Our local HS is built at the confluence of 2 rivers, and before they built a huge dike, it used to flood once or twice a year. We would go down there and fill sandbags to build a 4 to 5 foot dam around the buildings. The local sand company would send semi loads of sand and dump them in the nearest parking lot (about 200' away), and we'd take turns filling the bags, then we'd switch to moving them 'bucket brigade' style, to the proper location, and then we'd take turns stacking them in place. We'd do about 15-20 minutes in each position, until the job was done. Usually several hours to bag, pass, and stack a truck load of bulk sand this way.
After we finished sand bagging the school, we'd load up and head upstream to a small community up there to help them sandbag. The difference there, was that the sand company would send flatbed semis loaded with palletized 100# bags sand. Because of the road layout, they could back the semi to within a few feet of where it would be stacked. We had 2 people on the flatbed putting the bags on our shoulders, and we'd just walk over and drop the bags in position. It only took about 20 minutes to unload the semi trailer.
The sand companies had automatic baggers, but they were stationary units mounted at the factory.
