One of the Type IXs, the D2 I think, has something like
twelve torpedoes in the forward external store
Why?!?!?!? I hate external stores because they force you to surface in order to reload and hope the weather holds. In my type VII I have about a 50/50 chance of getting them under; half the time by the time I use a torpedo the weather turns bad, or I need one in a situation where I can't surface.
Even in the best of circumstances, getting 1 external in takes about an hour. With enemy ships around, that can feel like an eternity.