The difference between boats built and boats available for operations reveals the practical problem of force generation. Available strength depended on survival, maintenance, and where the submarines were employed rather than on the construction total alone. Large T-class boats suffered heavily in the confined and dangerous Mediterranean operating environment. Peacetime exercises had supplied reasons to believe the risk was manageable, but combat made supposedly exceptional hazards recur. Simulations and exercises can follow sound logic yet still misjudge how often a low-probability danger will appear in war.
Notable Point · 34:18-35:49
Mediterranean losses exposed peacetime assumptions
Heavy T-class losses in the Mediterranean showed that large submarines faced hazards peacetime exercises had understated.