Codebreakers Victory (15 page)

On December 13, 1942, the decisive change came. Shark was finally broken. This resulted from one last, all-important capture of German code materials and from the clever use Bletchley made of them.

The capture occurred in the Mediterranean, off the coast of Egypt. A British flying boat's crew sighted U-boat
U-559
and alerted four destroyers to pursue it. Later that night, a depth charge forced the sub to the surface, virtually under the guns of the HMS
Petard.
The
U-559's
commander ordered his crew to abandon ship. Before escaping, the U-boat's engineer opened the sea cocks to scuttle the sub. But she remained afloat, her conning tower just visible above the waves. Four of the
Petard's,
crewmen either swam to the sub or jumped onto it from the deck of their ship—survivors' accounts vary. Three of the crew, Lieutenant Tony Fasson along with Colin Grazier and Ken Lacroix, clambered into the sub's interior while the fourth, young canteen assistant Tommy Brown, ran up and down the conning tower ladder in order to hand over to a whaleboat what the others could deliver to him. They grabbed the four-rotor Enigma from the radio room and an armful of charts and papers that Brown managed to transfer to the whaleboat alongside. At that moment the U-boat went under. Lacroix just managed to escape up the conning tower; Fasson and Grazier never made it.

Their sacrifice gave the Hut 8 team what it needed to crack Shark. In adding the fourth rotor, the Germans had taken into account that at times, in order to communicate with three-rotor machines, that rotor would have to be put in a neutral position—as, for example, when the U-boat had to communicate with a shore weather station. Among the papers the brave men of the
Petard
had delivered were the current editions of the three-rotor codebook for the Short Weather Cipher and the four-rotor U-boat key. The result was that when Shark was used for weather signals, the three-rotor bombes could be used to decipher the messages, and the remaining part of the day's key could be reconstructed by testing no more than twenty-six letters of the nonrotating fourth rotor. In the first hour after this breakthrough, a message revealed the positions of fifteen U-boats.

Those in Hut 8 felt both deep relief and huge elation. Pat Bing, then a teenaged typist, later recalled the excitement of finally being able to tap out German text on long strips of sticky tape, fasten the tapes to paper and send them by the compressed-air tubes the young women called "Spit and Suck" to Hut 4 for the interpreters and disseminators to work on. The deciphered Shark messages were, she said, "a great gift from the brainy boys' department."

Historian Patrick Beesly has recorded the impact of the conquest of Shark. The flood of decrypts and translated signals that poured into the Admiralty's Operational Intelligence Center, he noted, "made it possible, for the first time, for . . . the Submarine Tracking Room to build up a comprehensive and accurate picture of the whole operational U-boat fleet."

At this point the cryptologic war reached a stalemate. BP was reading Donitz's copious exchanges with his U-boats, but B-Dienst was reading the Admiralty's output. As Hinsley put it, "Between February and June 1943 the battle of the Atlantic hinged to no small extent on the changing fortunes of a continuing trial of cryptographic and cryptanalytic resourcefulness between the B-Dienst and the Allies."

There was one significant difference. From their decrypts, Bletchley's cryptanalysts gained unmistakable proof that the Germans were breaking the Royal Navy's main code, and so set in motion the changes necessary to provide a more secure system.

It took the Admiralty until June to make the changeover. In the interim, U-boat warfare rose to its savage climax. As an example, during four days in mid-March, Donitz's wolf packs hurled themselves against two intermingled convoys, HX229 and SCI22, whose course had been plotted by B-Dienst, and sank thirty-two of their ships plus a destroyer, with a loss of only one U-boat. It was the greatest U-boat success of the war. Again the Admiralty was reduced to despair, even to considering that "we should not be able to continue convoy as an effective system of defence."

April produced a standoff. Shark decrypts enabled the Admiralty to reroute threatened convoys, but B-Dienst decrypts informed Donitz how to counter the instructions and reposition his boats to the best advantage. So exhausted were his crews and their equipment by the March onslaught, however, that he could not maintain their previous level of sinkings. April's toll dropped to 277,000 tons.

Then came what those in U-boat command regarded as "Black May." Two calamities struck the U-boats. One was a sharp rise in their own losses: thirty-one boats were sunk during the month, and the total for the first six months of 1943 rose past one hundred. The second was a wavering in morale. Less experienced commanders exhibited a drop-off in zeal and a rise in caution compared with their predecessors. Donitz was driven to increasingly shrill denunciations of his crews for their failures to press home their attacks.

The turn of the tide was dramatized by the passage of convoy SCI30 in mid-May. Though attacked by a pack of U-boats, not a ship was sunk. By contrast, six U-boats were lost and others damaged.

The price was more than the German admiral, who had lost his own son in one of the downed boats, was willing to pay. On May 24 he sent out orders for his U-boats to withdraw from the North Atlantic and shift to less hazardous patrols southeast of the Azores.

Dönitz refused to concede, however. He later wrote, "Wolfpack operations against convoys in the North Atlantic . . . could only be resumed if we succeeded in radically increasing the fighting power of the U-boats." He was determined that in the autumn of 1944 he would launch a new campaign, using U-boats equipped with new developments from German science. The improvements included superior radar, better antiaircraft protection and more efficient acoustic torpedoes.

It was an abortive effort. By then the odds were stacked overwhelmingly against Dönitz. Long-range aircraft made the air cover for convoys complete, especially after Portugal permitted the Allies to occupy the Azores. Escort carriers were plentiful. New technological developments included "hedgehogs" that enabled destroyers to throw depth charges ahead of their course as well as behind. To counter the acoustic torpedoes, the Allies perfected the "Foxer," a device towed astern of the escort vessels; it attracted the torpedoes and caused them to explode harmlessly.

Above all, the cryptographic advantage had swung completely to the Allies. As Beesly expressed it, Dönitz "was now groping in the dark while our picture was so clear that convoys could be converted, Support Groups transferred, air cover increased or reduced in accordance with the daily or even hourly demands of a situation."

Few Allied ships were sunk, and too many U-boats were destroyed. On November 16 Dönitz ordered another withdrawal.

In the meantime, control of Shark had passed to American cryptanalysts. With a flood of super-high-speed bombes being produced by the National Cash Register Company in Dayton, Ohio, the Yanks were better equipped to deal in a timely fashion with the vast numbers of permutations that had to be run through to reach Shark Enigmas' settings. During the second half of 1943, National Cash delivered seventy-five bombes, more than the British produced during the rest of the war. American analysts informed the Tracking Rooms in London and Washington.

Dönitz still would not give in. He pressed U-boat designers to apply new techniques in a series of Super U-boats. Informed by Shark decrypts, British and American commanders watched these new developments with grave misgivings. The new boats' streamlined hulls and quiet new electric motors allowed them to slip along underwater at speeds matching those of most Allied escort vessels. Most worrisome of all, they were equipped with snorkel devices that took in oxygen and recharged batteries as the boats traveled at hard-to-spot periscope depths, enabling the subs to stay submerged for up to ten days.

Dönitz planned his Super U-boat convoy battles for early 1945, but his ambitious plans were thwarted as Allied bombardments of U-boat assembly plants and bases caused delays. Then the finished boats revealed flaws that had to be corrected. Before he could deploy his new subs, the war ended.

The Battle of the Atlantic was the longest sustained conflict of the war, one that cost both sides heavily. The Allies lost 2,603 merchant ships and 175 naval vessels. The lives lost exceeded 40,000, including 26,000 civilians. German U-boat losses numbered 784, killing 28,000 crewmen—two-thirds of the total force. The casualty rate was the highest suffered by any service during the war.

By June 1943, Churchill wrote, "The shipping losses fell to the lowest figure since the United States had entered the war. The convoys came through intact, and the Atlantic supply line was safe."

 

 

For Some Codebreakers, Unhappy Endings

 

Triumphant as they were during the war, both Alan Turing and Gordon Welchman suffered ill-fated deaths in the years that followed. Turing's fondness for Christopher Morcom turned out to be more than an adolescent aberration. He slowly surrendered to his true nature—at a time when British law still regarded homosexuality as a crime. Arrested after a petty encounter with the police, he was unable, because of his secrecy pledge, to assert his heroic wartime stature in his defense and was subjected to a humiliating trial and a judgment that his "cure" include the injection of female hormones that made this sturdy man who had run marathons become obese and grow breasts. Not long after, at the age of forty-two, he committed suicide.

Welchman, after the war, emigrated to the U.S., became an American citizen and served as a consultant on intelligence security during the Cold War. He became concerned that Allied codebreakers were making the same mistakes that had betrayed the Enigma. When Winterbotham's
The Ultra Secret
broke the walls of secrecy, Welchman felt released from security restrictions and had his book
The Hut Six Story
published by an American firm. But whereas Winterbotham had said little about the actual codebreaking methods used at Bletchley Park, Welchman, as a warning to current cryptographers, spelled out the "comedy of errors committed by the Germans" and how these errors had been exploited by Allied cryptanalysts.

Because of these disclosures, the book met with a storm of protests by both British and American authorities. The British banned publication in Britain and issued criminal charges against Welchman. The Americans withdrew his security clearance, making it impossible for him to continue his employment. Because of the harassment, Welchman wrote, "my health was seriously affected." British historian Nigel West has claimed that the persecution drove Welchman to a "premature death."

For both Turing and Welchman, however, these postwar troubles cannot dim the glory of their wartime achievements. The techniques they developed became the machinery of a huge intelligence factory at Bletchley Park, which ran so smoothly that in the war's latter stages they had only to oversee its almost routine production of war-winning decrypts by the hundreds of thousands.

 

 

 

6

 

When Superior Intelligence Was Not Enough

 

 

After Adolf Hitler became chancellor of Germany, he was reported to have regretted revealing so much of his planning for the future in the book he dictated to Rudolf Hess while in prison in 1923-24 and later at an inn in Berchtesgaden. He called his book "Four and a Half Years of Struggle Against Lies, Stupidity and Cowardice," but his publishers sensibly shortened the title to
Mein Kampf,
or "My Struggle." The book spelled out his rejection of equality and democracy; inequality between individuals and races he saw as part of an unchangeable natural order. Topmost in this order was the "Aryan race," of which the German
Volk
was a supreme expression. Morality and truth were to be judged by their accordance with the interest and preservation of the
Volk.
As leader of the
Volk
the führer was endowed with absolute authority. Under the führer, the Aryans, as the superior race, must reign supreme over the
Untermenschen,
the lower orders that included the Jews and the Slavic peoples; these were to be eliminated or enslaved.

Hitler's racist beliefs underlay his plans for Germany's rise. As the master race, the Aryans were justified in acquiring
Lebensraum,
or "living space," land to be used in cultivating food and providing space for the expanding Aryan population. That land was to be taken by force from the
Untermenschen
in Poland and particularly from the hated Bolsheviks of Soviet Russia. "To guarantee to the German nation the soil and territory to which it is entitled," Hitler dictated to Hess, "we are bound to think first of Russia and her border states."

The opening step in this plan was to conquer France, following through to what he saw as the victory that was denied Germany in the Great War by political treachery and Jewish betrayal. The vengeful defeat of France would also secure the western border so that the Germans could then proceed to take over the lands to the east.

Once he was master of Germany, Hitler followed
Mein Kampf
as his blueprint for the future. He consolidated his power and made himself the führer. He directed Heinrich Himmler to begin excising the inferior peoples from among the Germans. He added living space by his occupation of Austria and his conquest of Czechoslovakia. He hoped to bluff France and England into accepting his invasion of Poland. When that part of his plan failed and precipitated war, he humbled the French and reduced England to a negligible barrier in the way of his larger goal: the submission of the USSR, the extermination or enslavement of its people and the absorption of its vast territories. He ordered his military chiefs to prepare for a campaign against Russia in the late spring of 1941.

Hitler was confident his surprise would be complete. He had ample evidence that Joseph Stalin was abiding by the German-Soviet nonaggression pact of 1939. Stalin was, for one significant instance, honoring his pledge to provide materials needed by the Reich's war machine. Trains bearing grain, petroleum and metals regularly rolled across the borders to supply the Wehrmacht.