The arrival of thirteen new Type VIIs in the Atlantic force in July and the decision to limit Type VII sailings to the Americas enabled Dönitz to resume group, or wolf pack, attacks against cargo convoys on the North Atlantic run. The first group, Wolf, was composed of ten VIICs that sailed in late June and early July. It was to establish a patrol line in the distant “air gap” between Iceland and Greenland.
As in the anticonvoy campaign during the summer and fall of 1941 in this area, the boats of group Wolf were to be individually relieved at sea by other boats as required, in order to maintain a continuous U-boat presence. When the arriving replacements and reinforcements outnumbered the original cadre, the pack was to be renamed. When the number of boats in the North Atlantic rose sufficiently high to permit it, additional groups were to be formed to operate simultaneously.
Group Wolf was an odd mixture of old and new skippers and boats. Seven boats came from Germany, three from France. The boats from Germany included five new VIIs, one older VII, U-454, transferring from the Arctic, and the aged Type IX U-43, returning from a long overhaul. Six of the ten skippers, including Hardo Rodler von Roithberg, age twenty-four, in the veteran U-71, sailing from France, and Hans-Joachim Schwantke, age twenty-three, in the veteran U-43, were making first patrols as captain. Two of the ten skippers were Ritterkreuz holders: Erich Topp in U-552 from France and Ernst Mengersen, who won his medal on the retired U-101, returning from Germany to the Atlantic in a new VII, U-607, his fourth U-boat command in the war.
The three boats sailing from French bases had to elude the intensified round-the-clock Coastal Command aircraft patrols. Topp in U-552 and von Roithberg in U-71 got through unscathed but Walter Schug in U-86 did not. On the night of July 5, when a Coastal Command Wellington bombed and sank the inbound U-502, another aircraft, as yet unidentified, caught and bombed U-86. Schug reported to Kerneval that the close depth-charge blasts had knocked out four of his five torpedo tubes and damaged the fifth. His crew repaired some of the damage—avoiding an abort—but U-86 was not fully combat-ready on this patrol.
En route to the patrol line, one of the five new boats sailing from Germany, U-90, commanded by Hans-Jürgen Oldörp, age thirty-one, reported a fast east-bound convoy on July 9. Dönitz ordered three other new boats sailing from Germany to home on U-90, but owing to U-379’s lack of training, he restricted Paul-Hugo Kettner from attacking except under the most favorable circumstances. Harassed by surface escorts and Iceland-based ASW aircraft, Oldörp in U-90 doggedly shadowed for almost 200 miles before Dönitz canceled the operation.
By July 13, nine of the ten group Wolf boats had formed a patrol line running southeasterly from Greenland. That day, von Roithberg in U-71 found and reported another eastbound convoy. Horst Kessler, age twenty-seven, in the new boat U-704, requested beacon signals. Erich Topp in U-552 encountered—and reported—two “destroyers,” which may have been convoy escorts. However, the convoy maneuvered radically and escaped into fog so dense that Dönitz was again compelled to cancel operations. He soon ordered a new patrol line to intercept yet another eastbound convoy reported by B-dienst. But heavy fog persisted for a full week, utterly frustrating group Wolf.
Finally, on the evening of July 24, Erich Topp in U-552 found and held on doggedly to a convoy. It was the westbound Outbound North 113, composed of thirty-three empty ships escorted by six warships: the four-stack destroyers Burn-ham of the Royal Navy and St. Croix of the Royal Canadian Navy, and four British corvettes. Upon picking up the U-boat shadow signals on Huff Duff, the Burnham and St. Croix raced ahead of the convoy and found two U-boats on the surface. Burnham chased one boat, the St. Croix the other. St. Croix’s quarry was Oldörp’s U-90, twenty-six days out from Kiel on her maiden voyage. Commanded by A. H. Dobson, St. Croix drove U-90 under and blasted her with three well-conducted depth-charge attacks. Running in for a fourth attack, St. Croix heard an unusually loud underwater explosion, then saw debris rising to the surface. That was all that could be found of U-90, which went down with all hands, the second confirmed U-boat to be sunk by Canadian surface forces.
While the two destroyers were off hunting U-boats, Topp in U-552 eased in to attack, bedeviled by a diesel-engine failure that reduced his maximum speed to 9 or 10 knots. He shot at and hit two British ships: the 8,100-ton tanker British Merit and the 5,100-ton freighter Broompark. Sailing in ballast, the damaged tanker reached port to be salvaged, but Broompark, badly wrecked, sank under tow. Gunfire from the freighter Salsten and perhaps from one or more of the four corvettes drove Topp off and under, foiling his second attack. No other U-boat could get close enough to shoot.
Despite the fog and his diesel-engine problems, Topp managed to hang on and to shadow Outbound North 113. During July 25, his beacons brought up the group Wolf boats for the second time. Using radar and Huff Duff to advantage, the six escorts held off most of the boats, pounding the aged Type IX U-43 with a heavy depth-charge attack. This time only the Ritterkreuz holder Ernst Mengersen in the new U-607 got in to shoot. He hit and damaged the 7,000-ton British freighter Empire Rainbow. A day or so later, Horst Kessler in the new U-704 encountered this same ship and finished her off with a torpedo. All other vessels of the convoy, save one, slipped into the fog off the Newfoundland Bank and reached port safely.*
The U-90 was the tenth boat of the Atlantic force to be lost since June 1. Dönitz well knew that the resumption of U-boat warfare against North Atlantic convoys would result in still greater losses. Believing that he should soften this coming blow to the German public, on July 27 he announced that the campaign in the Americas had been more difficult than portrayed in the media and that yet “harder times” lay ahead. Upon hearing this unusual public address, Rodger Winn in the Admiralty’s U-boat Tracking Room speculated correctly that it signaled a resumption of full-scale U-boat war against the North Atlantic convoy run.
As if to give emphasis to Dönitz’s statement, another U-boat was lost in that area. She was the new Type VIIC U-335, commanded by Hans-Hermann Pelkner.
Having sailed from Kiel on July 31, Pelkner, age thirty-three, was north of the Shetlands on August 3. His assignment was to probe west along likely North Atlantic convoy routes and to join whatever group was in operation. Another new boat, U-174, a Type IXC bound for the Americas, sailed close by with the same orders.
The Admiralty has not attributed the killing of U-335 to Enigma intelligence, but it seems likely that this was the case. Perhaps British codebreakers obtained information on her departure and that of U-174 from Werft dockyard codes or from the three-rotor Enigma traffic of the admiral commanding Norway. Whatever the case, on August 1, the Admiralty informed the new British submarine Saracen, which was in workup north of the Shetlands, to be on the lookout for two U-boats that might pass through her area during the next two days. Saracen, commanded by Michael G. R. Lumby, went on full alert.
Late in the afternoon of August 3, while running submerged, the periscope watch of Saracen picked up U-335 at 3,000 yards. Three minutes later, Lumby commenced firing all six bow tubes at seven-second intervals. One or more torpedoes hit and U-335 blew sky-high. Upon surfacing to collect debris for proof of a kill, Lumby found one German body and two survivors. When he attempted to fish them out, one refused to be rescued and deliberately drowned himself, Lumby reported. The other, Rudolf Jahnke, a signalman who was thrown from U-335’s bridge when the torpedo struck, willingly came on board. Saracen reloaded her tubes and remained on alert, hoping to find and kill the other boat, but she had no further luck.
On July 29 and 30 in the mid-Atlantic, the nine surviving boats of group Wolf refueled from the tanker U-461, commanded by the aptly named Wolf Stiebler. It was then discovered that U-90 was missing. At the same time, Walter Schug in U-86 conceded that the bomb damage he incurred crossing the Bay of Biscay had rendered his boat incapable of hard convoy warfare. He was therefore detached from group Wolf and ordered to patrol for single ships in the waters of the western Atlantic. When he eventually returned to France, he reported he had sunk only one 342-ton American sailing vessel, Wawaloam, by gun.
While group Wolf was refueling, on July 29 and 30, a newly sailed Type VII, U-210, commanded by Rudolf Lemcke, age twenty-eight, discovered another westbound convoy. This was Outbound North 115, composed of forty-one empty merchant ships, escorted by the all-Canadian group C-3, comprised of the destroyers Saguenay and Skeena and four corvettes. Acting on Lemcke’s contact reports, Kerneval hurriedly formed a temporary six-boat group—named Pirat—from the stream of nearby boats bound for the Americas along the northern routes. Pending contact by the other boats, Lemcke was prohibited from attacking, an infuriating restriction, softened somewhat by news from Kerneval that his wife had just given birth to twins and that all was well at home.
The Canadian escorts were handicapped by the lack of modern equipment, such as Type 271 centimetric-wavelength radar and Huff Duff. Nonetheless, as the six boats of group Pirat assembled to attack, the Canadians picked up their radio transmissions and the veteran escort commander, D. C. Wallace in Saguenay, responded with exceptionally aggressive maneuvers. As a consequence, not one of the boats of group Pirat could get into position to shoot. Moreover, on the night of July 31, two of the veteran Canadian escorts, the destroyer Skeena, commanded by K. L. Dyer, and the corvette Wetaskiwin, commanded by Guy S. Windeyer, trapped the experienced Type VIIC U-588, commanded by Viktor Vogel, and sank her by depth charges with the loss of all hands. She was the second U-boat after U-90 to fall to Canadian surface escorts in the North Atlantic within a week.
The aggressive maneuvering by the Canadian escorts burned fuel oil at a great rate. Therefore the destroyers Saguenay and Skeena were compelled to leave the convoy and go directly to St. John’s, Newfoundland. To make matters worse, the corvette Wetaskiwinseparated from the convoy, became lost in the fog, and also went directly to St. John’s. These departures temporarily reduced the escort to merely three corvettes, but two other destroyers, the British Witch and the Canadian four-stack Hamilton, and another corvette, Agassiz, put out from Newfoundland to reinforce the group.
Although convoy Outbound North 115 was sailing into the protective fog of the Newfoundland Bank and ever closer to radar-equipped land-based ASW aircraft, Dönitz directed the eight remaining boats of group Wolf to reinforce the six of group Pirat and attack as they completed refueling. The first of the Wolf boats to find the convoy was Erich Topp in U-552. He gave the alarm and shadowed, bringing up boats of both groups. In the confused, fogbound attacks which ensued on the night of August 2-3, Topp claimed sinking two 8,000-ton freighters, but postwar analysis reduced his confirmed score to damage to the 10,600-ton British tanker G. S. Walden, which was salvaged, and the sinking of the 7,200-ton freighter Belgian Soldier. Another Wolf boat, U-607, commanded by Ritterkreuz holder Ernst Mengersen, shared credit for sinking Belgian Soldier. Only one of the Pirat skippers, the veteran Karl Thurmann in U-553, sank a ship: the 9,400-ton British freighter Loch Katrine.
The British destroyer Witch and the five Canadian warships of the reorganized escort group put up a feisty defense. In the fog, the corvette Sackville, commanded by Alan H. Easton, came upon Topp in U-552, opened fire, and nearly rammed the U-boat. Sackville’s shells holed U-552’s main-engine air induction and exhaust pipes and damaged her rear periscope, forcing Topp to abort.* Hans-Joachim Schwantke, the new skipper of the aged U-43, reported that as a result of close and persistent depth charges, both air compressors were broken and two bow torpedo-tube outer doors were jammed half open, and he, too, had to abort. Thurmann in U-553 reported that an escort pursued and depth-charged him for five hours, but he escaped with slight damage. After taking on all the fuel oil Topp in U-552 could spare, Thurmann in U-553 proceeded to the Caribbean, as did four other boats that were temporarily diverted to group Pirat.
The aborts of Topp and Schwantke so reduced the original Wolf group that it was disbanded. The six remaining boats, all of which had refueled and had plenty of torpedoes, were used to cadre a new group.
The results of group Wolf and its temporary offspring, group Pirat, were not impressive. In a full month of operations—early July to early August—the ten boats of Wolf had firmly locked on to only two convoys, both westbound: Outbound North 113 and Outbound North 115. As in the case of the earlier small group, Hecht, only the Ritterkreuz holders (Topp and Mengersen) managed to penetrate the escort screens and carry out effective attacks. These attacks, however, had produced meager returns: three empty freighters sunk for about 20,000 tons, and two empty tankers damaged for about 19,000 tons. One boat of the Wolf group, U-90, had been lost and three, U-43, U-86, and U-552, had incurred heavy battle damage. In the short-lived group Pirat, Karl Thurmann in U-533 had sunk one ship for 9,400 tons, but one boat, Viktor Vogel’s U-588, had been lost.
While Topp in U-552 was crossing the Bay of Biscay on August 10 inbound to Lorient, a Coastal Command aircraft caught and bombed him. Fortunately for the Germans, the damage was slight and Topp reached port on August 13 without further incident. Inasmuch as his total claims had then reached 250,000 tons or more, Topp qualified for the addition of Crossed Swords to his Ritterkreuz,* the second submariner after Otto Kretschmer to earn that high distinction. Upon receiving the award from Hitler in person, Topp left U-552 to command the 27th Flotilla in the Training Command and did not return to combat.
A new group, Steinbrink, composed initially of eight boats (six left over from group Wolf and two newly arrived), formed in the “air gap” southeast of Greenland. On August 5, one of the latter, Gerd Kelbling’s experienced U-593 from France, found and shadowed an eastbound convoy.
This was Slow Convoy 94. Composed of thirty-three heavily laden merchant ships, it was escorted by Canadian group C-1. There were seven warships in the escort group: the (ex-British) Canadian destroyer Assiniboine, and three Canadian and three British corvettes. Although nominally Canadian, the group was commanded by a British officer, A. Ayer, in the British corvette Primrose. None of the escorts had Huff Duff. Only one vessel, the British corvette Nasturtium, had Type 271 centimetric-wavelength radar.
After other boats reported contact on the convoy, Kelbling in U-593 attacked an element of the formation that had separated from the main body. He claimed hits on two freighters, but in fact he had hit only one, the 3,600-ton Dutchman, Spar, which sank. The corvettes Nasturtium and Orillia counterattacked with depth charges, which exploded near Kelbling in U-593 and a new arrival from Germany, Jürgen Quaet-Faslem, age twenty-nine, in U-595. The boats hung on, bringing up others, but none was able to attack.
Later the following afternoon, August 6, the Canadian destroyer Assiniboine, commanded by John H. Stubbs, got a contact on her Type 286 meter-wavelength radar at about 2,000 yards. Moments later lookouts saw a U-boat stopped dead on the surface. Assiniboine fired one round from her 4.7” main battery, set up a salvo of shallow-set depth charges, and went ahead full speed to ram. Her target was the new U-210, commanded by Rudolf Lemcke, who had earlier found Outbound North 113, but had not yet fired a torpedo. Astonishingly, the single round from Assiniboine’s gun hit U-210 in a fuel ballast tank, impairing her ability to dive. Lemcke rang up maximum speed and ran for a patch of fog.
John Stubbs in Assiniboine was not to be denied that day. Tracking U-210 through fog patches by radar, he closed and fired several more rounds from his main battery. Maneuvering wildly to get so close to the destroyer that she could not depress her main guns, Lemcke’s men shot back at point-blank range with bridge guns. The German fire killed one man, wounded thirteen others, and set the destroyer’s bridge on fire. However, three or four 4.7” rounds from Assiniboine hit U-210, one at the bridge. It blew Lemcke to pieces, killed five other men, and smashed the bridge and conning tower.
Although wounded in the chest, U-210’s first watch officer, twenty-two-year-old Günther Göhlich, crew of 1938, assumed command of the wrecked boat. In desperation he fired a torpedo at Assiniboine but missed. Meanwhile, belowdecks, the chief engineer, Heinz Sorber, dived the boat. But it was too late. Assiniboine rammed U-210 twice and dropped shallow-set depth charges, which savaged the boat. When it was clear that the game was lost, Göhlich ordered the crew to scuttle and abandon ship. After opening the vents of one ballast tank, Göhlich and Sorber and thirty-five others clambered topside through the torpedo-loading hatch and jumped into the sea. Following correct procedure, a radio operator threw two Enigma boxes overboard. Thirty-eight minutes after Assiniboine first got radar contact, U-210 upended and sank.
In the meantime, the British corvette Dianthus appeared out of the fog and assisted Assiniboine in fishing the Germans from the sea. Dianthus picked up twenty-seven men, Assiniboine ten. During the search, Assiniboine’s commander realized that his own ship was too badly damaged to continue the voyage to the British Isles, so he took six Germans from Dianthus and turned about for Canada. Keeping the other twenty-one Germans, Dianthus proceeded with the convoy toward the British Isles. Repairs to Assiniboinekept her out of action until January 1943. In due course, Stubbs’s sixteen Germans, including Göhlich and Sorber, were turned over to American naval authorities.
The oft-maligned Canadians had reason to be proud. The U-210 was the fourth confirmed U-boat to be sunk by Canadian air or surface ships within a period of two weeks.
Slow Convoy 94 wallowed onward to the British Isles. Group Steinbrink, reinforced by a half dozen westbound boats, including two Americas-bound Type IXCs, U-174 and U-176, pursued. On the morning of August 8, three new Type VIIs, U-607, U-660, and U-704, closed the formation and each shot three torpedoes. All malfunctioned or missed. In the afternoon of the same day, two other boats, the new Type VII U-379, commanded by Paul-Hugo Kettner, age thirty, and the new Type IXC U-176, commanded by Reiner Dierksen, age thirty-four, boldly submerged ahead of the convoy and attacked by periscope in broad daylight.
The unexpected daylight attacks caused utter chaos. Kettner in U-379 hit and sank two freighters for 8,900 tons, one American, one British. Dierksen in U-176 fired six torpedoes and sank three freighters for 16,700 tons, two British, one Greek. In sheer panic, the crews of three other freighters abandoned ship. Prodded by the escort commander, two crews soon reboarded, but the third, from the 3,700-ton British freighter Radchurch, refused. Dierksen in U-176 found this abandoned ship and sank it as well.
Later that afternoon, a masthead lookout on the British corvette Dianthus, commanded by C. E. Bridgeman, spotted two U-boats about six miles away. Bridgeman immediately fired twelve rounds from his main 4” battery, but none hit and the U-boats dived. Combing the area for several hours, Dianthus finally regained contact with U-379 and fired off eight star shells. Kettner dived instantly, but his evasion was inept and Dianthus blew him back to the surface with five well-aimed depth charges.
When U-379 popped up, Dianthus fixed the boat in her searchlight, dropped five more depth charges, and slewed about to ram, with all guns blazing. Firing snowflakes to illuminate the scene, Dianthus crashed into the forward deck of U-379, rode over the U-boat, and dropped five more shallow-set depth charges. These explosions forced Kettner to scuttle and abandon ship. As Kettner and the crew were leaping into the sea, Bridgeman pumped another seven rounds of 4” shells into the U-379, raked her with machine-gun fire, and rammed her three more times. After midnight on August 9, the U-boat finally upended and sank. Bridgeman brought one of the twenty-one prisoners of U-210 to his bridge to help in fishing out the crew of U-379, but only five survivors were found, all enlisted men. Worried about his own considerable bow damage and fearful of a U-boat attack, Bridgeman soon suspended the search. He tossed over a life raft for any other Germans, but none of them survived.
During the next day, August 9, Western Approaches reinforced the escort of Slow Convoy 94. A B-24 Liberator bomber and a Catalina flew out from Iceland to circle overhead. Two destroyers, the British Broke, equipped with Huff Duff, and the Polish Blyskawica, joined. The skipper of Broke, A.F.C. Layard, who was senior officer present, assumed command of the escort.
That day a dozen U-boats were in close contact with the convoy. Three skip-pers, all on maiden patrols, attacked the formation. Ulrich Thilo, age thirty-nine, in the Type IXC U-174, shot three torpedoes into the center of the formation, but inexplicably, not one hit a ship. Hans Gilardone, age thirty, in the VII U-254, who had sunk a 1,200-ton freighter on his way out from Germany, also fired three torpedoes into the middle of the formation and missed. Odo Loewe, age twenty-seven, in the VII U-256, who missed a “destroyer” with four torpedoes while outbound from Germany, fired three more at a “destroyer” and missed again.
By August 10 more than a dozen U-boats were still trailing Slow Convoy 94. Three skippers in new Type VIIs submerged ahead and attacked the convoy by periscope in broad daylight. The first was Eberhard Bopst, age twenty-eight, in U-597. His torpedoes missed or malfunctioned and he got no hits. The other two were Rudolf Franzius, age thirty-one, in U-438 and Götz Baur, age twenty-five, in U-660. Both skippers simultaneously hit and sank the 4,400-ton Greek freighter Condylis, to share credit. Baur sank two British freighters for 10,000 tons and damaged another, the 6,000-ton Oregon. Coming upon the damaged Oregon, Franzius in U-438 put her under with a finishing shot, to share credit. Confirmed results of these attacks: four freighters for 20,500 tons sunk.
Beginning August 11, Western Approaches saturated the air in the area of Slow Convoy 94 and beefed up the surface escort with the onetime Coast Guard cutter Sennen and four fleet destroyers. The aircraft (Liberators, Catalinas, and a B-17 Flying Fortress) drove off the U-boats and forced Dönitz to cancel the operation. Five skippers reported “major” depth-charge damage from aircraft or surface ships or other defects that forced them to abort: von Roithberg in U-71 (yet again!), Kelbling in U-593, Quaet-Faslem in U-595, Bopst in U-597, and Kessler in U-704. They were joined on the homeward voyage by two boats that had only one remaining torpedo each: Hans Gilardone in U-254 and the Ritterkreuz holder Ernst Mengersen in U-607.
Berlin propagandists bragged that the U-boat attack on Slow Convoy 94 resulted in the sinking of “more than 84,000 tons” of shipping. The confirmed bag, run up by five green skippers, was eleven ships sunk for 53,421 tons. A dozen other skippers got in close and some shot torpedoes, but none sank anything. Two new U-boats, Lemcke’s U-210 and Kettner’s U-379, were sunk by the escorts; another, Pelkner’s U-335, was lost to the enemy en route to join in the battle. The “exchange” rate in this battle was thus an intolerable 3.7 ships sunk for one U-boat.
A new group, Loss, came into being August 12. It was composed of seven boats from group Steinbrink, including the two Type IXCs, U-174 and U-176, which had canceled patrols to the Americas, and three newly sailed boats from Germany. Based on information developed by B-dienst, Dönitz deployed group Loss on a line 500 miles due south of Iceland to intercept convoy Outbound North 120.
As the group was moving into position, one of the boats, the new U-705, commanded by Karl-Horst Horn, age twenty-five, found a convoy. It was not the one expected but rather the eastbound Slow Convoy 95. It was guarded by the one remaining American MOEF escort group in the North Atlantic, A-3, commanded by Paul Heineman. It consisted of the big Treasury-class Coast Guard cutter Spencer, the four-stack American destroyer Schenck, and four Canadian and two British corvettes.
The surprise appearance of Slow Convoy 95 confused the Germans. Nonetheless, Kerneval added three nearby new boats to group Loss, bringing the total to thirteen. But only three got into a favorable position in time to shoot. Horn in U-705 sank the 3,300-ton American freighter Balladier. Herbert-Viktor Schütze, age twenty-five, in the new U-605 shot at a freighter but missed. Odo Loewe in U-256 also missed a freighter. An escort caught and shelled U-256, but she got away. Still confused, Kerneval canceled the operations against the heavily laden east-bound ships of Slow Convoy 95 in favor of a renewed search for the empty westbound ships of Outbound North 120.
Three veteran boats sailed from France to join group Loss. These were the U-135, commanded by Friedrich-Hermann Praetorius; the U-373, commanded by Paul-Karl Loeser; and the U-578, commanded by Ernst-August Rehwinkel, the latter famous for having sunk the American destroyer Jacob Jones off New Jersey. Coastal Command aircraft caught and attacked all three boats in the Bay of Biscay on August 10 and 11. The plane that attacked U-135 killed two men by machine-gun fire. A Sunderland bombed Loeser in U-373, but he dived deep and escaped. The attack on Rehwinkel in U-578, carried out by a Wellington of the Czech-manned Squadron 311, piloted by Josef Nýlvt, was fatal. The U-578 went down with the loss of all hands. Nýlvt was killed in action a month later.
Believing the Allies were routing convoys farther north, Dönitz shifted group Loss in that direction. Praetorius in U-135 was not informed of the movement, and as a result, when he took up the southernmost position on the line, he was about 100 miles out of position. By happenstance, this error placed Praetorius directly in the path of convoy Outbound North (Slow) 122, which, exactly contrary to the German guesstimates, had been routed farther south than usual.
Due to an encoding error, Kerneval could not read Praetorius’s initial contact report. Three hours later, when he sent another, correctly encoded, Dönitz was puzzled and delayed any deployment for several more hours until the picture clarified. After receiving Praetorius’s third contact report, Dönitz finally conceded that it must be Outbound North (Slow) 122, routed to a southerly course rather than a northerly one. He radioed all boats to converge on U-135 and to attack.
Convoy Outbound North (Slow) 122 was escorted by group B-6, nominally British. Commanded by J. V. Waterhouse, it was comprised of the British destroyer Viscount, equipped with Type 271 centimetric radar, Huff Duff, and a Hedgehog, and four corvettes manned by Norwegian crews and fitted with Type 271 radar. A rescue ship, Stockport, also equipped with Huff Duff, brought up the rear.
By August 24, nine U-boats of group Loss had made contact with the convoy, but it sailed into fog cover and only three boats could attack: Reiner Dierksen in the Type IXC U-176, Rudolf Franzius in U-438, and Herbert-Viktor Schütze in U-605. Dierksen and Franzius hit and sank the same ship, the 7,500-ton British freighter Empire Breeze, to share credit. In addition, Franzius sank the 1,600-ton Norwegian freighter Trolla. Schütze sank two other British freighters for 8,200 tons. Total: four ships sunk for 17,300 tons.
Making good use of radar and Huff Duff in the fog, Viscount and the other es corts skillfully thwarted other attacks and counterattacked. Viscount carried out a Hedgehog attack—perhaps the first of the war—that resulted in a “tremendous rippling explosion” believed to be a kill, but it could not be confirmed. Six U-boats reported serious damage:
• Schütze in U-605: one escort holed his conning tower so badly he was forced to abort.
• Franzius in U-438: one escort drove him under and pounded him with depth charges, inflicting so much damage that he was forced to abort as well.
• Thilo in the new Type IXC U-174: an escort hit him with gunfire “at close range,” drove him under, and chased him for five hours with “well placed” depth charges, inflicting “considerable” damage.
• Horn in U-705: an escort hit him with gunfire, inflicting “several casualties,” forcing him to abort.
• Loewe in U-256: incurred such heavy damage from depth charges that he, too, was forced to abort.
• Praetorius in U-135: “heavy damage” from depth charges.
While inbound to France in the Bay of Biscay on August 31, Odo Loewe in the damaged U-256 was attacked and further damaged by two Coastal Command Whitleys piloted by Edward B. Brooks and E. O. Tandy. Fortunately for Loewe and his men, Rudolf Franzius in the damaged U-438 was close by. Franzius radioed Kerneval for assistance and took aboard thirty men from U-256, leaving only a salvage crew. Kerneval rushed air cover and motor torpedo boats to the scene and the latter towed the wrecked U-256into Lorient. The boat was found to be so badly damaged that she was withdrawn from combatant status, and Loewe and most of his crew were transferred to another boat.
Two Whitleys of Bomber Command Squadron 77, on loan to Coastal Command, found and attacked U-boats in the Bay of Biscay on September 3. One Whitley, piloted by A. A. Maclnnes, hit Karl-Horst Horn in U-705, who was aborting with damage and wounded. Maclnnes sank U-705 by depth charges with the loss of all hands. The other Whitley, piloted by T. S. Lea, hit Götz Baur in U-660, but he escaped with slight damage. The Admiralty gave wartime credit to Lea for sinking U-705, but upon later investigation credited Maclnnes.
In view of the growing number of Type VII U-boats operating against convoys, Kerneval welcomed the sailing from Kiel on August 8 of the sixth of the Type XIV U-tankers, the U-464, commanded by Otto Harms, age thirty-three. However, en route to the Atlantic, the boat developed an oil trace and Harms had to put into Bergen for repairs, delaying his final departure to August 16.
Four days later the U-464 reached a position about 160 miles east-southeast of Iceland. Although those waters were teeming with Allied warships plying between Iceland and the British Isles and with aircraft on local ASW patrol or convoy escort,* Harms was dangerously lolling on the surface at dawn when an American Catalina of the Navy’s Patrol Squadron 73, which was assigned to provide air cover for a small convoy, appeared out of the low and dirty clouds overhead.*
Inasmuch as the U-tanker was merely four miles from the convoy and visibility was very poor, the pilot, Robert B. Hopgood, thought at first that it might be one of the convoy’s destroyers. Accordingly, he flew low and shot off a recognition flare to establish his identity and to prevent friendly fire. Caught flat-footed in the clumsy, painfully slow-diving U-464, Harms could do nothing but bluff. Hoping to be taken for an Icelandic fishing vessel or Allied warship, he responded to the recognition flare by releasing one himself. It burned yellow-white, and bore not the slightest resemblance to the proper signal. Attempting to carry the deception a step further, Harms directed the men on his bridge to wave at the plane in a friendly fashion.
Hopgood realized by then that the vessel beneath him was a U-boat. With great presence of mind he attacked instantly, dropping five of his six Mark XVII depth charges, set for twenty-five feet. Two missiles straddled the conning tower and the explosions appeared to lift the boat clear out of the water. Per the ASW doctrine then in force, Hopgood notified all authorities concerned by radio. He then climbed, circled, and came in for a strafing run, raking the boat with 30- and 50- caliber machine-gun fire. The U-464 responded with superior and “accurate” fire from her two 37mm flak guns, mounted on platforms fore and aft of the bridge, and from a 20mm gun on the bridge. This fire held the Catalina at a distance and, as a result, Hopgood lost sight of the U-464.
But the blast of the depth charges had badly damaged U-464. Unable to dive or to escape on the surface, Harms concluded that other Allied aircraft and ships would arrive soon and that he had no choice but to scuttle. Fortunately for the Germans, an Icelandic fishing trawler, Skaftfellingor, appeared out of the fog and drizzle. Harms maneuvered U-464 close to the trawler and demanded rescue. While the German gunners held the trawler in their sights, part of the U-464 crew jumped into the sea, climbed on the Icelander, and “captured” it. After that, Harms raised a German flag on U-464 and scuttled. Hé and the rest of the Germans got on board the trawler, perhaps hopeful of escaping in the foul weather to Norway.
In the meantime, the Catalina pilot Hopgood found the heavily escorted convoy to which he had been assigned. By signal lamp he informed the British escort commander of his attack and requested help. The British were skeptical and reluctant to rob the convoy of protection, but finally released two of the four destroyers, the ex-American four-stacks Castleton and Newark. Hopgood guided the destroyers back to the site of his attack, arriving in time to see the Germans shift to the trawler and scuttle U-464. Castletonfired one warning round over the trawler, then closed to capture the Germans, who offered no resistance. Castleton took aboard fifty-two Germans, including one surgeon who, in accordance with international law, was treated as a noncombatant. Harms reported that in the Catalina’s initial attack, two of his men were hurled overboard and not recovered. The U.S. Navy awarded Hopgood a Navy Cross.
Earlier German U-boat prisoners had disclosed to British interrogators that U-tankers were operating in the Atlantic, but the British had dismissed these revelations as fanciful. Prisoners from Kettner’s U-379, who were recovered on August 8, and those from U-464, recovered August 20, talked freely of U-tanker operations. Even so, the British continued to doubt. “There may be some truth in the story,” the British Anti-Submarine Report for August 1942 smugly proclaimed, “but at present, it must be treated with reserve.”
By the closing days of August, there were enough U-boats in the North Atlantic to form two groups. These were the old Loss and the new Vorwärts, created from a stillborn group, Stier, and other boats sailing in August. Some boats of Loss refueled from the U-tanker U-462, commanded by Bruno Vowe, others from the Type IXC U-176, whose cruise to the Americas had been canceled.
Independently of these groups, Klaus Rudloff, age twenty-six, in the new U-609 patrolled during August off Reykjavik. He saw numerous warships (and twice shot at “destroyers”) but sank nothing. Late in August, Kerneval shifted the boat southerly into the convoy lanes to join group Vorwärts. While complying with these orders on August 31, Rudloff came upon the eastbound Slow Convoy 97. In response to his alert, Kerneval directed group Vorwärts, composed of more than a dozen boats—all green—to attack.
British operations research scientists had concluded from mathematical models that if North Atlantic convoys were nearly doubled in size, from about thirty to sixty ships, it would about halve the number of convoys available for U-boats to attack and thereby lessen ship losses by about 56 percent. Authorities at Western Approaches greeted this recommendation with no little skepticism, but nonetheless agreed to try it out and sailed Slow Convoy 97 with fifty-eight ships. It was escorted by Canadian group C-2, composed of two British four-stack destroyers, Broadway and Burnham, and four Canadian corvettes. The destroyers were fitted with Type 271 radar; a rescue ship carried Huff Duff.
Nine U-boats made contact with Slow Convoy 97. Four boats attacked, Klaus Rudloff in U-609 twice. In the first, he sank two freighters for 10,300 tons. In the second, he shot his last two torpedoes, singly, claiming one “possible” hit, but it could not be confirmed. Heinz Walkerling, age twenty-seven, in the new U-91 fired four torpedoes into the formation but all missed. Klaus Harney, age twenty-five, in the new U-756, merely seventeen days out from Kiel, and Horst Höltring, age twenty-nine, in the new U-604, shot but also missed.
Beginning September 1, long-range American and British aircraft (Catalinas and Sunderlands) gave Slow Convoy 97 close cover. Walkerling in U-91 reported that the aircraft forced him under “once or twice every hour.” Therefore it was impossible to haul around the convoy to get into a favorable shooting position ahead. Hans-Ferdinand Massmann, age twenty-five, in the new U-409, fourteen days out from Kiel, reported that aircraft bombs had smashed both of his periscopes, forcing him to abort. In these attacks the British airmen claimed sinking at least one U-boat. Later, when it was learned that Klaus Harney’s U-756 was lost at this time, September 3, with all hands, the Admiralty credited “British aircraft” with the kill. Upon further study after the war, Admiralty historians withdrew the credit and gave it to the Canadian corvette Morden. The U-756 was the fifth U-boat to be sunk by Canadian air and surface forces within a period of six weeks, a notable achievement but one that was not realized at the time.
The prediction by Dönitz on July 27 that the U-boat war was to turn “hard” was timely and correct. In the six-week period, July 24 to September 3, Allied air and surface escorts and submarines in the North Atlantic area sank nine U-boats (eight Type VIIs and one Type XIV U-tanker) and wrecked another VII, U-256, almost beyond repair. About 400 German submariners had been lost in the sinkings, ninety-four of them captured. Thirteen boats had been forced to abort with battle damage and casualties.
A close analysis of the renewed anticonvoy operations in the North Atlantic by the forty-eight attack U-boats sailing in July and August is revealing. Altogether thirty-eight of these patrols (80 percent) were carried out by new boats or new skippers. All the boats sank forty-four ships, an average of .91 ships per boat per patrol. Twenty-three boats, or nearly half of all those putting out, sank no ships.
* Includes two veteran boats with new skippers.
† Includes one veteran boat with a new skipper.
The most striking fact in this analysis is that nearly half of all the U-boats sank no ships at all and as a result, the average of the VII sinkings fell below one ship per boat per patrol. In part this was attributable to the very high percentage of hurriedly trained and inexperienced crews and skippers, but other factors contributed. Most have been identified earlier. All bear repeating:
• The Type VII U-boat that made up the preponderance of the Atlantic force was less than suitable for anticonvoy operations in the distant Greenland “air gap” owing to its limited range and torpedo capacity. It required supporting U-tankers to effectively carry on such operations. Although the U-tanker force had increased in strength, there were still not enough U-tankers† and, besides that, the need to refuel the VIIs resulted in a weak link in the operational chain.
• Two-hundred-mile “patrol lines” of twelve or more boats were useful for detecting some convoys but were disadvantageous in massing for a group attack. The boats most distant from the convoy were often unable to close up in time, especially in heavy seas or where Allied aircraft made surface travel hazardous. Therefore most successful “pack attacks” were still carried out on the first night by the few boats closest to the convoy.
• All anticonvoy operations were dependent on accurate navigation. The boat first making contact had to know where it was in order to notify U-boat Control and to bring up the other boats. They too had to know where they were in order to set a correct course to the gathering point. Lacking any kind of electronic aids, all the boats had to navigate by dead reckoning and by sextant readings on the stars, the sun, and the planets. Owing to weather conditions, sextant readings were often unobtainable for days at a time.
• If the contact keeper or shadower attempted to bring up the other boats of the patrol line by radio-beacon signals, as was usually the case, shore stations and/or convoy escorts usually detected the initial contact report and homing beacon by DF and/or Huff Duff. Thereupon one or more escorts of the convoy could “run down the bearing” and, assisted by radar, find and sink the shadower or drive it under with gunfire and depth charges while the convoy made a radical turn to port or starboard to elude the other U-boats attempting to gather for a mass attack.
• U-boats had no radar of any kind, only the Metox radar detector, which was useful in crossing the Bay of Biscay but too clumsy to use in a convoy battle. Hence at night or in the foggy weather often encountered in the Greenland “air gap” and on the Newfoundland Bank, radar-equipped aircraft and surface ships held a great advantage over U-boats in that they could “see” electronically in the dark or fog and therefore could pounce on a surfaced U-boat suddenly and with complete surprise.
• U-boat Control tightly directed most pack attacks by long-distance radio transmissions. Owing to atmospheric disturbances, especially in the Greenland “air gap” area, often these messages were not received or were received in garbled and undecipherable condition. In such cases, the U-boats involved in the operations had to wait for or ask for retransmissions, incurring considerable delays or the risk of being DFed.
Thus a sustained U-boat “pack attack,” so promising in theory, in actuality was still extremely difficult to mount. This was especially true if the U-boats were green and the escorting forces were experienced. Allied surface ships and aircraft, “signals intelligence” (codebreaking, traffic analysis, etc.), and electronic devices (radar, Huff Duff) about which the Germans were largely unaware, had already drastically reduced the U-boat threat to convoys.
Histories of the Battle of the Atlantic which imply that as more and more U-boats joined the Atlantic force in the summer and fall of 1942, the threat to North Atlantic convoys increased to a precarious level, are not correct. As will be seen, the number of U-boats that failed to sink any ships at all per patrol rose steadily and, for the Germans, ominously, from half of those sailing to the North Atlantic in July and August 1942, to well beyond that figure in the spring of 1943. Hundreds of convoys on the North Atlantic run—thousands and thousands of ships—crossed the North Atlantic in 1942 unharmed.