2. The Nazis created homing acoustic torpedoes, which almost changed the outcome of the Battle of the Atlantic
An acoustic torpedo, in contrast to a conventional torpedo, is defined by its ability to independently aim itself at a target either by listing to the vessel’s background noise to using sonar. Developed almost simultaneously by both the Allies and Germans during World War II, the Nazis edged out their Western scientific rivals when they created the G7e/T4 Falke, first deployed in March 1943; however, this model was ineffective, and was only used in combat by three U-Boats. Not deterred, in August 1943 the G7es T-5 Zaunkönig torpedo was rolled out and was extensively used throughout September 1943, in particular in attacks on merchant ship convoys during the Battle of the Atlantic.
The initial effects of the introduction of acoustic torpedoes by the Nazis in the campaign was enormous. The summer of 1943 saw significant setbacks for the U-boat campaign, facing impressive anti-submarine efforts by the Allies, the defensive convoy system, and a dedicated team of hunter-killer escorts; the acoustic torpedo turned the tide for the Axis in late-1943, providing the German U-Boats with a “fire and forget” weapon allowing for speedy getaways after identifying itself through attack. In the wake of the introduction of acoustic torpedoes Nazi submarine kills dramatically increased, rising from a near-insignificant total in the summer of 1943. In spite of this considerable impact, the usefulness of the acoustic torpedo was short-lived, as the Allies swiftly produced the “Foxer”: an electronic countermeasure towed several hundred meters behind the ship and designed to produce acoustic noise as a decoy target.