The formidable Nazi war machine was powerless to stop the build up in Britain of Allied troops shipped from the USA and Canada. But in early 1943 Doenitz was winning the Battle of the Atlantic against that other, essential, component that those troops needed, being transported in very vulnerable slow or just plain vulnerable, fast merchant ships. As Paul Kennedy wrote in his book Engineers of Victory:

The increasing flood of U.S. and Canadian troops to Britain was transported by an entirely different method — the great liners of Cunard, which, when stripped inside to the bone, could each carry 15,000 GIs at a speed that even a fleet destroyer couldn't keep up with, let alone a U-boat. But, to repeat an earlier question, what would two to three million fresh soldiers do in the United Kingdom if they lacked food, fuel, and munitions?

Tag words: Doenitz; Battle of the Atlantic; Paul Kennedy; Engineers of Victory; Cunard; Hitler; Fortress Europe; John Kennedy Ohl; Supplying the Troops; Somervell; U-Boat campaign; Third Reich; HX 229; SC 122; Operation Bolero; Operation Sledgehammer; Operation Roundup; Operation Overlord; General JCH Lee; WSA; War Shipping Administration; Lord Leathers; full and down; Operation Torch; The Center Task Force; Hank H Cox; The General Who Wore Six Stars; sos; Service of Supplies; C.S. Lewis; Chronological Snobbery; Gulf War; Operation Desert Storm; OPD; War Department General Staff, Operations Division; Victory Program;