A submarine is a watercraft capable of independent operation underwater. The term “submarine” is also sometimes used historically or informally to refer to remotely operated vehicles and robots, or to medium-sized or smaller vessels. Submarines are referred to as boats rather than ships regardless of their size.
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. The term is an anglicized version of the German word U-Boot, a shortening of Unterseeboot, though the German term refers to any submarine. Austro-Hungarian Navy submarines were also known as U-boats.
Type XXI submarines were a class of German diesel–electric Elektroboot submarines designed during the Second World War. One hundred and eighteen were completed, with four being combat-ready. During the war only two were put into active service and went on patrols, but these were not used in combat.
The Gato class of submarines were built for the United States Navy and launched in 1941–1943. Named after the lead ship of the class, USS Gato, they were the first mass-production U.S. submarine class of World War II.
The Type 212A is a class of diesel-electric attack submarine developed by Howaldtswerke-Deutsche Werft AG (HDW) for the German Navy, and the Italian Navy where it is known as the Todaro class. It features diesel propulsion and an additional air-independent propulsion (AIP) system using Siemens proton-exchange membrane (PEM) compressed hydrogen fuel cells. The submarines can operate at high speed on diesel power or switch to the AIP system for silent slow cruising, staying submerged for up to three weeks with little exhaust heat. The system is also said to be vibration-free and virtually undetectable.
The Greater Underwater Propulsion Power Program (GUPPY) was initiated by the United States Navy after World War II to improve the submerged speed, maneuverability, and endurance of its submarines. (The "Y" in the acronym was added for pronounceability.)
The Balao class was a design of United States Navy submarine used during World War II, and with 120 boats completed, the largest class of submarines in the United States Navy. An improvement on the earlier Gato class, the boats had slight internal differences. The most significant improvement was the use of thicker, higher yield strength steel in the pressure hull skins and frames, which increased their test depth to 400 feet (120 m). Tang actually achieved a depth of 612 ft (187 m) during a test dive, and exceeded that test depth when taking on water in the forward torpedo room while evading a destroyer.
Tench-class submarines were a type of submarine built for the United States Navy (USN) between 1944 and 1951. They were an improvement over the Gato and Balao classes, only about 35 to 40 tons larger, but more strongly built and with a slightly improved internal layout. One of the ballast tanks was converted to carry fuel, increasing range from 11,000 nautical miles to 16,000 nautical miles. This improvement was also made on some boats of the previous two classes. Further improvements were made beginning with SS-435, which are sometimes referred to as the Corsair class. Initial plans called for 80 to be built, but 51 were cancelled in 1944 and 1945 when it became apparent that they would not be needed to defeat Japan. The remaining 29 were commissioned between October 1944 (Tench) and February 1951 (Grenadier). The last submarine of the Tench class, as well as the last submarine which served during World War II, remaining in service with the U.S. Navy was USS Tigrone (AGSS-419) which was decommissioned on 27 June 1975.
Air-independent propulsion (AIP), or air-independent power, is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen. AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels.
An Elektroboot was a submarine designed to operate entirely submerged, rather than as submersibles that could submerge as a temporary means to escape detection or launch an attack.
Anti-submarine warfare is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades.
The history of the submarine goes back to antiquity. Humanity has employed a variety of methods to travel underwater for exploration, recreation, research and significantly, warfare. While early attempts, such as those by Alexander the Great, were rudimentary, the advent of new propulsion systems, fuels, and sonar, propelled an increase in submarine technology. The introduction of the diesel engine, then the nuclear submarine, saw great expansion in submarine use – and specifically military use – during World War I, World War II, and the Cold War. The Second World War use of the U-Boat by the Kriegsmarine against the Royal Navy and commercial shipping, and the Cold War's use of submarines by the United States and Russia, helped solidify the submarine's place in popular culture. The latter conflicts also saw an increasing role for the military submarine as a tool of subterfuge, hidden warfare, and nuclear deterrent. The military use of submarines continues to this day, predominantly by North Korea, China, the United States and Russia.
German submarine U-1226 was a Type IXC/40 U-boat of Nazi Germany's Kriegsmarine during World War II.
Seehund, also known as Type XXVII, was a midget submarine built by Nazi Germany during World War II. Designed in 1944 and operated by two-man crews, it was used by the Kriegsmarine during the closing months of the war, sinking nine merchant vessels and damaging an additional three, while losing 35 boats, mostly attributed to bad weather. The French Navy used four captured boats after the war until 1953.
German submarine U-766 was a Type VIIC U-boat built for the navy (Kriegsmarine) of Nazi Germany during World War II. She was later incorporated in the French Navy, where she served as Laubie.
German submarine U-1308 was the last Type VIIC/41 submarine to be laid down, launched and commissioned by Nazi Germany's Kriegsmarine during World War II. The Oberkommando der Marine or OKM,, had decided near the end of World War II to put all of its resources into building newer types of Unterseeboot, such as the types XXI and XXIII. U-1308 was part of a batch of eight U-boats ordered on 1 August 1942 to be built at Flensburger Schiffbau-Gesellschaft, Flensburg. She was laid down on 16 February 1944 and launched on 22 November. The eight boats were commissioned over a 12-month period between February 1944 and 17 January 1945.
Autolycus or Sniffer was a submarine detection system designed to detect diesel-engined submarines from aircraft. It was designed to detect exhaust fumes from their diesel engines. Named after the mythical Greek, Autolycus, who took part in the search for the Golden Fleece, it was developed by the British during the early Cold War period. The first version of Autolycus was deployed on Avro Shackleton aircraft in the mid-1950s, with an improved version re-appearing in the mid-1960s.
German submarine U-715 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 28 March 1942 at the H. C. Stülcken Sohn yard at Hamburg, launched on 14 December 1942, and commissioned on 17 March 1943 under the command of Oberleutnant zur See Helmut Röttger.
German submarine U-1003 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.
German submarine U-1053 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.
