5. The problematic Mark 14 continued to plague American submarines
The resolution of the depth problem in the Mark 14 revealed the problem with the magnetic exploder, which mainly consisted of premature detonation. From August, 1942 through the early summer of 1943, submarine commanders continued to report what appeared to be hit on target without torpedo detonation. The Bureau of Ordnance sent a technician to examine the problem aboard USS Sargo. His report blamed the problems with the exploders on the submarine’s crew. When Admiral Lockwood heard of the continuing problems with premature explosions, confirmed by intercepts of Japanese reports of attacks, he demanded the magnetic exploders’ removal.
The Commander in Chief, Pacific Fleet, (CINCPAC) Chester Nimitz concurred, and once the magnetic exploders were removed the problem of premature explosions ended. Soon, submarine commanders returned from patrols complaining of hits on enemy ships in which the contact exploder in the torpedoes failed to detonate. Once again, the Bureau of Ordnance claimed the new failure indicated problems with the crews, rather than the weapon. Extensive tests at Pearl Harbor convinced Admiral Lockwood the torpedo, not the crews, remained defective, when 70% of hits at 90 degrees failed to detonate. By September, 1943, the problem had been identified and corrected. After 21 months of underwater combat, the submarine force, at last, had a reliable torpedo, though still in short numbers.