Black May

by Michael Gannon

  Five days later, PBY-5A Catalina “F” of USN Patrol Squadron VP-84 from Fleet Air Base, Iceland, sighted a surfaced U-boat southeast of Iceland and attacked it while still surfaced with three 350-pound D/Cs dropped from 100 feet. The U-boat dived, and pilot Lt. R. C. Millard, U.S.N., making a second run, released a Mk.24 acoustic homing torpedo. Its hydrophones correctly fixed on the U-boat’s cavitation and brought oil and wreckage to the surface—FIDO’s second success of the month. The stern-punctured victim, U-467 (Kptlt. Heinz Kummer), went down with all hands.102

  At 1356 on the same day, U-436 (Kptlt. Günther Seibicke) was submerged, returning from her third Atlantic patrol, when she was picked up on asdic by the frigate H.M.S. Test, part of the escort of a U.K. to Gibraltar special convoy, KX.10. Test made two D/C attacks, then lost the contact. The nearby corvette H.M.S. Hyderabad joined Test in a box search and at 1434 acquired a contact, which she attacked with a ten-pattern. Eighteen minutes later, having regained contact, Hyderabad dropped a second ten-pattern, which brought to the surface oil, large quantities of wood, a sou’wester, a glove, cigars, and a piece of human flesh. There were no survivors.103

  On the afternoon of the 28th, northeast of Valencia, Spain, in the Mediterranean, Hudson “M” of 608 Sqdn. based at Blida (ElBoulaï'da), Algeria, sighted and sank a U-boat with R.P. It was the first successful use of rockets by the RAF. The victim was U-755 (Kptlt. Walter Going), from which thirty-eight crewmen were lost. Nine survivors were picked up by the Spanish Navy and later repatriated to Germany.104

  At 2036 on the same day, while on passage out from Reykjavik to meet convoy HX.240 in the mid-Atlantic, Liberator “E” of 120 Sqdn. sighted U-304 (Koch), seen earlier in the battle for SC.130, and attacked the partially surfaced boat with four D/Cs. One minute later, an oil patch and wood wreckage appeared. All hands went down on this boat’s only combat patrol.105

  Even before that last date, Grand Admiral Dönitz must have felt like an infantry company commander whose position was being overrun by waves of enemy assault troops; for on the 24th day of the month he came, reluctantly, to the conclusion that the losses in May had “reached an impossible height.” Where “not long ago” one U-boat was lost for every 100,000 GRT sunk, which was an acceptable if not an ideal figure, now a boat was being lost for every 10,000 GRT. In an analysis prepared by Konteradmiral Godt and the BdU staff, the RAF was credited with playing a “decisive” role in bringing about that change in fortunes—attributing to the RAF not only the land-based aircraft that the U-boats were encountering but also the carrier aircraft, which were not in fact RAF but Fleet Air Arm (Naval Aviation). Dönitz concluded that, “The excessive losses and the lack of success in operations against the latest convoys now force us to take decisive measures until the boats are equipped again with better defense and attack weapons.”

  The decisive measures were to withdraw U-boats from the northern transatlantic convoy lanes and transfer the main effort to the West African and Brazilian coasts, the Caribbean Basin, and the traffic between the United States and Gibraltar in the Central Atlantic. While reminding his boats in a “To All Commanders” signal that the North Atlantic remained the principal operational area, and that operations “must” be resumed there once new weapons were supplied the boats—he named an effective radar search receiver, the anti-escort acoustic homing torpedo (Zaunkönig), and the quadruple 20mm antiaircraft installations—for now, Dönitz stated, in “a temporary deviation from the former principles for the conduct of U-boat warfare,” the boats must in great part vacate the densest convoy lanes because, simply, he would “not allow the U-boats to be beaten at a time when their weapons are inferior.”

  Of course, he added, the North Atlantic could not immediately or completely be denuded of boats, for a number of reasons. Boats already operating there did not have sufficient fuel to make the Outer Seas and return. It would take time to top them up, and it would be dangerous to bunch them at bases where, because of the limited number of bays in the bombproof shelters, many boats would be exposed to air bombardment. In order to camouflage the general retirement, certain boats would be assigned to stay on Atlantic station and transmit dummy signals to simulate regular patrol line traffic. New boats just coming into Atlantic service from home waters would have to remain on station in the North Atlantic “in spite of the difficult conditions.” They would be expected to stand by until the next favorable conditions for attack, that is, the new moon, recurred, the next such period being the end of June. Wellproved, or veteran, boats would be assigned to support the newcomers at that date. In the meantime, Commanders must strive to maintain the good morale of their men in the face of these temporary expedients.106

  To all officers at sea Donitz sent an Order of the Day under the same 24 May date. Just the day before, he had signaled them that the development of new defenses against Allied radar and weaponry was receiving “maximum application at all our stations,” and that new technology should be ready shortly. The time until then, he told them, “must be passed with cunning and caution,” though “with your old inexorable severity in the battle itself.”107 Now, on the 24th, he repeated the theme, more poignantly:

  I know that operations for you out there at the moment are some of the hardest and most costly in losses, since the enemy’s defense at the moment is superior in view of new technical methods. Believe me, I have done everything and will continue to do so in order to introduce means to counter this enemy advance. The time will soon come in which you will be superior to the enemy with new and stronger weapons and will be able to triumph over your worst enemies, the aircraft and the destroyer.… We will therefore not allow ourselves to be forced into the defensive … and we will fight on with still more fortitude.… We will then be the victors.… Heil Hider.108

  To the Führer personally, at the Berghof on the Obersalzburg near Berchtesgaden on 31 May, Dönitz made the appropriate explanations, identifying Allied aircraft and radar—“We don’t even know on what wavelength the enemy locates us”—as the determining factors in his ordering of the U-boat dispersion. A stenographer took down his words:

  Our losses have increased during the last month from approximately fourteen U-boats, or thirteen percent of the U-boats at sea, to thirty-six or even thirty-seven, or approximately thirty percent of all U-boats at sea. [In fact, counting U-439 and U-659, which collided during operations on the night of 3/4 May, and the two boats, V-563 and U-440 sunk on the 31st, a total of 41 boats were lost during the month.] These losses are too high. We must conserve our strength, otherwise we will play into the hands of the enemy.109

  After naming the new detection gear and weapons that he hoped to have on stream soon, Dönitz proposed to Hitler an entirely new remedy: rapid development of a separate Naval Air Force to counteract Allied air with air of their own, with which both to fight off Allied bombers and to bomb convoy vessels.

  The naval flyers must learn navigation at sea, celestial navigation, drift computation, how to keep contact with a convoy, cooperation with the U-boats by means of direction-finder signals, how to be guided to the convoy by other planes, and the necessary communications.110

  The stenographer recorded: “The Führer agrees fully with these views.” Obviously, where the threat of Allied aircraft was concerned, Dönitz had come a long distance from August 1942, when he had stated, “The U-boat has no more to fear from aircraft than a mole from a crow.” But there is an air of unreality about this Berghof conversation. Even with new detection gear and weapons, there was hardly a chance that obsolete U-boats could again contend with enlarged Allied sea and air forces boasting state-of-the-art equipment operated by undiminished numbers of highly experienced personnel. And the likelihood that at that date, with no experience base and limited material and human resources, Germany could revive its 1930s Naval Air Arm—a fleet of over 700 aircraft was envisioned—was extremely remote, and must have been known to be so to both Dönitz and Hitler. “Just a pipedream” is how the historian of German naval air de
scribes it.111 And the U-Bootwaffe had to continue functioning under the haphazard, shortrange, and generally ineffective umbrella of land-based antishipping warfare aircraft from the Luftwaffe’s Fliegerführer Atlantik (Air Leader Atlantic) in western France—whose Atlantic grid charts did not even match those carried by the U-boats!112

  Of course, no one liked to recognize defeat when it came, least of all “The Lion” and the Führer: the former because he had invested his life’s energies in the U-Bootwaffe, which he had nourished to maturity from its post-1918 beginnings in 1935 and had expanded to the fleet that took to sea on 1 May 1943; the latter because he was aware that even with the reverses suffered in May, the U-boats were still his best weapon against the Allied buildup for an attempt to cross the Channel onto the Continent.

  It took Dönitz fifteen years (a ten-year prison sentence adding to the time) to acknowledge in writing the emptiness of his proposals to Hitler and the disingenuousness of his bellicose pledges of final victory to the U-boats. In the pages of his memoirs that address the end of what his staffers called “Black May,” the old Admiral acknowledged the cold reality of 31 May:

  “We had lost the Battle of the Atlantic.”113

  EPILOGUE

  THOUGH SUBSTANTIALLY DEFEATED in his campaign to throttle Britain’s maritime trade, and frustrated as well by his inability to interdict American military convoys, both to Gibraltar and the United Kingdom, Dönitz continued nonetheless to press the U-boat war in the Central Atlantic and the Outer Seas. He did so, he explained, after carefully considering his options: Should he “call off the U-boat war” in view of the enemy’s overwhelming force levels and technological advantage? Or should he “continue operations in some suitably modified form,” despite Anglo-American superiority that was likely to increase rather than diminish?

  Germany was on the defensive on all fronts. The Army was engaged in a series of hard-fought defensive battles. The air-raids on Germany itself were becoming increasingly severe. Under these conditions what effect would the abandonment of the U-boat campaign have on our war situation as a whole? Could we afford to abandon it? Were we justified, in view of our inferiority, in calling upon our submarines to continue the unequal struggle?1

  Dönitz reached the bitter conclusion that he had no alternative but to call for continuance of a sea war that was already lost. And these were his reasons: With only no bomb-sheltered berths available at the Biscay bases, many hors de combat boats in base would be dangerously exposed to air bombardment. Second, a cessation of U-boat operations would free up hundreds of Allied escort vessels and aircraft that were then tied down by ASW for use elsewhere against Germany. Similarly, a unilateral stand-down would release the vast Allied network of naval and air bases, including ground service personnel and civilian workers, as well as material resources, for employment on other operations. If, for example, the Coastal Command bomber fleet, then consumed in ASW, were permitted to reinforce Bomber Command raids on German cities, the civilian populations of those cities would suffer incalculable casualties and hardships. “Could the submariner stand aside as a spectator, saying there was nothing he could or would do and telling the women and children that they must put up with it?”

  Dönitz also considered a compromise strategy in which he would break off the fight until a new-generation boat, the fast electric Type XXI (see pages 387–88), became operational, at which time he would return to sea with enhanced chances of success. But that strategy would not work, he decided, since during such a hiatus the morale of even the best crews would suffer, perhaps irreparably. Furthermore, to have any chance at all, the U-Boat Arm must be in continuous engagement with the enemy in order to know his tools, tactics, and tendencies.

  Among Dönitz’s reasons for staying in the game, he did not offer Hitler’s reason, namely, that fighting a now-defensive battle in the Atlantic was preferable to defending the Third Reich on the beaches of Festung Europa. Furthermore, the U-boat war served Hitler’s policy of hamper and delay. Like Frederick II in dealing with his land enemies during the Seven Years War, the Führer hoped that unrelenting attrition at sea would induce one of the Allied powers to lose heart and withdraw, if not from the war, from invasion planning. It was a foolish hope, but after Stalingrad and Black May, it was, we may assume, the only hope he had.

  In light of the Führer’s Frederician policy, one must wonder if Dönitz, in drawing up his own options, really had a choice in the matter, except at the cost of his Command. By whatever route he reached his conclusions, the Grand Admiral presented them personally to the Flotilla Commanders of the Biscay bases, who unanimously expressed themselves in agreement with them, and went on to pledge the support of their officers and crews.2 This must have been reassuring to Dönitz. But it must also have been jarring for the Flotilla Commanders to hear their Lion step back from his long-enunciated principle: “Strategic pressure alone is not sufficient, only sinkings count.”3

  In a two-year-long dénouement that has been described extensively in the historical literature, the U-boats failed utterly to inflict further significant pain on Allied shipping, either in the Atlantic convoy lanes or in the Outer Seas. Discounted from the stature of menace to that of problem, they failed also to tie up Allied air and sea forces that might be wanted elsewhere: as early as 24–30 July 1943, Coastal Command aircraft from ASW Groups 15 and 19, with little U-boat threat to occupy them, took part in Bomber Command’s horrific firestorm raids on Hamburg.4 In the Outer Seas, including the U.S. seaboard, the U-boats had occasional successes, mostly against independently sailing traffic, but none at all against American UGS and GUS military convoys in the Central Atlantic. The most sinkings were scored in the Indian Ocean. But everywhere Allied defenses had stiffened, and the boats paid a heavy price: seventy-nine lost in the three months following Black May. Among the losses were seven of the ten available Type XIV milch cows, seriously retarding future long-distance operations.

  The new moon periods of June, July, and August 1943 passed without any concentrated return to the North Atlantic convoy lanes. Finally, in September, Dönitz ventured into the latitudes of prior glory south-southwest of Iceland and showed a flash of his old form in a four-day operation by nineteen boats against convoys ONS.18 and ON.202. Nine of the boats were equipped with one of the promised new weapons, T-V, or Zaunkönig (Wren), the “antidestroyer” acoustic homing torpedo that responded to the fast cavitation of a warship in the same way that the Allies’ Mark. 24 Mine reacted to the cavitation of a U-boat. In all, fifteen Zaunkönig launches were made against the escorts of the two convoys, which had joined company on the 20th.

  In one of the war’s more notable examples of overclaiming, the boats reported to Berlin twelve destroyers definitely sunk and three probably, all by T-Vs; also nine merchant ships sunk by conventional torpedoes; for the loss of two U-boats. Their success would have been greater, they added, had they possessed radar, since a dense fog hindered operations for a day and a night, when the boats were blind. The actual Allied losses were three escorts sunk and two damaged, and six merchant vessels sunk. And the U-boat casualties were three sunk (one 160 miles distant before the operation began) and three damaged.5 Still, the U-boats had achieved a “success,” though a Pyrrhic one. It was to be their last convoy “success” of the war. Six more operations against North Atlantic convoys were mounted in September and October, but all were costly failures. In October the exchange rate was one merchant vessel sunk per seven U-boats sunk. The U-Bootwaffe’s condition was terminal. After a disastrous run at Convoy ONS.29 during 16–19 February 1944, no more convoy battles were even attempted, the compelling interest of the crews being, it appears, not killing, but avoiding being killed—a peculiar mission to supervene the purely offensive purpose of the craft they crewed.

  By that last date, it should be noted, all the promised new weapons and devices had been supplied or fitted to the U-boat fleet. These included, in addition to Zaunkönig: quick-firing 20mm anti-aircraft cannon on quadruple mounti
ngs; Naxos-U, a search receiver capable of intercepting 10-centimeter radar, first introduced (after an incredible delay) in October 1943; and Aphrodite, a radar decoy consisting of aluminum foil streamed from a hydrogen-filled india rubber balloon that simulated the radar signature of a conning tower.6 But, as Günter Hessler conceded, “all the new weapons together could not give back to the old-type boats their striking power.”7 An engineering innovation that did improve the old boats’ safety if not their performance was the Schnorchel (a dialect word for “nose”), a double-pipe system invented before the war by the Royal Netherlands Navy that enabled a submarine to cruise and charge batteries on diesel power while submerged at, roughly, periscope depth. The “breathing” pipes that extended above the surface brought in air for human consumption and diesel combustion, while at the same time discharging exhaust. The snorkel returned to the U-boat what had once been its principal advantage: stealth, which at this stage meant, in practical terms, protection from aircraft. There were certain offsetting disadvantages, however. Underwater speed on the diesels was not high, and a crew’s health and comfort, even life, were threatened when carbon monoxide-laden exhaust gases leaked into the boat’s interior, or when the float valve on the intake pipe suddenly closed owing to surface turbulence or miscalculation by the planesmen, and all interior oxygen was sucked away by the engines.