The Battle of the Atlantic
By the beginning winter in 1941, Nazi Germany and its allies controlled most of Europe, the Soviet Union was in a difficult situation itself, while the United States was at the time neutral. After the Evacuation of Dunkirk and the Battle of Britain, the United Kingdom faced one of the most challenging struggles of all. If the Germans would prevail in the Atlantic, Winston Churchill feared that Britain could be starved out of war. What is more, it would prevent the Allied overseas projections including the Normandy landings. For that reason the Battle of the Atlantic was one of the most important battles of World War II.
The United Kingdom and the Allies had three main goals in the Battle of Atlantic:
- securing the overseas supply
- securing the overseas military projections
- blocking the Axis in Europe
The German objectives varied throughout the war but they were primarily focused on sinking the Allied shipping. Initially, the Germans used heavy ship to harass the Allies, however, German surface ships were no match for the Allied fleet. And after the loss of the pocket battleship Admiral Graf Spee and the Bismark, the German hopes to prevail on sea with large battleships virtually came to an end. In addition, the British commandos destroyed the Normandie dry dock at St Nazaire in German-occupied France in March 1942 by which the Germans lost the only dry dock that was suitable to repair large ships on the Atlantic coast. But before that, Britain had to find a way to protect its overseas shipping of food and military equipment from the U-boats which were a serious threat to Britain in 1940 and 1941 considering that the country is an island and that supplies could have been obtained only from overseas due to Axis occupation of Europe.
The German surface raiders were a major concern for the British as well but the damage they caused was negligible to that of U-boats. German battleships destroyed slightly over 6 percent of the Allied shipping, while 70 percent of the Allied ships were sunk by U-boats. The Germans quickly realized the potential of U-boats, especially when the future Grand Admiral Karl Dönitz (he was appointed the Commander-in-Chief of the German Navy in early 1943) developed the tactic known as "wolfpack" which caused serious damage to the Allied convoys. However, to starve Britain out of war Dönitz would need 300 U-boats and in the early 1940, he had less than 30 submarines. The production of new U-boats increased dramatically in 1941 but not as much as Dönitz wished. However, the Allies did not win the Battle for the Atlantic only because Dönitz lacked the sufficient amount of submarines.
Britain quickly realized that its shipping is too vulnerable to the attacks of the U-boats. The supply ships and convoys were relatively safe within the American and British waters but they were pretty much left to themselves in the international waters of the Atlantic Ocean. From the very beginning of the Battle of the Atlantic, Britain relied heavily on the early form of sonar known as the ASDIC which enabled the ships to detect submarines underwater. They were quite effective but they lost dramatically on their efficiency when Dönitz started to use the wolfpack tactic in the late 1940. According to this tactics, submarines emerged to the surface and attacked during the night in groups.
To reduce the damage caused by the German U-boats and the Dönitz's wolfpack tactic, Britain introduced new ships – corvettes. These small lightly armored warships filled the gaps in the escorts and dramatically reduced the effect of the wolfpack tactic. At the same time, the United Kingdom received a major help from the Royal Canadian Navy as well as the United States despite the fact that it was officially neutral. In September 1940, the United States gave the United Kingdom 50 destroyers in return for bases on various British possessions. In 1941, the US Navy also began escorting the Allied shipping and even got involved in a battle with the German submarines despite the fact that the US public heavily opposed an eventual US entry into World War II. The position of the Allies of course improved dramatically after the US entry into the war in December 1941.
Improved air cover and introduction of new weapons were another important factor in the outcome of the Battle of the Atlantic. To be able to fire a torpedo, the submarines had to come close to the surface allowing the planes to locate and destroy them. Introduction of long-range aircrafts such as Liberator was therefore of major importance.
The Intelligence played a major role in the struggle for the control of the Atlantic as well. The deciphering of the Enigma code by the British Intelligence enabled the Allies to listen to the German communication and locate the submarines which in turn enabled them to move the ships and convoys into safe waters.
Despite the fact that the above mentioned factors dramatically reduced the damage caused by the German submarines, these remained a very serious threat, especially in the first half of 1943 when Dönitz had on disposal 200 U-boats. The damage they caused arouse serious concern whether the Allied shipyards can produce new ships as fast as they are being sunk. However, the introduction of the Liberty ships which were cheap and fast to build along with the improved Allied strategy and weapons diminished the effect of the U-boats. Both Hitler and Dönitz realized that the old tactic is no longer giving the desired results. The German submarines continued to threaten the Allied ships and convoys until the end of the war but the Battle of the Atlantic was de facto won although the new types of German submarines could seriously threaten the Allies if they would be developed earlier.
The Battle of the Atlantic was the longest battle of World War II. About 28,000 (nearly two thirds) of the German U-boat crew was killed during the battle for the control of the Atlantic, while the Allies suffered about 75,000 casualties.
