by Paul Kennedy
What followed was two nights and one day of extraordinary fighting at sea. Attack after attack was launched by the U-boats at the now weakened escort screen; beset by so many predators, the destroyers, frigates, and corvettes could do nothing but race toward a U-boat, drive it away, drop some depth charges, then race back to the convoy. Four ships in the convoy and one straggler were sunk that night. Twenty-six merchantmen were left together, and as dawn came they were once again in an aerial gap between Greenland and Newfoundland. Another four merchantmen were sunk during the day. The second and even larger line of U-boats was waiting its turn. The only bright spot was provided by the little corvette HMS Pink and its intrepid lieutenant, Robert Atkinson, who had just returned to the service after eight months of battling severe seasickness. Detached by the escort commander to pick up stragglers, Atkinson soon found himself with a mini-convoy all his own, a mixed bag of three British, one Norwegian, one Greek, and one American merchantmen.22 Short on fuel, Pink steamed on only one boiler, shut down one dynamo, and rationed water—until Atkinson’s group was repeatedly attacked by an equally determined U 192 under Oberleutnant Happe and the corvette had to go to full power again. For hours the two vessels fought, losing and regaining contact on numerous occasions, with Atkinson almost running out of depth charges and his new Hedgehog grenades simply not working. After Pink’s last depth-charge volley, Atkinson decided that his ship must rejoin the straggler convoy, now at least 10 miles ahead. As the corvette turned, its crew heard a vast explosion in the water behind: U 192 had blown up. It was Happe’s first Atlantic command, and his last.
As HMS Pink rejoined its mini-convoy, the American merchantman West Madaket was fatally hit by a torpedo and started to break up. After driving away any possible further U-boats, the corvette’s next task was to pick up survivors—she now had sixty-one extra people on board. By this time Western Approaches Command had actually recognized Atkinson’s group as a separate subconvoy and reinforced it with HMS Sennen, a valuable former American Coast Guard cutter that drove off further U-boat probings until the Allied ships were rescued by dense fog. On May 9 Pink finally escorted her charges into St. John’s Harbor, Newfoundland, and Atkinson sat down to write his report.
The greater bulk of Convoy ONS 5 spent the night of May 5–6 in an epic battle, with the U-boats attacking no fewer than twenty-four times and the escorts giving no ground. HMS Loosestrife found itself fending off submarine probes throughout the night along the convoy’s starboard flank. At two-thirty in the morning it encountered U 638, which from only 500 yards away shot off torpedoes down the warship’s side before it submerged. As the Loosestrife raced across the submarine’s wake, it dropped a salvo of ten depth charges. The explosion was so near and so violent that the men in the corvette’s engine room thought their own stern had been blown off. But it hadn’t. The greatest cheers came from the seventy-one merchant sailors on board the Loosestrife who had just been rescued when their own vessels went down. As Ronald Seth slyly notes, “For the victims of the U-boats, the hunting and killing of one of the enemy had a special relish … and if moral encouragement played any part in the sinking of the U-638, then the merchant seamen aboard could claim to have had a hand in it.”23
A day and a half earlier, Horton had played his next trump card and ordered the 1st Escort Group to join the convoy. Its lead warship, the sloop HMS Pelican, soon pounced on U 438, but even before then the destroyer HMS Oribi, one of the last of the 3rd Escort Group, rammed and sank U 531. At virtually the same time the destroyer HMS Vidette attacked U 125 with her Hedgehog; this time the forward-launched grenades worked perfectly and the submarine was lost. This was deeply satisfying to the escort’s crew; like the Pink and the Loosestrife, the Vidette had been in close escort of the convoy from one side of the Atlantic to the other, suffering all the strains, storms, and hazards—and, now, successes. After that dramatic night, the next days saw the sky filled with patrolling aircraft, the local Canadian escorts coming in, the U-boats pulling back, and the damaged and exhausted warships sent ahead to port. The Oribi limped into St. John’s with its nose battered by the ramming action; the indomitable Pink had steamed in with a mere 18 tons of fuel in her tanks. They had won this convoy battle.
In the final tally, thirty-nine U-boats had managed to find and attack ONS 5, and together they sank twelve merchantmen. But the Allies had sunk seven U-boats, two more were lost due to a collision in the fog, and another five were badly damaged in action. What was more, the submarines were not just being sunk in close-battle encounters (the U 638 had little chance when it found itself only 500 yards from the charging HMS Loosestrife) but being picked off on the surface by American, British, and Canadian air patrols as much as 50 miles from the convoy. This bruising shambles of a contest marked the turn of the tide, although the grinding nature of the convoy war made it difficult to see that at the time.
In any case, if Doenitz was disturbed by these losses, he wasn’t showing it. By the middle of May, reinforced by a stream of new boats, his wolf packs had assembled in the North Atlantic again. Unfortunately for the Germans, they were pushed aside by the ranks of escorting warships and aircraft attending Convoy SC 129. Then, renewing their attacks, they sought to destroy Convoy SC 130, but their opponents were far too powerful. The convoy (thirty-seven merchantmen, with eight close escorts and a nearby support group) left Halifax for the Clyde under the command of Peter Gretton, who was furious at himself for having had to pull out to refuel during the height of the ONS 5 battles. It will be noted that among the escorts was not only his own destroyer, HMS Duncan, but also the cutter Sennen, which had come to the support of the Pink’s mini-convoy, the destroyer Vidette, and the corvettes Sunflower, Snowflake, Pink, and Loosestrife—the north Atlantic’s equivalent of the Magnificent Seven.24 And by now there was continuous daytime aerial support.
Thus, almost any of the thirty-three U-boats that surfaced was swiftly attacked by Liberator and Hudson bombers, which dispatched three submarines to the bottom, including the U 954—among its crew members was Doenitz’s own son, Peter. HMS Duncan helped to destroy a fourth attacker, and Sennen and HMS Jed the fifth. Amazingly, not a single merchantman was sunk; their crews could hear distant noises and observe great explosions on the horizon, but that was the closest the U-boats got. Despite this terrible blow, Doenitz urged his wolf packs to regroup in time for the next big convoy from Halifax, HX 239, but his instructions included the following amazing sentence, swiftly translated at Bletchley Park, which had now regained its capacity to break the Shark codes: “If there is anyone who thinks that combating convoys is no longer possible, he is a weakling and no true U-boat captain.”25
It was around this time that Horton at Western Approaches Command and senior staff at the Admiralty itself began to wonder if the German U-boat crews were starting to lose their nerve and resolution. Perhaps so (it will be discussed shortly), but one is bound to ask what even a determined submarine captain could do by this stage of the fight. For, in addition to the more distant Coastal Command aerial patrols, Convoy HX 239 was accompanied all the way by two of the new escort carriers, USS Bogue and HMS Archer, which sank two out of the three U-boats that perished. The convoy arrived in the United Kingdom on May 25, the same date as the slow convoy SC 130, which had enjoyed aerial protection both day and night. The very long-range aircraft had made twenty-eight sightings of U-boats, attacked ten of them, and sunk two. The merchantmen were unscathed. It was an extraordinary reversal of fortunes since HX 229 and SC 122.
At the end of May 1943, Doenitz, ever the sober realist, assessed the results over the past month—a catastrophic total of forty-one U-boats had been lost during those four weeks—and concluded that the North Atlantic had become too hostile an environment for his submariners. The boats would therefore be relocated to the U.S.-Gibraltar routes and farther afield, off the Brazilian and West African coasts or in the Caribbean. As they slipped in and out of their French bases, they would tightly hug the coast of northern Spa
in and thus avoid the western approaches. The grand admiral was certainly not beaten, but he needed time to think, and time to get newer U-boats, with better equipment, into the hands of his captains. While he did not know quite how it had been done, he could see that Allied forces had made immense leaps forward both in the art of detection and in their capacity for destruction.
What Caused This Change of Fortunes?
Another twelve months would pass, almost exactly, before many of the same Allied aircraft squadrons and escort vessels would be patrolling off the beaches of Normandy, so there was still a way to go. But this is as good a place as any to begin a more detailed analysis of the steady Allied ascendancy in the Atlantic. The first and probably the greatest factor has to be aircraft. The Second World War was the first in the entire history of human conflict in which sea power was decisively affected by airpower. Without the latter, one could not reign supreme in the former.
The best testimony to this fact comes from Doenitz. While he was personally a devoted, unpleasant Nazi, the daily War Book notes from his office were remarkably candid and soberly analytical, whichever way the Battle of the Atlantic was going. His confidential reports to Hitler about the increasing difficulties the German submarines faced were blunt and honest. Thus, despite his desperate message to his U-boat commanders (mentioned above), he was already writing a dispassionate assessment of the reversal of fortunes, just as convoys HX 239 and SC 130 were entering home waters. In his entry of May 24, 1943, he noted that “the enemy Air Force therefore played a decisive part.… This can be attributed to the increased use of land-based aircraft and aircraft carriers combined with the advantage of radar location.”26 And, years after the war, Doenitz wrote in his memoirs that the chief problem had been that “Germany was waging war at sea without an air arm.”27 That was like boxing with only one fist.
The growth of Allied airpower over the Atlantic took two forms. The first was the advent of VLR aircraft operating from shore-based stations, chiefly the extraordinarily robust American-built B-24 Liberator bombers, but also B-17 Flying Fortresses and the elegant Catalina flying boats, and the tough British-built Wellingtons and Sunderlands. But it was the long-range Liberators that first made the difference. The second was the appearance of purpose-built escort carriers, modest in speed and striking power compared with the Essex- and Illustrious-class fleet carriers (see chapter 5) but extremely suitable for accompanying an Atlantic convoy: their aircraft could patrol the seas for miles around and, like the VLR bombers, carried a whole armory of weapons specially designed to destroy U-boats. Rearmed and refueled on the carriers overnight, they would be ready at the crack of dawn to fly off and suppress, possibly sink, the enemy submarines. As their name implies, these carriers escorted the convoys from Halifax to Liverpool.
The whole phenomenon of “airpower at sea” became so ubiquitous during the Second World War that it can easily be taken for granted, but it is one of the most important and novel aspects of the entire conflict. Doenitz must have known it from the beginning, and it is hard not to feel some sympathy for the hand he had been dealt when he became commander in chief of the German navy at the beginning of 1943: he possessed a few vastly expensive, top-heavy surface warships (but no aircraft carriers), all badly constrained by geography, and a U-boat force (lacking much assistance from the Luftwaffe until too late) that had not only to contest the enemy’s warships but also to handle aircraft that came in fast and deadly.
It is impossible to overstress what this meant for the North Atlantic struggle. Doenitz’s submarine crews found themselves confronted by a whole variety of Allied countermeasures as the spring of 1943 gave way to the summer and autumn; the enemy possessed vastly improved systems of detection and destruction against which even the most modern of the U-boats had less and less chance of success. Above it all, though, there was the factor of continuous air cover for the convoys, and the increasing chance of a U-boat being attacked even as it was in transit, on the surface, perhaps hundreds of miles from a convoy. Aircraft always had the advantage of speed and suddenness over vessels on the surface of the sea. Now they had supplemented this with the newer weapons’ accuracy and lethality. Above all, they now had added range. By mid-1943 a VLR Liberator could be assisting a mid-Atlantic convoy 1,200 miles from its home air base, a phenomenal improvement. Even much earlier, in late May 1941, the German battleship Bismarck was spotted heading for Brest by a Coastal Command Catalina based in Iceland, a thousand miles to the north. The Bismarck’s crippling by torpedo aircraft and sinking four days later confirmed Doenitz’s prejudices against heavy surface ships, but the larger lesson of 1941 was this: without airpower, control of the seas was precarious, indeed impossible, even for submarines.e
No senior commander appears to have realized this before the Second World War began. Both the British and German navies were shortchanged by the existence of independent air services that had designed themselves for essentially land-bound purposes: the Luftwaffe in its focus upon tactical air support for the army, medium-range bombing, and (increasingly) the aerial defense of the Third Reich; and the RAF, which was dominated by Bomber Command’s obsession with destroying Germany’s industrial base and sapping the enemy’s public morale, such that only after 1935 did Fighter Command begin to gain more resources for short-range defense of the homeland. The Third Reich’s allocation of aircraft resources was at least understandable, if one assumed (as the German generals and admirals did) that Hitler’s conquests would be on land and that the Fuehrer’s diplomacy would keep the British Empire neutral. The Royal Air Force’s preferences were disastrous for an island nation so dependent for its survival upon long-range oceanic commerce. In 1939, not only was the Fleet Air Arm limited in that it could not specify aircraft suitable for carriers, as the American and Japanese navies could, but RAF Coastal Command—charged to patrol the maritime routes from land bases—was pretty much a Cinderella service compared with the aerial resources being lavished elsewhere.
By contrast, at the middle level, at least on the British side, there was extraordinary initiative as the importance of airpower at sea slowly grew. The brilliant and aggressive Peter Gretton writes in his memoirs about Coastal Command officers attending naval exercises, even a full ocean passage from the Clyde to Newfoundland, and of Royal Navy captains being taken aloft—he claims to have flown in every patrol aircraft type available between 1940 and 1943. But how much did this valuable experience count for if the aircraft squadrons were not there to be deployed? To Air Marshal Harris, appointed to be C in C of Bomber Command in June 1942 with the specific task of increasing the aerial campaign against German industry, diverting his precious long-range bomber squadrons to Coastal Command (i.e., to the Battle of the Atlantic) was, as he put it many times, “picking at the fringes of enemy power … looking for needles in a haystack.”28 Only immense pressures from the Chiefs of Staff compelled some reallocation; in that respect, General George Marshall and even King were a lot more appreciative than Harris of the dire need to get VLR aircraft into the Atlantic air gap by spring 1943. Doenitz had no such luck, at least not until the Fuehrer ordered additional Luftwaffe support for the Bay of Biscay battles later that year.
Closing the air gap did not happen because some great person decreed it. There was the team of chiefly Canadian air engineers who in early 1943 pulled one bomb bay from a B-24 Liberator, replaced it with extra fuel tanks, and at last created an aircraft that could reach the transatlantic gap. There were the scientists who designed the much more effective fuses for Allied depth charges, so they exploded more predictably. There was the combination of U.S. scientists and armaments manufacturers who produced the air-launched acoustic homing torpedo—nicknamed “Fido”—specifically to search for and destroy submerged enemy submarines.29 There were the groups behind the increasing effectiveness of the HF-DF detectors. There were the designers of the ungainly but wonderful Bogue-class escort carriers, and the management teams at the Tacoma yards that accelerated their launchings at a
critical time. Finally, there were the staffs of the formidable training schools in Scotland, Northern Ireland, and Newfoundland, who taught thousands of raw, civilian novices how to become professional aircrews and assume such grave responsibilities in the midst of a ferocious Atlantic battle.
In the early stages of the war, it was a rare event for a land-based aircraft to sink a U-boat, and there were no escort carriers at hand. From 1943 onward, aerial sinkings of German and Italian submarines rose spectacularly and steadily overtook those credited to Allied warships. Between June and August 1943, when the U-boats abandoned the North Atlantic and fanned out to prowl the seas off Zanzibar and Montevideo, they were followed by the Liberators and Catalinas. Seventy-nine submarines were sunk by hostile action in distant waters in late 1943, fifty-eight of them by Allied aircraft. Even in the middle of the Indian Ocean, there was no escape. During 1943 as a whole, 199 U-boats were sunk altogether, 140 of them by Allied aircraft, a proportion that would continue for much of the rest of the war.30