A story about something that looked like it shouldn't have been in the mainframe room, but actually should've, sort of.
Years ago I did sales engineering (ie making excuses to the client about why our kit didn't work) for a protocol converter company that made System/370 compatible printer converter boxes. One day I went to a large electricity board head office, where one of our printer boxes was playing up. The mainframe was sited in a large room, with a Heath-Robinson tent over it made out of wood and plastic sheeting.
I asked why it was there, and the bloke in charge said something like,
"Well, we couldn't afford a proper fire extinguisher system, so if the building catches fire and the sprinklers go off, the tent'll keep the mainframe dry. But if the computer catches fire, it'll burn through the plastic, and the sprinklers will put it out!"
That's proper engineering.