Engineers of Victory: The Problem Solvers Who Turned the Tide in the Second World War by Paul Kennedy Read Free Book Online

opportunities against a new enemy and his merchant fleet, almost completely unprepared for this type of warfare, all the way along the still floodlit eastern coast. Longer-range submarines were sent farther afield to pick off rich targets near Sierra Leone, in the eastern Caribbean, off Buenos Aires, and off the Cape. But Doenitz never stopped hammering away on the crucial North Atlantic routes.
    Total Allied shipping losses had jumped from about 750,000 deadweight tons in 1939 to an awful 3.9 million tons in the chaotic year of1940, increased in 1941 to 4.3 million tons, and then soared again in 1942, as we have seen, to a colossal 7.8 million tons. Of course, there were heavy losses in other regions—off Dunkirk, in the South Atlantic, in the Mediterranean, and by 1941–42 in the Far East—but the heaviest losses (for example, 5.4 million tons of the 1942 grand total) occurred in the North Atlantic. By comparison, Doenitz’s U-boat losses were moderate in those years: around twelve in 1939 and around thirty-five in 1941, increasing to eighty-seven in 1942. These U-boat losses were completely sustainable; the merchant ship losses—and equally the losses of their experienced crews—were much less so. 6
    It is therefore not surprising that the shipping losses of March 1943 scared Churchill and the Admiralty. If Doenitz’s wolf packs could inflict that much damage during dark and stormy conditions—the main attacks ceased only after March 20, when already rough waters were joined by what was essentially a massive Atlantic hurricane—the planners worried how their Allied convoys could survive in lighter and calmer times, with the moon shining across the waters. Would the loss rate double again by May and June? And were the submarines becoming harder and harder to trace and to sink? The jubilant U-boat crews and their determined admiral must have hoped so.
    And yet the one-sided results of the March battles were never repeated again. In fact, they turned out to be the high point of the submarine offensive against Allied shipping, a momentary peak that then fell away so precipitously that each side was stunned by the transformation. It is hard to think of any other change in the fortunes of war that was both so swift and so decisive in its longer-term implications. 7
    Precisely because it was so, it is important to take a closer look at the epic convoy battles of March to May 1943, when the balance of advantage swung so decisively from U-boat triumph to U-boat disaster. Fortunately, the sources for this story are excellent, down to the hour-by-hour tracking of virtually every submarine’s movements and the turn of every convoy. 8
    The month of March began badly for the Allies. While the American, British, and Canadian naval authorities were at their Atlantic Convoy Conference, hammering out decisions regarding zones of control, reinforcements, and the rest, a confident Doenitz was dispatching more and more submarines to join each of the four large wolf packs he hadestablished in the central Atlantic, usually two in the center and one each on the northern and southern flanks. Moreover, at this stage in the intelligence/decryption conflict the Germans very much possessed the upper hand; B-Dienst was providing its chief with extraordinarily complete descriptions of the time and course of the Allied convoys, sometimes even before they left harbor. By contrast, the code breakers at Bletchley Park and at the Admiralty were having difficulty reading German messages days after they were sent. In sum, the shepherds, though gallant, were more than normally disadvantaged, weaker than usual, groping in the dark. The wolf packs were ready to pounce.
    Thus their slaughter of Convoy SC 121, which sailed from New York to various British ports on March 5, 1943. Despite the weather being perfectly foul, some U-boats not picking up signals, and a late rush of a few Allied escort reinforcements, the odds were overwhelmingly in Doenitz’s