I'm listening to James Scott's "The War Below". In World War II, US Navy torpedoes detonated at the end of their range if they hadn't hit anything. So if a torpedo was fired and went its maximum range (4500y for the Mark 14) without otherwise detonating, it would self-detonate.
I'm curious why that is advantageous? Wouldn't it make more sense for a missed shot to be allowed to silently sink to the bottom? I'd think there would be many tactical situations where a commander would prefer that if his shots missed, the enemy remained unaware until he could shoot again.
There are numerous scenes in the book where commanders hear detonations that are long after the calculations showed they should have exploded if they'd hit, etc. so it was apparently standard.
To be clear, I'm not talking about any of the malfunctions or problems the US Navy had with its torpedoes in WWII. The torpedoes of that era were designed to explode at end of run.
A few related questions:
(1) Was that true only of the US Navy or did the torpedoes of the Germans, Japanese, etc. behave the same way?
(2) When the USN switched from steam-powered to electric-powered torpedoes, was this design carried forward?
(3) Do torpedoes still behave that way? I realize nowadays they seek their own targets in some cases but what if a torpedo is fired and runs out of power...self-detonate or sink to the bottom?