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by abirch 718 days ago
Your comment reminded me of college when they taught us: you don't ride in an elevator with a nitrogen tank because it can displace the oxygen in seconds.
2 comments

We broke major safety rules doing the opposite. Carrying various steel tanks up stairs that were way too heavy for two, under-gymed, college students, one step at a time, resting the tank on every step while half of it cantilevered over the edge, as we hand-stabilized it...

I wanted to avoid thinking about that failure mode where you accidentally cleave some part of the gas regulator by damaging it, and that turns the tank into a cold-gas rocket motor. We were shown pictures of the aftermath of those lab accidents—I think there was one were a tank embedded itself into a ceiling?

edit: Now I remember the follow-up—after a professor witnessed us, they showed us the correct method. It was simply to send the tank up in the elevator unattended—one undergrad pushing the "up" button and stepping out, the other waiting for it on the destination floor. Stupidly simple.

There’s a recent video game called “The Finals” where you can throw these steel tanks and the physics works basically as you describe.
The Finals is nuts and sports one of the most advanced game engines out there right now. Fine-grained, server side destruction physics that's synced perfectly to everyone's client so everybody sees the building crumble in exactly the same way.
I can't wait for the deep dive on how the finals works on a technical level, it's extremely impressive
Do you also put a sign on the tank saying "danger - do not enter elevator - risk of death" or something!?
> they showed us the correct method. It was simply to send the tank up in the elevator unattended—one undergrad pushing the "up" button and stepping out, the other waiting for it on the destination floor. Stupidly simple.

That works great until somebody in an intermediate floor enters the elevator oblivious to the risk and suffocates.

That's what service keys are for - with the key turned, the lift will go directly to the selected floor without stopping.
It’s possible this was between adjacent floors, in which case this risk would not exist.
Isn't that why you screw on the protective caps before moving tanks around?
Also the regulator is supposed to be off before it is moved.
Is because an elevator is a small confined space or is it because of some other unique property of an elevator?
It is a small confined space that you have little control over your ability to escape or open up.

A stairwell you can run up, or out a door. An elevator can get stuck - or just take awhile - and there is nothing you can do about it.

Also an issue with liquid nitrogen, but that usually takes a little longer to sublimate.

Dry ice is one of the few grocery store substances (in many areas) with a similar issue, but at least co2 causes a suffocation reflex we can feel. So less dangerous.