In June of 1944, a huge Japanese transport submarine, the I-52, was enroute from its home islands to German occupied France with a cargo of 290 metric tons of strategic materials. The Japanese were going to exchange this cargo, which included tin, tungsten, rubber, and two metric tons of gold, for German technology.
The Japanese submarine rendezvoused with a German support submarine in the mid-Atlantic to take on fuel and technicians who, ironically, were going to install anti-aircraft radar on the Japanese vessel for the dangerous sail to the Bay of Biscay. Unknown to the Japanese, the allies had broken their code. Each night when the Japanese submarine surfaced to recharge its batteries, its coded messages, which included its location, were being monitored.
The escort carrier USS BOGUE, enroute to the U.S. from Europe, was given new orders to find and destroy the Japanese submarine. After arriving in the area of the meeting, flights of Avenger torpedo bombers took off around the clock from the BOGUE, looking and listening.
On the night of June 24, 1944, an Avenger got a blip on its radar and dropped flares. The submarine dove, and sonabuoys, dropped from antisubmarine warfare squadron?s aircraft, picked-up the 357-foot Japanese submarine and commenced an attack. The first aircraft dropped depth charges and then a Mark 24 "mine." The Mark 24 was a code name for the then top secret acoustic torpedo that was being used for the very first time in the war.
The torpedo damaged the submarine, and the spot where the submarine was last located was marked with a float light. Another Avenger, piloted by Lt. William Gordon, arrived on the scene, its sonabuoys picking up the sounds of the damaged submarine's cavitating propeller noises. Another acoustic homing torpedo was dropped; finding and critically crippling the Japanese submarine as it tried to get away.
