Black May

by Michael Gannon

  While Stephenson’s work with new crews did not require a respite from combat to carry on, the efficiency training of Captains and Watch-Keeping Officers did. This was particularly true of the Western Approaches Tactical Unit (WATU), an operational ASW analysis facility established at the suggestion of Churchill in January 1942, coincidentally the beginning month of the U-boats’ American campaign. The facility was erected on the bomb-damaged top floor of the Tate and Lyle Exchange Buildings to the east of Commander-in-Chief Western Approaches (CinCWA) in Derby House, Liverpool. To organize and direct the WATU, Churchill sent an RN Commander (later Captain) named Gilbert Howlands Roberts who, like Peyton Ward at Northwood, had been invalided out of the Navy, in his case because of tuberculosis.

  A former destroyer Captain who was trained as a gunnery officer, Roberts modeled his facility on the floor plot used at gunnery school. He divided off a large linoleum-covered floor representing the open sea with lines ten inches apart indicating miles, and placed on that “Tactical Table” wooden models of convoy ships, escort vessels, and U-boats. Then, with canvas and string, he screened off any view of the ocean except for small apertures that gave only restricted views of an operational situation, akin to the restrictions prevailing at sea, particularly at night. Twenty-four “players” could work at the full floor plot, or three groups of eight players each could work at partitions of the plot. They sat at plotting tables around the viewscreens.

  While a staff mainly of seventeen-to twenty-year-old Wrens (Women’s Royal Naval Service, or WRNS) manipulated both the models and the views allowed of them, combat situations were simulated and escort group Captains and Watch-Keeping Officers were asked to make decisions about appropriate actions to take in the circumstances shown—the circumstances being based on intensive interviews Roberts had conducted with Senior Officers of Escort Groups. Every movement was tracked, those of the U-boats in green chalk, those of the escorts in white, so that at the conclusion of “The Game,” as the exercise was called, the participants could inspect their successes and failures in pursuit and attack. The tactical course lasted six days, and as the months progressed, the teenage Wrens gained sufficient competence to be able, discreetly, to advise sea-hardened officers on what might be their next best course of action—as remembered by a Lieutenant (later novelist) named Nicholas Monsarrat, who allowed in his The Cruel Sea, “Rather unfairly they seemed to know all about everything…. ”42

  Numerous innovative attack procedures evolved from these exercises, the first of them based on reports of U-boat attack behavior during the passage of Convoy HG.76 from Gibraltar to the U.K. in December 1941 that were given Roberts by an offensive-minded Senior Officer Escort (SO) named Commander (later Captain) Frederic John Walker, who commanded the convoy’s Escort Group 36. Whereas Walker’s escorts thought that a U-boat that attacked HG.76 was about a mile outside the convoy, Roberts deduced from a simulation on his plot that the boat attacked from within the convoy columns, having infiltrated from astern. He thereupon devised a countermeasure to catch such a boat as it attempted escape. Since one of the Wrens suggested that the new tactic would give a “raspberry” to Hitler, Roberts assigned it that name. CinCWA Admiral Noble informed Churchill of this correction to “a cardinal error in anti-U-boat tactics” and within twenty-four hours signaled instructions for Raspberry to the Fleet.43 This tactic and a modification called Half-Raspberry were the first universally prescribed escort counterattack maneuvers; prior to their decree each SO was free to devise his own maneuvers. Soon, after trials on the Tactical Table, other fruit-named tactics were developed: “Pineapple,” “Gooseberry,” and “Strawberry”; to be joined by “Beta Search,” “Artichoke,” and “Observant.”44 Meanwhile, sea training in these maneuvers went on at Londonderry, Greenock, Birkenhead, Freetown, Bombay, St. John’s, Newfoundland, and Sydney, Nova Scotia, where escort groups practiced as teams under their own SOs.

  It was these finely honed escort teams who met the U-boat men when the latter returned in force to the mid-Atlantic in early August, 1942. The slugging match between these two old enemies from that date until the start of May 1943 was fierce and relentless, but, as already indicated in this chapter and in the prologue, neither side was able to deliver a knockout blow. Nor was the renewed German effort against convoys limited to the major transatlantic trade routes. Admiral Donitz probed for soft spots in the Outer Seas where Allied defenses might have been attenuated by the need to reinforce the northern lanes; thus, he deployed boats to Freetown, Cape Town, and Madagascar, to the Atlantic Narrows between West Africa and Brazil, to the Brazilian and Panamanian coasts, and to the traffic area eastward of Trinidad in the Caribbean.

  In raw numbers the U-boats enjoyed commendable successes. During August, with 86 boats at sea, the U-Bootwaffe made an impressive number of convoy contacts per boat and sank 105 ships for 517,295 GRT; and in November, as noted earlier, the boats scored their highest monthly total of tonnage sunk in the entire Atlantic war. But throughout the period August 1942 to April 1943, their ever-increasing number of operational boats at sea generated diminishing returns in tonnage sunk per boat per day at sea—this despite the fact that U-tankers in midocean were multiplying their days at sea, deferring their maintenance, alleviating operational delays caused by the backlog of boats needing fuel at base, and frustrating Coastal Command’s Bay Offensive by eliminating the need for two transits per boat through the Bay. (In the twelvemonth period prior to the end of May 1943 the supply U-boats replenished 220 U-boats operating against Atlantic convoys as well as 170 boats assigned to Outer Seas.45)

  All the while, the experience and proficiency levels of the U-boat crews were declining, owing both to losses and to rapid expansion, while those of the escort crews were waxing, thanks in great part to the intense training regimen of January-July 1942, and to the fitting during the same period of new equipment such as HF/DF and 10-centimeter radar. From August through April 1943 the U-boats were being sunk at a monthly rate of 9.7, including February’s record 19. In the same period, three out of four ocean convoys made port without loss and 90 percent of those convoys that were attacked similarly reached their destinations. German intelligence and BdU completely missed the military convoys of the Anglo-American expeditionary force (Operation Torch) that sailed from the U.K. and the U.S. beginning on 18 October and effected landings on 8 November in French Northwest Africa, at Casablanca in Morocco, and at Oran and Algiers in Algeria. Only one of the 334 ships that participated was attacked by a U-boat, and it by accidental encounter. German records do not disclose a single sighting, even inkling, of that armada as such.46

  CERTAIN TITLES FOR TRADE AND MILITARY CONVOYS

  CU New York-CuraCao-United Kingdom.

  GU Alexandria-North Africa-U.S.A.

  HG Gibraltar-United Kingdom.

  HX Halifax-United Kingdom.

  KM F United Kingdom-North Africa-Port Said (Fast).

  KMS United Kingdom-North Africa-Port Said (Slow).

  KX United Kingdom-Gibraltar (Special).

  MKF Mediterranean-North Africa-United Kingdom (Fast).

  MKS Mediterranean-North Africa-United Kingdom (Slow).

  OG United Kingdom-Gibraltar.

  ON United Kingdom-North America.

  ONS United Kingdom-North America.

  OS United Kingdom-West Africa.

  SC Halifax-United Kingdom (Slow).

  SL Sierra Leone-United Kingdom.

  UC United Kingdom-Curaçao-New York.

  UG U.S. A.-North Africa.

  UGF U.S.A.-North Africa.

  UGS U.S.A.-North Africa.

  UT U.S.A.-United Kingdom (Military).

  WS United Kingdom-Middle East and India (Military).

  XK Gibraltar-United Kingdom (Special).

  EC Southend to Clyde, Oban or Loch Ewe (Coastal Convoys, North about).

  WN Clyde, Oban or Loch Ewe to Methil (Coastal Convoys, North about).

  Donitz, who had expected a possible Allied action at Dakar, and had s
tationed boats in the Freetown and Cape Verde Island zones as a precaution, found himself on 8 November completely out of position. His rushed disposition of boats to the Moroccan Atlantic coast and to the western approaches of Gibraltar to attack new supply shipping and thus strangle the invasion buildup led to the sinking of ten merchant ships, four transports, and five warships—including Werner Henke’s fleet repair ship H.M.S. Hecla on n/12 November—but at terrible cost: eight U-boats sunk, 19 damaged, and one Italian submarine sunk. With such thin results attended by disproportionately high losses, Donitz pulled his boats in early December for assignment to more productive areas of the Atlantic.

  Three notable command changes took place in the fall and winter of 1942–1943. On 17 November, Admiral Sir Max Horton, since December 1939 Vice-Admiral (later Admiral) Submarines, succeeded Percy Noble as CinCWA. Noble was named Chief of the British Admiralty delegation (BAD) in Washington. Horton had earlier turned down C-in-C Home Fleet because he thought that post to be too much under the thumb of Whitehall. At Submarine Command in Northways, Hampstead, he had forged close working ties with Coastal Command at nearby Northwood, and during three years of war became convinced “that fleets cannot operate without the close cooperation of air power”—a conviction that he would translate into deeds at Western Approaches.47

  Upon his arrival at the large gray block of buildings that was Derby House, he inspected its facilities, including the armored and gasproof Operations Room in its basement, and called for the principal officers to explain their duties. To Gilbert Roberts of the Tactical School he said, “What do you think you do?” Roberts replied, “Why don’t you come up and see properly?” Horton did, and at 9:00 the next morning he returned unattended to begin the six-day course.48 Not everyone so impressed Horton, however, and more than a few officers fell victim to deadwood cutting.

  Horton’s mandate as CinCWA was: “the protection of trade, the routing and control of all convoys and measures to combat any attack on convoy by U-boats or hostile aircraft within his Command.” (Military convoys and fast troopships remained under the control of the Admiralty.) He also saw as his responsibility the improvement and intensification of training. Early in February 1943 he received a yacht, H.M.S. Philante, and a submarine, sometimes two, with which, in effect, to take Roberts’s Tactical School to sea. At Larne in Northern Ireland each Escort Group prior to joining its convoy was put through exercises designed by Captain A. J. Baker-Creswell, R.N., to represent actual combat conditions to be encountered. What was more, the exercises were conducted in close cooperation with Coastal Command aircraft, in order to perfect navigation and rendezvous, TBS and signal code communications, and joint attack procedures. Furthermore, surface-air collaboration was to be practiced even while with the convoys en route. And the surface Escort Groups, a Percy Noble innovation, were to be kept together as teams.

  Another Noble innovation that, except for one prototype, had not been possible to implement in his predecessor’s time for lack of assets was Support Groups—small, highly trained, and offensively minded flotillas of destroyers, sloops, frigates, and cutters that would ride to the rescue of convoys and Escort Groups directly menaced or under attack. In Noble’s vision such groups would include, when they became available, auxiliary aircraft carriers. Horton embraced the concept and wrote almost daily to the Admiralty begging for ships to make the forces possible, eventually succeeding in obtaining the loan of a number of Home Fleet destroyers. To these he took the risk of adding sixteen warships obtained by reducing the strength of each Escort Group by one vessel. The result was, at the end of March, five Support Groups fully trained and ready to fulfill their sole mission: hunt down and kill U-boats.

  Meanwhile, in his glass-fronted office facing the Operations Room, Horton had constant access in an adjoining office to Air Vice Marshal Sir Leonard H. Slatter, commanding No. 15 Group, whose squadrons covered the North Atlantic convoy lanes from bases on the West Coast of Scotland, in the Hebrides, and in Northern Ireland, with a detachment at Reykjavik. Both men lived on the premises, though Slatter did not follow Horton’s somewhat eccentric daily schedule, which had him on the golf course all afternoon, at the bridge table after dinner, and in his office by 2330, usually in “worn and split” pajamas, drinking barley water while directing convoy battles on the huge wall plot opposite, and with, as one observer said, an “uncanny prevision” of what the U-boats would do next. Different in manner from the urbane and kindly Noble, for whom everyone at Derby House had affection as well as respect, especially the Wrens, Horton’s behavior prompted such descriptions as “ruthless,” “determined,” “selfish,” “intolerant,” “perfectionist,” and “maddening.”49 Apparently the flinty old submariner was just the type Churchill thought should lead the surface and air escorts into the dangerous new year—“a thief to catch a thief,” as it were.

  The second major command change affected that other thief, Karl Dönitz at BdU. When in December Adolf Hitler harangued Grossadmiral Erich Raeder, Commander-in-Chief Navy (Oberbefehlshaber der Kriegsmarine), over the failure of a surface force led by two heavy cruisers to advance successfully against an RN Arctic convoy escort screen, and went on to threaten the scrapping of all big ships in the fleet, the proud Hamburger veteran of the Imperial Navy and Battle of Jutland tendered his resignation, which the Führer, though surprised, accepted. On 30 January 1943 Dönitz was named Grossadmiral and C-in-C in his stead, while retaining his command as Flag Officer U-Boats. Now Dönitz had direct access to Hitler, whom he could importune for steel and shipyard workers; he had authority over the Naval Staff, Seekriegsleitung (Skl), whose approvals he need no longer seek; and he had freedom to prosecute the Tonnageschlacht without diversion of his forces to unprofitable waters. Just the preceding month he had written in his war diary: “The tonnage battle is the main task of the U-boats…. It must be carried on where the greatest successes can be achieved with the smallest losses.”50

  But the new appointment also had its disadvantages, principally, as Raeder, who nominated him for the post predicted, that as C-in-C Dönitz “would not be able to dedicate himself to the immediate conduct of the U-boat war to the same extent as formerly.”51 The “Lion,” as U-boat men admiringly called him, had already suffered physical distancing from his underseas fleet and their crews, when in March 1942 a British raiding party attacked St.-Nazaire; alerted to how easily such a raid might be made on BdU itself, Dönitz reluctantly abandoned Kernével and established his headquarters in an apartment complex on the Avenue du Maréchal Maunoury in Paris. Now, to consolidate BdU with his new post as C-in-C, he moved U-boat headquarters even farther east, to the Hotel am Steinplatz in the Charlottenburg suburb of Berlin (losing two railroad cars filled with equipment and papers in the process), where BdU became operational on 31 March 1943. It had been Dönitz’s presence on the dock at Lorient and the other bases, where he attended to his crews’ leavings and returnings, that cemented his standing as a father figure to his men and elicited a depth of loyalty from ranks and ratings that was unprecedented in the Kriegsmarine. Now his inspiring figure and voice were far from the bases, with what negative impact it is impossible to calculate.

  With his longtime Chief of Operations Branch (BdU-Ops), Konteradmiral Eberhard Godt, Dönitz incorporated BdU into the Naval Staff as its Second Section, with Godt, Chief of Staff, overseeing day-to-day conduct of U-boat operations—although in the war diary, where major convoy battles are described and where strategies or policies are declared, one continues to hear the voice of Dönitz, with the result that in the chapters that follow in this narrative the citations of passages from the diary assume their authorship by a Dönitz/Godt duumvirate. The entire BdU operations staff numbered barely more than a dozen officers, most of them in their early thirties (Dönitz was 51, Godt 42). Though it could draw upon the much larger Naval Staff for such things as Intelligence (3/Skl), Communications Service (4/Skl), Radar Countermeasures (5/Skl), and Meteorology (6/Skl), it remained a thin blue line for tr
ying conclusions with the combined staffs of the Admiralty and Coastal Command, not to mention GC&CS. (Western Approaches alone had a staff of over a thousand officers and ratings.)52

  The third major change in command came in RAF Coastal, where Joubert was succeeded as AOC-in-C by Air Marshal Sir John Slessor on 5 February 1943. A Royal Flying Corps pilot in the Kaiser’s war, Slessor had fought off Zeppelins over London and flown artillery observation missions over the trenches of France. His most recent posts in the Führer’s war were Commander of 5 Group of Bomber Command and Assistant Chief of the Air Staff (Policy). With Air Chief Marshal Sir Charles F. A. Portal, Chief of the Air Staff, he attended the Casablanca Conference, actually held in a residential suburb of the city called Anfa, where, from 14 to 23 January, Churchill, Roosevelt, and their Combined Chiefs of Staff conferred on the priorities to be established for future operations. He was present when the conferees approved their final Memorandum, “Conduct of the War in 1943,” with, at its head, the now well-known “First Charge” declaration: “The Defeat of the U-boat must remain a first charge on the resources of the United Nations.”53

  Slessor wrote after the war that the person responsible for having that strategic imperative given first ranking was Admiral Ernest J. King, though King’s biographer does not mention it, except to say that, “Everyone agreed that the Battle of the Atlantic took first priority.”54 Slessor did not think that the “First Charge” declaration had much practical influence on the anti-U-boat war, except to prod the Air Ministry to divert some of the newly available centimetric radar sets from Bomber to Coastal Command. It was not until March, however, that the first Coastal squadron equipped with 10-centimeter ASV Mark III became operational.55 That squadron, which flew L/L Wellingtons, was then in a position to defeat the Metox receiver, and so surprise the surfaced U-boats at night as L/L aircraft had done up to six months before. The pure hunt was on again. Or was it?