by Kahn, David
A little before dawn that same day, a Sunderland flying boat reported a radar contact, “possibly a submarine,” in the eastern Mediterranean roughly halfway between Port Said, at the northern end of the Suez Canal, and Tel Aviv in Palestine. Four destroyers were ordered to search the area. Among them was H.M.S. Petard.
Built in Newcastle and launched into the brown waters of the River Tyne on a rainy day in March 1941, the Petard was one of eight P-class (for Pakenham) fleet destroyers. She had a handsome trawler bow, a single funnel, and a top speed of 32 knots, with great maneuverability at high speed and stability in bad seas. As her main battery she carried only four 4-inch guns, but she was otherwise well armed with eight torpedo tubes, one hundred depth charges, and two sets of depth-charge throwers. Her nine officers had individual cabins; the 211 ratings slept in hammocks.
By far the strongest personality aboard was the captain, a Royal Navy career officer, Lieutenant Commander Mark Thornton. He had come to the Petard after service aboard another destroyer, where he had won a Distinguished Service Cross for sinking a submarine. Of medium height, with a square, muscular frame, a square head, closely cropped thick gray hair, and a face as battered as a boxer’s, he struck terror into many. At the commissioning he promised to send back a trophy to show the shipyard the results of its efforts; his ferocious talk about destroying the king’s enemies left some of the workmen shaking their heads with pity for his crew. His energy seemed barely contained. At Scapa Flow, he would sometimes leap up from the officers’ mess, beat the after bulkhead with his fists until it boomed, and shout, “I must have action with the enemy now!” Earlier, during the evacuation of Dunkirk in 1940, many of his ship’s inexperienced crew members had proved incapable of performing due to seasickness, strain, and lack of sleep, so on the Petard he was determined that events would not overwhelm the crew. He toughened his new men with relentless, almost merciless exercises. Once, just as the men were turning in from an exhausting day, he staged a false alarm: pretending the Petard had been torpedoed, he hosed them with icy sea water as they struggled to action stations. Gradually he whipped his crew into “a fully trained fighting machine.”
Thornton’s first lieutenant was Antony Fasson, a Scot from the border country. An experienced career officer, he exerted a firm discipline on his subordinates but also mixed easily with them. The ratings rarely took umbrage at his punishments; the junior officers found him a genial companion; those who fell short of the captain’s difficult standards found Fasson understanding. And Thornton considered him an exceptionally fine leader.
During the summer of 1942, the Petard was sent around the Cape of Good Hope through the Suez Canal to join the Twelfth Destroyer Flotilla. During that long cruise Thornton and Fasson spent many an hour in the captain’s cabin discussing the Mediterranean, an area Thornton knew very well. They formed a mutual determination to capture the confidential books from a U-boat: “Other destroyers might sink U-boats,” Thornton said later, in ignorance of the U-110 exploit, “but we would capture one!” So they drilled a boarding team, and Fasson, who would lead it, wore gym shoes and his personal boarding gear day and night while at sea. He and Thornton, never doubting that an opportunity would come their way, discussed the boarding from every angle.
On September 22, as the U-559 rocked at her berth in Messina, the Petard was moored fore and aft to buoys at Port Said, almost abreast of the statue of the builder of the Suez Canal, Ferdinand de Lesseps. The next weeks were filled with antisubmarine practices and patrols and a sudden sortie to investigate a reported high-speed surface contact that ended in the Petard’s repelling three Junker 88s. It was difficult to keep the sailors from the off-limits bars and brothels of Port Said. Off Haifa, the stench of animal skins piled on the quays produced for the men aboard what one called “a night of unforgettable nausea.” They spent seven days in Alexandria, where the crew, at sea on the night of October 23, saw the black sky to the southwest erupt with artillery flashes: the start of the battle of El Alamein! Thornton so itched for action that he repeated his bulkhead-beating performance. Then came the seaplane’s report of a U-boat sighting as the Petard and other ships were sailing to Haifa. Being nearby, they were ordered to hunt the submarine.
* * *
The four destroyers reached the U-boat’s suspected position a little after noon and began their sweep. The day was sunny, the wind light, the sea flat. The Pakenham obtained the first asdic contact, but the Petard attacked first, dropping five depth charges set to 250, 350, and 500 feet at 12:57 P.M. After the explosions, the Petard’s crew saw oil and heard a noise of escaping air—but saw no submarine. A moment later, the Dulverton dropped ten depth charges. As the Petard was heading in for her second attack, she and the other ships heard a heavy explosion apparently under her. But they saw no disturbance of the water, and the cause remained a mystery. The Petard dropped ten depth charges, and soon the asdic operator reported a hissing noise. This contact was held for fifty-five minutes but eventually proved not to be the submarine. Perhaps underwater bands of different density and temperature, aggravated by the fresh water from the Nile, were affecting the asdic.
The hunt continued for hours, with intermittent attacks. In the U-559 the men were naturally fearful, but none lost control. Heidtmann, with the calm that had won his men’s admiration, repeatedly announced “Alarm!” in a quiet voice, so unlike the anxious, dramatic “Alaaaaarm!” of other skippers. As time went on, the air in the submarine, bad at the best of times with the smell of unwashed bodies, old cigarette smoke, toilets, garbage, diesel oil, diesel fumes, and cooking, grew even fouler.
The attacking destroyer was directed by a cross-bearing of asdic contacts by two other ships. Thornton seemed to have a sixth sense: when contact was lost, he conned the Petard back on target, constantly changing course and speed. Tension on the ship remained high. At slow speed, all hands topside scanned the sea for a periscope and torpedo tracks. When revolutions increased, men braced themselves against the thuds of the underwater explosions.
Darkness fell. The wind rose, and clouds covered the sky. A torpedoman aft sent Thornton word that he thought the submarine was below 500 feet—the maximum setting then on Royal Navy depth charges—but if he stuffed soap in the holes of the depth charges, the water pressure would build more slowly and the charges would sink deeper before going off. He was granted permission to do so, and at 6:42 the Petard loosed ten soaped-up charges. The wait for the explosion was longer than usual, then the crew members saw the shiver on the surface and felt the thumps on the hull. The trick worked: the sub moved and contact was regained. Over the next three and a quarter hours, three more attacks were made.
A little after 10 P.M., Thornton signaled to the Dulverton his intention to attack and, when the ship replied with ranges and bearings that matched the Petard’s the ship’s company felt that the hunt was nearly up; the sub must be close at hand. At 10:17 the Petard dropped depth charges. The heavy detonations and the fountains of water were followed by silence except for the noises of the ship and the sea. In Thornton’s mind was only the lust to see the U-boat blown to the surface.
In the submarine, the crew counted 288 depth-bomb explosions; the last ones holed the bow and stove in plates on the starboard quarter. The air was intolerable: it seemed as if the oxygen had run out. Heidtmann ordered the ship up.
As the Petard nosed forward into the wind and the dark, a gun crew, the men on the bridge, and the gun director team suddenly and simultaneously smelled diesel fuel; a moment later, the asdic operators cried out that they could hear a submarine blowing its tanks. Guns were trained on the port bow bearing given by the asdic team; eyes strained to pierce the darkness. At 10:40, a patch of white water appeared on the black sea. The port signal lantern picked out a conning tower; a few moments later a 36-inch searchlight brilliantly illuminated a submarine with a white donkey painted on her conning tower and a few white figures bursting from it, then crawling and skidding along the slippery deck into the sea.
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Thornton ordered his guns to open fire. The pom-poms and one of the Oerlikons did so at once. At that range one of his forward 4-inchers could not be depressed enough to fire at the target, so Thornton turned the ship away long enough to give the gun crew a shot. With their one round the crew members hit the base of the conning tower. Many of the 114 pom-pom and 79 Oerlikon rounds struck the U-boat, but it rapidly became clear that she was stopped and being abandoned and that further gunfire damage would make it harder to save her. Fasson rang the cease-fire bells. Thornton issued orders to put his boarding plan into effect.
By this time, the Petard had stopped and the submarine was lying to port in the destroyer’s lee, down by the bows in the roughening chop. Fasson was on the starboard side aft, starting to have the starboard boat lowered. Thornton roared at the gunnery control officer, Sub-lieutenant G. Gordon Connell, to dive over the side and swim to the U-boat. As Connell started to strip off his clothing, a young ablebodied seaman, Colin Grazier, joined him, shouting that he would swim across with him. Just then Fasson appeared. He told Connell to take charge of the whaler and bring it around the Petard to the U-boat. He himself was tearing off his uniform. Within moments he and Grazier had dived naked into the sea and were swimming to the U-boat. So was the fifteen-year-old canteen assistant, Tommy Brown, who had lied about his age to join the service. He dived into the sea before the canteen manager could stop him. A few moments later, the whaler, encumbered by German sailors clinging to it, reached the U-boat and made fast.
That vessel was in desperate shape. Its deck was awash, and waves broke over it continuously. The rigging and wireless aerials had been almost completely shot away. The top of the conning tower was a shambles; at its base was the hole made by the 4-inch shell; in the middle were two or three dozen punctures an inch in diameter, through which water sloshed. Plates on either side were stove in. The searchlight pinned the U-boat in its dazzle. The Germans in the water cried for help. In the darkness beyond, the Petard’s sister ships circled, listening for other U-boats.
Fasson and Grazier reached the submarine and climbed down into her control room. The U-boat’s lights were on, and they could see two bodies there. Fasson shouted up that the submarine was holed forward. Then, using a machine gun, he smashed open cabinets in the captain’s cabin and, finding some keys behind a door, opened a drawer. From it he took out some documents, apparently secret ones.
Tommy Brown had gone below to help Fasson and Grazier, water from the 4-incher’s hole pouring onto his back as he went down the ladder. Now he carried these precious papers up the conning tower and gave them to the men in the whaler. Another sailor, K. Lacroix, at the top of the conning tower, pulled up some books with a line. Brown went down again to bring up more documents, managing to keep them dry despite the leaks and splashes. On his third trip, the water, which had been rising gradually, stood 2 feet deep on the submarine’s inside deck.
Back in the control room, Fasson was trying to free a box containing some instrument—perhaps a radio or radar—from a bulkhead to which it was attached by wires. The water was getting deeper; outside, it was starting to cover the aft gun platform. Brown told the lieutenant that they were shouting on deck for them to come up. Fasson directed Brown to take up the next batch of papers. The teenager climbed the ladder with the documents and passed them into the whaler. Meanwhile, Fasson and Grazier had managed to break away the instrument box and tie it to a line to be lifted up. As the sailors hauled it out, Fasson called out that they were pulling too fast, that the instrument appeared delicate and important and that they should be careful with it.
By now the sea was over the afterdeck platform, and Connell told Brown not to go down again but to tell Fasson and Grazier to get out at once. Brown saw them at the bottom of the conning tower and shouted, “You had better come up!” twice. They had just started up when, unexpectedly and swiftly, the submarine sank. Brown jumped off; Lacroix, still on the conning tower, had to pull against the water pouring down as he climbed the last two rungs of the ladder. He swam away against the suction, and he and Brown were picked up by the whaler. But Fasson and Grazier had not been able to overcome the inrushing water. They went down with the submarine.
The whaler with its precious documents came alongside the Petard and was hoisted on the run as she and the Dulverton, their searchlights extinguished, moved at speed away from the possible danger of other U-boats. The euphoria of the crew members at having destroyed a hated enemy quickly turned to an inexpressible sorrow as they realized that they had lost a competent and well-liked officer and a regular serviceman who was an asset to the ship. The Petard continued to Haifa, where the valuable documents were given to naval intelligence officers. Thornton, true to his word that he would send a trophy to the ship’s builders, sent a U-boat seaman’s life jacket to Newcastle. After deciding that Fasson and Grazier could not be granted Britain’s highest decoration for valor, the Victoria Cross, because they had not acted in the face of an enemy, the Admiralty posthumously awarded them Britain’s second highest decoration for bravery, the George Cross.
The documents that had cost the lives of Fasson and Grazier included two that were most useful for G.C.&.C.S. in its stalled attack on the U-boat Enigma. One was the current edition of the Short Signal Book. But it was less immediately useful than the second edition of the Short Weather Cipher. That reached Bletchley Park—after the excessive delay of more than three weeks—on November 24. Once again Hut 8 could work the crossruff. It could turn Hut 10’s solutions of broadcast weather messages back into the form the weather messages had when the U-boats enciphered them into Enigma, thus obtaining cribs. But because the second edition of the Short Weather Cipher, unlike the first, did not list the twenty-six rotor settings, each indicated by a letter, to be used in enciphering weather reports, the cryptanalysts thought that all four rotors were used to encipher weather messages. The tedious testing on the bombes of the possible weather kisses began.
On Sunday, December 13, 1942, Hut 8 struck pay dirt. One of the weather cribs that Archer had brought over yielded a key. It used the fourth rotor in the neutral position, making M4 equivalent to the three-rotor Enigma, the only kind the shore weather stations had. Shaun Wylie, on the night shift, was having breakfast in the canteen when somebody came in and said, “It’s out!” Wylie left his food and went back to Hut 8, where he confirmed the work and telephoned a superior about it. Then he went to Hut 6, Hut 8’s military counterpart. John Monroe was on duty, running the night shift. “It’s come out in the zero position!” Wylie exulted. “Can I have six bombes?” Though Bletchley then had forty-nine bombes, they were in such demand that getting their allocation changed would almost require an act of Parliament, Monroe thought. But recognizing both the importance of the matter and the limitations of his power, he said yes, Wylie could have them—until the day shift came in. In fact, Hut 8 kept them longer.
The cryptanalysts learned that the four-letter indicators for regular U-boat messages were the same as the three-letter indicators for weather messages that same day except for an extra letter. Thus, once a daily key was found for a weather message, the fourth rotor had to be tested only in twenty-six positions to find the full four-letter key. This gave Hut 8 little difficulty. Later that Sunday, solutions of the four-rotor Enigma U-boat key, called SHARK by G.C.& C.S., started to emerge.
Late in the afternoon, Hut 8 telephoned the Submarine Tracking Room to report the break into SHARK. The call was taken by Winn’s assistant, Reserve Lieutenant Patrick Beesly. The news thrilled him. In an hour the first intercept came off the teleprinter. It revealed the position of fifteen U-boats. Other intercepts arrived in an endless stream until the early hours of the next morning. Beesly began struggling with the difficult and confusing situation revealed by the intercepts. The night was exhausting but exciting. Gradually over the next weeks the situation clarified. The solutions again permitted evasive routing of the convoys, and sinkings were halved in January and February 1943 from th
e highs of the two previous months. And, as with the Magdeburg, the U-33, the U-110, the Krebs, and the weather ships, the precious papers that helped make this success possible had come from an enemy warship.
19
ENTER THE AMERICANS
THE GERMAN NAVAL MESSAGES THAT WERE MUCH OF B.P.’S RAISON d’être were intercepted at two main posts: one on the cliffs near Scarborough on the North Sea coast, the other in the center of southern England, near Winchester. Some of the intercept operators, or monitors, were Royal Navy sailors; many others were Wrens.
Among the latter was Alice Axon, a prim and proper teenager who also did direction-finding. As a child in Gravesend, east of London, she had always been keen on signals: she had practiced semaphore as a Brownie and Morse code as a Sea Ranger. At seventeen, the slim young woman volunteered for the Wrens, hoping to be a wireless operator. She stood at the top of her class during the first three months of radio training in London and the second three months in the country. Axon and her fellow students were puzzled because they were taught only to receive Morse, at twenty-five words per minute, and not to send it.
