Bomber Command was ordered to devastate ports such as Lorient even though concrete shelters already protected the submarines. Arthur Harris objected that the available bombs could not penetrate the pens. Destroying the surrounding towns would impede maintenance without stopping it and would alienate the Breton population. Coastal Command had previously requested frequent attacks while the shelters were still being built, but those requests were rejected as a diversion from bombing Germany. The sequence contrasts an opportunity to disrupt construction with the much harder task of destroying completed fortifications. The challenge of bomb-proof structures also helps explain the demand for very large bombs such as Grand Slam.
Notable Point · 2:01:55-2:05:37
Why bombing the French U-boat pens came too late
Completed concrete shelters resisted the available bombs after earlier requests to disrupt construction had been refused.