There ism some good info on that site. There are principles that even the welders of those years had to follow. If you wherewelding2 plates together that where almost 2 inches thick, if you tried to weld thejointin one pass the entire weld could crack. not to mention the intense heat building up at the arc location for an extended period of time. Stringers beads did mean heating the metal more times but the time exposure was much less, inturn putting less stress on the base metal.