It's also probably worth mentioning that wood-stave oil and water tanks were
produced clear up into the 1960s; these were made by coopers. I imagine the
coopering industry was largely mechanized by then, but the basic techniques and
knowledge were, presumably, the same as the Romans used.
I remember my dad telling me about assembling a 25,000 gallon wood-stave tank
at Camp Island on Kodiak in the late 50s. There's a good story behind that,
but I won't digress. Instead, I'll just repeat my query for information about
the dating of fuel drums.
Kris Farmen
Northern Land Use Research, Inc.
Fairbanks, Alaska