The M51 was a dump truck used to haul sand, gravel, dirt, rubble, scrap, and other bulk materials. It had a 10footlong (3. 0 m), 5cubicyard (3. 8 m 3) dump body with cab protector and a tailgate that could hinge at either the top or bottom. They could be equipped with overhead bows, tarpaulin, and troop seats, but the relatively small size of the body limited their passenger or cargo load.