Holy hell, really? The USN mounted predecessors to the Mk 32 SVTT as early as 1944 on a limited basis, and the direct predecessor to the Mk 46 went into service in 1950.
Well, the USN did have a few things going for them that few other navies could boast of. They were exclusively a blue water navy and they had the single largest pool of electronics technicians and engineers available to anyone anywhere in the world. Both were rather important since ASW torpedoes were considered more or less useless in shallow water until the eighties at least and because early electronics was hands on in a way that's completely alien to our modern minds.
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“Close” only counts with horseshoes, hand grenades, and tactical nuclear weapons.
That which does not kill me has made a grave tactical error
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