I worked for Shell UK in the late 70s, using Univac 1108 and 1110 machines.
They had rows and rows of drum store, each a 1/4 ton cylinder, maybe 1m diameter, rotating at 20,000 rpm. Fixed heads running in a strip down the side, a form of memory somewhere between main and disk, allowing full memory dumps during crash.
They used to take 3 hrs to power up, and Univac engineers used to describe how, if they came off their bearings the outcome was called 'creaming'.
Apparently one came off on a site and 'walked' out of the machine room, pausing only to stroll through a CAU (command Arithmetic Unit - a device as big as a wardrobe), another drilled down through a building.