[r00fus]

This sounds inhumane and thus unlikely to happen in modern prison design (which tbh is more of a jobs program these days than actually designing for restitution or rehabilitation)

"The rotary jails had many design problems. For example, in the event of fire, it was not possible to evacuate the inmates fast enough".

[choonway]

Well, you could make it such that in event of a fire, the external cage would drop down low enough to facilitate evacuation into a designated fenced up area.

[nextlevelwizard]

I don't really buy the quote. You could mitigate a fire in many ways and on top of that unless it takes you minutes to move from a cell to another evacuating 8 prisoners wouldn't take that much time.

Only real fire related threat I can see is if a prisoner for some reason wants to set himself on fire and succeeds. Putting him out might take too long.

As for the inhumane part. I personally don't see it and I think our prisons are little too nice currently, but I'm from a country that doesn't run for-profit prisons.