RCN ships tried to capture U-boat after prison break

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Navy News / April 27, 2020

You might think the following events took place in an elaborate spy novel.

But they actually happened.

In the fall of 1943, German U-boat captains attempting to escape from a prisoner of war (POW) camp in Ontario led the RCMP directly to a rendezvous site on the northern shore of New Brunswick.

Warships of the Royal Canadian Navy (RCN), under the command of Lieutenant-Commander (LCdr) Desmond Piers, waited quietly nearby for a U-boat to surface and attempt rescue of its compatriots.

German U-boats were the scourge of the ocean. As the Battle of the Atlantic raged during the Second World War over 75 years ago, they prowled the depths, attempting to sink Allied convoys bound for Europe with supplies.

Four German U-boat captains had been captured after battles, including the ace of the U-boat fleet, Otto Kretschmer, who had sunk more than 208,000 tons of allied shipping.

Called the “Atlantic Wolf” for his successes, his reign of terror came to an end in March 1941 when his U-boat was sunk southeast of Iceland.

Three other submarine captains, Horst Elfe, Hans Ey and Hans Joachim Knebel-Döberitz, were also captured, and all four were sent to Camp 30, a POW camp in Bowmanville, Ont.

Camp 30, unlike most prison camps, was not really a hardship. It had lots of things that others lacked such as an indoor pool, athletic complex, soccer and football fields. Meals were good and prisoners had access to medical and dental care. They could send and receive mail from home, and they were paid by Germany as usual.

But they were still locked up. Kretschmer began to formulate a plan to escape.

Before proceeding though, he needed permission from the senior submarine commander in the German Navy, Karl Donitz. This was accomplished by sending coded letters via Red Cross packages. He proposed that a U-boat be sent to pick up the escapees, and suggested a location near Pointe de Maissonette in Chaleur Bay, N.B.

The escape attempt was approved and shortly afterwards preparations began.

Kretschmer intended to burrow under the camp in a tunnel. To throw off camp guards, three tunnels were created. Over 150 prisoners took part in the digging. The intended escape route would extend beyond the camp and the barbed wire that surrounded it. At the same time, others prepared false identification papers, civilian clothes and dummies to be used as substitutes for the escapees.

While the work was being carried out, coded letters with progress reports and updates were sent to Germany.

In August 1943, through a coded letter and radio transmission, the date was set for the break out and Kretschmer was advised that U-536 would surface every night for two weeks beginning on September 23, 1943.

Kretschmer and his men would have 14 days after their escape to make it to the rendezvous location.

Unbeknownst to Kretschmer, his coded messages had been intercepted by Canadian military intelligence and the RCMP, who were screening all prisoner communications.

Charles Herbert Little, Commander of Canadian Military Intelligence during the Second World War, tells how they discovered the escape plan: “A suspicious parcel was sent to one of the German prisoners at the Bowmanville camp. After opening it cautiously, we found a map for a rescue operation in the Chaleur Bay. Alerted of this, I went to see Admiral (Percy) Nelles [Chief of the Canadian Naval Staff], as well as the Army officer responsible for the prisoner of war camps, to explain the situation to them and to propose a plan.”

Part of the plan allowed the prisoners to begin their efforts to escape.

The military, RCMP and camp guards monitored the prisoners as they began to dig several tunnels. The prisoners had created a crude railway to haul the soil out of the tunnel. The weight of the excavated soil collapsed part of the ceiling in the building where they were hiding it.

The camp guards, aware of what was going on, let the tunnelling continue.

When the prisoners attempted their escape, the RCMP moved in and seized them. In the confusion, one of the German officers, Wolfgang Heyda, also interred at the camp, managed to escape over the walls using a crude zip-wire on electrical cables.

Heyda eluded search parties and the massive police response and somehow made his way on Canadian National Railway passenger trains from southern Ontario to Pointe de Maisonnette. He arrived at the location at the appointed time to meet the U-boat, only to be arrested by the RCMP and naval personnel already there.

LCdr Piers, after questioning him, unmasked Heyda, despite his initial denials.

Recollecting the event after the war, LCdr Piers remarked, “I offered my regrets, but I had to return him to detention. I telephoned the RCMP. They came in a car and, a few moments later, I handed him over to them.”

Now authorities set their sights on capturing the U-boat.

The RCN and the Canadian Army established a portable surface radar array on shore at the Pointe de Maisonnette lighthouse, which would be used to locate the submarine by the naval task force, led by His Majesty’s Canadian Ship (HMCS) Rimouski.

Rimouski, under the command of Lieutenant (Lt) John Pickford, was outfitted with an experimental diffused lighting system that was considered revolutionary at the time.

The camouflage used light projectors to make a ship nearly invisible to enemy vessels after dark. It rendered the ship invisible from a distance, difficult to see and identify when closer.

Lt Pickford described Rimouski’s role in the operation: “They had installed a radar station and observation posts on the beach, and when they received an indication of the presence of a U-boat, HMCS Rimouski with its luminous camouflage was to abandon the patrol and enter the bay on its own. Sailing slowly with its navigation lights and its luminous camouflage, it would create the illusion of being a small ship until it was able to capture the submarine.”

The rest of naval task force, including HMC Ships Chelsea, Agassiz, Shawinigan and Lethbridge, waited nearby in Caraquet Harbour, obscured by Caraquet Island.

On the night of September 26, 1943, U-536 arrived off Pointe de Maisonnette for its scheduled nightly rendezvous.

The RCN and Canadian Army personnel on shore signaled with a light that the escapees were to have used. An English officer who spoke German also attempted to contact U-536, but was unsuccessful.The U-boat commander was now suspicious, particularly after his hydrophones picked up the sound of the Canadian task force nearby.

He opted to remain submerged and began to evade the Canadian warships, which searched throughout the night and attempted unsuccessfully to attack it with depth charges.

Despite evading the Canadians’ trap that night, U-536 was sunk the following month northeast of the Azores by HMC Ships Calgary and Snowberry, along with His Majesty’s Ship Nene, claiming 38 lives.

While it may read like a gripping spy novel, it was the skill, determination, ingenuity and teamwork of combined military and civilian forces that caught the POW escapees, and almost ended U-536’s reign at sea.


A Blue Water Navy” by W.A.B. Douglas

Escape from Camp 30” by Chris Chlon, Esprit de Corps, May 2015