The Battle of the St. Lawrence (33 page)

The cryptic sentence “Only Aunt Kate is coming to dinner” told Lieutenant Commander Desmond (“Debbie”) W. Piers, RCN, all he needed to know. Instead of four escapees heading his way, his men and the ships hiding behind the small islands that dot the south side of New Brunswick’s Baie des Chaleurs had only one man and the U-boat sent to pick him up to hunt. “I didn’t know it at the time,” Piers recalls, “but the man turned out to be Wolfgang Heyda. Our plans were set to catch the really big fish, including U-boat ace Otto Kretschmer, who were planning to escape from a POW camp in Bowmanville, Ontario, and make their way to the shores of New Brunswick to be picked up.
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But they never got out of the camp. Heyda did, and the plan worked. We caught him before he could make contact with the waiting submarine. Unfortunately, we were unable to coax the U-boat to the surface. Lieutenant Pickford’s task force depth-charged it, but it escaped,” recalls Piers, who stayed in the RCN after the war, rising to become a rear-admiral.

By the time Piers received that message, Operation Kiebitz, the planned breakout of Otto Kretschmer (U-99) and nineteen other men—including Horst Elfe (U-93), H. J. von Knebel-Doberitz (Kretschmer’s executive officer) and Wolfgang Heyda (U-434)—had been underway for more than a year. The plan, developed by Kretschmer in the Bowmanville POW camp and approved by BdU, was audacious. The Lorient Espionage Group—the name Kretschmer gave to the 150 cell—set out to build a tunnel that would pass under Camp 30’s fence. Since the camp’s guards were constantly on the lookout for tunnelling, Kretschmer decided to hide the main tunnel by having his diggers build several 90-metre-long false tunnels that if found would throw the camp’s authorities off the scent.

Called “a masterpiece in engineering” by Inspector Clifford W. Harvison, who later became Commissioner of the RCMP, the main tunnel was almost 300 metres long. Reinforced by beams and ventilated by air ducts made from cans placed end to end, it was lit by a string of lights that tapped into the camp’s power supply. As well, secreted within it were five hundred boxes of food. Kretschmer’s engineers even built a push-cart rail system that allowed the quick removal of soil, which was then put in sacks and carried to the barrack’s attic. There the soil was packed behind the cork insulation.

Dönitz learned of the planned breakout in the first week of April 1943 when his receptionist, Mme. von Knebel-Doberitz, received a letter from
her husband through the Red Cross. Using the Ireland code, memorized by all U-boatmen, Knebel-Doberitz informed BdU of the plan to break out of Bowmanville and make their way to Pointe Maisonette on the Baie des Chaleurs.
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Hidden in Mme. Knebel-Doberitz’s response to her husband was confirmation of the rendezvous planned for September 27 or 28. Later, using radio equipment either smuggled into the camp or constructed by an imprisoned aviator, Kretschmer was able to send and receive short Morse-code messages.

The Lorient Espionage Group was not, however, the only group active. In late July, Canadian Naval Intelligence summoned Harvison to a meeting where he was told that Naval Intelligence had cracked “certain codes” which indicated that the prisoners in Camp 30 were planning a mass breakout and that once escaped, the prisoners were to be picked up by a U-boat in the Baie des Chaleurs. To his surprise, as Harvison recorded in his memoir,
The Horsemen,
the navy did not want the RCMP to move into the camp, search it and put an end to Kretschmer’s plans. The navy “added an almost equally incredible request. They had very compelling reasons for wanting to capture the German submarine, reasons that went far beyond the normal desire to make such a catch.” Written in 1967 before the Ultra secret was declassified, this tortured circumlocution refers obliquely to the navy’s desire to capture the submarine’s Enigma machine.

The RCN wanted to use the escapees as bait to lure the U-boat to where it could be captured, but, according to Harvison, everyone at the meeting recognized that “‘shadowing’ escapees for some six hundred miles must be ruled out as totally impracticable.” Instead, Harvison and Naval Intelligence decided on a two-phase operation. They would let the planned breakout occur, but they would station guards around the camp to immediately capture the escapees. To lure the submarine closer, as soon as the escaped prisoners were recaptured Naval Intelligence would broadcast information on radio frequencies monitored by German submarines off the Canadian coast—“news regarding the mass break, but nothing about the capture of the escapees.”

To establish the perimeter, Harvison needed to know where the tunnel’s exit would be. Along with Major Fairweather, a technician at Camp 30, Harvison spent a night “crawl[ing] along the lip of earth between the fence
and the ditching working with a microphone attached to a long probe which we pushed into the ground every few yards.” It did not take long for him to hear sounds of tunnelling. “Judging from the sounds that reached us over the microphone, the tunnel already extended a considerable distance from the main building toward the centre of the wooden fence” that ringed the camp. “We could clearly hear sounds of digging—long drawn-out scraping noises, as the receptacles containing loose earth were dragged back along the tunnel. At times, we could hear voices. The sounds were distant and muffled but unmistakable.” Using this information, Harvison planned where he would place his men.

At the Crime Detection Laboratory in Regina, RCMP staff sergeant Stephen H. Lett examined a copy of a popular novel that had been sent to a POW in the camp. In his 1974 article, Lett reported finding that the cover binding “concealed a number of valuable escape documents in the form of a marine map of the eastern Canadian coast, a forged Canadian National Registration card and a quantity of Canadian and American currency.” Lett’s skill as an analyst was, if anything, equalled by his skill as a forger. For the navy’s plan to work, the POWs in Bowmanville had to receive the intercepted information without knowing that it had been tampered with. Under Lett’s direction, the Crime Detection Laboratory reconstructed the book—its poor-quality yellow cover was photostated—and secreted within its binding the intercepted information.

Three-quarters of a continent away from Regina, the RCN was putting together its own plans. “Admiral Murray sent for me,” recalls Piers.
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“When I entered the room I saw a submarine captain [Captain W. L. Puxley, a Royal Navy captain on loan to the RCN] and captain in charge of the destroyers [Captain J. S. Prentise, RCNVR], all of them senior to me. The admiral cut right to the point, saying, ‘Gentlemen, I want you to know that this is absolutely super-secret. You are to tell nobody, not even your wife. Up in Bowmanville, there is a POW camp, and there are people like Kretschmer there who are planning to break out. Piers,’ he said, turning to me, ‘your job is to capture the submarine.’ He told us that we had the date and the place, and indeed the challenge that the shore would make and the reply that would be expected from the U-boat.”

Piers left Halifax immediately. His cover story, used even with his wife,
was that he was going to New Brunswick to look for an area where the water conditions were better for anti-submarine training—believable enough, since Piers was then anti-submarine training commander.

When he came back, Piers presented his plan to Murray, who then sent it to the British Admiralty. Piers’s plan called for the installation of two radar trucks, a mile on either side of the lighthouse at Miscou Point, in which he would set up his headquarters. To capture the U-boat, Piers commandeered a lobster boat, had it armed and trained a boarding party. “We trained them very thoroughly in the tactics for boarding the U-boat,” he recalls. “Once they jumped from the lobster boat, which we chose because of its low keel, they’d throw a chain through the open conning tower. The party had grenades, revolvers, daggers and smoke grenades if necessary.”

Several days after sending the plan to the UK, Murray received orders to shelve it, because, Piers said in a 1998 interview with Tony German, “the Admiralty was concerned that if they had successfully captured the U-boat, the Germans would have immediately realized that the Enigma cipher system [the Ultra secret] was compromised.” Instead of trying to capture the U-boat, Piers was now ordered to set up a shore party to capture any POWs who might slip through Harvison’s net and to have ships at the ready to sink the U-boat if it was seen or picked up by radar.

Piers’s revised plan was divided into two parts, the second of which was only somewhat less audacious than his plan to board the U-boat. The first part of the revised plan retained the installation of the radar sets and the shore patrol centred on the lighthouse at Miscou Point. The second part involved one of Canada’s most experimental ships, HMCS
Rimouski.

During their 1943 refits, in addition to having their fo‘c’sles lengthened and their bridges widened,
Rimouski
and HMCS
Edmundston,
original Flower-class corvettes, were equipped with an experimental system called “diffused lighting.” “It may seem counterintuitive,” says Marc Richard, a McGill University researcher who has studied Professor Edmund Godfrey Burr, the system’s originator, “but what Burr discovered by accident—he had been watching a plane landing at night when suddenly it all but vanished as it passed over a field of newly fallen snow that reflected the light of the moon into the sky—was that diffused lighting reduced the brightness
contrast between the ship and the background, which made the ship almost invisible from a distance.”

Even on the darkest night, because of starlight, moonlight and even light reflecting off high-level atmospheric dust, the sky is not completely dark. The contrast between the sea and sky allows sailors to see the horizon. It also allowed U-boat captains to spot the distinctive silhouette of blacked-out ships.

“Diffused lighting,” says Richard, “was achieved by the use of fifty-nine bluish-green floodlights—twenty-six aimed at
Rimouski
‘s hull and thirty-three at its superstructure. The light did not make the ship completely disappear, but it did make it much more difficult to see. Depending on weather conditions and the range at which the ship was being observed, diffused lighting could reduce a ship’s visibility by up to 70 per cent.”

Captain John Pickford, who at twenty-two was the youngest commander of a major Allied warship in the Second World War, later recalled the effect as being “really weird. After years of being on a darkened ship, you could suddenly read messages on the bridge while knowing that you couldn’t be seen.”

Piers’s plan was for
Rimouski
to lead a flotilla that included a British destroyer, three other Canadian corvettes and three Bangor minesweepers against the U-boat. We were “to steam slowly with navigational lights and diffused lighting on, pretending to be a small coastal vessel. Once in range, our orders were to open fire. If she dived, our orders were to fire depth charges,” recalled Pickford, now a retired rear-admiral.

As Piers fine-tuned his plan, U-536, an IXC-40 U-boat commanded by
Kapitänleutnant
Rolf Schauenburg, left Lorient. No doubt the mission, code-named Operation Kiebitz in Schauenburg’s sailing instructions, appealed to both his sense of adventure and his ideology. Schauenburg’s war record gives ample proof that he was a committed, “fanatical and idealistic Nazi,” as he was characterized by the British intelligence officers who interviewed him after he was captured. Interned after the scuttling of the pocket battleship
Graf Spee
on December 17, 1939, in the harbour of Montevideo, Uruguay, Schauenburg escaped and made his way across South America disguised as a merchant. Recaptured, he escaped and was captured again before returning to Germany through Chile in January 1941.

On September 12, 1943, U-536’s radioman decoded the message “Execute Operation Kiebitz—No Amplification.”
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Soon after Schauenburg ordered his navigator to shape a course that would take them from the Azores to the Baie des Chaleurs. Two weeks later, U-536 was close enough to Maisonette Point for Schauenburg to “see [through his periscope] cars driving around, houses, even people.”
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His orders were to wait there for two weeks, surfacing for two hours each night.

But on September 14, two days after Schauenburg left the waters off the Azores and a week before the planned escape, Kretschmer’s plans fell apart. In the middle of the night, the ceiling in the barracks collapsed under the weight of the earth secreted above it. Alerted by the noise of the collapse, the camp’s guards rushed into the barracks and, realizing what had been going on, began searching for tunnels. Kretschmer and the Lorient Espionage Group did not, of course, know that the RCMP knew precisely where the main tunnel was, so they could not know that the search was carried out so that only the dummy tunnels were found.

Relieved that the main tunnel had apparently gone undetected, Kretschmer ordered the escape moved up to the following night. Then, during the afternoon of the fifteenth, after a heavy rainfall, a prisoner digging close to the camp’s fence to fill a flower box pushed his shovel into the ground and the earth beneath the shovel gave way, exposing the main tunnel to the guards, who, rifles at the ready, reportedly said to the exposed subterranean diggers, “Well, well—where do you guys think you’re going?”

The collapse of Kretschmer’s escape plans did not, however, put an end to the operation of the Lorient Espionage Group. Elfe and Knebel-Döberitz immediately conceived of an even more daring plan. Using wires and wood taken from a window sash, they fashioned a bosun’s chair that could slide along the power lines and thus out of the camp. Kretschmer’s group chose twenty-nine-year-old Wolfgang Heyda, commander of U-434, for the breakout because he was only five foot six and slightly built.

Late in the afternoon of September 24, Heyda changed into civilian clothes that had been smuggled into the camp, and hid in the camp’s sports shack. To cover his absence during the evening parade, his fellow inmates walked a mannequin in his place. After dark, to draw the guards’ attention away from where Heyda was planning to scale a pole and then slide to freedom down
the power line, the prisoners staged a fight on the far side of the camp. It took Heyda just a few moments to climb the pole, affix his bosun’s chair to the power cable and slide to safety.
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