You allude to this, but one of the reasons the Mark 14 didn't work was that they were clockwork masterpieces that were so expensive that the Navy didn't want to

You allude to this, but one of the reasons the Mark 14 didn't work was that they were clockwork masterpieces that were so expensive that the Navy didn't want to expend any of them in testing, and didn't do a single live-fire test! (It was the Great Depression, after all. Penny wise, pound foolish.) They proceeded to full-rate wartime production completely blind: https://en.wikipedia.org/wiki/Mark_14_torpedo#Development https://en.wikipedia.org/wiki/Mark_14_torpedo#Development