Operation Drumbeat

by Michael Gannon

  We had to improvise very rapidly and on a large scale. We took over all pleasure craft that could be used and sent them out with makeshift armament and untrained crews. We employed for patrol purposes aircraft that could not carry bombs, and planes flown from school fields by student pilots. We armed merchant ships as rapidly as possible. We employed fishing boats as volunteer lookouts. The Army helped in the campaign of extemporization by taking on the civil aviation patrol.28

  The reader is left to reflect, in view of the foregoing chapters, how “rapidly” on the “large scale” King extemporized his defenses. In 1946 the admiral published his official wartime reports to the Secretary of the Navy under the title, U.S. Navy at War, 1941-1945. In a chapter called “The Atlantic Submarine War,” he wrote that directly upon the outset of hostilities the Navy “accelerated its program of acquiring such fishing boats and pleasure craft as could be used and supplied them with such armaments as they could carry. For patrol purposes we employed all available aircraft—Army as well as Navy. The help of the Civil Air Patrol was gratefully accepted.”29 It is not recorded how Marshall accepted King’s dissembling or whether he knew it to be a cover. King was not well regarded at the Munitions Building. A bright brigadier general in charge of War Plans had confided his opinion of the admiral to a personal diary entry for 12 March. Wrote Dwight David Eisenhower: “One thing that might help win this war is to get someone to shoot King.”30

  To balance the record it must be stated that after July 1942, King and the Navy performed creditably in the creation and operation of an antisubmarine force that became so formidable, sophisticated, and well trained that, in concert with the British during the following year, it overwhelmed the U-boats in every quadrant of the Atlantic. In May 1943, King organized all ASW warfare units and personnel, surface and air, into what he called the Tenth Fleet, with himself as commander and Rear Admiral Francis S. (“Frog”) Low as chief of staff. In a stroke he eliminated most of a large number of organizational problems and conflicts that had bedeviled the frontiers and CINCLANT, not to mention the Army Air Force, with which Navy relations were periodically strained. (The writer has not engaged in any lengthy discussion of these organizational conflicts, for example, should the Army or the Navy have primary control over land-based ASW aircraft, or should CINCLANT authority intervene in sea frontier operations, or should district commandants be expected both to run their districts and to conduct ASW operations at sea? A thorough airing of these and other command-relations problems is given in the Eastern Sea Frontier war diary for April and July 1942 and April and July 1943.) Navy fighting effectiveness in 1943 and after was helped by the addition to convoy lanes of new-class destroyers, and particularly, the new destroyer escorts (DE) which, with their high reserve buoyancy and freeboard, excellent compartmentation, and easy working space, immediately became recognized as the ideal escort vessels. That they could be built for just over half the cost of a Benson-class destroyer did not go unnoticed by Congress. (After the war King charged that construction of the much-needed DEs had been frustrated by President Roosevelt’s “predilection for small antisubmarine craft.” Documents in the Bureau of Ships refute this charge, proving instead that FDR was one of the DE program’s earliest advocates, from June 1940.31) Convoy escorts bristled with new armament, including a fast-sinking six hundred-pound Mark IX torpex depth charge and two versions of a British-invented throw-ahead contact bomb projector, called “Hedgehog” and “Mousetrap,” which fired patterns of small rocket projectiles at a submerged U-boat while the attacking vessel maintained sonar contact with the target. Sonar equipment and operator training improved, and uniform use was made, finally, of British tactical doctrine. A significant addition to the Atlantic Fleet was the Escort Carrier Group (CVE), the first of which was organized in March 1943 around the small carrier USS Bogue. With four flush-deck destroyers operating as a screen for the carrier, Grumman F4F-3 Wildcat and TBF-1 Avenger aircraft followed radar and Huff-Duff bearings to surfaced U-boats in daylight hours and, because of their high speed, bombed or strafed the boats before they could completely submerge. Eventually eleven carrier groups would operate in the Atlantic, five chalking up enviable records as “hunter-killers” of unwary U-boats. From Spring 1943 forward to the end of the war it would be British and U.S. “hunter-killer” groups of various sea and air compositions, and not convoy escorts, that would be the great destroyers of U-boats; thus challenging Admiral King’s convert belief that convoy was “the only way” of defending against the U-boat menace. Not the least of new advantages afforded both the Americans and the British was the penetration, at last, of the U-boats’ TRITON (“Shark”) cipher. Bletchley Park announced the triumph on Sunday, 13 December 1942. Patrick Beesly took the call. Winn had collapsed from overwork.

  Arguably the most valued American contribution to the Atlantic war apart from the CVE was the Consolidated Liberator four-engine bomber, known to the Army Air Force as the B-24 and to the Navy as PB4Y-1. The British had converted one of its three bomb bays to auxiliary fuel tanks, which gave the aircraft up to twenty hours continuous flying time. This VLR (very-long-range) Liberator with RAF Coastal Command crews patrolled the North Atlantic convoy routes from bases in Northern Ireland and Iceland. The western half of the Atlantic, or the Greenland Gap, went for many months unprotected, however, due to Admiral King’s procrastination over basing some of the Navy’s Liberators in Newfoundland. At the January 1943 Casablanca Conference of Roosevelt and Churchill together with their nations’ Combined Chiefs of Staff, it was agreed that the defeat of the U-boat was the first priority in the battle for Europe, and that to achieve that goal eighty VLR aircraft should be deployed immediately to cover the Greenland Gap. King, who was a participant in the conference and had 112 Liberators at his disposal, did nothing to meet this charge until 18 March when, after the previous day’s losses of sixteen merchant ships in Atlantic convoys HX 229 and SC 122, Roosevelt asked him where all the Navy Liberators had been. Once the Greenland Gap was closed beginning in April and May by Liberators from Newfoundland, U-boats surfaced at their peril in the western North Atlantic. Acknowledging the probability that VLRs would eventually plug that remaining Air Gap, Admiral Dönitz anguished to his BdU war diary as early as the foregoing August: “These developments will lead to irreparable losses and to the end of any chance for a successful conclusion of the U-boat war.”32

  USN training and tactics improved to the point that Admiral Dönitz’s successor as BdU, Konteradmiral Eberhard Godt, stated after the war that in the years 1943-45 any distinction between U.S. and British combatant skill was not observable.33 The Royal Navy complimented USN ships on their engineering plants, armament, cleanliness, and generally superior standards.34 Where antisubmarine equipment was concerned the British seem to have been the more originally inventive, while the Americans were the more successful at development and perfection; although the Americans did have their inventive moments, as, for example, with “Fido” (Mark 24 Mine), a deadly airborne torpedo that homed in on a submerged U-boat’s propeller cavitation. The British came up with two airborne devices that in combination succeeded so well in detecting U-boats on the surface that they veritably took the night away from the Ubootwaffe. The first was the Leigh Light, a twenty-four-inch searchlight devised for placement in the lower turret of a Wellington bomber by Squadron Leader Humphrey de Veré Leigh, RAF. These lights, and later more powerful ones of U.S. design, enabled aircraft to sight surfaced boats, particularly when used in tandem with airborne radar. Although the use of early radar sets of long wavelength type could be counter-detected by a U-boat employing a search receiver (“Metox” or one of four successor systems), U.S. improvements to a British design resulted in the airborne installation of microwave (ten-centimeter) radar equipment (ASV) that for a long while the Germans had great difficulty detecting.

  Thus, beginning in 1943, ASV-equipped Liberators and Leigh-Light Wellingtons achieved near-total control of the ocean’s surface and made the Bay of
Biscay in particular a killing sea. The Germans countered with the Schnorchel (a dialect word for nose), a prewar Royal Netherlands Navy invention that enabled a U-boat to travel and charge batteries on dieseis underwater by “breathing” the air needed for combustion and expelling exhaust through a double pipe that extended above the surface of the water. Float valves on the pipe closed automatically when the boat submerged to use electric power alone. The advantage provided by the Schnorchel was that boats could thereby escape both lights and radar. Disadvantages were that underwater speed on the dieseis was not high, and the effect on crews of both leaked carbon-monoxide-laden exhaust gases and of sudden interior oxygen loss to the engines when the pipe closed owing to surface turbulence or to miscalculation by the planesmen could be very unpleasant, not to mention dangerous. Even the Schnorchel was defeated eventually by American development of a 3-cm radar that picked up the head of the U-boat’s pipe. In the end the microwave radar was one of four major reasons cited by Admiral Dönitz for Germany’s loss of the U-boat war, the others being: (1) Hitler’s radical reduction of U-boat construction in favor of tanks during 1940; (2) the appearance in mid-Atlantic of ASV-equipped VLR aircraft; and (3) the phenomenal output of new merchant vessels by America’s shipyards, which completely frustrated the touted “tonnage war.” The attempt to sink more ships than the enemy could build was doomed from late 1942 forward, but not without one last transcendent effort by Dönitz to avoid that fate.

  Dönitz and his staff greatly underestimated the capacity of America’s ninety-nine shipyards to replace and then exceed the number of bottoms lost to U-boats. In October 1942 a “Liberty” category ship named Joseph N. Teal came off the ways only ten days after her keel was laid. Faster records would be set. Construction of prefabricated “Liberty” and “Victory” ships, conceived by shipbuilder Henry Kaiser and put together by “Rosie the Riveter,” proceeded at such a pace that the 7.75 million deadweight tons of merchant shipping produced in 1942 increased to 19.2 million tons in 1943.35 In the same period naval construction also multiplied dramatically. Thus, it has been estimated that if every major unit of the entire U.S. Navy had been destroyed at Pearl Harbor, and if Japan had been able to complete its own construction program unimpeded, the newly built U.S. fleet would outnumber the Japanese fleet by mid-1944.36 Plainly, American industrial power won World War II.

  Still, one could not overlook the fact that Germany for its part was building U-boats at a furious rate, and faster than the British, Canadians, and Americans could sink them—121 built as against 58 sunk in the last six months of 1942. At the onset of the critical year 1943 Admiral Dönitz had 212 operational boats out of a total of 393 in service compared with the numbers with which he began the previous year—91 operational and 249 in service. The stage was set in winter-spring 1943 for a climactic and decisive collision of the enlarged forces at sea, which through March seemed to go the Germans’ way. In that one month alone U-boats sank 97 Allied ships in twenty days, about twice the rate of replacement, while losing only 7 boats and gaining 14 more placed in service. At that pace the Germans would win the Atlantic. The crescendo was reached in midmonth (from the seventeenth to the twentieth) when more than 40 boats engaged east-bound convoys SC 122, HX 229, and HX 229A in the still-existing western Air Gap. Twenty-two merchant ships were sunk for the loss of one boat, U-384. The Germans expended 90 torpedoes, the Allies 378 depth charges and bombs.37 Berlin radio broadcasts called it the greatest convoy battle of all time. The British Admiralty ruefully conceded that “the Germans never came so near to disrupting communication between the New World and the Old as in the first twenty days of March 1943.” Official Royal Navy historian Stephen Went-worth Roskill reflected thirteen years later: “For what it is worth this writer’s view is that in the early spring of 1943 we had a very narrow escape from defeat in the Atlantic; and that, had we suffered such a defeat, history would have judged that the main cause had been the lack of two more squadrons of very long range aircraft for convoy escort duties.”38 To Admiral King inevitably would have gone the primary blame for that defeat, although it must be said that the British were of no help in the matter either: Bomber Command, obsessed with the generally futile area bombing of Germany, stubbornly resisted the call to divert Liberators to maritime operations. Shortly after the March disaster the trial of strength turned in the Allies’ favor. The Air Gap closed and the lethal combination of American and British carrier groups, escorts, Support Groups of British hunter-kjller destroyers, frigates, and sloops, Leigh-Light Wellingtons, and ASV-equipped Liberators bore down hard on the U-boats that returned to sea after refitting. The cracked TRITON cipher betrayed U-boat movements. During what the Germans called “Black May” forty-one U-boats were destroyed. Kills in June and July brought the three-month total to ninety-five. The Bay of Biscay, which now had to be transited underwater as far as 18W, if it could be transited at all, filled with iron coffins. The long-awaited introduction at this time of a new generation of “electro-boats” Types XXI (1,600 tons) and XXIII (250 tons) which, with submerged speeds as high as 18 knots, transformed the U-boat from a diving boat to a true submarine, came on stream too late, owing to Allied strategic bombing of U-boat construction and assembly yards, to avert total defeat. Had these Types been available in significant numbers but one year earlier they might well have frustrated the Normandy invasion and turned the Atlantic campaign around in Germany’s favor. The Biscay massacre continued through August 1944, when, after the Allied invasion of France and the entrance of the U.S. Third Army into Brittany, the U-boats were forced to operate from Norwegian bases, with the result that their operations became limited toan area north of a the Gibraltar-Hatteras line where Allied naval strength could concen trate with increased economy of forces. All the while the experience level of commanders declined sharply, a not-inconsiderable factor while skill levels and confidence among crewmen also deteriorated markedly. In these circumstances morale (though not courage) inevitably faltered. The Ubootwaffe would stay at sea, with commendable determination, but never again would it be the effective fighting force that was once the scourge of the ocean. Dönitz shifted his dwindling units to various suspected “soft spots” in the Atlantic, including, again, the American shore, but for the next two years no such spots existed. The titanic struggle was decided. Poignant, unanswered wire less calls went out repeatedly from BdU to boats: “U- report position…. U- report situation.” The huge hostile ocean stood ominously silent. The attempt to wage unlimited war with limited means was over. As Dönitz wrote simply in his memoirs: “We had lost the Battle of the Atlantic.”39

  Upon final surrender of German forces in May 1945, Dönitz bade farewell to his U-boats by wireless: “My U-boat men: six years of war lie behind us. You have fought like lions. An overwhelming material superiority has driven us into a tight corner from which it is no longer possible to continue the war. Unbeaten and unblemished you lay down your arms after a heroic fight without parallel.”40 In the same month the United States Navy and British Admiralty announced jointly that there would be no further armed convoys: “Merchant ships by night will burn navigation lights at full brilliancy and need not darken ship.”41

  In a war’s-end report Kenneth Knowles, who as the USN’s Rodger Winn observed the progress of the U-boat war more closely than any other American, declared: “The Battle of the Atlantic was the most important single operation in World War II for upon its outcome rested the success or failure of the United Nations’ Strategy in all other theaters of operation.”42 Morison concluded that the battle was “second to none in its influence on the outcome of the war.”43 These were certainly correct judgments. They reaffirmed the soundness of the “Germany First” strategic assumption adopted by American planners, principally Admiral Stark, before U.S. entrance into the war—namely, that the defeat of Germany ensured the defeat of Japan, but not vice versa. Not only the Normandy invasion but the success of the Soviet armies in the East depended on weapons and supplies carried over the
Atlantic bridge, and therefore on British-American mastery over the U-boat. After victory on the Eurasian landmass the total weight of Allied strength, east and west, could be brought to bear on the less-advanced military machine in the Japanese islands. (Admiral King, whose interests lay primarily in the Pacific, seems never to have understood this.) The Germans’ attempt to rupture Allied sea communications was the longest battle fought during the Second World War, beginning on 3 September 1939, and ending on 8 May 1945. It was also, overall, the most complex battle in the history of naval warfare.44 In understanding the battle one could do worse, as German naval historian Michael Salewski was quoted in the Prologue to this book, than to study one single heavily engaged U-boat, which, pars pro toto, “mirrored at once both the greater strategy of war and its everyday horror.” Few individual boats served that purpose better than U-123.

  14 April 1942. U-/23′s forty-fourth day at sea. Position DB 6329, due east of Savannah, on new home course 55 degrees. Boat on the surface in a small sea, port engine back on line, both langsame Fahrt (slow ahead) so as not to overstress the twisted shafts which were performing noisily but well, and to conserve fuel. For Reinhard Hardegen the war at sea was ending early. He doubted that there would be any more reprieves. This was the end of his last patrol. So it was with a sense of finality as well as accomplishment that he read the signal that emerged at 1200 from the Schlüssel M: BRAVO HARDEGEN! THIS TOO WAS A DRUMBEAT, COMMANDER IN CHIEF.45 Two days later a similar congratulatory signal arrived from Grossadmiral Erich Raeder.

  Hardegen found occasion to give one last rap on the drumhead. While still daylight at 2200 hours (CET) on the sixteenth, at DC 2361 about 260 miles east of Cape Hatteras, lookouts sighted two steamers athwart the U-boat’s course. Hardegen selected the target steering 150 to 160 degrees, which turned out to be a freighter, and changed heading to place himself in front. A half hour before dusk he submerged and waited for the freighter to close, finally getting a good look through the periscope from three hundred meters range. About 5,000 CRT, he estimated; speed, eleven knots; no heavy armament; hinged loading arms flapped upward on the masts; trucks and huge yellow-painted gas or water tanks on the upper deck, four fore, four aft—a worthwhile target. There were no torpedoes left, of course, but he did have twenty-nine rounds, eight of which were wet, for the 10.5 Bootskanone and plenty of rounds for the 3.7 cm and the 2 cm. After the freighter passed he pursued the target on E motors until dark when he was able to surface, speed past the vessel, and take a bow-attack position as though he was making a torpedo approach by the book. When the freighter’s starboard beam was four hundred meters distant and 90 degrees off the 10.5′s muzzle, Hardegen gave permission to fire.