light metal alloy that had been melted down from the engine of a Japanese airplane that had crashed on Oahu during the bombing of Pearl Harbor. Both solutions were installed into torpedoes and the submarine force had a mostly reliable weapon 21 months after the war started. This was the third strike for the Mark 14 torpedo. It started with the USS Sargo missing 13 of 13 easy shots in December 1941. Finally in June 1942, Admiral Lockwood, the Commander of Submarines South West Pacific (COMSUBSOWESPAC), arranged to have torpedoes – with special non-exploding warheads (but unlike the exercise heads of that time and later they were filled to make them just as heavy as the actually explosive-filled warheads) – shot at fishnets. They were set to run at . away they went through the nets at depth. The Bureau of Ordnance (BUORD) wouldn't accept this until they were forced to face the facts and conduct their own experiment. They confirmed Lockwood's experiments on 1 August. But that was not the end. In April 1943 BUORD admitted that the magnetic influence exploder was susceptible to premature explosions. Even then it wasn't until 24 July when Admiral Nimitz ordered that the influence exploders be disabled on all Pacific Fleet submarines. This did not apply, however, to COMSUBSOWESPAC. Admiral Christie then in command had been the officer in charge of testing the super secret influence exploder in the 1930s and he just could not give up on the concept and he ordered that his boats continue to use the defective magnetic exploder. This set the stage for Dan Daspit, USS Tinosa and the Tonan Maru to show that the contact exploder was defective as well, as described above. Third patrol, September–October 1943 Tinosa next departed Pearl Harbor on 23 September. Near the Carolines on 6 October, Tinosa sighted a lone tanker. In a midday torpedo attack, she damaged the ship; then dove to . Four depth charges exploded nearby, springing open lockers and knocking men off their feet in the aft torpedo room. Moments later, a fire broke out in the motor room but was brought under control. Throughout the afternoon, Tinosa and continued to harass the tanker until evening, when their target went down. At sunset on 6 October, Tinosa bombarded a radio station on Alet Island, near Truk. She ended the patrol at Midway on 16 October. Fourth patrol, October–December