Black May

by Michael Gannon

  Gretton had been the first to laud Sherwood’s performance. He had been in Tay with Sherwood during the battle for HX.231, and “I knew that he could compete.” In his own analysis of the 5/6 May engagement, produced shortly after the arrival of the B7 Captains at St. John’s, Gretton wrote that, “Lieutenant-Commander Sherwood of HMS TAY handled a very dangerous situation with ability and coolness. I consider he did exceptionally well, being ably backed up by the group.” It is worth adding that the two-and-a-half-ringed reservist won his victory in the presence of two RN Captains.51

  With the after-action reports in hand, Gretton offered further comments on the two stages of the battle: He agreed with his Captains that the convoy had been routed too far to the north, where ice and gales retarded forward progress, prevented fueling, and scattered ships. (This view subsequently was endorsed by Rear Admiral Murray. Recognizing that the far northern route had been selected for evasive purposes, Murray concluded, “It is very much doubted if the game is worth the candle.”)52 Since near Greenland W/T ship-to-shore communication was impossible on any frequency, and the U-boats, which had superior wireless gear, were having the same trouble, the Admiralty should not assume, said Gretton, that a convoy in those latitudes was not being shadowed because of an absence of signals. EG3 was a model of cooperation and assistance, and the presence of Offa and Oribi on 5/6 May made a significant difference in the battle. Aircraft, particularly the Liberators, which flew to the extreme limit of their endurance in appalling weather, deserved great credit for their coverage, as did the RCAF Cansos from Newfoundland that attacked two U-boats on the 4th, though fog prevented further air assistance from that quarter.

  Crediting her as exhibiting “the most outstanding performance” in his B7 group, Gretton singled out Snowflake for “carrying out at least 12 attacks and finally bagging a U-boat"; though in fact Snowflake, which made seven attacks during the voyage, did not actually sink a boat, and the palm might more fittingly have been awarded to Vidette, which sank two. His only criticism was reserved for Pink, which, he said, made “an incorrect decision” in leaving his straggler station to go after a U-boat (U-358) on the 5th, but, he conceded, “I would have made it myself.” In his operation against ONS.5, the enemy had been “dealt a blow that may have far-reaching results on their future tactics and which must inevitably increase the proportion of day to night attacks.”

  In what was perhaps Gretton’s most provocative observation—one that would draw comment from the demanding, some would say irascible, Captain G. W. G. “Shrimp” Simpson, R.N., Commodore (D) Western Approaches in Londonderry—he stated that the just-completed convoy battle proved, as had HX.231 before it, that in favorable seas, an efficient close screen in correct station could alone prevent surfaced night attacks on a convoy.53 Simpson’s read on Gretton’s confidence in the close screen was more differentiated and searching:

  A point which is brought out is that when a close R.D.F. [radar] ring of well-trained escorts is round the convoy they can defeat the U-boat on practically every occasion, as was proved by the action on the night of 28/29 April, when six attacks were beaten off without loss. It is noted that losses to the convoy did not occur until the close screen had been reduced to five and then to four escorts. It is considered that it is essential for the safety of a convoy that there should be eight escorts stationed on the close screen. On the night of 4th/5th May, five merchant vessels were torpedoed after the close screen had been reduced to five escorts, and it is considered that if Offa and Oribi, who were on the extended screen, had been brought in to support the close screen, as was done the following night, better protection for the convoy would certainly have resulted.… Offa and Oribi, disposed singly on the outer screen, could not contribute much to the safety of the convoy and were themselves in considerable danger of being torpedoed.

  Admiral Horton concurred in this criticism, noting only that a close escort of eight was the minimum required “at night under normal circumstances.” Where Simpson went on to criticize Tay for taking the ahead station on the screen when her asdics were out of action, Horton thought that under the circumstances her position ahead was the correct one. And where Simpson criticized the escorts for not firing Hedgehog in incidents where its use was appropriate, and for sometimes using inaccurate depth settings on D/Cs—“the errors have been pointed out to the vessels concerned”—Horton countered generously: “The skill and determination of all escorts engaged in this operation leaves little to be desired.” In that compliment he specifically included the Third and First Support Groups commanded by Captain McCoy and Commander Brewer, respectively, who “loyally gave complete cooperation with the Junior Officer in command of the close escort.” And to all involved he had earlier, on 6 May, sent a W/T message: “My heartiest congratulations on your magnificent achievements.”

  Even by-the-book Simpson acknowledged the final showing as “a major victory,” and the fact that there were only two failures among the 340-odd D/Cs fired or dropped by B7 and its support elements he attributed to “a very high standard of depth charge efficiency in these groups, and [that] is definitely the result of stiff training.” In Horton’s comments on Simpson’s appreciation of the ONS.5 screen operations, the CinCWA judged that not only were those operations “a classic embodying nearly every method and form of tactics current at the time,” they probably marked the end of large U-boat pack attacks: “It may well be,” he wrote to the Lords Commissioners of the Admiralty, “that the heavy casualties inflicted on the enemy have gravely affected his morale and will prove to have been a turning point in the Battle of the Atlantic.”54 Like Winn, Horton may have been more optimistic than correct about the battle’s effect on German morale. But he was proved right on the second point: In the remaining twenty-four months of war no other U-boat group would attack with the same apparent pluck and confidence. The wolfpack mystique lay at ruinous discount.

  How much Horton was now beginning to edge from a defensive to an offensive posture, as a result of this battle and subsequent events in May and early June, is exemplified by his relatively open response to a recommendation put forward on 9 May by Captain McCoy, SO, EG3, in Offa, who thought that evasive tactics, such as those employed in the long routing of ONS.5 to the north, were wasteful and unnecessary. Echoing Gretton’s confidence in the close screen, McCoy argued that, “Escorts that are fitted with radar and which are handled with determination, will always defeat the U-boat at night or in fog.” Therefore, he recommended directly to the CinCWA, “Our policy should be to invite the enemy to attack so that he can be destroyed.” This was to use merchant ships as bait, which Horton had rejected as “undesirable” in his Tactical Policy signal of 27 April. On 14 June, Horton responded (present writer’s emphases): “It is not agreed that it was desirable at the time this convoy was run to route convoys—particularly slow ones—so as to invite attack. If the changed situation which now prevails in the Atlantic were to be maintained, the routing of fast convoys when covered by support groups across the end of a patrol line so as to invite attack by a small number of U/Boats deserves consideration.… “55 Even at that date, in mid-June, Horton was guarded and hesitant in his expressions, but in retrospect it is clear that his long-established policy of Defender was tentatively yielding primacy to one of Hunter.

  On 13 May, the Newfoundland Daily News published a front-page article under the headline: 10 nazi subs destroyed in convoy attack. The account, datelined London the day before and transmitted by Reuters, was based on an Admiralty communiqué that did not identify the convoy but did give a summary of anti-submarine attacks by escort ships, which were named, and by RCAF aircraft, though the number of U-boats definitely destroyed in the story did not match up to the number in the headline. The Times of London ran basically the same story on the same day, but was more discriminating in citing the U-boat casualties as four destroyed, four very probably destroyed, and two probably destroyed.56 Following these two accounts, however, there was little public attention
and even less scholarly notice given to the Battle for ONS.5. Prime Minister Winston Churchill, who was in Washington, D.C., at the time of the communiqué, sent a congratulatory message to the escorts via the Admiralty on 9 May—my compliments to you on your fight against the u-boats—but eight years later, in 1951, when writing the fifth volume of his history, The Second World War, the volume that treated of the Atlantic war in this particular period, he did not think the battle noteworthy enough to mention.57 Similarly, the official historian of Royal Navy operations during the war, Captain Stephen W. Roskill, D.S.C., R.N., devoted a mere page and a half to the battle in his three-volume history, The War at Sea, 1939–1945, published in 1956. To be fair, he allotted only twenty-one lines to the big battle of SC.122/HX.229 in the foregoing March.

  Horton seems to have been the first to have grasped the decisive character of the ONS.5 triumph, suggesting that it would prove to be a “turning point” in the Atlantic struggle. Rodger Winn, in the OIC Tracking Room, wrote sometime within two and a half years of the battle: “This was probably the most decisive of all convoy engagements. It represented the extreme and, as it happens, the last example of coordinated pack attacks.”58 The Most Secret documents containing Winn’s appreciation were not released to the Public Record Office until 1975. In the meantime, Captain Roskill’s assessment of the place that this individual battle occupied in the war against Germany underwent a striking transformation. Where the most that he was willing to say in 1956 was that ONS.5’s “adventurous passage” had led to “grave losses” for the U-boats, three years later, in a review of Karl Dönitz’s Memoirs in The Sunday Times, he was emboldened to state: “[Dönitz] considers that the passage of convoy ONS.5 in April-May 1943 marked the turning point in the long struggle, and I fully agree with him.” Comparing Gretton and Sherwood to the likes of Hawke and Nelson, Roskill added this flourish: “The seven-day battle fought against thirty U-boats is marked only by latitude and longitude and has no name by which it will be remembered; but it was, in its own way, as decisive as Quiberon Bay or the Nile.”59 Perhaps, when viewed on the larger stage of World War II, it would not be unreasonable to say that the set-piece Battle for ONS.5 was the Midway of the Atlantic.

  The pendulum of war, which had swung so dangerously to the German side in March and had reverted to center in April, now swung sharply to the Allies’ side. In reflecting on the long, bitter combat experienced by both belligerents during the passage of ONS.5, one’s attention is particularly drawn to the B7 flotilla that was the convoy’s original escort. In late April that force of seven warships, of which the majority were corvettes, set out to protect an argosy of forty-three light-ballasted ships whose best speed was seven and a half knots. Their passage would take them through bow-stopping gales and iceinfested seas. Their base course would be anticipated by German intelligence, resulting in their being attacked and chased at their northernmost position. They would have to pass through what remained of the Air Gap, with scanty overhead protection. And then they would fall into the fatal embrace of the largest U-boat attack force ever assembled against a single convoy—a force comprising as many U-boats as, at the time, the convoy and escorts had ships, and five times the number of RN defenders. By any objective standard their condition was desperate. Little wonder that Captain McCoy, whose EG3 had joined in support, said on 5 May that “the convoy was threatened with annihilation.” And merchantmen did suffer grievous losses. But B7 close escort ships alone exacted a heavy toll from their assailants, and supporting escorts, both surface and air, made additional U-boat kills. Every man who had been on board the B7 vessels, starting with Gretton, who drew up the game plan, and Sherwood, who executed it, down to the lowest ratings in the boiler and engine rooms, deserved the highest credit. Against all odds, the B7 ships and crews survived and prevailed. In the long Atlantic struggle against the U-boats, theirs truly was a sword-from-the-stone triumph. In looking through British naval/military annals for comparisons, one is tempted to recall Rorke’s Drift in 1879, where eighty men of the 24th Regiment of Foot defended the mission station against similarly overwhelming numbers. But Captain McCoy of EG3 will have the last word: “The skill, determination, and good drill displayed by all ships of B.7 Group during the time the Third Escort Group was supporting O.N.S.5 was beyond all praise.”60

  * All times are expressed in Greenwich Mean Time (GMT) unless otherwise noted.

  8

  TO HUNT

  The Bay in May

  The effectiveness of the present sorties over the Bay can be raised from a low to a real killing effectiveness only when they become part of a larger organized and co-ordinated force, devoted to surprising, hanging on, and killing.

  STEPHEN RAUSHENBUSH

  If we strike a decisive blow at the trunk in the Bay, the branches will wither.

  AIR MARSHAL SLESSOR

  … take up arms against a sea of troubles, and by opposing end them.

  HAMLET, ACT III, SCENE 1

  The U-boat has no more to fear from aircraft than a mole from a crow.

  ADMIRAL DöNITZ

  4 AUGUST 1942

  IT IS NOT KNOWN WHETHER forty-seven-year-old American economist Stephen Raushenbush had ever seen a submarine or a bomber before he was suddenly posted to London in December 1942 to help develop a new battle plan for the Bay of Biscay. Military tactics were not something in which he had had any great interest since 1917–1919, when he and most of his graduating class at Amherst College went to France with the American Expeditionary Force, he to serve as a volunteer ambulance driver. Though in that capacity he pursued his famous father’s compassionate ideals, he did not follow the Reverend Walter Raushenbush (1861–1918), a leading exponent of the Social Gospel, into the Baptist ministry. Instead, after the Armistice, he studied economics at the University of Rennes in France, worked in the oil industry in Mexico and Venezuela, researched coal and power issues in New York City, taught at Dartmouth College, and served for eight years as advisor on public utilities to the governor of Pennsylvania, while taking time out in 1934–1936 to be chief investigator for the Special U.S. Senate Committee that inquired into the munitions industry. In his spare time he wrote seven books, ranging in subject matter from The Anthracite Question (1923) to The March of Fascism (1939).

  His last pre-World War II position, beginning in 1939, was with the U.S. Department of the Interior as chief of the Branch of Planning and Research in the Division of Power. He was described at that period of his life as a reserved but friendly person; he wore a mustache and smoked a pipe; though a registered Republican, he expressed political views that were liberal and progressive. Shortly after Pearl Harbor, he took a leave of absence from Interior to serve as a civilian economist and statistician in the office of the Chief of Naval Operations (CNO) in the Navy Department. From there, in late 1942, he was plucked by Captain Thorvald A. Solberg, U.S.N., Head of the Navy Technical Station, Office of the U.S. Naval Attaché (Alusna), London, to undertake air operations planning for the Bay of Biscay.1

  In the U.K., Raushenbush quickly familiarized himself with the attack opportunities in the Bay as well as with Coastal Command’s disappointing success rate there. Since June 1942 Coastal had flown about 7,000 hours and lost aircraft at a rate of about sixteen for every U-boat sunk in the Bay. Since October only twenty-two air attacks had been mounted on the estimated 290 boats that had passed through the Bay.2 The effort was out of all proportion to the meager results obtained. Raushenbush then set about studying the hardware. Near Glasgow on the Clyde he examined the Type VIIC U-570, captured in August 1941 and renamed H.M.S. Graph, and learned her operating characteristics, paying special attention to the boat’s capacity for remaining submerged (36–41 hours) and the time required on the surface for fully charging her batteries (6.77–7.77 hours).

  At various Coastal bases he studied the type of aircraft that were being flown on Bay patrols and took fascinated notice of new centimetric radar equipment that was just then becoming available for airborne use.
At both Whitehall and Northwood he availed himself of the vast operations research data that had been accumulated by Professors Blackett and Williams and their scientific teams, whom Raushenbush found “tired and exhausted from too many seven day weeks.”3 From Williams in particular, who had continued Bay Offensive studies at Coastal during the year following Blackett’s departure for other ASW challenges at the Admiralty, and who was later quoted by Blackett as saying that while his scholarly specialty was quantum theory, he “found the subtle intricacies of the U-boat war of comparable intellectual interest,” the American economist drew generous guidance and support.4 In the end, not surprisingly, plans put forward to Churchill’s A.U. Committee by Raushenbush and Williams would bear a certain resemblance in conception, if not in details.

  When he thought he understood the basic problems that the Bay presented, Raushenbush devoted himself to intense deskwork studies and statistical tables. His roommate at Alusna, Commander Oscar A. de Lima, U.S.N.R., remembered the economist’s “endless days and nights of complicated computations,” though the endless period was just over a month.5 Raushenbush’s interests were most closely focused on the new availability of “Most Secret” 10-centimeter airborne radar, for which the Germans had no search receiver (G.S.R.). According to a report submitted on 22 December by radar pioneer Watson Watt, the Kriegsmarine would probably not figure out the wavelength, develop an answering G.S.R., and install it in the majority of their boats before “two or three months at the most” after first use of the Allied equipment.6