“The battle escalated slowly from its commencement at the outbreak of war in 1939 to its violent climax in the spring of 1943.”

By James Brun

IN LEWIS Gilbert’s 1960 film, Sink the Bismarck!, the First Sea Lord, Sir Dudley Pound, remarks on the type of commander needed to win the Battle of the Atlantic: “I want a man who’s cold. I’d like a man with no heart at all, no soul. Just an enormous brain. The Battle of the North Atlantic is a grim business and it isn’t going to be won by charm and personality.”

Within this passage, Pound conveys the essence of the Atlantic campaign: A complex, grinding, managerial effort that was only interrupted by episodes of brutal violence.

Indeed, the term ‘Battle of the Atlantic’ itself reinforces the impression of a relentless fight upon the world’s second largest ocean.

In reality, combat operations in the North Atlantic retained little semblance to battles in a traditional sense. The campaign lasted years, but ferocious action was sporadic. Further, while the Atlantic was the main operational theatre, the campaign expanded throughout the war into a global effort.[1] Maintaining the maritime communication routes was vital to the Allied war effort; and therefore, attacking the same communication lanes was crucial to the German’s.

At the outbreak of war, the British Empire controlled 18 million tonnes of shipping, supported by a highly functioning shipbuilding industry that could replace losses of a million tonnes, annually.[2] To disrupt the merchant capacity that would supply an Allied war effort in Europe, Germany estimated that it would need to sink seven million tonnes each year.[3] Although images of intense submarine convoy battles have made an impression on our collective memory, this is due to the Battle of the Atlantic’s narrative being framed by the dramatic moments of conflict, more than the challenge of moving ships, material, and personnel across a vast unsecured ocean.

In hindsight, the battle escalated slowly from its commencement at the outbreak of war in 1939 to its violent climax in the spring of 1943. The Allies used the relative calm of the battle’s early stages to develop defensive measures against their subsurface enemies. Convoy composition and anti-submarine maneuvers and tactics were improved, allowing Allied forces to withstand the increasingly aggressive German wolf-packs. Amidst the terrible losses of merchant shipping as the fighting intensified, American industrial capacity was able to overcome the deficit and allow supply lines to remain effective.[4] Concurrently, a confluence of innovation and strategic decisions enabled the Allies to turn the tide in the Atlantic.[5]

In May of 1943, decisions to increase air coverage, convoy size and escort support, combined with the introduction of new anti-submarine weapons and sensors were showing positive results. That month, the Allies sunk 41 German submarines. Admiral Dönitz, commander of Hitler’s U-boat fleet, withdrew his remaining vessels from the Atlantic.[6]

The story of the Atlantic war, however, is best understood through the Allied mechanisms of defence, rather than offence. Allied operations during the battle emphasized enemy avoidance, and success in the Atlantic was determined by “[t]he safe and timely arrival of the convoy at its destination,” rather than the destruction of U-boats.[7] Critical supplies were transported from North America to Europe in merchant ships, and guarded from the Axis fleets by three lines of defence, namely: the Royal Navy’s Home Fleet, naval control of shipping, and convoy escorts.^[8]

The Royal Navy’s Home Fleet was Britain’s main European battle fleet. Its primary purpose was to contain the German navy, and prevent it from breaking out into the North Sea. As such, the Home Fleet’s operations allowed the Allied convoys to transit without serious fear of attack from major German surface combatants.[9] When German ships did manage to enter the Atlantic, they were invariably hunted down and destroyed. The most famous example of this occurred in May of 1941, when the great battleship Bismarck and her consort, Prinz Eugen, broke into the Atlantic. The sinking of Bismarck marked the end of any significant German surface threats against Atlantic convoys.[10]

To avoid the German vessels that did make it into the Atlantic, the Allies analyzed maritime traffic patterns and radio intelligence to direct merchant shipping away from suspected enemy hunting grounds.[11] Naval historian Marc Milner describes naval control of shipping as “the regulation of the movement of merchant shipping so that it may be protected either directly or indirectly by the navy.”[12] The system was devised by the British during the First World War, and upgraded throughout the interwar period. In 1939, the British Commonwealth maintained a global system to direct oceanic convoys at their disposal.[13] Naval shipping control arranged convoys, provided routing, and coordinated civilian and naval forces. The system worked to route convoys away from suspected enemy forces, while tracking those enemy forces that were detected.

Notwithstanding the great organizational efforts used to avoid enemy forces, the last line of defence in the duty to protect the merchant ships resided with the convoy escorts. Despite the Allies’ best effort, convoys routinely came under attack from enemy forces. Generally, a convoy’s escort was comprised of a number of small corvettes, and a faster and more capable destroyer. The escort vessels’ role was to engage and harass an enemy submarine or wolf-pack, while the bulk of the convoy evaded and cleared the area. This concept was detailed in the Western Approaches Convoy Instructions, issued in 1941, which placed “The safe and timely arrival of the convoy” as the escort force’s primary objective.[14]

The policy was reinforced in 1943, with the release of the Western Approaches Tactical Policy, which stated that “Evasion attains the primary object and should therefore be the first course of action considered.”[15] However, failure to destroy U-boats would not lessen the risk to convoys in general. Therefore, in the right tactical circumstances, escorts pursued and prosecuted the wolf-packs to destruction. This aggression was more tenable in the latter part of the war with Allied air superiority and technical advances in anti-submarine aviation weapons. When matched with improved sensors, the combined Allied air and surface units were a formidable force.

The Atlantic campaign was a herculean effort to move huge amounts of supplies and troops to where they were most needed. To achieve this, the Royal Navy guarded against German surface combatants escaping into the North Atlantic. Naval control of shipping arranged and dispatched convoys of merchant ships, routing them away from known concentrations of enemy combatants. If these measures failed, the task of guarding the sheep fell to the sheepdogs, the minor warships that escorted merchantmen to their destination.

James Brun is an officer in the Royal Canadian Navy and regular contributor to MilitaryHistoryNow.com. For his daily tweets of rare and fascinating World War Two photos, follow him at @lebrunjames81

END NOTES

[1] Christopher M. Bell, and Marcus Faulkner. “Introduction.” Essay. In Decision in the Atlantic: the Allies and the Longest Campaign of the Second World War. (Lexington, Kentucky: Andarta Books, 2019), 8-9.

[2] Eric Grove, “’The Battle of the Atlantic’: A Legend Deconstructed”, The Mariner’s Mirror, 105:3, 2019, 336.

[3] Eric Grove, “’The Battle of the Atlantic’: A Legend Deconstructed”, The Mariner’s Mirror, 105:3, 2019, 336.

[4] Marcus Faulkner, Christopher M. Bell, and Kevin Smith. “’Immobilized by Reason of Repair’ and by the Choice ‘Between Lithgow and Hitler’: Class Conflict in Britain’s Merchant Shipping Repair Yards.” Essay. In Decision in the Atlantic: the Allies and the Longest Campaign of the Second World War. (Lexington, Kentucky: Andarta Books, 2019), 76-81.

[5] Marc Milner, Battle of the Atlantic. (Stroud, Gloucestershire: The History Press, 2014), 146.

[6] Eric Grove, “’The Battle of the Atlantic’: A Legend Deconstructed”, The Mariner’s Mirror, 105:3, 2019, 339.

[7] “Western Approaches Tactical Policy, April 1943.” Juno Beach Centre, April 8, 2014. https://www.junobeach.org/canada-in-wwii/articles/submarines-attack-in-the-st-lawrence/western-approaches-tactical-policy-april-1943/.

[8] Marcus Faulkner, Christopher M. Bell, and Marc Milner, “The Atlantic War, 1939-1945: The Case for a New Paradigm.” Essay. In Decision in the Atlantic: the Allies and the Longest Campaign of the Second World War. (Lexington, Kentucky: Andarta Books, 2019), 16-17.

[9] Marcus Faulkner, Christopher M. Bell, and Marc Milner, “The Atlantic War, 1939-1945: The Case for a New Paradigm.” Essay. In Decision in the Atlantic: the Allies and the Longest Campaign of the Second World War. (Lexington, Kentucky: Andarta Books, 2019), 16.

[10] Eric Grove, “’The Battle of the Atlantic’: A Legend Deconstructed”, The Mariner’s Mirror, 105:3, 2019, 337.

[11] Marcus Faulkner, Christopher M. Bell, and Marc Milner, “The Atlantic War, 1939-1945: The Case for a New Paradigm.” Essay. In Decision in the Atlantic: the Allies and the Longest Campaign of the Second World War. (Lexington, Kentucky: Andarta Books, 2019), 17.

[12] Marc Milner, “Naval Control of Shipping and the Atlantic War: 1939-1945” The Mariner’s Mirror, 83:2, 1997, 169.

[13] Marc Milner, Battle of the Atlantic. (Stroud, Gloucestershire: The History Press, 2014), 15.

[14] Marcus Faulkner, Christopher M. Bell, and Marc Milner, “The Atlantic War, 1939-1945: The Case for a New Paradigm.” Essay. In Decision in the Atlantic: the Allies and the Longest Campaign of the Second World War. (Lexington, Kentucky: Andarta Books, 2019), 17.

[15] “Western Approaches Tactical Policy, April 1943.” Juno Beach Centre, April 8, 2014. https://www.junobeach.org/canada-in-wwii/articles/submarines-attack-in-the-st-lawrence/western-approaches-tactical-policy-april-1943/.