Black May

by Michael Gannon

  Proctor swung the heavy craft around and made another pass, expending 180 cannon rounds against the tower and foredeck. Though his report does not state that the U-boat finally did dive, Proctor released a FIDO at 1931. Three minutes later, he reported, the U-boat could be seen on the surface down by the stern, circling, “in difficulties.” At 2143, he began the return flight to base, where he arrived at 0115 on the 21st. Proctor’s after-action report in the Squadron’s Operations Record Book makes no mention of the Mk.24 but states instead that he released a “600 lb D/C.” This was the code for Mk.24, and a cleverly chosen one, since there was a Mark I 600 lb. depth bomb just coming into service. When a weapon was cited in print as a depth “bomb (D/B)” it was in fact a large depth charge; when the citation read “600 lb. D/C” it was the Mk.24. One may have further confidence here that Proctor’s weapon was indeed the Mk.24 because No. 120 Sqdn. had not yet been equipped with the 600-lb. D/B.63 In any event, the Mk.24 was dropped on this occasion without effect: the intended target, U-418, made off with no further injury (until 1 June when, homeward bound, she was destroyed by Beaufighter “B” of 236 Sqdn. in the Bay of Biscay).64

  Among the merchant ship columns of SC.130, stationkeeping was excellent throughout the battle, even during the twenty emergency turns that Gretton ordered in its course. As he commented in his Report of Proceedings, “The convoy was executing blue turns with the precision of a battlefleet.”65 The last such evasive alteration was made at dawn on the 21st, but it was an unnecessary precaution by that time, since, on the evening before, BdU signaled the U-boats to break off the operation and move away westward.66 The remainder of the passage was uneventful, except that the weather deteriorated and the convoy’s speed on the 22nd dropped to 4 knots in an easterly gale. At 1100 that day, on orders from CinCWA, Gretton detached EGI. The major escort work was done. Though heavily beset during its passage, SC.130 arrived unscathed in home waters on the 25th. Some merchant ships entered Loch Ewe escorted by Loosestrife, the remainder, with Vidette, anchored at the Mull of Kintyre. Duncan and the other B7 escorts put into Moville near Londonderry, and, to relieve the reader’s suspense, Gretton got himself to the church on time. A “safe and timely arrival” indeed!

  In the Admiralty’s Naval Staff wash-up on this convoy it was decided that the successful passage was owed to four factors: (1) the heavy air support during the time that U-boats were in contact; (2) the timely arrival of the First Support Group on the 19th; (3) the accurate appreciation of the situation throughout by the Senior Officer escorts; and (4) the successful evasive steering of the convoy both away from known U-boat positions and immediately before dawn each day while in contact in order to hook or slice submerged boats into the rough.67 What might well have been added was: (5) the efficient use by Duncan, Tay, Sennen, and Zamalek of HF/DF, which enabled Gretton at considerable distances to vector his air and sea assets economically to fixed targets. Said Gretton in his Comments of Senior Officer, Close Escort: “Directing an escort without reliable HF/DF information is like entering a ring blindfolded.”68

  In the retrospect of a half-century and more, SC.13o’s was one of the more significant convoy passages of May, since it demonstrated dramatically both how effective Allied escort operations had become and how far the U-boat fortunes, so promising at the beginning of the month, had declined. It is striking also how few of the Donau and Oder boats dared to run the Allied gantlet. Were their Commanders practicing a caution approaching timidity, or were they simply denied every chance to advance? We shall probably never know, since the few survivors among them today would not be able to speak for all or even most.69 What is clear is that an already grim exchange rate worsened further, falling from one-to-one in Convoy ONS.7 to a negative balance of three U-boats (counting U-273 but not U-381) lost for zero merchant ships sunk in SC.130. The bar graphs at BdU could be hung with black crepe for the dire tale they told. The mighty U-Bootwaffe, once the scourge of the oceans, only twenty-five days after its strongest-ever month’s start, wallowed at worsening discount. Fortuna secunda, denique adversa, uti 70

  On 21, 22, and 23 May the Allies pulled off what might be called a trifecta. On those three days, successively, a British submarine sank a U-boat; an American escort carrier (CVE), U.S.S. Bogue, got its first kill; and a U-boat was sunk by the first rocket used successfully in naval warfare. Although it may not seem obvious that one side’s submarine might sink another side’s submarine, since they were two scorpions that rarely got into the same bottle, it was hardly unknown for that to happen: since the war’s start eight U-boats had been sunk by British submarines, the most recent being U-644 (Oblt.z.S. Kurt Jensen), sunk by H.M.S. (submarine) Tuna on 7 April in the North Sea northwest of Narvik. In fact, on the 18th of the same month, the German boat U-123 (Oblt.z.S. Horst von Schroeter) sank a British submarine, H.M.S. P.615, south of Freetown. On 21 May, H.M.S. Sickle was patrolling in the Mediterranean off the southern coast of France when, at 1456, she sighted a Type VIIC boat leaving the port of Toulon on a test run. Sickle closed the range to 2,600 yards and, at 1510.29, launched two Mark VIII torpedoes 2½ seconds apart set to depths of 8 and 10 feet. One torpedo struck the U-boat about 30 feet abaft the conning tower, sending up a towering detonation column of water and smoke. The boat settled by the stern and the crew were seen jumping into the sea. The bows of the boat stood up at an angle of 50° and then slid under at 1512.20. Sickle made no attempt to pick up survivors, since it would have “unnecessarily hazarded” the submarine. The victim was U-303 (Kptlt. Karl-Franz Heine). Twenty of the forty-four-man crew were lost.71

  On 20 May the U.S. Navy created the Tenth Fleet, a paper organization with no warships of its own, which would allow Admiral King, by that date heavily committed to ASW, to bring together all anti-submarine ships, aircraft, weapons, radar and HF/DF, Intelligence, operations research, communications, convoy routing, and tactical attack doctrine and training under one overall command—his own. While a Tenth Fleet chief of staff, Rear Admiral Francis S. “Frog” Low, handled day-by-day administrative duties, and Admiral Royal E. Ingersoll, Commander in Chief Atlantic Fleet (CINCLANT), directed operations at sea, King supervised Tenth Fleet and Low in much the same way that his German counterpart, Dönitz, superintended BdU and Godt. On the date of Tenth Fleet’s epiphany—long-awaited, it should be said, by critics, particularly in the Army and USAAF, who thought that the Naval service’s approach to the U-boat threat had been too random, reactive, and unstructured72—the Tenth Fleet’s prize Atlantic weapons platform was in mid-Atlantic steaming toward a pack of twelve wolves. This was U.S.S. Bogue, the first American-built escort carrier to fight U-boats under the United States flag.

  Converted from a C-3 merchant hull at Tacoma, Washington, named after Bogue Sound in North Carolina, launched on 15 January 1942, and commissioned by Captain Giles E. Short on 26 September of that year, Bogue was classified an ACV for Auxiliary Aircraft Carrier (until July 1943, when the classification would be changed to CVE for Escort Carrier). In service she would be designated CVE-9. Popularly, she would be known as a “Jeep” carrier. Bogue’s flight deck was 442 feet 3 inches long. A narrow “island” (five feet wide, twenty-five long, fifteen high) stood on the starboard side. The vessel’s steam turbines and single screw produced a maximum speed in open water of 17.75 knots. Her normal crew complement was 890, but it quickly grew to a crowded 97 officers and 921 men.73 In November 1942, at San Diego, Bogue embarked her aircraft: nine Grumman TBF—1 Avenger torpedo-bombers and twelve Grumman F4F4 Wildcat fighters. Together they formed the Escort Scouting Squadron Nine (VGS-9), redesignated Composite Squadron Nine (CV—9) on 1 March 1943. Commanding Officer was Lieut.-Comdr. William M. Drane, U.S.N.

  In many ways, though not all, the Avenger represented an advance over the Archers and Biters Fairey Swordfish. Where the latter, a fabric-covered biplane, had a weight of 9,250 lbs., a maximum speed of 139 mph, and a range of 546 miles, the aluminum monoplane Avenger had a weight of 15,905 lbs., a top speed of 270 mph, an
d a range of 1,215 miles. On two counts, however, they were similar: the Swordfish had a crew of two or three and the Avenger a crew of three (pilot, radioman, and gunner); and both had a bomb load capacity of 1,600 lbs.

  The Avenger’s speed enabled it to deliver an attack before the targeted U-boat could submerge, while exposing the aircraft to flak for the shortest possible time. Again, the Avenger’s endurance permitted it to remain on patrol or over a target for an effective period of time. The preferred type of attack, worked out in theory and practice, was a long power glide at maximum speed out of cloud or cloud bases, followed in the final stage by a pushed-over 20° dive with wheels lowered to reduce speed for the D/C drop. While the D/C depth was set to 25 feet in keeping with the doctrine learned at the Fleet Air Arm Anti-Subma-rine School, Ballykelly, Northern Ireland, which all of Bogue’s TBF-I pilots would attend, Squadron Nine chose to reduce the 100-foot spacing recommended there to 75 feet because of the speed of their aircraft.

  The purpose of the Wildcats was primarily to provide defense against air attacks, not likely in midocean but possible when operating near the U.K., and secondarily to strafe surfaced U-boats in coordinated attacks with the TBF-Is. In the latter case Lt.-Cmdr. Drane was insistent that the Wildcats restrain themselves by not engaging in highspeed maneuvers that condensed vapor in humid air and gave away the attack, and by not dashing about madly without orders from the accompanying Avenger and thus compromising an attack by driving a U-boat down prematurely. Ideally, a Wildcat should be available on call to strafe the U-boat from three to five seconds before the D/Cs were dropped. The operational endurance of each aircraft type was, for the TBF-16 hours at 125 knots, for the F4F4 3.5 to 4 hours at 125 knots. Both types could be launched by the flight deck catapult without the carrier having to turn into the wind, a wind component of only 16½ knots along the track being required by a fully loaded TBF—1, and a component of only 6 knots being required by an F4F4. Without the catapult, wind velocity over the deck necessary to fly off aircraft was 31 and 24 knots, respectively.74

  Bogue was named the centerpiece of a pioneer aggressive USN sea force called the “Hunter-Killer Group.” Her mission, not unlike that of Archer and Biter, was to hunt down U-boats in the vicinity of convoys and destroy them. It was thought at first by Ingersoll that Bogue s best use was on the Central Atlantic routes to and from Gibraltar, where generally good weather conditions favored aircraft launches and recoveries, but as it happened, Bogue found herself from the outset in the thick weather and heaving seas of the North Atlantic lanes. On 6 March 1943, out of Argentia, Newfoundland, accompanied by two “flush-deck” destroyer escorts, U.S.S. Belknap and George E. Badger, she joined the U.K.-bound Convoy HX.228. Four days later, Avenger pilot Ensign Alexander C. “Goose” McAuslan, U.S.N.R., sighted a U-boat and dove to attack it. Both D/Cs he was carrying hung up in their racks. (In pitching seas the squadron was fitting only two D/Cs in the TBF-IS to assist takeoff.) The U-boat initiated a dive while McAuslan swung around for a second run. Again his D/Cs failed to release. Bogue was ordered to return to Argentia; on the way, TBF-1 pilot Lt. H. S. “Stinky” Roberts, U.S.N.R., mistook a gam of porpoises for a U-boat and had yet another bomb rack failure, to the very good fortune of the sea mammals. Something would have to be done about the bomb hangups, and it was.

  On 20 March, Bogue began a second partial crossing as air escort to SC.123, but rough seas and wet gray curtains caused her aircraft to stand useless in their lashings for most of the voyage. On the 26th she began a return to Argentia, arriving there four days later. On 25 April she joined Convoy, HX.235, which was routed to the southward through better weather. This time, with the addition of three more flush-deck destroyers, U.S.S. Greene, Lea, and Osmond Ingram, the carrier had a five-escort screen. The entire support force was designated Task Group 92.3. Their passage was uneventful until the afternoon of the 28th, when Lt. Roger “Stomp” Santee, U.S.N.R., in an Avenger, caught a fully surfaced U-boat about 50 miles distant from the convoy and attacked it with two D/Cs that released well enough but ricocheted off the surface, owing to too much speed on the dive, and went under to explode too far from the target.

  Two days later, TG 92.3 was detached to make for Belfast, where, during the following two weeks, Bogue’s officers passed through the Anti-Submarine School at Ballykelly, a British HF/DF set was installed in the carrier’s island (see chapter 2), and VC-9's TBF-I quota was increased from nine to twelve, while the F4F4 fighter complement was reduced from twelve to six.75 Interestingly, in his comments on the new aircraft composition, Captain Short suggested that four slower type-aircraft, such as the Swordfish, be substituted for three TBF-is: “The Swordfish, for instance, can be operated in weather which precludes the landing and take-off (except by catapult) of the TBF. They could be used for night operations and rough water work when the employment of the heavy and faster TBF would be unduly hazardous in this class of vessel. Further, a slow aircraft at night would prove more effective in spotting submarines than a fast one.”76 The suggestion was not followed.

  Bogue departed Belfast Lough at 1837 on 15 May. Three and a half hours later she rendezvoused with her surface escorts, minus Lea, to form the Sixth Escort Group, and proceeded to Iceland. From there, on the 18th, the Group, taking with it the freighter S.S. Toltec, intersected the route of the westbound convoy ON.184, which it was to accompany in support of the close screen. Destroyer Lea overtook the remainder of the Group on the 18th, and at dawn the next day, Bogue and her four-stackers took assigned convoy stations, Bogue in the Commodore’s column astern of the escort tanker. Heavy weather made flying impossible until the 21st when, coincidentally, ON.184 stumbled on a pack of U-boats that had been assembled not to meet it, but another, eastbound, convoy, HX.239 (escorted by Archer), crossing 30 miles to the south, which had been betrayed by Naval Cipher No. 3. Again, as in the case of Convoy SC.130 in the middle of the month, B-Dienst had decrypted HX.239's position, course, and speed, and BdU had formed a patrol line of twenty-one boats named Mosel (after the river) across it.77

  Subsequent decryptions by B-Dienst enabled BdU to know the convoy’s estimated positions for the 20th, 21st, and 22nd.78 Since these positions were farther to the south than BdU had anticipated, twelve Mosel boats were instructed to proceed southeastward to make contact. Boats of the Donau group withdrawing from SC.130 were also vectored to intercept at AK 97 (51°25'N, 30°15'W). None of these orders was decrypted by the Allies before 22 May, and some signals relating to the dispositions of southern Mosel were not read until 3 June.79 On the 20th, B-Dienst intercepted a signal giving the position of convoy ON.184 as 51°01'N, 33°5O’W.80 Ironically, it was the carrier escort of ON. 184 that the southern Mosel boats would encounter first as the two convoys passed in opposite directions some 520 miles southeast of Cape Farewell.

  The morning of the 21st broke CAVU—Ceiling and Visibility Unlimited—and Squadron VC-9 flew continuous search patrols. At twilight on that perfect day, squadron skipper Bill Drane, flying an Avenger with four D/Cs at 3,000 feet 60 miles ahead of the convoy, sighted and pursued a streak of silver with a black splinter at its head. He increased speed to 200 knots, circled, and made his approach from dead ahead, lowering his landing gear on the final run in to reduce speed and avoid the D/C ricochets that had ruined Lt. Santee’s chances the month before. This time four Mark 44 flat-nosed D/Cs, released by intervalometer from 50 feet, dug in properly and blanketed the U-boat with explosive geysers. Nothing was seen of the boat thereafter, and no evidence of damage appeared except for some unidentified dark specks in the center of the Torpex slick. Having reached PLE (30 gallons left on return), Drane called for destroyers to investigate and returned to Bogue. After the war it would be learned that he had severely damaged U-231 (Kptlt. Wolfgang Wenzel), forcing her back to base.81

  There was no action overnight, but on the 22nd, which dawned clear with occasional rain squalls, VC-9 made no fewer than five Avenger attacks on three separate U-boats of Mosel’s southern wing, beginnin
g at 0635 when Lt. (jg) Roger C. “Bud” Kuhn, U.S.N.R., dropped four D/Cs up the wake of U—468 (Oblt.z.S. Klemens Schamong), which, unable to dive for slightly over an hour, circled slowly, emitting a bluish oil streak. Kuhn’s call for backup went unanswered both because he had erred in plotting his position and because he was in a “null” area where ship’s radar could not get a fix. Finally, the U-boat sank stern first, and though seriously damaged, managed to make a successful Rückmarsch.82 Second out of the box, at 1103, was Ensign Stewart E. Doty, U.S.N.R., who found a fully surfaced boat proceeding at high speed almost broad on the convoy’s bow 18 miles distant. Just before he mounted an attack the U-boat was DFed by Bogue. Coming out of an overcast sky at 1,500 feet, Doty survived incoming flak and released four D/Cs on the U-boat, obtaining one explosion, apparently under the hull between the conning tower and bow, the other three D/Cs falling well to port ahead. As the spray subsided, the U-boat was observed to shake violently to starboard, then to submerge slowly. A bluish oil bubble, about 50 feet in diameter, came to the surface. Shortly afterwards, the boat lifted its bow out of the water at an angle of 45°; then it settled back under at the same angle. Like “Bud” Kuhn’s boat, U-305 (Kptlt. Rudolf Bahr) was forced out of the hunt and back to base.83

  At 1325 Lt. (jg) Robert L. Stearns, flying 26 miles off the convoy’s starboard quarter, sighted 5 miles distant a “large dark object” leaving a long wake on a course of 035°, directly opposite to that of the convoy. It was the same U-305, on her way home to Brest with a severe headache. Stearns dove out of a 1,200-foot cloud base and attacked through heavy flak, dropping a four D/C salvo from 125 feet. The charges exploded close aboard U-305, inflicting additional damage (she would spend nearly three months in Brest) and sending her under again to lick her wounds.84