From HIGH SPEED COMPUTING DEVICES, ERA Inc, 1950:
The whole book actually reeks of vapor.
Um... ERA were the people who built the "Project 13" machines during
WW II. The 1101 used a drum, and built the follow on 11xx machines
in the Twin Cites. ref "A Few Good Men From Univac" "From Dits To
Bits", etc.
WISC was designed around he same time, and used a drum.