During July 1942, U-Boat Command shifted its attention to the Allied transatlantic convoy routes which had been largely neglected since the autumn of 1941. After the entry of the United States into the war in December 1941 Germany had exerted the main thrust of its submarine effort in the coastal waters of the western hemisphere where Allied shipping had suffered heavy losses. The first battle of the new mid-ocean campaign, which would last until the defeat of the wolf packs in May 1943, occurred in late July 1942 when German U-boats intercepted the westbound convoy ON 113. The battle for ON 113 established the pattern for the months to come.(1)
The U-boat invasion of American and Caribbean waters forced the dispersal of Allied escorts. During the spring of 1942 Allied authorities reduced the number of escort groups operating in the Mid-Ocean Escort Force [MOEF] from fourteen to eleven (six British, four Canadian, and one American) to allow a transfer of escorts to the coastal waters of North America. One British and four American groups were withdrawn from the MOEF and replaced by only two British groups.(2) The extension of the convoy system in the Caribbean in July necessitated additional reductions in North Atlantic escort strength. Instead of cutting the number of mid-ocean escort groups further to ten, the size of the groups was reduced to a minimum of six escorts on the premise that summer weather conditions would allow them to operate below strength. This move released ten Canadian corvettes for coastal escort duty.(3)
The coastal convoys introduced in the spring and summer of 1942 deprived Axis submarines of easy targets in the North American area. The extreme distance from the U-boat bases in France and the proximity to shore-based aircraft made Caribbean and American waters unsuitable for the use of wolf pack tactics against the new convoys. Large wolf packs could, however, still be successfully employed in the central North Atlantic in the air cover gap between Iceland and Newfoundland. The short distances from their Biscay bases to the mid-ocean allowed the U-boats to mass for sustained operations. Admiral Karl Dönitz, Commander-in-Chief, U-boats, later recalled the decision made in July 1942: "the main weight of our attack in the war on shipping had now to be transferred back to operations against convoys to and from Britain, in mid-Atlantic, where they were beyond the range of land-based air cover".(4)
The acute shortage of escorts compelled Allied convoys to use the most direct route between North America and Great Britain. The forced adherence to the great-circle path limited Allied opportunities for the evasive routing of convoys, making them easier to intercept for the Germans. As it was, the 1,750 mile run between Newfoundland and Northern Ireland tested the fuel endurance of destroyers and corvettes.(5) To compound these difficulties, the introduction of a new cipher for Atlantic U-boats in February had interrupted the flow of Allied special intelligence. The Admiralty Submarine Tracking Room (the U.S. Navy's tracking room, OP-20-G, was just organizing at this stage), under the direction of Commander Rodger Winn, RNVR, was still able to maintain a general estimate of U-boat deployments, largely through High Frequency/Direction Finding [HF/DF]. The picture, however, was increasingly hazy. The Tracking Room's report for the week ending 20 July, for example, placed twenty U-boats west of 30O West.(6) In fact, fifteen to eighteen submarines lurked in this zone.(7) In spite of the Admiralty's reasonably accurate appreciation, the absence of precise daily fixes for individual U-boats and the limited fuel endurance of escort groups left routing authorities with little choice but to continue to route convoys through this area of heavy enemy concentration.
By contrast, B-dienst, the German naval intelligence branch, was providing U-Boat Command with timely and accurate radio intercepts. German decrypts of Allied naval signals revealed that North Atlantic "convoys on the whole still seemed to follow the great-circle path".(8) Dönitz formed Group Wolf in early July to herald the return of the wolf packs to the vital shipping lanes between North America and Great Britain. Initially, Wolf consisted of seven U-boats, U-71, U-86, U-90, U-379, U-552, U-559, and U-704. Two additional boats, U-43 and U-454, were assigned to the group on the following day to bring its strength up to nine. Several of these submarines were on their first war cruise but the pack also included seasoned veterans (U-43, U-71, U-552) each with seven or more patrols under their belts. In addition, the group boasted a bona fide ace in Erich Topp who had already sunk thirty-two Allied ships, including the destroyer USS Reuben James.(9)
Group Wolf formed a reconnaissance line on 9 July in the eastern Atlantic at the outer limits of air cover. The pack received orders to sweep westward along the great-circle route in search of convoys. If none were found the boats would operate independently off the coast of the United States and in the Caribbean Sea. Almost immediately, U-90 glimpsed an eastbound convoy during the night of 9/10 July. U-90 reported five merchant ships, two light cruisers and eight destroyers at a speed of 14-16 knots--the American troop convoy AT 17. Dönitz ordered only two of the other U-boats, U-704 and U-597, to operate against AT 17 because its high speed made pursuit futile for the more distant boats. In desperation U-90 fired a spread of four torpedoes but missed "owing to excessive distance". After a few hours, Dönitz abandoned the hunt.(10)
Group Wolf beat across empty seas until 13 July when U-71 (Oberleutnant Hardo Rodler von Roithberg) sighted ON 111, a fast westbound convoy under the protection of Escort Group B6. Roithberg reported that the convoy was on a northerly course. U-Boat Command surmised from his signal that it was an eastbound convoy and instructed Group Wolf to operate accordingly. Several hours later U-71 radioed that the convoy was, in fact, westbound, but by this time Dönitz did not want the pack to waste fuel in a high speed chase that held little prospect of success in rough weather. Meanwhile, U-552 (Korvettenkapitän Erich Topp) had also sighted ON 111, but sweeps by the escorts forced both this boat and U-71 to lose contact.(11) The brief pursuit of ON 111 revealed the presence of Group Wolf to the Allies through HF/DF bearings. Commander Rodger Winn thought that enemy submarines were shadowing the eastbound convoy HX 197 which, as a result, received several U-boat warnings, and Western Approaches diverted ON 111 to avoid the U-boats presumed to be around HX 197 which may have helped shake U-71 and U-552 off the trail of ON 111. Winn misinterpreted the HF/DF evidence as indicative of U-boats "outward bound from Germany to American waters" and not of the presence of a new reconnaissance line. Thus, Allied routing authorities remained unaware that a wolf pack lurked in the midst of the convoy lanes.(12)
Another three days of empty seas followed for Group Wolf until 16 July when Dönitz realigned the patrol line to lie "in wait for an incoming convoy" reported by B-dienst.(13) This was either SC 91 or HX 198, both eastbound convoys, which were southwest of the pack.(14) Heavy fog shielded the merchant ships from enemy eyes. For three days, the patrol line hunted northeast and then southwest in vain as both convoys slipped through unseen. Dönitz reflected that the "operations of Group Wolf are heavily dependent on [the] weather situation (continuous bad visibility)" and concluded "that had the weather been more favourable, the group would have found targets for attack".(15)
U-Boat Command intended to refuel the boats from a supply submarine, or "milch cow", and deploy them in the Caribbean Sea if no traffic presented itself and the poor weather persisted. On 19 July, however, B-dienst decrypted a signal giving the position, course, and speed of ONS 112. The slow westbound convoy was in position 55O01' North, 29O33' West that morning. Dönitz directed Group Wolf to form a new patrol line in order to make the interception the following morning.(16) Thick fog again intervened. Topp broke radio silence on 20 July and again on 21 July to report "No engagement of enemy possible because of poor visibility".(17) HMS Primrose, the Senior Officer of Escort Group C1, the mid-ocean escort of ONS 112, similarly observed that "The voyage was remarkable for the amount of fog experienced". The escort was blissfully unaware of the convoy's peril because Allied intelligence failed to detect the presence of the pack. Shore authorities issued no U-boat warnings to Primrose for the period 19-22 July when Wolf was searching for ONS 112.(18)
Group Wolf swept westward but by 21 July U-Boat Command concluded that ONS 112 had evaded the patrol line and made arrangements for the pack to refuel.(19) The B-dienst then reported an eastbound convoy, probably SC 92, before refuelling could be carried out, and Dönitz instructed Wolf to form a new patrol line in order to intercept SC 92 after dawn on 23 July.(20) Even though the fog had cleared, the slow convoy slipped past to the north of the pack, unseen. Over 100 miles to the south, U-379 and U-552 instead made contact with a westbound convoy. They had found ON 113, south of Greenland, still some 600 miles from Newfoundland. It had been routed south of SC 92 but the strict adherence of Allied convoys to the narrow band of the great-circle path allowed the pack to stumble upon the fast westbound convoy.(21) Subsequent histories have emphasized inaccurately that decrypts made possible the German interception of ON 113. The Admiralty narrative The U-Boat War in the Atlantic suggests that enemy "Radio Intelligence discovered the position of the westbound convoy, and consequently a patrol line was formed which led to the sighting of ON 113" but there is no mention of such a decrypt in the German sources. The pack was, in fact, searching for the eastbound SC 92 when it intercepted the westbound ON 113 by coincidence.(22)
The convoy had sailed from Great Britain on 18 July with thirty-four merchant ships. One had straggled and returned to port, leaving thirty-three for the ocean passage. Most of them were sailing in ballast, bound for New York. The mid-ocean escort of ON 113, Escort Group C2, consisted of two town-class destroyers (ex-USN four-stackers), one British and one Canadian, HMS Burnham and HMCS St.Croix, and four flower-class corvettes, three Canadian, HMCS Brandon, Drumheller, Dauphin, and one British, HMS Polyanthus. Commander Thomas Taylor, RN, captain of Burnham, was Senior Officer of the group. The escorts had not worked together before: the two British warships had joined C2 for ON 113 and it was only Dauphin's second voyage with the group. None of them possessed ship-borne HF/DF, but the two British escorts were equipped with the new type 271 centimetric radar. The Canadian escorts had radar types which were much less effective at detecting surfaced U-boats.(23)
The first few days of the voyage were uneventful except for delays which prevented HMCS St.Croix and Drumheller from joining until 22 and 23 July. The convoy had crossed the CHOP line two days earlier thus passing from British to American control, exercised by the Convoy and Routing Section [CONNAV] of COMINCH's staff in Washington.(24) The fog lifted on the 23rd and U-552 glimpsed the mast of a corvette at 1608 [all times GMT], perhaps that of the rejoining Drumheller. Two hours later Topp sighted smoke from the convoy. Within minutes of U-552's first sighting report at 1906, U-Boat Command received reports that U-379 and U-90 had made contact. U-597 came up to the convoy two hours later.(25) Naval Service Headquarters in Ottawa [NSHQ] obtained a DF bearing on one of the first two sighting reports and relayed it to the Admiralty which warned ON 113 at 2051 that a U-boat was in contact.(26)
The escort's first hint that it had company had come twenty minutes earlier when Burnham sighted and chased a submarine to the northwest. Gunfire forced the U-boat to submerge at 2132 at a range of seven miles and the destroyer picked up an asdic echo briefly. St.Croix joined in the hunt but to no avail.(27) Topp "was forced away by a screening vessel for a short period" at the same time but did not observe gunfire. Defects in U-552's port engine limited her surface speed to 10 knots but funnel smoke allowed Topp to re-establish contact.(28) Shortly before dusk St.Croix (Lieutenant-Commander Andrew H. Dobson, RCNR) glimpsed U-597 on the surface and gave chase at 26 knots. The destroyer opened fire but the shells fell "fairly wide of the mark". Kapitänleutnant Eberhard Bopst crash dived at 2337 when the range had closed to 3,000 yards. Dobson failed to make asdic contact but dropped a pattern of depth charges for good measure. Burnham joined the search and both destroyers obtained contacts at 0020/24 but lost them by crossing paths. Bopst reported a destroyer directly overhead but no further attacks. The two destroyers abandoned the search after an hour without finding further trace of U-597.(29)
Taylor had ordered a course alteration of 60O to port at 2130/23, for three hours, and then 30O to starboard to steer a new course of 225O for the duration of the night.(30) The evasive turns, before and after nightfall, threw the pack off the convoy's scent. Topp reported that he lost contact at twilight and that the other shadowers also "had been forced off".(31) The night passed quietly for the convoy. The two destroyers, Burnham and St.Croix, rejoined in the morning, when Taylor stationed St.Croix at the range of maximum visibility ahead of the convoy and corvettes at the same distance on either beam for the daylight hours. After he had lost contact, Topp guessed that ON 113 had altered to the south. Dönitz ordered the pack to form a new patrol line to the west, but Topp, convinced that he would soon make contact, ignored the signal and continued south. His hunch was rewarded when he sighted the convoy shortly after daybreak in "very good visibility".(32) The Admiralty intercepted U-552's sighting report at 0908/24 and warned the escort.(33)
Throughout the morning and afternoon of 24 July Topp shadowed ON 113 from astern, which he believed was the position safest from surprise by the escort. The merchant ships eased the task of shadowing by smoking heavily, in particular SS Senga belched "thick black smoke continuously".(34) One after the other, five more submarines, U-71, U-86, U-454, U-704, and U-90, made contact during the afternoon. Dönitz urged the pack that "Attack takes precedence over anything else. Aim to attack by day as well. Prospects for success in daylight attacks are very good, as the protective screen has been deployed as an outer screen detached from the convoy". The clear visibility obviously had enabled the shadowers to thoroughly reconnoitre ON 113.(35)
That good visibility could also work against the pack. St.Croix's masthead lookout sighted two U-boats at 1735, ahead of the convoy, on either bow. St.Croix increased to 28 knots and chased the closest one, U-90, only five miles away. Burnham went in pursuit of the other, more distant submarine which escaped further detection (and subsequent identification by the historian). With enough daylight left to overtake U-90, Dobson withheld fire in an effort to keep her on the surface until the range had closed as much as possible in order to improve the odds of underwater detection. Kapitänleutnant Hans-Jürgen Oldörp obliged for an hour by attempting to outrun the destroyer on the surface until he finally submerged when the range had fallen to 6,000 yards.(36)
Asdic conditions were good in the calm sea running. Dobson proceeded to the diving position where a brief search produced an asdic echo at a range of 2,400 yards. St.Croix classified it as a submarine at 1856 and ran in to attack. The contact was lost at 700 yards, revealing that U-90 had gone very deep. The depth-charge crew changed to a deep setting during the run-in and fired a pattern of six depth charges which produced no visible results. Dobson circled back and re-established contact. This time the echo, showing no movement, was lost at 500 yards and six depth charges set to 150 and 350 feet were dropped at 1909. After the explosions "small pieces of splintered wood, bubbles of air and" oil rose to the surface in the destroyer's wake.(37)
Dobson opened up the range to 2,200 yards, regained contact and ran in to attack. During the approach run the target showed no movement and "was held until close in" until finally lost at 100 yards. At 1922 St.Croix fired a pattern of six depth charges set shallow to 100 feet. The third and final depth charge attack brought scattered debris and human remains up to the surface, marking the destruction of U-90. Shortly afterwards, Burnham arrived from her unsuccessful search for the other U-boat to screen St.Croix while she collected the grim evidence of her kill as proof for the sceptical Admiralty assessment committee.(38) The two destroyers remained in the vicinity of the wreckage of U-90 until 2040 when they sailed to rejoin their flock. Shortly after sunset, Taylor sighted a submarine on the surface at a range of five miles. The U-boat crash dived and Burnham and St.Croix swept the area for over an hour without result.(39)
In the meantime, six submarines still shadowed ON 113. After the initial sighting by St.Croix, Taylor had instructed the commodore to alter course to due north for three hours and then back to the west.(40) Evasive action did not fool the pursuers. Topp had assumed the convoy would turn south, but quickly learned his error. Smoke guided him back to ON 113 and at 2157/24 he reported it on a northerly course. Against a bright horizon, he observed five other U-boats in pursuit. The weather deteriorated at dusk with thunder storms, heavy rain, and poor visibility.(41) In his absence, Taylor had left Drumheller in command of the escort. Commander George H. Griffiths, RCN, ordered night screen NE-4: Drumheller and Dauphin on the starboard bow and quarter, and Polyanthus and Brandon on the port bow and quarter. Unknown to Griffiths, two merchant ships, SS Harpefjell and Stancleeve, straggled in the worsening weather.(42)
The growth of the pack was watched with grave concern by Allied shore authorities. While ON 113 steered the northerly course ordered by Taylor, CONNAV radioed a diversion to due south for twelve hours after dusk to shake off the U-boats. Griffiths passed the signal to the convoy commodore and reminded him that if it was obeyed the convoy would retrace its steps to the scene of the earlier U-boat sightings. Commodore Roy Gill, RNR, aboard SS Empire Rowan, recommended instead a course alteration to the east after dusk and then, after midnight, to comply with CONNAV's diversion to the south. Griffiths agreed and informed Burnham. The immediate impact of this radical evasive manoeuvre, which later caused much controversy, was that a westbound convoy sailed due east for several hours.(43)
The unexpected diversions to the east and south, combined with heavy seas, gusts of rain, and deteriorating visibility, threw most of the pack off the convoy's scent but the tenacious Topp held contact, following the "large circling movement over 360 degrees".(44) Running blind through the pouring rain, U-552 penetrated the reduced screen through the gap in the stern and manoeuvred in between the two starboard columns. At 0150/25, Topp fired a double salvo at the rear ship in the ninth column. SS British Merit, an 8,093-ton tanker, was fitted with anti-torpedo net defences which stopped one torpedo but not the other which struck her port quarter, just behind the nets. The explosion killed one man and seriously injured another who was pulled from the flooded engineroom to safety by the Chief Engineer. The tanker fired two white rockets and made a distress call that was intercepted clearly by U-552. Griffiths ordered the escort to perform Operation Raspberry in an effort to locate the attacker on the surface outside of the convoy. In his log, Erich Topp described what followed: "The convoy comes to life. Gunfire flashes out. Star shells flare luridly in the hazy, rain-saturated air in all sectors astern. But no one suspects that we're right here in the middle of them".(45)
While the corvettes hunted in the distance, U-552 turned and pushed up between the sixth and seventh columns. (The stern ship in the eighth column had straggled a few hours earlier). Topp felt "quite comfortable" in the midst of the convoy and manoeuvred to launch stern and bow attacks against the rear ships of both columns. At 0212/25, he torpedoed the 5,136-ton SS Broompark on the port side, amidships in her stokehold. The impact killed two men. Topp then ordered his crew to reload the bow tubes while preparing to fire a stern shot at the tanker in the sixth column. SS Solsten, however, disrupted the attack with accurate gunfire which forced "a sharp blast of air" in the faces of the sub's bridge crew. U-552 crash dived immediately. The gunfire alerted Lieutenant John C. Littler, RCNR, captain of Brandon, astern of the convoy. Littler was uncertain if the shells were meant for him or for a U-boat, but gave Solsten "the benefit of the doubt and" fired starshell. The fireworks were too late to catch U-552 before she slipped below the surface and asdic failed to locate the enemy.(46)
The victims remained afloat, but the crews abandoned ship quickly. Brandon's starshell guided the two destroyers back to the scene of the attack. St.Croix steamed ahead to the convoy but Burnham remained behind until Polyanthus dropped back to screen the rescue work. Brandon picked up forty-six survivors out of Broompark's crew of forty-nine in "seas of considerable height". The ship's captain drowned, being unable to reach one of the lifeboats or rafts, but all of the other men who survived the torpedoing were rescued. Littler then went to attend to the British Merit and picked up thirty-two men from two lifeboats. The other twenty-two survivors had remained on board the tanker which seemed "perfectly seaworthy" although it was unable raise steam. Taylor ordered the two corvettes to stand by the derelicts to determine if they were salvageable, and for one of the corvettes to rejoin if possible. Low on fuel, Brandon later had to detach with the survivors for base while Polyanthus waited for the tugs to arrive. The British Merit subsequently made port under tow of the US naval tug Frisky but Broompark, which had survived a previous torpedoing in 1940, sank when just twenty-seven miles from St. John's, Newfoundland.(47)
In the meantime, U-552 had surfaced after the attack and re-established contact when a "destroyer coming up from astern" at 0630/25 forced the boat under. Kapitänleutnant Walter Schug, captain of U-86, sighted a destroyer at 0857 (perhaps Burnham returning from astern) and submerged to 130 metres. When it was clear above, Schug surfaced and went in pursuit. Dönitz, uncertain of the pack's prospects, discussed the situation in the morning with Topp by means of a radio cipher conversation. The U-boat commander emphasized that the "strong protective screen" and "suddenly arising storm" had thwarted Wolf's attempts to attack ON 113 and he attributed the failure to maintain contact to the convoy's extreme course alterations. Topp assessed the odds of re-establishing contact as "exceedingly slight" but guessed that ON 113 had altered course to southwest at dawn.(48)
The convoy altered course from 180O to 253O at 1100/25 when Burnham rejoined. Shortly afterwards, the Admiralty obtained a DF bearing on a signal from U-86 and warned C2.(49) ON 113 was now within range of the Newfoundland-based aircraft of the Royal Canadian Air Force [RCAF]. During the morning and afternoon of 25 July a Catalina flying boat of 116 Squadron and two Digby aircraft of 10 Squadron provided air escort. None of them found the convoy because of "heavy fog" and inaccurate position reports. Still, at 1413 the Catalina surprised U-597 which crash dived immediately; the aircrew did not sight the U-boat.(50) In variable visibility U-86 ran "into the rearward column of the convoy" at 1535 and identified a destroyer, a corvette, and five merchant ships. Schug dropped back to shadow from a comfortable distance and radioed contact to U-Boat Command. Group Wolf slowly closed in around ON 113: U-43 glimpsed one of the two destroyers at 1823, and within an hour U-454 and U-704 had also made contact.(51) Another Digby furnished air cover in the evening and located the convoy at 1837 with the help of radar. The aircraft did not make any sightings, nor did it disturb the pack. COMINCH warned Taylor an hour later that U-boats still shadowed the convoy.(52)
The destroyer unwittingly pushed U-43 off three times but Oberleutnant Hans-Joachim Schwantke repeatedly re-established contact. To home the other boats, at 1950/25 Schwantke made medium frequency [MF] homing signals which were intercepted by the convoy's MF/DF guard, bearing 170O.(53) Ten minutes later, a sudden improvement in visibility allowed St.Croix to sight U-43 bearing 175O, five miles distant. U-454, which was nearby, submerged immediately but Schwantke tried to out-run the destroyer on the surface at full speed. Dobson gave chase and after the range had closed to 2,000 yards at 2034, U-43 crash dived. St.Croix obtained a good asdic echo and fired a pattern of depth charges on the target. Schwantke went deep to 110 metres where the explosions crushed the boat's main blow-out pipe. Dobson failed to regain contact and Burnham joined to assist in a box sweep, but U-43 eluded them. Schwantke surfaced at 2159, observed one of the four-stackers 6,000 metres away, and descended to periscope depth. As the destroyer closed to 3,000 metres he went deep to 120 metres. The destroyers did not regain contact, and U-43 later surfaced to move off and make repairs.(54)
The sweeps of the escorts had also pushed U-704 away but U-86 had continued to shadow during the hunt for U-43. Schug was joined in the meantime by U-597 and U-607; the latter was an outbound boat which reinforced Group Wolf. Both U-597 and U-607 submerged ahead of the convoy to launch attacks before nightfall. The absence of the two destroyers left only Drumheller and Dauphin to screen the convoy. Through the periscope of U-597 Bopst counted 12-14 merchant ships in the distance and a lone corvette in station on the starboard side. The convoy made a sudden course alteration to port at 2140/25 which knocked U-597 out of position, ruining the attack.(55) Next, Kapitänleutnant Ernst Mengersen, veteran captain of U-607, closed in at periscope depth in the "advancing twilight". Steep seas and rain showers complicated his approach. When the hydrophones showed that he was in the midst of the convoy, mist covered the periscope and made an attack impossible. The sound of screws approaching persuaded Mengersen to withdraw.(56)
Taylor abandoned the hunt for U-43 because he "considered it essential to be with the convoy at night". Burnham encountered the neutral SS Irish Plane while returning to the convoy. The Irish vessel was also sighted by U-454 which mistakenly chased her to the east for several hours and was drawn away from the real prey. The two destroyers rejoined at 2330/25 shortly after dusk. Fifteen minutes later, ON 113 altered 40O to starboard to a new course of 283O. Taylor adopted night screen NE-4: St.Croix and Burnham on the port and starboard bows, and Drumheller and Dauphin on the port and starboard quarters. The night was moonlit and bright.(57) COMINCH warned Taylor at 0048/26 that a U-boat had made a sighting report in his vicinity.(58) The sweeps of the two starboard escorts pushed U-86 off at 0100/26, almost breaking enemy contact, but at the same time U-607 surfaced and re-established contact in the bright moonlight. U-379 and U-71 followed suit within the next hour.(59) Allied shore authorities obtained DF bearings at 0122 and 0228, the latter on U-71's sighting report, and warned the escort.(60)
Taylor ordered an evasive turn of 40O to port at 0245/26 to shake off the shadowers but they stubbornly held contact in the clear visibility. The bright moonlight also worked against the U-boats by making it too light for them get close on the surface but too dark for a periscope attack. In these conditions the escort frustrated the pack's efforts to penetrate the screen. C2 forced U-71 off three times while closing to attack. The stern escorts drove U-607 back when Mengersen tried to push forward. Towards the middle of the night cloud-cover darkened the sky and visibility fell to two or three miles. Astern, Mengersen drove across to the darker, northern side of the convoy at three-quarter speed. The "turning around and running back" of Dauphin forced U-607 wide around the starboard quarter. Mengersen overtook U-71 at 0450 and pushed forward at full power along the northern side of ON 113. When U-607 "had caught up to the destroyer" on the starboard bow, he "turned sharply inward in order to make contact with the convoy once more".(61)
Dark and cloud-covered, the night augured well for attack. U-607 slipped through the large gap in the screen between Dauphin and Burnham at 0530/26 and observed the three ships in the starboard column. At the same time, U-704, stumbled on to the convoy from ahead. As Mengersen approached to attack fog descended and reduced visibility to less than one mile. At 0557 he fired a spread of four torpedoes from 1,500 metres at the lead ship and, after turning away, attempted a stern shot at the second ship but misfired. Two torpedoes struck the 6,942 ton SS Empire Rainbow amidships on the starboard side. Sixty seconds later Mengersen observed a third detonation against another ship (which has not been identified). Taylor heard the initial explosion and ordered Operation Raspberry which, however, proved ineffective because the starshell was obscured by the fog. Dauphin came "very close" to U-607 without sighting the U-boat which, remaining on the surface, eluded the corvette and disappeared in the fog to the north.(62)
While U-607 escaped, U-704's hydrophones revealed the convoy "directly ahead". Smoke could be seen from the conning tower and ON 113 slowly came into view. The fireworks startled Kapitänleutnant Horst Kessler but he realized that they were meant for another U-boat. At 0611/26 he fired a spread of four torpedoes at a large freighter from a range of 2,000 metres. Turning hard a-starboard, Kessler heard four detonations and observed his victim "dead in the water". Mengersen also heard the hits as he crept away to the north. No other merchant ships were torpedoed, however, and it is possible that they were end-of-run detonations which appeared to be on the vessel already hit by U-607. Kessler crash dived to 150 metres at 0623 with dawn breaking.(63)
Dauphin (Lieutenant Robert A.S. MacNeil, RCNR(64)) and Burnham set about rescuing the survivors and picked up the entire crew of the Empire Rainbow. Kessler rose to periscope depth at 0715/26 to have a look around and glimpsed an escort only 1,000 metres away. He hurriedly went deep to 160 metres but Dauphin and Burnham made asdic contact, however, and broke off the rescue work. Four well-placed depth charges exploded around U-704, damaging the lighting circuits and cracking the diesel exhaust flaps. The submarine plunged to 192 metres with the flange of torpedo tube III "leaking badly". Kessler stabilized his boat with water "beginning to rise above the floor plates" and ejected a Bold asdic decoy. Two more patterns of depth charges cascaded down at 0740 and 0804 which were farther off, though still "quite impressive" to the submariners. The batteries and oxygen supply were running low as U-704 crept clear of the scene. Taylor and MacNeil fired their final pattern at 0823 which fell far from the mark.(65) Dauphin and Burnham then turned their attention back to the Empire Rainbow. The abandoned vessel appeared salvageable so Taylor left MacNeil to reboard the crew and bring her in to port while Burnham rejoined the convoy. Dauphin and Empire Rainbow finally got under way at 1240.(66)
In the meantime the "thick damp fog" that had concealed Mengersen's escape after the torpedoing of Empire Rainbow, now worked against the pack. U-71 re-established contact with ON 113 in a brief clearing at 0630 but visibility soon closed down again to 200 metres. U-552 and U-597 glimpsed the convoy an hour later but could not maintain firm contact. The fog lifted again at 0915 allowing U-71 to observe "heavy smoke" and an escort which rapidly disappeared into a "thick wall of fog". U-607 fled from a destroyer which suddenly appeared out of the mist. The U-boats had little hope of re-establishing contact in these conditions.(67) The escort had other problems. Weather again prevented effective air cover from being furnished although ON 113 was well within the range of Newfoundland-based aircraft. Burnham detached for St. John's in the morning because of fuel shortage, leaving only a destroyer and a corvette to screen the convoy. Griffiths, captain of HMCS Drumheller, was once again Senior Officer.(68)
During the afternoon three U-boats stumbled upon Dauphin and Empire Rainbow making their way to St. John's. In the poor visibility U-552, U-597, and U-704 at first thought they had found the convoy. Topp gradually realized that he was shadowing "a steamer protected by a corvette" and "apparently damaged or torpedoed". Thick fog descended shortly after 1600/26 causing all three submarines to lose contact. The two ships continued to plod towards port until 2150 when Empire Rainbow began to sink quickly. MacNeil removed the crew and began shelling her to speed her descent. Topp heard the gunfire in the fog and cautiously approached. The derelict sank at 2305 and U-552 glimpsed Dauphin in a brief improvement in visibility. Topp moved in at full speed to attack but the corvette suddenly vanished in the fog.(69)
The main body of the convoy had not been troubled further during the day. HMCS Annapolis, another town-class destroyer, reinforced C2 from St. John's in the afternoon. The western local escort, two destroyers, HMS Walker (Commander James M. Rowland, RN) and HMCS Columbia, and two corvettes, HMCS Chicoutimi and Calgary, rendezvoused with ON 113 in the evening. They brought the strength of the combined escort up to four destroyers and three corvettes. CONNAV ordered a diversion to starboard to avoid a U-boat ahead of the convoy but "thick fog" prevented compliance with the order until 2300 when a "very slight improvement in visibility" occurred.(70) St.Croix chased a radar contact at 2315 but German records suggest that U-boats no longer shadowed ON 113. During the night of 26/27 July, Group Wolf found no trace of the convoy's scent. Dönitz terminated the operation on the following morning and recalled Group Wolf for refuelling. Poor visibility ultimately had prevented the pack from re-establishing contact on the 26th and 27th, although the break-up of the convoy and escorts into separate groups after the final attack led some of the boats astray.(71)
Nevertheless, the enemy delivered another blow against ON 113. St.Croix, Drumheller, and Annapolis detached on 27 July, leaving the four western local escorts to screen the convoy while it continued along the southern coasts of Newfoundland and Nova Scotia toward Boston. The passage was uneventful until 29 July when COMINCH obtained DF bearings at 1401 and 1753 and warned HMS Walker. Commander James M. Rowland, RN ordered HMCS Columbia to sweep astern to force off the shadowers and a Hudson bomber arrived from 11 Squadron, RCAF, Dartmouth, but enemy submarines had not made contact yet.(72) Later that day, at 2215/29, U-132 sighted ON 113 southwest of Sable Island, and submerged ahead to await its approach. As the convoy drew near, Kapitänleutnant Ernst Vogelsang rose to periscope depth and from a range of 800 metres torpedoed the lead ship in the fourth column, the 6,734-ton SS Pacific Pioneer. Vogelsang immediately "dived to avoid an oncoming vessel" but then could not stop his boat from plunging uncontrollably to the bottom in 80 metres of water.(73)
The four escorts searched for the attacker without luck. Chicoutimi picked up a non-sub echo and dropped a pattern of depth charges for good measure but none of the group obtained a firm contact. Rowland instructed Calgary, whose asdic had broken down, to rescue the survivors and she retrieved the entire crew. Chicoutimi returned to the convoy leaving the two destroyers to continue the hunt. They failed to find any trace of U-132 even though Columbia searched the area until morning.(74) Four hours after his initial attack, Vogelsang lifted his boat free from the ocean floor, rose to periscope depth, and crept away from the lone destroyer in the distance.(75)
Dönitz instructed U-132, having fired its last torpedo, to locate and shadow the convoy. In an unusual attempt to use wolf pack tactics in coastal waters, he formed three independent U-boats off Nova Scotia, U-89, U-458, and U-754, into a makeshift pack to hunt for ON 113 based on the assumption that it was headed for Boston.(76) During the following morning Calgary and Columbia put into Halifax to disembark the survivors and refuel. They were replaced by the minesweeper HMCS Quinte, hardly a fair trade.(77) U-458 glimpsed two escorts but found no trace of ON 113 in poor visibility. A Hudson of 11 Squadron sighted U-89 on the surface at 1944/30 twenty miles on the convoy's port beam. The aircraft attacked the U-boat as it crash dived in the pouring rain with four depth charges but failed to inflict serious damage. The attack kept U-89 submerged for three hours while the convoy took evasive action.(78)
During the night of 30/31 July the small wolf pack failed to make an interception but Dönitz continued the hunt in the morning. Naval Service Headquarters in Ottawa obtained a DF bearing on a signal made by U-754 while searching for ON 113 and passed it to the Royal Canadian Air Force. Squadron Leader N.E. Small's Hudson aircraft of 113 Squadron took off from Yarmouth and at 1450/31 surprised the U-boat on the surface. Small executed a swift and accurate depth charge attack which produced large air bubbles on the surface for an hour "until a heavy underwater explosion brought a large quantity of oil swirling up to mark the grave of U-754". The RCAF had scored its first U-boat kill of the war.(79) Strong air cover frustrated the remaining submarines during the afternoon and evening. By the time the submarines were ordered to break off the operation after midnight ON 113 had already dispersed off Cape Cod without suffering further losses.(80)
The balance sheet of ON 113 showed three merchant ships sunk and one damaged in exchange for two U-boats destroyed. The human cost to the Allies was light, only four fatal casualties out of some 200 merchant sailors aboard the four torpedoed ships. The Germans lost two full U-boat crews totalling about 100 men. In total, fourteen submarines had operated against the convoy: the ten of Group Wolf and the four independents off Nova Scotia. The meagre results achieved by Wolf against ON 113 disappointed the Germans. With four submarines in contact during the night of 23/24 July, six the following night, and eight the third night, U-Boat Command could have expected ON 113 to pay a much heavier price than just three torpedoed merchant ships. Dönitz attributed the pack's lack of success primarily to the unfavourable weather and the "movements of the strongly escorted convoy".(81) The unexpected alterations of course made by ON 113 confused the shadowing U-boats and frequently disrupted contact. Evasive turns at nightfall were particularly effective in shaking off the pack. Ernst Mengersen, captain of U-607, commented that the defence of ON 113 exhibited "a clever exploitation of these critical moments [at dusk] by the convoy commander, taking route and time into account, to an extent which has never been observed up to now".(82)
The weather was also unquestionably an important factor. Poor visibility and heavy seas frustrated German attempts to maintain visual contact with ON 113. In spite of these conditions, all ten U-boats of Group Wolf made contact with ON 113, and five managed to reach firing positions. Nevertheless, only the two most experienced commanders, Mengersen and Topp, scored hits. Five of the pack's ten captains were making their first war cruise in command, a ratio that would continue as increasing numbers of new construction U-boats became operational. Dönitz observed that "the carrying out of convoy operations without the help of inexperienced boats is unavoidable. We cannot alter the fact that the difficult school of convoy attack cannot be completed at home, but first of all when in direct contact with the enemy".(83)
In spite of the failure of Group Wolf to achieve greater success against ON 113, the operation had whet U-Boat Command's appetite for more convoy battles. Dönitz decided that, after refuelling, the Wolf boats would remain in the North Atlantic to conduct further convoy operations instead of proceeding to coastal waters as originally intended. Once replenished, the pack was reconstituted first as Group Pirat and then as Group Steinbrink for operations against ON 115 and SC 94 in early August. The battle for ON 113 marked the renewal of the mid-ocean campaign which raged until May 1943. "This resumption of North Atlantic operations without previous approval by the Naval Staff later caused some feeling among the latter" which, however, made no move to halt the new U-boat offensive.(84)
The renewal of convoy battles in the North Atlantic also captured the attention of Western Approaches in Liverpool which was disturbed by the extreme course alterations made to shake off the U-boats. Canadian and British naval officers charged with the defence of ON 113 had emphasized in their reports the confusion caused by diversion ordered by CONNAV on 24 July. Taylor argued that when a convoy was being shadowed the Senior Officer "is in a better position to suggest evasive manoeuvers to [the] Commodore, than the shore authorities, whose information cannot be up to the last minute".(85) Griffiths, who served briefly as escort commander in Burnham's absence, seconded Taylor's recommendation, "When convoy is in contact with submarines it is considered that the S.O. of escort is in the best position to judge what alterations of course should be made".(86)
These reports aroused heated discussion among the staff at Western Approaches. Commander R.D.S. Crosse, RN, Staff Officer (Convoys and Submarine Tracking), observed that they showed "the futility of shore authorities attempting to specifically control the course of a convoy after an attack".(87) Captain R.W. Ravenhill, RN, Deputy Chief of Staff, Western Approaches, reflected that the incident showed "the need for a full analysis being carried out by someone competent to assess the correctness or otherwise of the action taken. It seems to be most desirable that in cases where the convoy has had a 'stormy' passage the whole proceedings of the voyage should be thoroughly gone into in order to correct mistakes". The staffs at Liverpool and Londonderry already attempted this but did not have the time for thorough analyses. Ravenhill recommended that a staff officer be appointed for the sole purpose of evaluating convoy battles. Perhaps aware that a turning point had been reached in the Atlantic, he concluded that "We are supposed to be the highest authority in S/M warfare & we dictate policy but we do not analyze results....I think we are definitely missing something by not carrying out this procedure".(88)
Crosse tried to fill the gap by drafting a report for Sir Percy Noble, Commander-in-Chief, Western Approaches, about the objections to the diversion by CONNAV.(89) As Noble in turn informed the Admiralty, "the result of this attempt to throw off U-boats is remarkable" because, from the time of the course change until two ships were torpedoed, ON 113 "made good NIL and in fact went to the Eastward". The convoy had, in fact, turned a complete circle in U-boat infested waters. The staff at Liverpool, by implication, blamed the sinkings that night on the radical diversion. Noble recommended to the Admiralty that "As long as escorts are allowed to carry out evasive steering at their own discretion, shore authorities must never attempt to divert solely to throw off U-boats known to be in contact". In addition, while such action might shake off the shadower it would not get the convoy into safer waters more quickly and "might well 'evade' into another U-boat".(90) The Admiralty informed the British Admiralty Delegation [BAD] in Washington of these views and requested that they be presented to the Navy Department. The British won their point. CONNAV accepted the suggestions and "intended to reduce the present scale of evasive diversions which" in the future would "be confined to special cases after consultation" with OP-20-G, the U-boat tracking room.(91)
In the midst of this uproar, Western Approaches and the Admiralty seem to have lost sight of the fact that it was not the diversion by CONNAV which had redirected the westbound convoy to the east. That decision was made by Commodore Roy Gill, RNR, the convoy commodore, and endorsed by Lieutenant-Commander George H. Griffiths, RCN, the escort commander at the time. Why they altered back to the east after the turn to the north, instead of to the west as Taylor had intended originally, is not at all clear from their reports. The submarines to the south obviously prevented compliance with CONNAV's diversion in that direction but the motive behind the adoption of an easterly course is a mystery. It may have allowed the two destroyers, which were absent astern, to rejoin more easily, although this seems an unlikely explanation considering their high turn of speed.(92) CONNAV's diversion caused some confusion, perhaps, but it certainly did not order an easterly course. Although British comment implied that the backtracking was responsible for the losses, in fact, the extreme turns had shaken off all of the shadowers but one (U-552) and quite possibly averted a devastating attack with the two destroyers absent. However, the course changes lengthened ON 113's voyage through the air-cover gap by several hours and offered the U-boats a chance to regroup for the following night. Thus, the "safe and timely arrival" of the convoy was delayed considerably.
Allied reaction to the performance of the escort was largely favourable. Commodore Roy Gill, RNR, observed that an "Excellent offensive spirit was displayed by [the] Escort Group especially [by] HMS Burnham and HMCS St.Croix".(93) Taylor singled out Littler for his role in the rescue operation: "Brandon worked among the boats of survivors in a most seamanlike and efficient manner and deserves praise for the despatch used under difficult conditions".(94) Not surprisingly, the sinking of U-90 by HMCS St.Croix pleased shore authorities. Captain E.R. Mainguy, RCN, Captain (D), Newfoundland, "considered that particular credit is due for switching the pattern to deep on losing contact at long range. This is evidence of good drill on the part of the Depth Charge crews. HMCS St.Croix carried out an efficient hunt and thoroughly deserves her success".(95) Commander C.D. Howard-Johnston, RN, Staff Officer (Anti-Submarine) at Western Approaches, agreed "entirely" with Mainguy's assessment and added that "The rate of delivery of the three attacks, one after the other, was most satisfactory". Dobson later was awarded the Distinguished Service Cross for his efforts.(96)
It is surprising that there was not more comment on Taylor's performance as Senior Officer. The preoccupation with the diversions evidently allowed him to escape critical scrutiny. Although the sweeps by the two destroyers had indeed disrupted the gathering pack, the frequent and prolonged absences of these powerful ships from the screen made ON 113 vulnerable for most of the first two nights of enemy contact. The lengthy chases resulted in the destruction of U-90 but reduced the screen to four corvettes (and deprived C2 of the guiding hand of its escort commander) on nights when four to six submarines shadowed the convoy. Fortunately, the pack, with the sole exception of Erich Topp, failed to exploit the weakened escort because of the severe weather and extreme course alterations. Taylor had very rightly "considered it essential" to remain with the convoy during the third night (25/26 July) after the sinkings during the second night. The reduced escort, two destroyers and two corvettes, then held up to eight shadowers at bay: only when visibility fell drastically did Mengersen slip by the screen to torpedo Empire Rainbow. This was an impressive performance, although the employment of the other two corvettes in rescue work astern should have attracted some negative comment (as it would in future convoy battles). On balance, however, the escort had done well, especially when considering the extent to which the return of the wolf packs to the mid-ocean had caught the Allies by surprise.
The role played by intelligence in the defence of ON 113 also might have stimulated more rigorous Allied analysis. Shore-based HF/DF stations intercepted and relayed bearings on German U-boat signals to the escorts at sea regularly from 23-26 July. A rough count shows that ON 113 received one warning signal on the 23rd, six on the 24th, and five on both the 25th and 26th. Delays of 2-6 hours in receipt of this intelligence and the fact that the escorts almost invariably had actually sighted the enemy prior to the arrival of warnings reduced its operational utility. At the same time, the DF bearings furnished evidence of the growth of the shadowing pack and confirmed Taylor's appreciation of the situation. None of the mid-ocean escorts possessed ship-borne HF/DF which would have been much more effective for directing sweeps. The role played by MF/DF was not significant although it did contribute to one U-boat sighting.(97)
Allied intelligence inferred from the U-boat operations against ON 113 that convoy battles in the North Atlantic were about to resume on a large scale. The pursuit of ON 113 and a public broadcast by Dönitz warning of higher U-boat casualties in the future led Rodger Winn to conclude that "the recent decrease in sinkings in the American zone" had persuaded "the Germans to change their strategy". The new mid-ocean offensive was "unlikely to involve a complete withdrawal from American waters" but the recent attacks revealed "that the comparative immunity recently enjoyed by transatlantic and UK-African convoys is a thing of the past". Though Winn had failed to detect the presence of Group Wolf astride the convoy lanes, subsequent U-boat operations in the North Atlantic would not catch him by surprise.(98)
The battle for ON 113 was but a mild foretaste of the bitter struggles of the coming months. The mid-ocean campaign would involve vast numbers of U-boats, surface escorts, and aircraft, and would continue with only fleeting lulls until the decisive defeat of the wolf packs in May 1943 cleared the way for the Allied invasion of Europe.
1. The author would like thank Dr. Roger Sarty for his assistance in the preparation of this article.
2. Jürgen Rohwer and Gerhard Hümmelchen, Chronology of the War at Sea, 1939-1945, (Annapolis, MD: Naval Institute Press, 1992), pp.124, 135-6.
3. COMINCH to Admiralty and NSHQ, 1610/9 June 1942, Public Record Office [PRO], Great Britain, MT 59/1998.
4. Karl Doenitz, Memoirs: Ten Years and Twenty Days, (Annapolis, MD: Naval Institute Press, 1990), pp.237-8.
5. Routing and weather could make for much longer voyages than the great-circle distance of 1,750 miles. For example, with ON 113 HMS Burnham steamed 2,820 miles.
6. Great Britain, Admiralty, Operational Intelligence Centre, U-boat Situation Report, 20 July 1942, PRO, ADM 223/15.
7. Befehlshaber der U-bootes [BdU] War Diary, 20 July 1942, Director General of History [DHist], National Defence Headquarters, Ottawa, 79/446, Vol. 6.
8. BdU War Diary, 19 July 1942.
9. BdU War Diary, 9-11 July 1942; Jürgen Rohwer, Axis Submarine Successes, 1939-1945, (Annapolis, MD: Naval Institute Press, 1983), pp.23-103.
10. BdU War Diary, 9-11 July 1942.
11. BdU War Diary, 13 July 1942; and Jürgen Rohwer and Gerhard Hümmelchen, Chronology of the War at Sea, 1939-1945, p.150.
12. Naval messages, 13 July 1942, DHist, 88/1 mfm, Vol. 9, ON 111; and Great Britain, Admiralty, Operational Intelligence Centre, U-boat Situation Report, 20 July 1942, PRO, ADM 223/15.
13. BdU War Diary, 16 July 1942. The patrol line was reformed between German naval quadrants AK-43 and AK-85.
14. Naval Control Service Officer [NCSO] Halifax, Convoy Records, DHist, 77/553, Vol. 5, SC 91 and HX 198.
15. BdU War Diary, 17-19 July 1942; and NCSO Halifax, Convoy Records, DHist, 77/553, Vol. 5, SC 91.
16. BdU War Diary, 20-22 July 1942; and Commodore's Report, ONS 112, DHist, 88/1 mfm, Vol. 9, ON 112. The decrypt revealed that the convoy was in quadrant AK-64.
17. U-552, War Diary, 20-21 July 1942, DHist, 83/665.
18. HMS Primrose, Report of Proceedings, ONS 112, 27 July 1942, DHist, 88/1, Vol. 9, ONS 112. C1 received six U-boat warnings between 23-26 July, once clear of the danger.
19. BdU War Diary, 21-22 July 1942.
20. U-552, War Diary, 22-23 July 1942. The new patrol line was between quadrants AK-72 and AK-78.
21. BdU War Diary, 23 July 1942; and Commodore's Report, SC 92, PRO, ADM 199/716. SC 92 was in position 54O08' North, 38O43' West (quadrant AK-47). The U-boats made contact with ON 113 in quadrant AK-78.
22. Great Britain, Ministry of Defence (Navy), The U-Boat War in the Atlantic, 1939-1945, (London: Her Majesty's Stationery Office, 1989), II, p.33; BdU War Diary, 21-23 July 1942; German Naval Staff, Operations Division, War Diary, Part A, 22 July 1942, DHist, SGR II/261 mfm; and U-552, War Diary, 22 July 1942. The War Diaries of the German Naval Staff and U-552 both state that the decrypt referred to an eastbound convoy.
23. HMS Burnham, Report of Proceedings, ON 113, 27 July 1942, PRO, ADM 237/87.
24. HMS Burnham, Report of Proceedings, ON 113.
25. U-552, War Diary, 23 July 1942; and BdU War Diary, 23 July 1942.
26. Admiralty to CTU 24.1.12, 2151B/23 July 1942; and Commander J.M. de Marbois, Deputy Director Signals Division, RCN, Memorandum to Director, Anti-Submarine, "DF Fixes in Relation to ON 113", 8 October 1942; both in DHist, 89/34, Vol. 17, ON 113.
27. HMS Burnham, Report of Proceedings, ON 113; and HMCS St.Croix, Report of Proceedings, ON 113, 27 July 1942, PRO, ADM 237/87. The U-boat was probably U-90 or U-379. They were both destroyed later on this cruise and as a result their war diaries have not survived.
28. U-552, War Diary, 23 July 1942.
29. HMCS St.Croix, Report of Proceedings, ON 113; and U-597, War Diary, 23-24 July 1942, DHist, 83/665.
30. HMS Burnham, Report of Proceedings, ON 113.
31. U-552, War Diary, 23-24 July 1942. Sunset was at 2230. Topp lost contact at 2305.
32. U-552, War Diary, 24 July 1942; and BdU War Diary, 23-24 July 1942. The new patrol line was to be formed between quadrants AJ-98 and BC-35. U-552 made contact with ON 113 in quadrant BC-33.
33. Admiralty to Escorts of ON 113, 1148B/24 July 1942, PRO, ADM 237/87.
34. U-552, War Diary, 24 July 1942; and HMS Burnham, Report of Proceedings, ON 113.
35. BdU War Diary, 24 July 1942; and U-552, War Diary, 24 July 1942.
36. HMS Burnham, Report of Attacks on ON 113, 29 July 1942, PRO, ADM 237/87 [Taylor made two separate reports for ON 113]; and HMCS St.Croix, Report of Proceedings, ON 113.
37. HMCS St.Croix, Report of Proceedings, ON 113; and HMCS St.Croix, Report of Attack on U-boat, 24 July 1942, National Archives of Canada [NAC], RG 24 D15, Vol. 11465, 1942 file.
38. HMCS St.Croix, Report of Proceedings, ON 113; and HMS Burnham, Report of Attacks on ON 113.
39. HMS Burnham and HMCS St.Croix, Reports of Proceedings, ON 113; and CTU 24.1.12 to COMINCH, 0017Z/25 July 1942, DHist, 89/34, Vol. 17, ON 113. The submarine sighted at 2245 was probably U-379.
40. HMS Burnham, Report of Proceedings, ON 113. U-597 had made contact in the meantime.
41. BdU War Diary, 24 July 1942; and U-552, War Diary, 24-25 July 1942.
42. HMCS Drumheller, Report of Proceedings, ON 113, 30 July 1942, PRO, ADM 237/87.
43. HMCS Drumheller, Report of Proceedings, ON 113; and CONNAV to CTU 24.1.12, 1446/24 July 1942, DHist, 89/34, Vol. 17, ON 113.
44. BdU War Diary, 24 July 1942; and U-552, War Diary, 25 July 1942.
45. U-552, War Diary, 25 July 1942; HMCS Brandon, Report of Proceedings, ON 113, 27 July 1942, PRO, ADM 237/87; Commodore's Report, ON 113, PRO, ADM 237/87; and SS British Merit, Attack on Merchant Vessel by Enemy Submarine, 24 July 1942, NAC, RG 24 D1, Vol. 4025, NSS 1062-10-13.
46. U-552, War Diary, 25 July 1942; Commodore's Report, ON 113; HMCS Brandon, Report of Proceedings, ON 113; and Report of Interview with Chief Officer of SS Broompark, 17 February 1943, PRO, ADM 237/87.
47. HMS Burnham and HMCS Brandon, Reports of Proceedings, ON 113; and Flag Officer, Newfoundland Force, Monthly Report of Proceedings, July, 1942, DHist, NSS 1000-5-20(1). The salvage attempt is described by Farley Mowat in The Grey Seas Under (Toronto: McClelland & Stewart, 1958), pp.263-4.
48. U-552 and U-86, War Diaries, 25 July 1942, DHist, 83/665; and BdU War Diary, 25 July 1942.
49. HMS Burnham, Report of Proceedings, ON 113; BdU War Diary, 25 July 1942; and Admiralty to Escorts of ON 113 and ONS 112, 1723B/25 July 1942, DHist, 89/34, Vol. 17, ON 112.
50. Eastern Air Command, No 1 Group, Weekly Intelligence Report, 31 July 1942, DHist, 181.003 (D2178); and U-597, War Diary, 25 July 1942.
51. U-86, U-43, U-704, and U-454, War Diaries, 25 July 1942, DHist, 83/665.
52. Eastern Air Command, No. 1 Group, Weekly Intelligence Report, 31 July 1942, DHist, 181.003 (D2178); and COMINCH to CTU 24.1.12, 1933/25 July 1942, DHist 89/34, Vol. 17, ON 112.
53. U-43, War Diary, 25 July 1942; and Commodore's Report, ON 113. SS Pacific Pioneer was the MF/DF guard.
54. U-43 and U-454, War Diaries, 25 July 1942; HMS Burnham and HMCS St.Croix, Reports of Proceedings, ON 113.
55. U-597 and U-704, War Diaries, 25 July 1942.
56. U-607, War Diary, 26 July 1942, DHist, 83/665.
57. HMS Burnham, Report of Proceedings, ON 113; Commodore's Report, ON 113; and U-454, War Diary, 26 July 1942.
58. COMINCH to CTU 24.1.12, 0048/26 July 1942, DHist, 89/34, Vol. 17, ON 113 and ON 112.
59. BdU War Diary, 25 July 1942; U-86, U-607, and U-71, War Diaries, 26 July 1942, DHist, 83/665.
60. COMINCH to CTU 24.1.12, 0527/26 July 1942; and Admiralty to Escorts ON 113 and ONS 112, 0522B/26 July 1942; both in DHist, 89/34, Vol. 17, ON 112.
61. U-71 and U-607, War Diaries, 26 July 1942, DHist, 83/665.
62. U-607, War Diary, 26 July 1942; HMS Burnham, Report of Proceedings, ON 113; and Jürgen Rohwer, Axis Submarine Successes, p.111.
63. U-704, War Diary, 26 July 1942; and Jürgen Rohwer, Axis Submarine Successes, p.111.
64. Lieutenant Robert A.S. MacNeil was the father of Robert MacNeil (of MacNeil-Lehrer Report fame) whose memoir, Wordstruck (New York: Viking, 1989), contains many reminiscences of his father's naval career.
65. U-704, War Diary, 26 July 1942, DHist, 83/665; HMCS Dauphin, Deck Log, 26 July 1942, NAC, RG 24 D2, Vol. 7253; and CTU 24.1.12 to COMINCH, 0815Z/26 July 1942, DHist, 89/34, Vol. 17, ON 113. Surprisingly, these attacks are not described in either ship's Report of Proceedings. The depth charge attack at
0740 is listed in Dauphin's Deck Log while one signal reads "Burnham and Dauphin attacking contact in the vicinity of torpedoed ship, 0815Z", confirming the identity of the attackers.
66. HMS Burnham and HMCS Dauphin, Reports of Proceedings, ON 113, 4 August 1942, DHist, 89/34, Vol. 17, ON 113. The destroyer left the corvette and merchant ship at about 0840.
67. U-71, U-552, U-597, and U-607, War Diaries, 26 July 1942, DHist, 83/665.
68. HMS Burnham, HMCS St.Croix, Dauphin, and Drumheller, Reports of Proceedings, ON 113.
69. HMCS Dauphin, Report of Proceedings, ON 113; HMCS Dauphin, Deck Log, 26 July 1942; U-552, U-597, and U-704, War Diaries, 26-27 July 1942.
70. HMS Walker, Report of Proceedings, ON 113, 4 August 1942, NAC, RG 24 D10, Vol. 11020, COAC 7-2-1, vol. 4; HMCS Drumheller, Report of Proceedings, ON 113; and BdU War Diary, 26 July 1942.
71. BdU War Diary, 26-27 July 1942; and HMCS St.Croix, Report of Proceedings, ON 113.
72. HMS Walker, Report of Proceedings, ON 113; and W.A.B. Douglas, The Creation of a National Air Force: The Official History of the Royal Canadian Air Force, Volume II, (Toronto: University of Toronto Press, 1986), p.519.
73. Michael Hadley, U-Boats Against Canada: German Submarines in Canadian Waters, (Kingston and Montreal: McGill-Queen's University Press, 1984), p.108.
74. HMS Walker, Report of Proceedings, ON 113.
75. Michael Hadley, U-Boats Against Canada, pp.108-109.
76. BdU War Diary, 29-31 July 1942.
77. HMS Walker, Report of Proceedings, ON 113.
78. Eastern Air Command, Monthly Anti-Submarine Report, July 1942, DHist, 181.003 (D25); U-89, War Diary, 30-31 July 1942, DHist, 85/77, part 19; U-458, War Diary, 30 July 1942, DHist, 83/665; and Commodore's Report, ON 113.
79. W.A.B. Douglas, The Creation of a National Air Force, p.520; and Eastern Air Command, Monthly Anti-Submarine Report, July 1942, DHist, 181.003 (D25).
80. BdU War Diary, 31 July 1942; U-89, U-132, and U-458, War Diaries, 31 July 1942, DHist, 83/665; and HMS Walker, Report of Proceedings, ON 113. All three surviving U-boats crash dived several times during the 31st to avoid aircraft.
81. Great Britain, Ministry of Defence (Navy), The U-Boat War in the Atlantic, II, p.33. These themes arose in the radio cipher conversation between Topp and Dönitz on 25 July 1942.
82. U-607, War Diary, 27 July 1942.
83. BdU War Diary, 25 July 1942. Walter Schug (U-86), Hardo Rodler von Roithberg (U-71), and Paul-Hugo Kettner (U-379) were moderately experienced while Ernst Mengersen (U-607) and Erich Topp (U-552) both had ten or more war cruises under their belts.
84. Great Britain, Ministry of Defence (Navy), The U-Boat War in the Atlantic, 1939-1945, II, p.33.
85. HMS Burnham, Report of Attacks on ON 113.
86. HMCS Drumheller, Report of Proceedings, ON 113.
87. Western Approaches, Staff Minute Sheet, ON 113, 9 August 1942, PRO, ADM 237/87.
88. Western Approaches, Staff Minute Sheet, ON 113, 14 September 1942, PRO, ADM 237/87.
89. The rough draft of the summary is titled "Convoy ON 113", dated 17 September 1942, in PRO, ADM 237/88.
90. Commander-in-Chief, Western Approaches to the Secretary of the Admiralty, 28 September 1942, Memorandum, "Subject: Reports of Proceedings ON 113 and ON 115", PRO, ADM 237/88.
91. Admiralty to BAD Washington, 1900A and 1911A/20 October 1942, PRO, ADM 237/88; and BAD Washington to Admiralty, 2009Z/28 October 1942, PRO, ADM 237/87.
92. HMCS Drumheller and HMS Burnham, Reports of Proceedings, ON 113; and Commodore's Report, ON 113. None of the reports state why the 090O course was taken.
93. Commodore's Report, ON 113.
94. HMS Burnham, Report of Proceedings, ON 113.
95. Captain (D) Newfoundland to Flag Officer, Newfoundland Force, 22 August 1942, PRO, ADM 237/87.
96. Western Approaches, Staff Minute Sheet, 10 September 1942, PRO, ADM 237/87.
97. DF bearings from U-boat warning signals in DHist, 89/34, Vol. 17, ON 112 and ON 113, and PRO, ADM 237/87.
98. Great Britain, Admiralty, Operational Intelligence Centre, U-boat Situation Report, 27 July 1942, PRO, ADM 223/15.