U-boat operations in the North Atlantic were interrupted on May 22 by the most dramatic event in the naval war to that time: the Atlantic sortie of the super battleship Bismarck.
Accompanied by the new heavy cruiser Prinz Eugen, Bismarck sailed from Kiel in the early hours of May 19. Bletchley Park could not read naval Enigma on a current basis in May; thus the Admiralty had no advance warning from that source. But the British naval attache in Stockholm learned of the sortie on the night of May 20 and alerted the Admiralty. The next day, British reconnaissance planes spotted the two ships near Bergen. Bletchley Park broke an old (April) Enigma message which stated that Bismarckhad taken on board “five prize crews” and “appropriate charts,” which led the Admiralty to believe, correctly, that Bismarck and Prinz Eugen were embarked on a convoy-raiding sortie in the North Atlantic. When he got the news, Winston Churchill gave a simple—but legendary—order: “Sink the Bismarck!” All available capital ships of the Home Fleet and Force H from Gibraltar put to sea.
Bismarck and Prinz Eugen, equipped with primitive radar, entered fog-shrouded Denmark Strait on May 23, hugging the ice pack off Greenland. Two 10,000-ton heavy cruisers, Suffolk and Norfolk, also equipped with primitive radar, were patrolling the passage. Suffolk, which had better radar than Bismarck, found the Germans late that evening and brought up Norfolk. Bismarck detected Norfolk on radar and fired her first salvos of the war. She got no hits; moreover, the shock of her 15” guns damaged her radar. As a consequence, Prinz Eugen moved into the van. Tracking by radar, Suffolk and Norfolk hung on tenaciously.
In response to the alert, the new commander of the Home Fleet, Admiral John Tovey, sent the big (42,000-ton) battle cruiser Hood and the new battleship Prince of Wales, with destroyer screens, to intercept the German ships in the south end of the Denmark Strait. The four converging British ships significantly outgunned the German ships. Hood, like Bismarck, had eight 15” guns; Prince of Wales had ten 14” guns. Suffolk and Norfolk, like Prinz Eugen, each had eight 8” guns. But Hood was ancient and thinly armored, and Prince of Wales was still in workup and some of her guns were not yet firing properly. Suffolk and Norfolk, also ancient, were less well-armored than Prinz Eugen.
In the early morning hours of May 24, the opposing naval forces met. The British made the mistake of opening the attack on a slanting course, which prevented them from bringing all guns to bear simultaneously, and which offered the Germans a better target. Mistaking Prinz Eugen for Bismarck, Hood opened fire on the former at a range of fourteen miles. Bismarck and Prinz Eugen responded immediately with deadly accurate fire. Taking a hit in her magazines, Hood blew up and sank within minutes. The British destroyer Electra could find only three of her 1,419-man crew. Badly damaged by two hits and bedeviled with malfunctioning guns, Prince of Wales disengaged and retired behind a smoke screen. But she had got two or three 14” hits in Bismarck’s forward fuel tanks and a fuel-transfer station, which deprived Bismarck of a crucial thousand tons of fuel oil.
In view of the damage to Bismarck, the German commander, Admiral Günther Lutjens, changed plans. The Prinz Eugen was to separate from Bismarck and raid British shipping alone. Bismarck was to go directly to St. Nazaire for repairs. Before the new plan could be executed, however, Lutjens had first to shake his shadowers, Suffolk, Norfolk, and the damaged Prince of Wales, and the destroyers. He swung Bismarck at the shadowers—as if to attack—and during the resulting confusion, Prinz Eugen slipped away, southbound into the vast Atlantic.*
When Dönitz learned that Bismarck had been hit, he volunteered the entire Atlantic U-boat arm to assist. Lutjens hastened to accept the offer and, as a first step, he requested that Dönitz set a submarine trap in grid square AJ-68, 360 miles due south of Greenland. The plan was that Lutjens would “lure” his shadowers into the square on the morning of May 25 so that the U-boats could attack them, causing sufficient diversion for Bismarck to elude them.
On the afternoon of May 24, Dönitz directed five boats to form the trap. Three of the boats were commanded by Ritterkreuz holders: Lüth in the old Type IX U-43, Endrass in the old Type VIIB U-47, and Kuppisch in the Type VIIC U-94, who had only a few torpedoes. The other two boats, fresh from Germany on maiden patrols, had not fired any torpedoes: the first Type IXC† to reach the Atlantic, U-66, commanded by Richard Zapp, age thirty-seven, and the VIIC U-557, commanded by Ottokar Paulshen, age twenty-five. Kleinschmidt’s IXB U-111 was to join the trap after refueling from one of Bismarck’s supply ships, Belchen. Two other boats, Helmut Rosenbaum’s U-73, fresh from Lorient, and Claus Korth’s U-93, took stations slightly to the east of the trap.
Dönitz set a second submarine trap in the Bay of Biscay, 420 miles due west of Lorient. It was comprised initially of four Type VII boats: Herbert Schultze’s U-48, outbound from Lorient, and three inbound boats. One was Udo Heilmann in U-97, who had sunk three ships for 17,852 tons, including the 6,466-ton tanker Sangro, an ex-Italian prize. The others were Robert Gysae’s U-98, and Herbert Wohlfarth’s U-556, who had no torpedoes; they were to serve as “lookouts” for the other boats. Two other boats in Lorient which were nearly ready for patrols, Klaus Scholtz’s U-108 and Erich Topp’s U-552, were alerted to sail on the night of May 25 to reinforce this trap, if necessary. Another boat, Kentrat’s U-74, inbound with severe depth-charge damage, voluntarily joined the trap.
By late afternoon, May 24, Dönitz logged proudly, “all available” forces of the U-boat arm had been committed to assist Bismarck: a total of fifteen boats, seven in western waters, eight in the Bay of Biscay. This was the largest commitment of the U-boat force to a single task since the invasion of Norway, fourteen months earlier. Every skipper and crew involved was keenly aware of the historic nature of the mission and determined to do everything possible to support Bismarck.
Late that evening, May 24, Bismarck’s shadowers drew the new aircraft carrier Victorious onto her track. When Victorious had closed to within 120 miles of Bismarck, she launched nine old Swordfish biplanes, each armed with a single 18” aerial torpedo and fitted with primitive ASV radar. The Swordfish picked up a contact and prepared to attack, but the “blip” turned out to be the Norfolk, which by radio put the planes back on the correct course. A second “blip” proved to be three U.S. Coast Guard cutters, Modoc, Northland, and General Greene, on “neutrality patrol.” Immediately afterward, however, the planes found Bismarck. Courageously flying into a wall of antiaircraft fire, the Swordfish attacked within view of the Coast Guard cutters, scoring one hit. Astonishingly, all nine Swordfish survived and returned to Victorious.
The single torpedo hit on Bismarck did no damage, but the attack had important consequences. During Bismarck’s violent maneuvering to avoid the torpedoes, the makeshift repairs to the damage sustained earlier in the day from Prince of Wales fell apart and Bismarck lost more oil and took on tons of water, which slowed her. This mishap led Lutjens to abandon the plan to “lure” his pursuers into a submarine trap, and he headed directly for Brest, which was closer than St. Nazaire. Accordingly, Dönitz shifted seven of the eight boats (leaving U-111 to refuel) in western waters east toward the presumed track of Bismarck and moved the five boats in the Bay of Biscay trap farther to the north.
During the early hours of May 25, Bismarck shook her pursuers. The Germans rejoiced. If Lutjens could remain undetected and maintain speed, Bismarck would soon reach the Bay of Biscay U-boat patrol line and would be within range of Luftwaffe aircraft based in France, which could provide an aerial umbrella. The onset of nasty Atlantic storms would help Bismarck remain undetected. The British wept. The great prize had unaccountably slipped from their grasp. The stormy weather diminished hope that she could be found again.
Unaware of the severity of the damage to Bismarck and of her critical loss of fuel, the British did not know where she was going. South in the Atlantic? North back to Germany? East to France? Based on incorrect or botched plotting of DF fixes on Bismarck’s radio transmissions, Admiral Tovey leaned to the view that Bismarck was to break back to Germany via the Iceland-Faeroes passage, and wrongly deployed Home Fleet forces accordingly. At the same time, however, First Sea Lord Dudley Pound at the Admiralty directed Force H (the carrier Ark Royal and the battle cruiser Renown), coming up from Gibraltar, to deploy on the assumption that Bismarck was headed for France. Thus two of the three possibilities were covered, albeit thinly. But the nasty weather worked in Bismarck’s favor, restricting and blinding carrier- and land-based air patrols.
During the desperate but fruitless hunt for Bismarck on May 25, the codebreakers at Bletchley Park, who were reading the Luftwaffe Red Enigma currently, but not naval Enigma, picked up an important message in Red that related to Bismarck. In response to a query from the chief of staff of the Luftwaffe, who was in Athens for the German airborne assault on the island of Crete,* Berlin informed him that Bismarck was “making for the west coast of France.” Bletchley Park rushed this vital information to the Admiralty, but by that time both the Admiralty and Admiral Tovey had intuitively concluded that Bismarck was headed for France and were redeploying all naval forces accordingly. Nonetheless, the information from Bletchley Park was reassuring.
In the foulest possible weather, on the morning of May 26, the First Sea Lord Pound directed Coastal Command and carrier-based air to concentrate reconnaissance along a presumed track to Brest. At 10:30—thirty-one hours after Bismarck had been lost—a newly arrived, American-built Coastal Command Catalina found her. Ironically, the pilot was a U.S. Navy ensign, Leonard (“Tuck”) Smith, who was “on loan” to indoctrinate RAF pilots to the peculiar flying characteristics of the Catalina. While Smith zoomed into the clouds to avoid the heavy ack-ack from Bismarck, the British pilot, Flying Officer D. A. Briggs, got off a contact report in a simple code, which B-dienst quickly broke and transmitted to Bismarck and to Dönitz.
Bismarck was then 690 miles west of Brest—about thirty-five hours out—but Force H was only seventy-five miles to the east, blocking her way. The Force H commander, James F. Somerville, directed a radar-equipped cruiser, Sheffield, and a succession of ASV-radar-equipped Swordfish biplanes from Ark Royal to shadow Bismarck while he prepared to launch a flight of Swordfish with torpedoes. The first flight of fourteen Swordfish mistakenly attacked the Sheffield, which only escaped destruction by resorting to violent maneuvers. The second flight of Sword-fish (fifteen aircraft), firmly guided by Sheffield, attacked Bismarck at 8:47 P.M., launching thirteen torpedoes. Two hit, one amidships on the armor blister to no effect, the other all the way aft, wrecking Bismarck’s steering gear, propellers, and rudder, leaving her unmaneuverable.
From the contact reports of British aircraft intercepted by B-dienst and one message from Lutjens on Bismarck, Dönitz was able to plot the probable track of Bismarck and her pursuers. He directed the Bay of Biscay submarine trap, which had been reinforced by Rosenbaum’s U-73 but less Topp’s U-552, which did not sail (making a total of seven boats), to the most likely point of action and by the evening of May 26, notwithstanding the gale-whipped, raging seas, all were within a few miles of Bismarck and Force H. At 8:00 P.M. the carrier Ark Royal and the battle cruiser Renown of Force H, making high speed, nearly ran down one of the boats, Wohlfarth’s U-556. But Wohlfarth, serving as a “lookout,” had no torpedoes! In frustration he logged: “If only I had torpedoes now! I should not even have to approach, as I am in exactly the right position for firing. No destroyers and no zigzagging. I could get between them and finish them both off. The carrier has torpedo bombers on board. I might have been able to help Bismarck.” He reported the contact and shadowed, but the big ships soon outran him.
When Dönitz got word that Bismarck could not maneuver, he ordered all seven boats of the Biscay trap (including Gysae’s U-98, critically low on fuel and out of torpedoes) to converge on Bismarck and defend her. Gysae in U-98 and Wohlfarth in U-556 were to continue as “lookouts” and guide other U-boats to the enemy. Homing on Bismarck’s beacon signals, Rosenbaum in U-73 found her first, shortly after midnight May 27. Bismarck was then under torpedo attack by a flotilla of five destroyers, commanded by Philip Vian in Cossack (which had a Type 286 radar), responding to Sheffield’s shadow reports. Rosenbaum observed and reported this destroyer action, which resulted in two more torpedo hits on Bismarck, but he was unable to attack the wildly maneuvering destroyers or to find Sheffield, and soon lost contact in the foul weather.
Homing on Bismarck’s or U-73’s beacons, the “lookout” Wohlfarth in U-556 arrived next, critically low on fuel. He logged: “What can I do for Bismarck? I can see her star shells and gun flashes. Sudden bursts of gunfire. It is an awful feeling to be so near, yet unable to help. I can only continue to reconnoiter and guide the U-boats that still have torpedoes.” By this time the battleships King George V (ten 14” guns) and “Rodney (nine 16” guns) and the heavy cruisers Dorsetshire and Norfolk were closing on Bismarckin raging seas. Knowing he was doomed, Lutjens sent off a message to Hitler: “We fight to the last in our belief in you my Führer and in the firm faith in Germany’s victory.”* The last signal from Lutjens, at 0710 (German time), was: “Send U-boat to save War Diary.”
Dönitz ordered Wohlfarth in U-556, who appeared to be closest to Bismarck, to carry out the risky mission of picking up the war diary. But Wohlfarth responded that he was so low on fuel that he had to abort to Lorient then and there. The next nearest boat, Kentrat’s heavily damaged U-74, drew the assignment. But before Kentrat could even attempt to carry it out, King George V and Rodney opened fire with big guns and the cruisers Dorsetshire and Norfolk hit Bismarck with one or more torpedoes. Fighting back with all operating guns and flags still flying, the wrecked Bismarck sank beneath the waves at 10:40 A.M.,* with the loss of over 2,200 men.
British ships moved in to rescue Bismarck survivors. They fished out 110, but further rescues were broken off when one of the ships radioed a U-boat alarm, forcing all British vessels to evacuate the area, leaving behind hundreds of German survivors in the sea. Later that evening, Kentrat in U-74 found three survivors and hauled them aboard, prompting Dönitz to mount an organized search by six boats over the next four days. Herbert Schultze in U-48 reported finding wreckage and “a number of floating corpses,” but no survivors. A German weather-reporting trawler, Sachsenwald, found two other survivors, making a total of five recovered by German forces before Admiral Raeder canceled the search on May 31.
Kentrat in the severely damaged U-74 had a very difficult time returning to Lorient with the Bismarck’s survivors. By the time he arrived off the coast, saltwater had leaked into the battery, creating chlorine gas. He was thus unable to dive and make the customary submerged approach to Lorient. An unidentified British submarine spotted U-74 and fired torpedoes from dead astern, but the bridge watch was keenly alert and managed to “comb” the torpedoes. The necessary repairs kept the boat out of action until late July.
The loss of Bismarck marked a turning point in the German naval war. Its humiliating failure, together with the failure of the battle cruisers Gneisenau and Scharnhorst to inflict any substantial damage on British maritime assets, brought to a close the dominance of the big surface ships in the Kriegsmarine. Never again was one to sortie into the Atlantic. Virtually overnight the U-boat became the Kriegs-marine’s preferred ship, the only possibility for defeating Great Britain at sea. Admiral Raeder’s influence on Hitler declined; that of Dönitz rose commensurately.
President Roosevelt seized upon the Bismarck sortie to nudge the United States closer to open intervention. On May 27, the day Bismarck went down, he legally declared a state of unlimited national emergency. “The Battle for the Atlantic,” Roosevelt said somewhat expansively, “now extends from the icy waters of the North Pole to the frozen continent of the Antarctic.” The blunt truth, he went on, was that the Nazis were sinking merchant ships three times faster than British and American shipyards could replace them and everything pointed to an eventual attack on the Western Hemisphere. “It would be suicide to wait until they are in our front yard,” he concluded. Therefore he had ordered the Army and Navy to intensify air and surface-ship patrols in the North and South Atlantic and had directed the U.S. Maritime Commission to dramatically increase the production of merchant shipping. Two weeks later, he froze German and Italian assets in the United States and closed down all the consulates of those two nations.
Behind the scenes, Roosevelt initiated even more warlike measures in the Atlantic area. He directed the Army and Navy to prepare an expeditionary force to join the British, should they decide to seize the Spanish Canaries (and the Portuguese Azores and Cape Verde Islands). When that operation was again deferred, Roosevelt volunteered another expeditionary force to relieve the British garrison in Iceland, an operation (Indigo) that was to be carried out on July 7. As agreed earlier in ABC-1, the U.S. Navy stepped up measures to provide escort of convoys on the leg between Canada and Iceland.
The Bismarck affair brought the U-boat war against shipping in the North Atlantic to a virtual standstill in the last ten days of May. The twenty boats in that area sank only two ships. Ottokar Paulshen in the new U-557, which nearly had been lost in an accident during its Baltic workup, got a 7,300-ton freighter; the Type IID duck U-147, commanded by Eberhard Wetjen, on an indoctrination patrol to the Atlantic, got a 2,500-ton freighter. When the new IXB U-109, commanded by Hans-Georg Fischer, age thirty-three, reached Lorient on May 29, having sunk only one ship on an eighteen-day patrol, Dönitz judged that Fischer was incapable of commanding a U-boat and sacked him. To replace Fischer, Dönitz brought back the Ritterkreuz holder Heinrich Bleichrodt, then commanding U-67, which was in the Baltic conducting sonar R&D work.
Altogether 347 loaded ships sailed from Halifax to the British Isles in Slow and Halifax convoys during May. The U-boats sank thirteen (or 4 percent) of these vessels—nine from convoy Halifax 126 and four stragglers from other eastbound convoys. In addition, U-boats in this area sank seven ships from the westbound convoy Outbound 318 plus six other ships that were sailing alone for 31,500 tons. The duck U-138 sank another lone freighter near North Channel. Total sinkings in the northern area in May: thirty-one ships.*
The successful attack on convoy Halifax 126 near 41 degrees west longitude, hastened the plans of the Admiralty and Western Approaches to deploy convoy-escort groups from Halifax out to 35 degrees west, where they were to hand over to the Iceland-based British escort groups. The first such Canadian escort group (of the Newfoundland Escort Force) sailed from St. John’s on June 2 to rendezvous with eastbound convoy Halifax 129. Commanded by J.S.D. (Chummy) Prentice, the group was composed of three Canadian corvettes, Chambly, Collingwood, and Orillia. Bedeviled by communications and engine problems, this pioneering Canadian force did not shine, according to the British, but all things considered, Prentice judged, his ships performed well, at least individually.
This convoy, Halifax 129, would be recorded as the first transatlantic east-bound convoy to be escorted “clear-across” or “end-to-end.” That is, a Canadian escort group from St. John’s to 35 degrees west; an Iceland-based British escort group from 35 degrees west to 20 degrees west; a British escort group from 20 degrees west to North Channel. Canadian and British aircraft in Newfoundland and Iceland provided limited air escort to the convoy but, as will be seen, no U-boats were available to attack Halifax 129. In a reverse procedure, convoy Outbound 331 was recorded as the first transatlantic westbound convoy to be escorted “end-to-end.” To field enough escort groups to provide this “end-to-end” transatlantic service, it was necessary to reduce the number of ships in each group, a calculated risk but one deemed worth running.