War Diary and War Standing Orders of Commander in Chief, Submarines
There is so much damage to U 32’s engines that they will have to be exchanged. The boat was to have sailed within the next few days. Now she will be out of action for several weeks. She was just about to load mines. This will have far reaching consequences.
U 31 will have to take over her operation and will thus not be able to sail until 3 days later. The operation originally assigned to this boat will have to be postponed. This is an excellent example of what happens almost all the time.
Again and again plans are reversed because completion dates for the boats are postponed. One thing is certain: the M.A.N. engines have not proved their worth because their casing is too light. Presumably things will not improve until all the boats have been fitted with the new casings.
Admiral Donitz
Among the German military & Nazi leaders captured at war's end, the allies rated Dönitz the most intelligent, followed, strangely enough, by Göring.
So if we take the old saying that "amateurs study tactics, professionals study logistics," then ask: what does military genius study?
Answer: the thickness of engine casings.