Unreliable detonators must be distinguished from defects in the torpedo body itself. German and American services both struggled with their fuzes, while the British encountered comparable problems early and corrected them sooner. Worldwide testing revealed that Earth's magnetic field varies by location, so an influence setting that works in one area may fail elsewhere. Weapon reliability therefore depends on environmental testing and an institution's willingness to recognize a fault.
Notable Point · 50:48-51:07
Why magnetic torpedo fuzes needed worldwide testing
German and American torpedo failures are contrasted with British worldwide testing that exposed how local magnetic fields could upset influence fuzes.