HMS Black Swan's participation in Operation Torch introduces a force-allocation problem that can distort campaign statistics. The amphibious operation drew nearly every spare British and American anti-submarine asset into its theatre. Other routes consequently operated with escort levels reminiscent of the war's opening, before converted sloops, corvettes, and Hunt-class escort destroyers had filled out the system. A temporary rise in U-boat success elsewhere can therefore reflect Allied concentration for Torch rather than a sudden German technical improvement or collapse in escort skill. Operational graphs can record changes in deployment as much as enemy performance.
Notable Point · 11:22-12:20
Operation Torch drains escort strength elsewhere
The concentration of British and American anti-submarine forces for Operation Torch helps explain temporary weakness on other convoy routes.