The Battle of the Atlantic is a popular historical name (Britain’s Prime Minister Winston Churchill first began using the phrase in August 1940) for the long struggle—spanning the entire six years of World War II, from 1939 to 1945—to secure the Atlantic convoy routes, which were the lifeline for the European Allies. It was by no means a battle in the traditional military sense but, rather, a long series of numerous encounters, engagements, attacks, and campaigns. For the Allies, the overall objectives of the struggle were straightforward: blockade Axis Europe; secure sea movements, especially of vital convoys; and attain and maintain the ability to project military force overseas.
The first objective was achieved with relative ease, since the Allied navies far outnumbered German and Italian naval forces. Although Germany enjoyed very limited success with blockade-running operations, generally the Allied naval blockade was quite effective. It is also true, however, that the European Axis did not have to rely on the Atlantic for most of its supplies, since, through much of the war, Germany controlled many European overland routes and had conquered numerous manufacturing and agricultural centers.
The third objective depended largely on the development of amphibious warfare doctrine, techniques, and tactics, which had not fully matured until Operation Overlord and the Normandy landings (D-day) of June 1944. By that time, the second objective, securing Allied sea movements, had been largely achieved, which also enabled achievement of the amphibious warfare objective.
That second objective, securing Allied sea movements, was, however, extremely difficult to attain. While the surface fleet of the Kriegsmarine, the Navy of Germany, was not large, its submarine (or U-boat) fleet was substantial, modern, and growing. It was the German U-boat that was the most destructive weapon in the Battle of the Atlantic, and the menace posed by submarine warfare largely dictated Allied operations in the battle.
Yet the U-boat did not immediately come to the fore in the Battle of the Atlantic. During the opening months of the war, after the invasion of Poland in September 1939 and before the fall of France in June 1940, the Kriegsmarine operated against Allied shipping mainly using surface ships, including so-called pocket battleships (smaller than conventional battleships, but typically with even greater firepower) and cruisers, collectively called surface raiders. These vessels were augmented by smaller cruisers called auxiliary cruisers. This early phase of the Battle of the Atlantic largely consisted of German surface raiders harassing Allied shipping.
After the fall of France, Germany acquired French and Norwegian bases from which submarines could operate with little interference by the hitherto quite effective British naval blockade. Moreover, the German objective in the Battle of the Atlantic was no longer the catch-as-catch-can destruction of cargo and transport shipping or even battling the Royal Navy. With Great Britain cut off from the European continent, the objective was now to strangle and starve the nation by cutting off all Atlantic communication and supply routes. It quickly became apparent that submarines were the most effective weapon for this destruction, and the Battle of the Atlantic evolved into perhaps the most serious threat Germany posed. (Another important German vessel deployed in the Battle of the Atlantic was the merchant raider, better known as the Q-ship. Heavily armed warships disguised as civilian freighters, the Q-ships would sneak up on Allied merchant vessels and open fire.)
STATISTICAL COURSE OF THE BATTLE OF THE ATLANTIC
The overall course of the Battle of the Atlantic can be charted year by year by looking at tonnage lost and to what cause: Table of Allied tonnage lost and to which cause:
(See Sven 4/26/2010)
In terms of actual numbers of ships lost, the battle looked like this:
What accounts for the general direction of these statistics? German U-boats were plentiful and, early in the war, developed Wolfpack U-boat tactics, by which several boats coordinated a single attack for greatly enhanced effectiveness. Moreover, by December 1941, when the United States entered the war, U-boats were already capable of operating as far as the Caribbean and the Gulf of Mexico and could attack shipping even off the East Coast of the United States. The effectiveness of the U-boat increased alarmingly through 1942. However, by early 1943, several Allied technological and tactical advances began sharply to turn the tide against the U-boats, transforming the hunters into the hunted. sonar technology (by which surface ships could detect U-boats underwater) was developed from earlier ASDIC technologies. Long-range bombers became available, thereby extending the range of antisubmarine patrol. Developments in radar technology greatly increased the effectiveness of these patrols. Tactically, the Allies perfected both the convoy system and more effective means of escorting the convoys.
Further reading: Gannon, Michael. Operation Drumbeat: The Dramatic True Story of Germany’s First U-Boat Attacks Along the American Coast in World War II. New York: Harper Perennial, 1991; Ireland, Bernard. The Battle of the Atlantic. Annapolis, Md.: Naval Institute Press, 2003; Morison, Samuel Eliot. The Battle of the Atlantic: September 1939–May 1943. New York: Castle Books, 2001; Pitt, Barrie. The Battle of the Atlantic. Boston: Little, Brown, 1977; Williams, Andrew. The Battle of the Atlantic: Hitler’s Gray Wolves of the Sea and the Allies’ Desperate Struggle to Defeat Them. New York: Basic Books, 2003.
