published on: 23/10/2023
Author:
Sonic
Submarines have long been an integral part of naval warfare, but their significance reached new heights during World War II. As technological advancements rapidly transformed the capabilities of submarines, they became indispensable in the strategies of the warring nations. This essay delves into the evolution and impact of submarines during World War II, focusing on their roles in the conflict, the technical innovations they underwent, and the influence they had on the outcome of the war.
During World War II, submarines played a significant role in naval warfare. Germany used submarines to devastating effect in the Battle of the Atlantic, where it attempted to cut Britain’s supply routes by sinking more merchant ships than Britain could replace 1. The Imperial Japanese Navy operated the most varied fleet of submarines of any navy, including Kaiten crewed torpedoes, midget submarines, medium-range submarines, purpose-built supply submarines and long-range fleet submarines 1. The United States Navy used submarines heavily, with 263 US submarines undertaking war patrols and claiming 1,392 ships and 5,583,400 tons during the war 2.
Early Developments in Submarine Warfare
Submarine technology evolved significantly in the decades leading up to World War II. The German U-boats of World War I, while effective, were limited in range and capabilities. However, the interwar period saw the development of more advanced submarines, such as the American Gato-class and the German Type VII, which boasted increased range, diving depth, and speed. These innovations allowed submarines to become powerful tools for both offensive and defensive warfare.
Submarine Warfare in the Atlantic
In the Atlantic, German U-boats emerged as a formidable force, employing a strategy known as the "wolfpack" to hunt down and sink Allied merchant ships. By attacking in coordinated groups, the U-boats were able to maximize their impact on the vital supply routes between North America and Europe. The Battle of the Atlantic, as it came to be known, saw the Allies developing new tactics and technologies, such as sonar, convoy systems, and long-range aircraft, to counter the U-boat threat. The cat-and-mouse game between the German U-boats and the Allied naval forces played a pivotal role in determining the outcome of the war in Europe.
Submarine Warfare in the Pacific
The Pacific theater also witnessed extensive submarine warfare, with the United States and Japan both deploying their own fleets. American submarines, including the Gato, Balao, and Tench classes, played a crucial role in disrupting Japanese supply lines and sinking a significant portion of the Japanese merchant fleet. The Imperial Japanese Navy, on the other hand, struggled to utilize its submarines effectively. While the Japanese had large and technologically advanced submarines, such as the I-400-class, they were often misused in reconnaissance and transportation roles, rather than offensive operations.
Technological Innovations
World War II saw remarkable advancements in submarine technology, which proved crucial in the conflict. Innovations included the snorkel, which allowed submarines to operate submerged while still drawing in air for their diesel engines; improved sonar systems, which increased the effectiveness of anti-submarine warfare; and the development of advanced torpedoes, such as the German "G7e" electric torpedo and the American "Mk 18" electric torpedo. These innovations increased the range, speed, and stealth of submarines, making them even more formidable adversaries.
During World War II, the Allies utilized submarines extensively, particularly the United States and the United Kingdom. While the Soviet Union, Australia, and other Allied powers also used submarines, it was the U.S. and U.K. that fielded the largest and most technologically advanced fleets.
United States: The U.S. Navy employed several classes of submarines during World War II, including the Gato, Balao, and Tench classes. These submarines played a crucial role in the Pacific theater, conducting commerce warfare against the Japanese Empire. By the end of the war, U.S. submarines had sunk more than half of all Japanese vessels destroyed, despite accounting for only 2% of the American Navy. These submarines were equipped with advanced technology for the time, such as sonar and radar, and their weapons systems primarily consisted of torpedoes.
United Kingdom: The Royal Navy operated several classes of submarines during the war, including the T-class, S-class, and U-class. British submarines operated in various theaters, from the Mediterranean and the Atlantic to the Far East, performing a variety of roles, including interdicting enemy shipping, laying mines, and providing support for commando operations. Some were even used for intelligence-gathering and clandestine operations.
Soviet Union: The Soviet Navy utilized submarines extensively in the Baltic, Black, and Northern Seas to disrupt Axis shipping. Notably, the Soviets operated the S-class and Shchuka class submarines, which contributed significantly to their efforts in the Baltic Sea and Pacific Ocean.
Australia: The Royal Australian Navy, although smaller in scope compared to other Allied nations, also employed submarines in their fight against the Axis. Notably, the British-made Oberon-class submarines were used primarily in the Pacific theater.
These submarines underwent several improvements throughout the war, including better propulsion systems, increased diving depth, improved torpedoes, and advancements in sonar and radar technologies. Despite their differences, they all shared a common mission: to disrupt enemy supply lines and provide critical naval support for their respective countries during World War II.
Axis submarines
The primary Axis powers deploying submarines during World War II were Germany, Japan, and Italy. Their submarine fleets played significant roles in their war efforts, although with varying degrees of effectiveness.
Germany: The Kriegsmarine, the navy of Nazi Germany, used U-boats (from "Unterseeboot," which means "undersea boat") as the backbone of their naval strategy. The most common of these were the Type VII and Type IX classes. German U-boats waged a deadly campaign in the Atlantic against Allied shipping in what is known as the Battle of the Atlantic, seeking to cut off supply routes from North America to Europe. They often operated in groups known as "wolf packs." New technologies such as the snorkel, which allowed a submerged U-boat to run its diesel engines and recharge its batteries, significantly enhanced their capabilities.
Japan: The Imperial Japanese Navy had one of the most diverse submarine fleets of the war, including the largest submarines then built, the I-400 class, which were capable of carrying and launching seaplanes. Despite their technological prowess, Japanese submarines were generally used less effectively than their German counterparts. Instead of being used to disrupt American supply lines, they were often used for long-range reconnaissance or to transport supplies to isolated island garrisons.
Italy: The Regia Marina (Royal Italian Navy) utilized a range of submarines, including the Marconi class, which were used in the Atlantic to disrupt Allied shipping. Italian submarines operated from bases in Italy, Spain, and the captured French Atlantic naval base at Bordeaux (BETASOM). Despite initial successes, the Italian submarine force suffered from technological and training deficiencies, and their effectiveness was further hampered by the Italian Armistice in 1943, when many were captured or scuttled.
These submarines, especially those of Germany and Japan, underwent continuous technological advancements throughout the war. The German U-boats, in particular, introduced sophisticated technology and tactics, while Japanese submarines displayed a remarkable diversity of design. Nevertheless, by the end of the war, both were largely defeated by advancements in Allied anti-submarine warfare and strategic missteps in their own use of submarines.