Big submarine stills

[00Buck]

I guess this could apply to other big stills also but way back when some of the old timers were running 3-500 gallon rigs I wonder if they did all their fermenting in the pot too. Even a 20 gallon takes a few trips with a bucket to fill up so the idea of 10-15 55 gallon barrels all getting emptied one bucket at a time seems insanely time consuming. And if they sour mashed it that also would be tons of labor. Anybody have any stories or knowledge on it?