1:72 for OO or 20mm
I saw this in a book about Germany during WW2. It was set up to block off streets from advancing infantry and vehicles.
The drum was on a ramp and held up by 2 thin wooden stakes. When the stakes were knocked out the drum rolled down until the
flat face was on the road thus blocking the street. Neat... but not much use against a Churchill AVRE petard.
Dimensions : Length 90mm Width 50mm Height 35mm