In November 1940, just over a year before Roberts caught the train to Liverpool, in a salubrious restaurant in a tiny village outside of Lorient, Germany’s trio of U-boat aces gathered to celebrate Kretschmer’s recent decoration by Hitler. The restaurant, frequented by German officers, had, it was said, the best food on the Atlantic coast. There was certainly plenty of champagne, subsidised to the officers, who paid soft-drink prices for bottles that in peacetime would be far beyond their budget. By the time coffee and brandy were served, alcohol had played its party trick of exaggerating the personality traits of each man.
At thirty-two, Prien was four years older than the others and keenly disliked by his crew. He would drill the men for hours during shore leave, and piously forbade them from cursing in all but ‘the most exceptional circumstances’.1
‘When a man joins the forces… personal liberty is reduced to a minimum,’ Prien had written in an autobiography published in Germany during the early years of the war. ‘Its place is taken by the word of command, the iron discipline of service under arms. The sailor is always on duty.’2
War had hardened Prien’s support of Hitler’s ideologies, leading him to look down on other U-boat captains, whom he judged to be holding back in their attacks on British convoys. Twenty-eight-year-old ‘Silent Otto’ Kretschmer was more educated than the others and revered by the men who served under him. One of his crew members told a German newspaper that Kretschmer’s ‘coolness’ gave the crew a feeling of ‘absolute security’.3 Nonetheless, the rigours of war had led Kretschmer to further retreat into brooding.
By contrast, the physical and psychic pressures of combat had only heightened Schepke’s boisterousness. Alcohol further inflated the performance of the lithe and striking philanderer, whom Doenitz once described as ‘a real thruster’,4 to something approaching the theatrical. The bravado was surely a carapace. The German press wrote regularly and adoringly about the three aces (Kretschmer was once forced to fend off an overbearing Berlin publisher who, mid-war, repeatedly implored the U-boat captain to write his memoirs5), which added the burden of celebrity to the already considerable pressures of war. There were whispers among U-boat staff that Schepke had been overstating his reports, claiming that every vessel sunk was a 10,000-tonner, while failing to provide the ship names required to verify the claims.
That night Schepke proposed a bet, designed to settle the pecking order between the three men.
‘Let us wager on which of us reaches 250,000 tons first,’ said Schepke, all consideration of the devastation to life and families behind the number absent from his mind.6 If Schepke lost, he continued, he would buy the others as much champagne as they could drink. If he won, however, the others would buy him as much food and wine as he could stomach. The trio shook hands. As Doenitz’s first protégées, rivalry, not friendship, had united the men. But if rivalry characterised their time together, it was character that would define each man’s destiny.
The three commanders left the restaurant and returned to the Beau Séjour hotel. In the lounge, they drank more coffee. Kretschmer chose the moment to once again try to persuade his rivals of his tactic: sneak past the escort ships in order to attack from within the convoy lanes.7
Kretschmer’s boat, U-99, was due a refit. The commander was given three weeks’ leave, during which Doenitz tried to convince him to give up operational command and instead become chief instructor at the U-boat training school. Doenitz was desperate not to lose his favourite ace. He also wanted Kretschmer to pass on his knowledge and expertise to the next generation of U-boat crews. Kretschmer forcefully rejected the idea. He had neither the political nous nor the ingratiating social flair for shore work; he was at peace only at sea, beneath the realm of politics.
‘No man can take what you are doing without a rest–if only for the safety of his crew,’ admonished Doenitz, while the pair drove to Paris from Lorient. ‘A tired captain is a menace at sea.’8
Kretschmer would not relent and, on 22nd February 1941, three days after Prien left port, U-99 departed Lorient harbour. Behind the refitted U-99 a river steamer sailed. On the decks, a brass band played a new composition titled, simply, ‘The Kretschmer March’.
On 25th February, Prien spotted a convoy of thirty-nine ships in the North Atlantic, guarded by seven escorts. After being driven off by Allied air patrols, Prien signalled Doenitz in Lorient with a fix on the convoy’s location.
Doenitz dispatched three Condor bombers from Gruppe 40–planes transferred from the Luftwaffe to the U-boat arm following Kretschmer’s successful appeal to Hitler during lunch. The planes sank seven merchant ships. Under the cover of darkness, Prien, ever truculent, sank three more. Two days later, Kretschmer arrived on the scene.
A mist had settled on the ocean, and Prien and Kretschmer took advantage of this cover to pursue the badly wounded convoy as it limped toward Halifax. As suddenly as it had descended, the mist lifted to unveil two destroyers, one of which turned and, with great frothing wake, tore toward them. Prien and Kretschmer dove, and the captains and their crews listened as the muffled rumblings of depth-charge explosions sounded overhead.
The depth charge was a rudimentary piece of technology, unchanged since its invention in 1917: a drum filled with explosives that was dropped over the side of a ship with a timer that could be pre-set to explode at a specified depth. It was an imprecise tool in a skirmish that required precision within three-dimensional space: the explosion needed to occur within twenty feet of a U-boat to have any effect on its intended target.*
Experienced U-boatmen would be able to listen to the smacking sound of a depth charge hitting the water and, based on the assumption that the bomb sank at a rate of four metres per second, use a stopwatch to calculate the depth-setting. Even if they got lucky, it was difficult for the navy to confirm a ‘kill’, although the smell of oil in the air and the sound of bubbling on the headphones implied success. If they could be spared, two escort ships would sit over the site of the suspected hit for forty-eight hours, a sufficient amount of time that, if the U-boat was merely playing dead, its air supply would run out, forcing the crew to resurface.
That day the two aces evaded the depth charges and, after waiting for the escort ships and the convoy to pass, continued on their Atlantic prowl.
Seven days later, on 6th March, Prien spotted another huge convoy, OB.293, heading westwards. After shadowing the forty-one ships, in the early hours of the next morning Prien led a small pack of four U-boats in an attack. Kretschmer employed his preferred technique, manoeuvring into the centre of the convoy. Once there, he sank two ships. While Kretschmer executed his attack, two of the escort ships, HMS Camellia and HMS Arbutus, spotted one of the other U-boats, U-70, captained by Joachim Matz. For four hours the corvettes hunted Kapitänleutnant Matz and his crew, who had executed a crash dive, dropping fifty-one depth charges, the last of which hit the U-boat, causing it to sink to more than 650 feet.
Matz, realising his U-boat was mortally wounded, blew the ballast tanks and rose to the surface. Such was the pressure inside that, when the hatch was opened, he and a number of his crew were blasted onto the deck. Twenty-six of the crew managed to disembark to await rescue. The other half of the crew were trapped inside as the U-boat sank.
U-70 was not the only victim of the night’s action. Kretschmer’s U-99 was pitched and thrown about by the force of the volleys of depth charges, but evaded damage. Prien’s U-47 was, apparently, less fortunate. At some point in the night, Prien’s radio went quiet. Doenitz, feeling ‘great anxiety’, radioed U-47 asking for a situation report. There was no response.
In the days and weeks that followed Doenitz struggled to relinquish hope of Prien’s survival, choosing to believe that his ace’s radio had merely broken and that, any day now, he would surely reappear in Lorient. Understanding the effect that the news would have on public morale, Hitler reportedly forbade the announcement of Prien’s death. It was not until 26th April 1941, two months later, that the three stars denoting a loss were placed beside U-47 on BdU’s logs. Then, on 23rd May, the news of Prien’s death was formally announced to the nation. The announcement, issued by the high command of the Wehrmacht, read:
‘The U-boat commanded by Korvetten-Kapitän Günther Prien has failed to return from its last patrol. The vessel must be presumed lost… He and his brave crew will live forever in German hearts.’9 The first of the aces was gone from the fight.
At the time of Prien’s death, Captain Donald Macintyre was in Liverpool. Ever since the outbreak of war Macintyre–whose face, with his eyes squeezed into a squint by chubby cheeks, earned him the nickname ‘Bulldog’–had longed to hunt U-boats, a showdown that he considered to be ‘the perfect expression of a fighting sailor’s art’.10
As a junior commander Macintyre had been consigned to a fleet destroyer, ‘aiming guns at a barely visible target some dozen miles away’. But at the start of 1941, Macintyre was transferred to the Atlantic battlefield as commander of the destroyer HMS Hesperus. Early frustrations at the ‘wild goose chases’ he and his crew were sent on by command at Western Approaches had been quelled by the arrival of Sir Percy Noble at Derby House, who, in Macintyre’s view, brought a sense of ‘intelligent purpose’ to the organisation of convoy escorts that had been previously lacking.
In early March 1941, Macintyre was told he was to be moved to a new ship, HMS Walker. The decision was a ‘rude shock’, and one that he deeply resented. Not only did this mean he would have to leave his experienced crew, which had become ‘an efficient fighting team’, but his new ship was a ‘battered veteran of the First World War’.11 Walker had sustained serious damage in September 1939 when it collided with another vessel 200 miles south-west of Ireland, killing fourteen men. (The first lieutenant shot some of his injured men, who were trapped in the wreckage.12) Walker had been fitted with a new bow of which Macintyre had grave misgivings.
‘I could not have the same confidence in her,’ he later wrote.
Nevertheless, in the first week of March, Macintyre departed Gladstone Dock in Liverpool in HMS Walker as leader of the newly formed 5th Escort Group, pleased to discover that the majority of the ship’s officers were ‘experienced and professional’ and ‘accustomed to searching dark horizons in search of the low-slung silhouette of a U-boat’. Walker made its way into the Atlantic, where the remaining two of the U-boat aces lay in wait.
Shortly before midnight on 15th March 1941, Fritz-Julius Lemp, the U-boat captain who had sunk Athenia on the first day of the war, sighted Macintyre’s ships before they spotted him. Kapitänleutnant Lemp, piloting one of the new Type IXB U-boats, which had greater range and speed than the Type VIIs, reported the sighting to Doenitz in Lorient, then torpedoed the 6,200-ton tanker Erodona. Macintyre watched in ‘shocked silence’ as the tanker exploded, the first of this kind of ‘appalling night disaster’ that he had seen. He gathered his pack of escort ships, the destroyers Vanoc, Volunteer, Sardonyx and Scimitar, and the corvettes Bluebell and Hydrangea, and staged a haphazard search for the U-boat, to no avail.
Frustrated and fearful, Macintyre ordered a drastic alteration of course. For a while the evasive tactic worked. Then, at 22:00, Kretschmer and Schepke found the convoy. Kretschmer again penetrated the convoy’s columns to attack from point-blank range, scoring direct hits with seven of the eight torpedoes he fired, sinking five ships and damaging a sixth. It would be the single most destructive salvo of the war.13 In the dense smoke issued from the burning tankers, Kretschmer hid, plotting a course back to Lorient.
As the ocean lit up with the fires of devastation, Macintyre was ‘near to despair’, fumbling for some kind of tactic to ‘stop the holocaust’.14 The escort ships frothed to and fro, dropping so many depth charges over suspected U-boat positions that the ASDIC operators were unable to distinguish barrel from boat.
Two hundred feet below, Schepke and his crew waited. The men counted thirty-four explosions, each one a little closer than the last, ratcheting the tension. The thirty-fifth was a direct hit. As the vessel rocked with shattering force, the lights went out and whistling leaks sprang along the length of the boat. U-100 began to sink, stern first, to a depth of 750 feet–deeper than any surviving U-boat had gone before.
Schepke, afraid not only that the sound of the hissing would be picked up by the destroyers, but also that the U-boat’s hull might be crushed like a tin can under a jackboot, shouted for his crew to surface, in the hope that they might slink away in the chaos. As U-100 broke the waves, Schepke opened the hatch and took the U-boat’s deck gun in his hands.
Just after three o’clock in the morning, the ASV operator on HMS Vanoc, which was equipped with one of the first seaborne radar devices, reported contact 1,000 yards on the starboard side. Vanoc’s captain, Jim Deneys, judged his speed to be sufficient to attempt to ram the stricken U-boat. He steered the destroyer hard toward the target, cutting the engines five seconds before collision.
As he spotted the incoming destroyer from the conning tower Schepke called for full power, but neither U-100’s diesel nor electric motors would spark. After a cold moment, he called down to his crew: ‘It is all right, the destroyer is going to pass under our stern.’15
It was a miscalculation. At 03:18 the destroyer struck U-100 midships. Schepke was crushed between the U-boat and Vanoc’s bow. In the years that followed, the ace’s death was embellished with gruesome, outlandish detail: cleaved legs, a torso arcing through the air. Indisputably, Schepke’s body sank into the ocean, and did not surface. Just six crew members, including Lieutenant Siegfried Lister, a torpedo officer who before the war frequently went yachting with English friends, survived the attack to record his commander’s final words.
While Vanoc began to pick up survivors from the water, Walker circled protectively. Kretschmer remained close by, on the surface, trying to sneak away. From the bridge, Kretschmer’s lieutenant Heinrich Petersen spotted Walker a few yards away. Petersen, believing the U-boat must have been spotted, ordered a crash dive. In fact, none of Walker’s crew had seen the Germans, who likely could have escaped had they remained surfaced.
Instead, shortly afterwards Macintyre’s sonar operator shouted ‘Contact! Contact!’, having detected a ‘ping’. Walker dropped six depth charges over Kretschmer’s U-99, at least one of which was close enough to damage the vessel, breaking the crucial main depth gauge, which indicated the U-boat’s position in the water. With both lights and gauges out, Kretschmer was double-blind in the dark, and sinking. At a depth of around 700 feet, the oily water rising inside the U-boat, Kretschmer blew all of the surviving ballast tanks, and with ear-popping speed U-99 shot to the surface.
At 03:52 a searchlight beam from Vanoc illuminated U-99 as it broke the water, and gun crews from both ships fired tracer bullets, lighting up the night sky in what Macintyre later described as a showy, but inaccurate, display. By now Kretschmer knew that U-99’s engines were broken, and the steering gear mangled. He issued a final, unencrypted message to Doenitz: ‘Two destroyers. Depth charges. 53,000 tons. Capture, Kretschmer.’
Next Kretschmer opened the hatch and, as U-99 began to loll on its side, sat in the shelter of the conning tower while drawing on a cigar. His men, as devoted as ducklings, lined up along the U-boat before him. Finally, Kretschmer ordered scuttling charges to be set, to ensure that no British could board the U-boat and extract useful documents and cyphers. The door to the compartment in which the charges were kept, however, was jammed shut.
Kretschmer stood and the men listened while their captain, hanging from the guard rail, apologised that he would not be able to deliver them safely home. Then he warned them that they might need to endure the freezing Atlantic water before being rescued. Finally, he sent his men below decks to retrieve their warmest clothes and await the order to abandon ship.
Kretschmer knew what it was like to abandon a U-boat. While carrying out training exercises in the Baltic two years before the war, he had been fiddling with a faulty stopper that was leaking water into the muzzle of the U-boat’s gun, when he heard the angry hiss of air being released from the ballast tanks and the sound of the engines coughing to life. When Kretschmer reached the conning tower to head below deck, he found the hatch clamped tight. He stamped on it, hoping the sound might be heard below. No one answered and, after a few seconds, the U-boat began to dive. Kretschmer was lifted into the water. Grasping the periscope, he allowed the force of the rising sea to slide him up to its tip. Now, holding his breath, Kretschmer pressed his face against the eye lens to let his fellow crew members inside know they had left him behind.
Thirty-five feet below the surface, Kretschmer’s lungs were burning. He let go, to return to the surface, where he struggled in his cold, waterlogged clothes to stay afloat. When his boat finally surfaced, Kretschmer was so weak he had to be lifted onto the deck.
This was the memory to which U-99’s captain returned when the boat’s stern jolted downwards, apparently sinking of its own accord, and threw half the crew into the sea.
Kretschmer hauled his first lieutenant, Petersen, from the hatch, while ordering him to sling a portable battery flashlamp over his shoulder in order to signal to the destroyer crew for rescue. From the lilting side of the U-boat, Kretschmer dictated the message: ‘From captain to captain… Please pick up my men drifting towards you in the water. I am sunking [sic].’16
Walker, its scrambling nets lowered, approached U-99 at a suspicious crawl, unaware that Kretschmer had expended all of the U-boat’s torpedoes. Some of the men hauled aboard were in the ‘final stages of exhaustion’17, as Macintyre later recalled, and needed assistance. Kassel, the petty officer who had given pineapple and coffee to the concussed Englishman Joseph Byrne the previous year, seemed to be dead, until, having been laid in the ship’s warm galley, he miraculously woke. All but three of U-99’s crew–the only men to serve under Kretschmer to lose their lives–were recovered.
Kretschmer, still wearing his white, brass-bound cap, had been hanging from the scrambling nets and counting his men as they climbed up. Now, with the prize pair of Zeiss binoculars presented to him by Doenitz still slung around his neck, he attempted to climb the nets. His waterlogged boots, and the drag of the water as Walker began to increase its speed, held him back and, for a moment, he thought that he might be forced to let go.
U-99’s boatswain saw what was happening and scrambled down the nets to help his captain. With legs buckling, Kretschmer stood on deck to find a Colt .45 ignobly pointed at his face. He moved to throw the binoculars overboard, preferring that they be lost to the sea than go to an enemy sailor, but Peter Sturdee, a sub lieutenant aboard Walker, caught and passed them to Macintyre. Macintyre examined the glasses and, seeing how much better they were than his British pair, placed them around his neck, where they stayed for the remainder of the war.*
The rescued men were searched, and any documents deemed to be of interest seized. Macintyre’s crew found newspaper and magazine clippings lauding the exploits of the U-boats, which one article termed ‘Sea Wolves’. A sketched drawing was taken from another man. This document was of a different category to the clippings. It showed the crude outline of a convoy with a U-boat attacking from within the columns, a hand-drawn illustration of the tactic that had sent so many people, and hundreds of thousands of tons of food and supplies, to the ocean bed. Here, depicted in a few lines, was the secret to the U-boats’ success.
Kretschmer was escorted to the Captain’s day cabin, where he sank into a chair and dropped into a dreamless sleep while, outside, a sentry guarded the door.
On the morning of 21st March 1941, HMS Walker pulled in to Liverpool with the captain and the majority of the crew of the most notorious U-boat of the war lined up along the ship for all to see.
Kretschmer’s capture had not been kept a secret. While sailing toward Liverpool, Macintyre received a signal from Admiralty asking for a positive identification of the U-boat crews that had been sunk or captured; Churchill, the signal explained, wanted to make an announcement in the House of Commons. As Macintyre moored at the Prince’s Landing Stage, a dock ‘usually reserved for more lordly vessels’,18 he saw Sir Percy Noble and the high-ranking members of the Western Approaches staff lined up along shore. Kretschmer, wearing his leather jacket and peaked cap, strode down the gangway to be greeted by two armed soldiers. As the ace was escorted into an army station wagon to take him to a cell where he would be placed in solitary confinement, his watching crew, still paraded on Walker’s deck, stood to attention and saluted.
There was no chauffeured comfort for the crew of U-99, who were now marched through the bomb-wrecked Liverpool streets to Lime Street station, where they were to take a train for London. News had spread and by the time they started their march of shame, spitting, jeering crowds–mainly women–lined the streets.19 Almost everyone knew someone who had been injured or killed in Blitz or battle and, in these moments, the forty-two members of U-99’s crew symbolised the source of every wound and indignity of the past two years. This was the collective grief of the rabble and, for the U-boatmen, it seemed at times as though the police cordons could not hold back the crowd.
Josef Kassel later said that he had been more afraid for his life while marching past these baying women than he had while steadying himself in the U-boat as it rocked with the violent energy of depth charges a few days earlier.20 So fevered and disruptive was the demonstration that the line of traipsing men missed the train and, to their dismay, were forced to march back into Liverpool again–to Walton Gaol, where, six months earlier, a German bomb had partially demolished a wing, killing twenty-two inmates.
That same day, one of Vanoc’s officers submitted the official report into what had happened at sea. In stark terms and with clear time stamps it laid out the key events of the night of 17th March, as well as highlighting crew members who the captains believed should be considered for official commendation.
One unassuming bullet point also mentioned the fact that U-99’s crew had been searched and, among their possessions, an illustration of the point-blank tactics pioneered by Kretschmer had been found. The importance of the document apparently evaded those who read the report. The revelation was neither noted nor communicated to the escort commanders. The three aces were gone, but their pioneering tactic remained in play. Roberts, when he arrived in Liverpool, would have to discover it for himself.