Saphroneth
Banned
No you don't need a big change. You just need a part or two changed in the warhead. The USA had some issue with the strength of the metal in the firing pin. So this is a simple POD. We still have OTL stuff. Norway ships get away, etc. France still falls. Then we get to after France is clearly falling. We have the reports of bad torpedoes. An Admiral tells the people to retest the torpedo. It fails. You get a series of rapid, minor changes in the factory, the problem is fixed.
It is really a no more complicated change than the scrap metal the USA welded on tanks to fix a problem. Something is not working. You get reports. Reports taken seriously. You try to fix. You fix it.
The cost is actually negative. You have to go out and fire a small number of torpedoes (say 20). You start recovering the used ammo every time a German captain does not need to use an extra torpedo to sink a ship. You gain U-boats everytime you don't lose a U-boat to a battle after a fail torpedo.
Right. But in order to have a situation where reports ARE taken seriously, then you need to have a generally better attitude in the system, basically. That means that they put more effort into testing things which DID work OTL - for starters.