 Cursory trials had allowed bad designs to enter service.Both the Navy Bureau of Ordnance and the United States Congress were too busy protecting their own interests to correct the errors, and fully functioning torpedoes only became available to the USN twenty-one months into the Pacific War.British submarines used torpedoes to interdict the Axis supply shipping to North Africa, while Fleet Air Arm Swordfish sank three Italian battleships at Taranto by torpedo and (after a mistaken, but abortive, attack on ) scored one crucial hit in the hunt for the German battleship .