Sink and Destroy

by Edward Kay

  When the war began, Canada’s Navy, like its Army and Air Force, was small, understaffed and ill-equipped for a major conflict. The Great Depression had thrown the Canadian government into a decade-long financial crisis, resulting in a slash-and-burn approach to spending that left the military services critically underfunded. Even when Adolf Hitler came to power and began talking tough while building up the German armed forces, Canada’s prime minister, William Lyon Mackenzie King, at first reduced funding for the country’s armed forces, until it became clear that war was very likely. Then the government hurriedly began expanding its military.

  Even so, on the eve of World War II the Royal Canadian Navy’s total combat forces consisted of only six destroyers and five minesweepers, along with two training vessels. Astonishingly, for a country with so many thousands of kilometres of coastline, Navy personnel totalled only 145 officers and 1674 men. To put that in perspective, it is less than half the number of personnel serving in the navy of the land-locked nation of Bolivia in 2014.

  Stretched between bases on both the Atlantic and Pacific coasts, in Halifax and Victoria, that small number of ships and sailors was clearly inadequate even to protect Canada’s own waters, let alone offer much support to its allies.

  At the beginning of the war Canada and the other Allied nations were much more concerned about the Nazi’s surface fleet of battleships and heavy cruisers than they were about German submarines. The latter were known as U-boats, after the German U-boot, an abbreviation for Unterseeboot — literally meaning “undersea boat.” At first the German Navy, or Kriegsmarine, didn’t take their U-boats as seriously as their surface fleet either. But following some spectacular military failures by the German Navy’s surface fleet, combined with some equally spectacular successes by the submarine forces under the command of Admiral Karl Doenitz, Hitler began focusing his attention on his submarine fleet as the best way to choke off the supply of food, weapons and other supplies to Great Britain.

  In 1940 when Hitler’s forces steamrolled their way over France, Belgium, the Netherlands and Luxembourg in the so-called Blitzkrieg or “Lightning War,” strangling Britain’s supply lines became a distinctly more likely scenario.

  The fall of Western Europe was a dangerous situation for the Allies for a number of reasons. Because Germany now controlled France, Belgium, the Netherlands and Luxembourg, they now also controlled the industry and agriculture of those countries. They could appropriate defeated nations’ goods and labour forces while denying those same resources to Great Britain.

  Some may have viewed Britain as an “unsinkable aircraft carrier” from which the fight could be taken to the Nazis. But as unsinkable as the island might have been, lacking weapons to fight with and food to feed the soldiers and civilians, Great Britain would become an aircraft carrier with a starving population and dwindling resources, while its enemy grew stronger.

  The United Kingdom had been a trading nation for hundreds of years. Its wealth had come from importing raw materials, then turning those raw materials into finished products it could sell for a good profit all over the world. Following that policy, Great Britain became so successful that its population outgrew its capacity to feed itself. In peacetime that didn’t matter. Britain could simply import the food it needed. But in wartime, isolated on an island and fighting an enemy determined to blockade it, the situation became very different. The equation was simple, and seen through the lens of the early war years, it must have been frightening. Britain needed to import half a ton of food per person per year to feed itself. It also needed to import gasoline and oil to power its airplanes and tanks, and run its industries. All of it had to be brought in by ship. Knowing that, Hitler was determined to sink those merchant ships so that Britain would be starved into submission and forced to surrender.

  After the Nazis had defeated France, the U-boats could be moved from ports on the Baltic Sea in Germany to bases on the French coast — close to Great Britain and the Allied shipping lanes. In one stroke the Germans had brought their submarines 800 kilometres closer to the battle zone, cutting down their travel time to the killing fields and giving the U-boats as much as two weeks more time at sea to stalk and sink merchant ships before returning to port. Things went so well for the U-boat crews that they began to refer to this as the “Happy Time.” German and Italian submarines sank nearly three hundred Allied merchant vessels between June and October of 1940. That was far faster than they could be replaced. If the carnage continued at that rate, the Allied merchant fleet would be torpedoed into oblivion, and Great Britain starved into surrender.

  At the beginning of the war Allied fighting ships were equipped with ASDIC, a technology developed by Great Britain more than twenty years earlier, during the First World War. ASDIC, or “sonar” as the Americans called it, was a device that searched for submarines by using acoustical pings, not unlike the echolocation system that bats use to track their prey as they fly through the dark. Under the ship were several hydrophones, which picked up the sound of the returning echoes. If the echo of a ping came back, the ASDIC operator knew there was something beneath his ship, reflecting the signal back to him. By gauging the tiny differences between when the echo reached each of the hydrophones, a good ASDIC operator could judge not only the depth of the submarine, but its course in relation to his own ship.

  Once the ASDIC operator had the submarine under surveillance, he gave a constant stream of updates to the captain, who then gave orders through the chain of command to the depth-charge crew. The depth charge, developed during World War I, was the key weapon used against submarines throughout much of the Battle of the Atlantic. Each one, looking like an oil drum, was packed with 130 kilograms of explosives. Its fuse was controlled by the amount of water pressure it detected, so the charges could be set to detonate at a particular depth. The operators would adjust the charges to explode at whatever depth the ASDIC operator believed the submarine to be. The charges could be rolled off a rack at the back of the ship, or fired from launchers. Under the right conditions it was an extremely effective way of killing submarines.

  But many factors could make ASDIC inaccurate. Sometimes the equipment mistook whales and large schools of fish for submarines. Other times, as often happens in the ocean, the various layers of water under a ship were different temperatures, and that variation distorted the ASDIC signal even if contact was genuinely made with a U-boat, creating an inaccurate picture of where the submarine was lurking. Although depth charges created a massive explosion and huge columns of water that were satisfying for crews to watch, their detonation disrupted the ASDIC signals, sometimes giving enemy submarines a chance to escape if the sub wasn’t fatally damaged in the first volley. It has been estimated that a depth charge had to explode within 5 metres of a submarine to sink it, and in the vastness of the ocean, landing a depth charge within 5 metres of an invisible target is extremely difficult.

  But although ASDIC was effective under the right conditions, it had one major limitation: it could only detect submerged submarines. U-boats were slower underwater and required battery power when submerged, so they usually ran on the surface when they weren’t afraid of being spotted — for example, at night when they were moving in on a target. In the early stages of the war, the Allied sailors had nothing to detect surfaced submarines with, except for their eyes. That limitation often proved deadly.

  Later, Canadian warships became equipped with radar, which allowed them to detect surfaced submarines even on moonless nights or in fog. Another device that was useful for convoy duty was something known as HuffDuff, the sailors’ slang for High-Frequency Direction Finder. The Allies had secretly created a web of radio signal detection stations from land bases throughout the North Atlantic region. The Germans had a powerful encryption device, known as Enigma, that for much of the war outsmarted Allied intelligence. But it made the Kriegsmarine so confident that their radio messages couldn’t be decoded, it apparently didn’t occur to the U-boat commanders that even if th
ey weren’t giving away the contents of their encoded orders and reports, they were giving away their positions simply by sending radio signals. With the Allies’ multiple radio-signal detection stations all over the North Atlantic region, they could triangulate the U-boats’ radio signals and with reasonable accuracy detect where German submarines were. This, for a time, allowed Allied Naval commanders to steer convoys away from the unwitting German submarines, which would lie in wait in large wolf packs, only to find the sea around them completely empty of targets, which had been re-routed far to the north or south.

  The advantage shifted once again when the Germans for a time cracked the Allied codes. Then, even when Allied commanders ordered their convoys to change direction around a wolf pack, they would discover the Germans waiting for them wherever they went.

  Aircraft played a major role as well. German long-range bombers — in particular the four-engine Focke-Wulf 200, known to the Allies as the Kurier — were deadly. Operating from bases in Norway and France, the Fw 200 bombers could attack Allied ships far out in the Atlantic. The Allies tried to counter that threat with shore-based fighter planes, but the Kurier’s long range initially allowed it to prey on Allied convoys that were beyond the reach of land-based Allied fighter planes.

  Gradually the Allies closed the gap here too. At first the British built CAM ships, merchant vessels with one catapult-launched Hawker Hurricane fighter plane on each. When a German bomber was detected approaching a convoy, the Hurricane was catapulted into the air to shoot down the bomber before it could attack the ships or report their position to U-boats. It was a truly desperate measure, since there was no flight deck for the Hurricane pilot to make a return landing. After his single mission, he had to bail out of his plane and parachute as close to a rescue ship as possible. It was very risky, as parachuting into the frigid and rough water of the North Atlantic was an extremely dangerous undertaking in which a pilot could easily drown. A few months after this stopgap measure was adopted, the Allies built proper flight decks on several merchant ships, allowing fighter planes and light anti-submarine aircraft to operate.

  By early 1942 the Germans were building three U-boats for every one that the Allies sank. The Allies were barely containing the U-boats already in service. In the first half of that year the Allies lost nearly six hundred merchant ships.

  Gradually, as the Allies gained experience and made some technological improvements, they became more of a match for their German counterparts, raising the numbers of U-boats sunk. But then the Germans modified their Enigma coding machine again, and until the Allied code breakers could catch up, which happened in the final days of 1942, convoy commanders were again working almost in the dark.

  In late 1942 the Germans were producing more U-boats than ever, and despite the Allies’ best efforts they lost more than 100 ships per month during October, November and December of 1942. Then came a reprieve of sorts in January and February of 1943. It was partly because of the Allied code breakers’ success in late December, and partly because the winter storms were particularly vicious. The waves were so towering, they kept the U-boats out of action much of the time because their torpedoes couldn’t be targeted accurately in high seas.

  In March 1943 the Germans once again gained the upper hand. In just one four-day period that month, the U-boats sank 21 ships. This rate of loss was completely unsustainable for the Allies.

  Just as quickly as the scale had tipped in the Nazis’ favour, it shifted to the Allies’ advantage. B-24 Liberator bombers were at last assigned to convoy escort duty instead of being monopolized for bombing campaigns over Europe. Operated by the RCAF from bases in Newfoundland, and by Coastal Command on the other side of the Atlantic, the VLR B-24 Liberators were finally able to provide continual air cover, even in the middle of the Atlantic, attacking U-boats outright as well as acting as spotters for surface vessels. It has been argued that the Battle of the Atlantic might have been won much sooner had more Liberators been made available for convoy patrol duty instead of being used on bombing missions against ground targets over Europe.

  In May of 1943 Allied ships and aircraft sank forty-two German U-boats, a record number. Admiral Doenitz’s son was among the victims. The admiral was so shocked by the staggering losses, he temporarily withdrew his U-boat fleet from the North Atlantic.

  Some historians say that was the end of the Battle of the Atlantic, because the German submarines never came back in the same numbers as before, and never achieved anything approaching their previous success rate.

  Allied convoys increasingly sailed across the North Atlantic unscathed. But while the Battle of the Atlantic might have officially ended from an historical point of view, for two more long years, until May 7, 1945, sailors and submariners continued to die.

  Allied forces had taken an immense toll on their enemy. Of the approximately forty thousand German submariners who went to sea, nearly thirty thousand never made it home, one of the highest mortality rates of any branch of any armed force in the world. But the Battle was very costly for the Allies as well: 36,200 Allied military personnel were killed, and 36,000 merchant seamen lost their lives.

  Images and Documents

  Image 1: Corvette HMCS Chambly in Halifax in April 1941. The ship took part in missions, and was used for training, throughout the war.

  Image 2: A flotilla of escort ships sails to Britain from Canada in 1941. The photo is taken from HMCS Chambly.

  Image 3: Though corvettes were very seaworthy, they were far from comfortable — getting soaked was a constant experience for the crew.

  Image 4: Two ASDIC operators aboard HMCS Battleford listen intently for telltale pings that indicate the presence of a nearby submarine. American forces referred to ASDIC as sonar.

  Image 5: DEMS (Defensively Equipped Merchant Ships) personnel take part in a gun drill.

  Image 6: A depth charge is fired from the deck of the corvette HMCS Pictou.

  Image 7: The corvette HMCS Chebogue shows signs of massive damage inflicted by a torpedo from Germany’s U-1227 submarine. Her stern was torn off and she was towed to Wales, out of commission.

  Image 8: Allied sailors hoist the White Ensign over Germany’s Kriegsmarine flag on captured U-boat U-190 in St. John’s, Newfoundland.

  Image 9: As the war ended, German U-boat U-889 surrenders off Shelburne, Nova Scotia. A Royal Canadian Navy crew prepares to board the submarine.

  Image 10: Pale grey areas indicate where Allied planes could provide cover for the convoys. The size of the mid-Atlantic Air Gap shrank as planes with longer range became available.

  Credits

  Cover cameo (detail): Mr. Carl Bedal, Royal Canadian Navy Volunteer Reserve, © and by permission of The Memory Project/Historica Canada and Carl L. Bedal.

  Cover scene (detail): Depth charges exploding after being dropped by the destroyer HMS VANOC…, Lt. H.W. Tomlin, Admiralty Official Collection, Imperial War Museum, A 4570.

  Cover details: Andreykuzmin | Dreamstime.com; aged paper © Shustterstock/Filipchuck Oleg Vasilovich; belly band © raplett/istockphoto; (back cover) label © Shutterstock/Thomas Bethge.

  Image 1: Corvette HMCS Chambly in Halifax, April 1941, Library and Archives Canada / Department of National Defence, PA-105255.

  Image 2: View from H.M.C.S. Chambly, the First Corvette Flotilla en route from Halifax, [N.S.], to St. John’s, Newfoundland, 23 May 1941, Library and Archives Canada / Department of National Defence fonds, PA-037447.

  Image 3: View — probably aboard H.M.C.S. Trillium, 1943, Library and Archives Canada / Department of National Defence fonds, PA-037474.

  Image 4: R. Cosburn and Lieutenant F.A. Beck (right) at the Asdic set on the bridge of H.M.C.S. Battleford, Sydney, Nova Scotia, Canada, November 1941, Library and Archives Canada / Department of National Defence fonds, PA-184187.

  Image 5: DEMS (Defensively Equipped Merchant Ships) personnel taking part in gun drill aboard an unidentified merchant ship, Halifax, Nova Scotia, Canada, 29 November 1942, Libra
ry and Archives Canada / Department of National Defence fonds, PA-016528.

  Image 6: Firing of a depth charge from the corvette H.M.C.S. Pictou at sea, March 1942, Library and Archives Canada / Department of National Defence fonds, PA-116838.

  Image 7: Damage done to the Canadian Frigate H.M.C.S. Chebogue after a torpedo from a German U-Boat ripped into her port quarter, 1944, Library and Archives Canada / Department of National Defence fonds, PA-141300.

  Image 8: Conning tower of German submarine U-190, showing Schnorkel mast and White Ensign flying over Kriegsmarine flag, 1945, Library and Archives Canada / Department of National Defence fonds, PA-145577.

  Image 9: Surrender of the German submarine U-889 off Shelburne, Nova Scotia, Canada, 13 May 1945, Library and Archives Canada / Department of National Defence fonds, PA-173333.

  Image 10: Map by Paul Heersink/Paperglyphs.

  The publisher wishes to thank Janice Weaver for her detailed checking of the factual elements, and naval historian Dr. Roger Sarty, co-author of No Higher Purpose: The Official Operational History of the Royal Canadian Navy, Vol. II part 1: 1939–1943 and A Blue Water Navy: The Official Operational History of the Royal Canadian Navy, Vol. II, Part 2: 1943–1945, for his comments on the manuscript.

  About the Author

  Edward Kay became interested in the Battle of the Atlantic when he found a wartime newspaper article which included an interview with one of his uncles, Bob McDonald. In the article, Petty Officer McDonald was interviewed about his World War II experiences, particularly the time when his ship sank a U-boat. Three of Edward’s uncles served on combat vessels of the Royal Canadian Navy during the war, but he says “they were humble and never spoke of their experiences. This article made me curious to find out more, and when I did, I knew it was a story that should be told.” The story of Bill O’Connell’s family in Iroquois is also partially based on Edward’s own family history.