99% of the air to be removed from the tube, so it is complete vacuum from the lethality / safety and structure / pressure perspective.

I am not sure what do you mean by 'ubes are not air tight and actually breathe', but they definitely are not air permeable.

[TylerE]

Depressurize the tube first.