Coastal submarineA coastal submarine or littoral submarine is a small, maneuverable submarine with shallow draft well suited to navigation of coastal channels and harbors. Although size is not precisely defined, coastal submarines are larger than midget submarines, but smaller than sea-going submarines designed for longer patrols on the open ocean. Space limitations aboard coastal submarines restrict fuel availability for distant travel, food availability for extended patrol duration, and number of weapons carried.
Scapa FlowScapa Flow ('skɑːpə,_'skæpə; ) is a body of water in the Orkney Islands, Scotland, sheltered by the islands of Mainland, Graemsay, Burray, South Ronaldsay and Hoy. Its sheltered waters have played an important role in travel, trade and conflict throughout the centuries. Vikings anchored their longships in Scapa Flow more than a thousand years ago. It was the United Kingdom's chief naval base during the First and Second World wars, but the facility was closed in 1956.
Wolfpack (naval tactic)The wolfpack was a convoy attack tactic employed in the Second World War. It was used principally by the U-boats of the Kriegsmarine during the Battle of the Atlantic, and by the submarines of the United States Navy in the Pacific War. The idea of a co-ordinated submarine attack on convoys had been proposed during the First World War but had no success. In the Atlantic during the Second World War the Germans had considerable successes with their wolfpack attacks but were ultimately defeated by the Allies.
Hedgehog (weapon)The Hedgehog (also known as an Anti-Submarine Projector) was a forward-throwing anti-submarine weapon that was used primarily during the Second World War. The device, which was developed by the Royal Navy, fired up to 24 spigot mortars ahead of a ship when attacking a U-boat. It was deployed on convoy escort warships such as destroyers and corvettes to supplement the depth charges.
Midget submarineA midget submarine is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to six or nine, with little or no on-board living accommodation. They normally work with mother ships, from which they are launched and recovered and which provide living accommodation for the crew and support staff. Both military and civilian midget submarines have been built. Military types work with surface ships and other submarines as mother ships.
Deck gunA deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose weapon used to sink merchant shipping or shell shore targets, or defend the submarine on the surface from enemy aircraft and warships. Typically a crew of three operated the gun, while others were tasked with supplying ammunition. A small locker box held a few 'ready-use' rounds.
Type 212A submarineThe Type 212A is a class of diesel-electric submarine developed by Howaldtswerke-Deutsche Werft AG (HDW) for the German Navy (German: U-Boot-Klasse 212 A), 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.
G7e torpedoThe G7e torpedo was the standard electric torpedo used by the German Kriegsmarine submarines in World War II. It came in 20 different versions, with the initial model G7e(TII) in service at the outbreak of the war. Due to several problems, leading to the German "Torpedokrise" which lasted until the end of 1941, the improved G7e(TIII) took over as the standard electric torpedo used by German U-boats for the rest of the war. G7e torpedoes measured in diameter and about in length.
Mark 24 mineThe Mark 24 mine (also known as FIDO or Fido) is an air-dropped anti-submarine weapon (ASW) incorporating passive acoustic homing system and torpedo integration. It was used by the United States, the British and Canadian forces during the Second World War and entered service in March 1943 and remained in use with the US Navy until 1948. Approximately 4,000 torpedoes were produced, with 340 ultimately being deployed during the war. Two-hundred and four torpedoes were launched against submarine targets, with 37 Axis submarines being sunk and a further 18 damaged.
Air-independent propulsionAir-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 (by surfacing or using a snorkel). AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels. Modern non-nuclear submarines are potentially stealthier than nuclear submarines; although some modern submarine reactors are designed to rely on natural circulation, most naval nuclear reactors use pumps to constantly circulate the reactor coolant, generating some amount of detectable noise.
