A very new weapons system, the lurking submarine with its self-propelled torpedoes fired from ambush changed the complexion of naval warfare forever. Both warships and merchant ships were at risk. In 1914 U-boats demonstrated their capability to sink major warships. During 1915 they turned their attention to merchant ships and began to sink or capture them in wholesale lots. U-boats nearly won the First World War for Germany by forcing Great Britain into peace negotiations in late 1917. U-boats sank or captured over 6,100 ships during WW I. In April 1917 England had only six weeks grain supply left, and apparently had no adequate way to deal with the unrestricted U-boat offensive that Germany unleashed in February of that year. Submarine Operational Effectiveness in the 20th Century deals with the first strategic submarine campaign and its outcome. It goes on to outline submarine development by major nations during the 1920s and 1930s, including submarine use during the Spanish Civil War. It ends in 1939, on the eve of World War Two, a war in which two massive submarine campaigns would be waged: the first by Nazi Germany against the Allies; and the second by the United States against the Empire of Japan.

The submarine emerged as a serious weapons system during the First World War (1914 - 1918). During that conflict Germany with its unrestricted submarine warfare campaign of 1917 nearly drove Great Britain to the negotiating table. Its U-boats sank 6,196 ships of 13,438,632 gross register tons. Despite post-war attempts to ban the submarine from warfare, it survived. Both Italy and Germany used submarines, covertly, during the Spanish Civil War (1936 - 1939). This book, Part Two of a series, discusses the use of submarines during World War Two (1939 - 1945) and their effectiveness. It focuses principally on two strategic submarine campaigns. The first is about German U-boats against British and neutral commerce. That campaign finally failed during the Battle of The Atlantic in 1943. The second deals with American submarines against Japanese shipping from Southeast Asia to the home islands, a campaign that successfully isolated Japan from its sources of raw materials and foodstuffs during 1944 and effectively defeated Japan.

The submarine emerged as a serious weapons system during the First World War (1914 - 1918). During that conflict Germany with its unrestricted submarine warfare campaign of 1917 nearly drove Great Britain to the negotiating table. Its U-boats sank 6,196 ships of 13,438,632 gross register tons. Despite post-war attempts to ban the submarine from warfare, it survived. Both Italy and Germany used submarines, covertly, during the Spanish Civil War (1936 - 1939). This book, Part Two of a series, discusses the use of submarines during World War Two (1939 - 1945) and their effectiveness. It focuses principally on two strategic submarine campaigns. The first is about German U-boats against British and neutral commerce. That campaign finally failed during the Battle of The Atlantic in 1943. The second deals with American submarines against Japanese shipping from Southeast Asia to the home islands, a campaign that successfully isolated Japan from its sources of raw materials and foodstuffs during 1944 and effectively defeated Japan.

This is the first comprehensive account of how intelligence influenced and sustained British naval power from the mid nineteenth century, when the Admiralty first created a dedicated intelligence department, through to the end of the Cold War. It brings a critical new dimension to our understanding of British naval history in this period while setting naval intelligence in a wider context and emphasising the many parts of the British state that contributed to naval requirements. It is also a fascinating study of how naval needs and personalities shaped the British intelligence community that exists today and the concepts and values that underpin it. The author explains why and how intelligence was collected and assesses its real impact on policy and operations. It confirms that naval intelligence was critical to Britain’s survival and ultimate victory in the two World Wars but significantly reappraises its role, highlighting the importance of communications intelligence to an effective blockade in the First, and according Ultra less dominance compared to other sources in the Second. It reveals that coverage of Germany before 1914 and of the three Axis powers in the interwar period was more comprehensive and effective than previously suggested; and while British power declined rapidly after 1945, the book shows how intelligence helped the Royal Navy to remain a significant global force for the rest of the twentieth century, and in submarine warfare, especially in the second half of the Cold War, to achieve influence and impact for Britain far exceeding resources expended. This compelling new history will have wide appeal to all readers interested in intelligence and its crucial impact on naval policy and operations.

A very new weapons system, the lurking submarine with its self-propelled torpedoes fired from ambush changed the complexion of naval warfare forever. Both warships and merchant ships were at risk. In 1914 U-boats demonstrated their capability to sink major warships. During 1915 they turned their attention to merchant ships and began to sink or capture them in wholesale lots. U-boats nearly won the First World War for Germany by forcing Great Britain into peace negotiations in late 1917. U-boats sank or captured over 6,100 ships during WW I. In April 1917 England had only six weeks grain supply left, and apparently had no adequate way to deal with the unrestricted U-boat offensive that Germany unleashed in February of that year. Submarine Operational Effectiveness in the 20th Century deals with the first strategic submarine campaign and its outcome. It goes on to outline submarine development by major nations during the 1920s and 1930s, including submarine use during the Spanish Civil War. It ends in 1939, on the eve of World War Two, a war in which two massive submarine campaigns would be waged: the first by Nazi Germany against the Allies; and the second by the United States against the Empire of Japan.

The first comprehensive technical history on the subject, with photos: “A must-read for all professionals, designers and scholars of modern submarines.” —Australian Naval Institute The Royal Navy’s greatest contribution to the Allied success in World War II was undoubtedly the defeat of the U-boat menace in the North Atlantic, a victory on which all other European campaigns depended. The underwater threat was the most serious naval challenge of the war, so it was not surprising that captured German submarine technology became the focus of attention for the British submarine service after 1945. It was quick to test and adopt the schnorkel, streamlining, homing torpedoes, and, less successfully, hydrogen-peroxide propulsion. Furthermore, in the course of the long Atlantic battle, the Royal Navy had become the world’s most effective anti-submarine force and was able to utilize this expertise to improve the efficiency of its own submarines. However, in 1945 German submarine technology had also fallen into the hands of the Soviet Union—and as the Cold War developed it became clear that a growing Russian submarine fleet would pose a new threat. Britain had to go to the US for its first nuclear propulsion technology, but the Royal Navy introduced the silencing technique that made British and US nuclear submarines viable anti-submarine assets, and it pioneered in the use of passive—silent—sonars in that role. Nuclear power also changed the role of some British submarines, which replaced bombers as the core element of British Cold War and post-Cold War nuclear deterrence. As in other books in this series, this one shows how a combination of evolving strategic and tactical requirements and new technology produced successive types of submarines. It is based largely on unpublished and previously classified official documentation, and to the extent allowed by security restrictions, also tells the operational story—HMS Conqueror is still the only nuclear submarine to have sunk a warship in combat, but there are many lesser-known aspects of British submarine operations in the postwar era.