As German troops were entering Poland and the "Phoney War" began on the Western Front in late 1939, the longest naval battle of the Second World War was already raging. The Battle of the Atlantic, the ultimate objective of which was to control navigation in the North Atlantic Ocean, was the most costly Allied naval engagement in terms of human lives, ships and goods. This fierce struggle between the most highly industrialized nations of the world ultimately made a significant contribution to the Allied victory in Europe by maintaining the supply line between North America and Great Britain. As one of the belligerents involved, Canada played a key role by providing a convoy assembly point from the beginning through to the end of the war.
As German troops were entering Poland and the "Phoney War" began on the Western Front in late 1939, the longest naval battle of the Second World War was already raging. The Battle of the Atlantic, the ultimate objective of which was to control navigation in the North Atlantic Ocean, was the most costly Allied naval engagement in terms of human lives, ships and goods. This fierce struggle between the most highly industrialized nations of the world ultimately made a significant contribution to the Allied victory in Europe by maintaining the supply line between North America and Great Britain. As one of the belligerents involved, Canada played a key role by providing a convoy assembly point from the beginning through to the end of the war.

© 2008, CHIN. All Rights Reserved.

An escort of Corvettes

An escort of Corvettes

Musée naval de Québec, Deguise collection.

© Musée naval de Québec, Deguise collection.


On September 9, 1940, the forty-one merchant vessels assembled in Bedford Basin at the port of Halifax were about to embark on a perilous trans-Atlantic crossing. This convoy – named HX 72 – was the seventy-second convoy to begin the crossing between Halifax and Liverpool since September 16, 1939. These British, Canadian, Norwegian, Greek, Dutch and Polish ships carried thousands of tons of petroleum products, steel, cotton, wood, TNT (explosives), phosphorus, sulphate, aircraft engines, aircraft, tanks and other pieces of military equipment. The convoy sailed under the supervision of the Royal Canadian Navy’s Naval Control of Shipping Division. For the first two days of the crossing – a trip expected to take fifteen days – HX 72 was escorted by the warships HMCS Saguenay and HMCS French. The escort group was later changed to seven Royal Navy warships, many of whose crews included sailors from the Royal Canadian Naval Volunteer Reserve.

Tragedy occurred at mid-crossing. On September 20 the German submarine U-47 made initial visual contact with HX 72. With only one torpedo remaining onboard, the German submarine waited until eight other sub Read More
On September 9, 1940, the forty-one merchant vessels assembled in Bedford Basin at the port of Halifax were about to embark on a perilous trans-Atlantic crossing. This convoy – named HX 72 – was the seventy-second convoy to begin the crossing between Halifax and Liverpool since September 16, 1939. These British, Canadian, Norwegian, Greek, Dutch and Polish ships carried thousands of tons of petroleum products, steel, cotton, wood, TNT (explosives), phosphorus, sulphate, aircraft engines, aircraft, tanks and other pieces of military equipment. The convoy sailed under the supervision of the Royal Canadian Navy’s Naval Control of Shipping Division. For the first two days of the crossing – a trip expected to take fifteen days – HX 72 was escorted by the warships HMCS Saguenay and HMCS French. The escort group was later changed to seven Royal Navy warships, many of whose crews included sailors from the Royal Canadian Naval Volunteer Reserve.

Tragedy occurred at mid-crossing. On September 20 the German submarine U-47 made initial visual contact with HX 72. With only one torpedo remaining onboard, the German submarine waited until eight other submarines (U-29, U-32, U-43, U-46, U-48, U-65, U-99 and U-100) arrived before acting. In the two days which followed, eleven ships in the convoy were sunk. German Kapitänleutnant (Lieutenant-Captain) Joachim Schepke’s submarine, U-100, single-handedly sank seven merchant ships during the night of September 21/22. The crews of the escorting British destroyers and corvettes could see nothing but fire and there was no way for them to retaliate against the German submarines.

The attack was a considerable innovation from the point of view of undersea warfare tactics and represented a shift in German naval strategy. Indeed, the failure of convoy HX 72 was the first major success for the "Wolfpack" attack strategy developed by the German naval commander, Admiral Karl Dönitz. In addition, instead of conducting attacks in coastal waters with combined air and surface ship support, the field of action for the U-boats was shifted to the black zone – a much safer area – of the mid-Atlantic.

It was the combined effect of surprise and the vulnerability of convoys in this part of the ocean that enabled the German navy to break up convoy HX 72 and sink 72,727 tons of cargo. Over the next six months over twenty-percent of every Allied convoy met the same fate. This equalled more than 350 ships sunk, some with all of their crew members lost.
-- Hague, Arnold, The Convoy System 1939-1945 : Its Organization, Defence and Operation, St. Catharines (ON), Vanwell Publishing Limited, 2000. 208 p.
-- O’Brien, David, HX 72 First Convoy to Die: The Wolfpack Attack that Woke up the Admiralty, Halifax, Nimbus Publishing Limited, 1999. 168 p.
-- Sarty, Roger, Le Canada et la Bataille de l’Atlantique, Montréal, Art Global, 1998.
167 p.

© 2008, CHIN. All Rights Reserved.

Lieutenant William George Mylett, who joined the Royal Canadian Naval Volunteer Reserve in Quebec City in July 1941, became the second-in-command of HMCS Dunver – the first frigate to be launched by the Royal Canadian Navy – in 1944. Mylett, the ship’s movement officer, was involved in escorting the largest convoy of the Second World War, between July 17 and August 3, 1944.

HXS 300, which consisted of 167 merchant vessels and four merchant ship aircraft carriers, assembled in nineteen columns and covered an area of thirty square nautical miles. Lieutenant Mylett’s frigate and six Royal Canadian Navy corvettes – HMCS Algoma, Dauphin, Hespeler, Longbranch, New Westminster and Westakiwin – were the close escort warships provided for the convoy. The convoy left the port of New York, sailed towards the Grand Banks off Newfoundland in order to start crossing the North Atlantic, and was divided upon arrival in the waters north-west of Ireland. Some of the merchant ships sailed to Iceland, others to northern ports in the Soviet Union, and still others to British ports at Loch Ewe, Oban, Belfast, Liverpool and Bristol. HXS 300 suffered no los Read More
Lieutenant William George Mylett, who joined the Royal Canadian Naval Volunteer Reserve in Quebec City in July 1941, became the second-in-command of HMCS Dunver – the first frigate to be launched by the Royal Canadian Navy – in 1944. Mylett, the ship’s movement officer, was involved in escorting the largest convoy of the Second World War, between July 17 and August 3, 1944.

HXS 300, which consisted of 167 merchant vessels and four merchant ship aircraft carriers, assembled in nineteen columns and covered an area of thirty square nautical miles. Lieutenant Mylett’s frigate and six Royal Canadian Navy corvettes – HMCS Algoma, Dauphin, Hespeler, Longbranch, New Westminster and Westakiwin – were the close escort warships provided for the convoy. The convoy left the port of New York, sailed towards the Grand Banks off Newfoundland in order to start crossing the North Atlantic, and was divided upon arrival in the waters north-west of Ireland. Some of the merchant ships sailed to Iceland, others to northern ports in the Soviet Union, and still others to British ports at Loch Ewe, Oban, Belfast, Liverpool and Bristol. HXS 300 suffered no losses on its trans-Atlantic crossing and safely delivered 1,019,829 tons of much-needed cargo.

There were many reasons for the convoy’s success reflecting changes in the dynamics of the Battle of the Atlantic seen from 1943 onward. First of all, there were improvements in convoy formation. For HXS 300, for example, the letter "S" – for slow – meant that the convoy’s cruising speed was slower than the nine knots averaged by convoy HX 72, allowing more merchant ships to remain concentrated in one large, defensible group. Secondly, the Allies had also succeeded in cracking the German’s communications code, providing convoys with forewarning of many impending attacks. But, above all, the key to the success of the Allies in the Atlantic fighting was the acquisition of smaller ships like HMCS Dunver. Indeed, it was these Royal Canadian Navy warships, with experienced crews and sophisticated technology such as radar, which assumed responsibility for escorting all trans-Atlantic convoys from the spring of 1944 until the end of the war.

Seasoned by his years of combat, Lieutenant Mylett played an active role in the destruction of the German submarine U-484 on September 3, 1944. As mentioned in despatches issued on June 16, 1945:
This Officer, in nearly three years afloat, has always displayed outstanding efficiency and integrity. In action against the enemy, his alertness and organizing ability have done much, through the good teamwork of the ship’s company, to bring about the probable destruction of a submarine. (Cited in: "Despatches – RCNVR / HMCS Dunver", Canada Gazette, Ottawa, 16 June (1945).

Lieutenant Mylett was awarded the 1939-1945 Star, the Atlantic Star, the Canadian Volunteer Service Medal with maple leaf and the 1939-1945 War Medal with oak leaf. After the war, he became the commanding officer of the University Naval Training Corps at Laval University. He then commanded the Royal Canadian Navy Reserve unit at Quebec City, HMCS Montcalm, until 1963.
-- Hague, Arnold, The Convoy System 1939-1945 : Its Organization, Defence and Operation, St. Catharines (ON), Vanwell Publishing Limited, 2000. 208 p.
-- Milner, Marc, Canada’s Navy. The First Century, Toronto, University of Toronto Press, 1999. 356 p.
-- « The War’s Largest Convoy », Convoy HXS 300, Ottawa, Direction de l’histoire et du patrimoine, 1er avril (1964). 2 p.
-- Tucker, Gilbert Norman, The Naval Service of Canada : Its Official History, vol. 2 : Activities on Shore during the Second World War, Ottawa, Imprimeur de la Reine, 1952. 579 p.
-- « Despatches – RCNVR / HMCS DUNVER », Gazette du Canada, Ottawa, 16 juin (1945).

© 2008, CHIN. All Rights Reserved.

HMCS DUNVER

HMCS DUNVER

National Defense

© National Defense


Crew of HMCS DUNVER

Crew of HMCS DUNVER in 1943. Lt Mylett: first row, third from left

Musée naval de Québec, Mylett collection

© Musée naval de Québec, Mylett collection


Cartographic planning tool

Cartographic planning tool: Lt Mylett’s parallel rule.

Musée naval de Québec, Mylett collection

© Musée naval de Québec, Mylett collection


Learning Objectives

  • Develop an understanding of the participation and role of Canada’s Navy in the World War II.
  • Examine the contributions, sacrifices and experiences of individuals who participated in naval events during World War II.
  • Identify the locations in which Canada’s Navy operated during World War II.
  • Evaluate the weapons and technology involved in the war at sea.

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