 "Tampa" accordingly screened ahead, some 3,000 yards from "Dorchester", while "Escanaba" and "Comanche" were deployed on each flank, 5,400 yards from "Lutz" and "Biscaya", respectively.Convoy SG-19 soon came into the periscope sight of , which maneuvered astern to bring her tubes to bear.The U-boat torpedoed "Dorchester" astern at 0355.