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Hecht (submarine)
''Hecht'' (German: "Pike"), also known as Type XXVIIA, was a two-man all-electric German midget submarine created during World War II. History The origin of the ''Hecht'' began with the salvage of the two British X class submarines and which had been sunk during Operation Source, an attempt to sink the German battleship Tirpitz. ''Hauptamt Kriegschiffbau'' subsequently produced a design for a two-man submarine based on inspection of the British boats, designated Type XXVIIA and named ''Hecht'' ("Pike") Like the British X class boats, the Type XXVIIA was designed to carry explosive charges to be laid beneath enemy ships, but it was markedly smaller and had substantial differences from the X class. It dispensed with a dual diesel/electric propulsion system, relying instead solely on electrical power in the form of a 12 hp AEG torpedo motor, on the basis that since it would operate submerged there was no need for a diesel engine. However, this resulted in a very low endurance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Battleship Tirpitz
''Tirpitz'' was the second of two s built for Nazi Germany's ''Kriegsmarine'' (navy) prior to and during the Second World War. Named after Grand Admiral Alfred von Tirpitz, the architect of the ''Kaiserliche Marine'' (Imperial Navy), the ship was laid down at the Kriegsmarinewerft Wilhelmshaven in November 1936 and her hull was launched two and a half years later. Work was completed in February 1941, when she was commissioned into the German fleet. Like her sister ship, , ''Tirpitz'' was armed with a main battery of eight guns in four twin turrets. After a series of wartime modifications she was 2000 tonnes heavier than ''Bismarck'', making her the heaviest battleship ever built by a European navy. After completing sea trials in early 1941, ''Tirpitz'' briefly served as the centrepiece of the Baltic Fleet, which was intended to prevent a possible break-out attempt by the Soviet Baltic Fleet. In early 1942, the ship sailed to Norway to act as a deterrent against an Allied inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seehund
''Seehund'' (German: "seal"), 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'' (German Navy) 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. History The origin of the ''Seehund'' began with the salvage of the two British X class submarines and which had been lost by the Royal Navy during Operation Source, an attempt to sink the German battleship ''Tirpitz''. ''Hauptamt Kriegschiffbau'' subsequently produced a design for a two-man submarine based on inspection of the British boats, designated Type XXVIIA and named ''Hecht'' ("Pike"). XXVIIA (Hecht) Like the British X class boats, the Type XXVIIA was designed to carry explosive charges to be laid beneath enemy ships, but it wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyrocompass
A gyrocompass is a type of non-magnetic compass which is based on a fast-spinning disc and the rotation of the Earth (or another planetary body if used elsewhere in the universe) to find geographical direction automatically. The use of a gyrocompass is one of the seven fundamental ways to determine the heading of a vehicle. A gyroscope is an essential component of a gyrocompass, but they are different devices; a gyrocompass is built to use the effect of gyroscopic precession, which is a distinctive aspect of the general gyroscopic effect. Gyrocompasses are widely used for navigation on ships, because they have two significant advantages over magnetic compasses: * they find true north as determined by the axis of the Earth's rotation, which is different from, and navigationally more useful than, ''magnetic'' north, and * they are unaffected by ferromagnetic materials, such as in a ship's steel hull, which distort the magnetic field. Aircraft commonly use gyroscopic instrumen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welman Submarine
The Welman submarine was a Second World War one-man British midget submarine developed by the Special Operations Executive. It only saw action once and was not particularly successful. Design Designed by the Commanding Officer of SOE's Inter Services Research Bureau (ISRB), John Dolphin, Lt Col. John Dolphin, as a method of delivering a large explosive charge below an enemy ship, the Welman was a submersible craft in length (including explosive charge), weighing about . Unlike the "Chariot" human torpedo, the operator was enclosed within the craft, and did not need to wear scuba set, diving gear. The Welman could transport a time-fused explosive charge of Torpex, which was intended to be magnetically attached to a target's hull.Akermann, p. 462 Vision was through armoured glass segments in the small conning tower, and no periscope was fitted. Production Following trials in the Queen Mary Reservoir near Staines towards the end of 1942, the Welman was put into production, the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limpet Mine
A limpet mine is a type of naval mine attached to a target by magnets. It is so named because of its superficial similarity to the shape of the limpet, a type of sea snail that clings tightly to rocks or other hard surfaces. A swimmer or diver may attach the mine, which is usually designed with hollow compartments to give the mine just slight negative buoyancy, making it easier to handle underwater. Types of fuses Usually limpet mines are set off by a time fuse. They may also have an anti-handling device, making the mine explode if removed from the hull by enemy divers or by explosions. Sometimes limpet mines have been fitted with a small turbine which would detonate the mine after the ship had sailed a certain distance, so that it was likely to sink in navigable channels (to make access difficult for other ships) or deep water (out of reach of easy salvage) and making determination of the cause of the sinking more difficult. Development In December 1938, a new unit was cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Dönitz
Karl Dönitz (sometimes spelled Doenitz; ; 16 September 1891 24 December 1980) was a German admiral who briefly succeeded Adolf Hitler as head of state in May 1945, holding the position until the dissolution of the Flensburg Government following Germany's unconditional surrender to the Allies days later. As Supreme Commander of the Navy beginning in 1943, he played a major role in the naval history of World War II. He began his career in the Imperial German Navy before World War I. In 1918, he was commanding , and was taken prisoner of war by British forces. While in a POW camp, he formulated what he later called ''Rudeltaktik'' ("pack tactic", commonly called "wolfpack"). By the start of the Second World War, Dönitz was supreme commander of the ''Kriegsmarine'' U-boat arm ( (BdU)). In January 1943, Dönitz achieved the rank of (grand admiral) and replaced Grand Admiral Erich Raeder as Commander-in-Chief of the Navy. Dönitz was the main enemy of Allied naval forces in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballast Tank
A ballast tank is a compartment within a boat, ship or other floating structure that holds water, which is used as ballast to provide hydrostatic stability for a vessel, to reduce or control buoyancy, as in a submarine, to correct trim or list, to provide a more even load distribution along the hull to reduce structural hogging or sagging stresses, or to increase draft, as in a semi-submersible vessel or platform, or a SWATH, to improve seakeeping. Using water in a tank provides easier weight adjustment than the stone or iron ballast used in older vessels, and makes it easy for the crew to reduce a vessel's draft when it enters shallower water, by temporarily pumping out ballast. Airships use ballast tanks mainly to control buoyancy and correct trim. History The basic concept behind the ballast tank can be seen in many forms of aquatic life, such as the blowfish or argonaut octopus. The concept has been invented and reinvented many times by humans to serve a variety of purpo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diving Plane
Diving planes, also known as hydroplanes, are control surfaces found on a submarine which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when submerged. Bow and stern planes Diving planes are usually fitted in two pairs, the '' bow planes'' at the front of the submarine and the ''stern planes'' at the rear. The stern planes function in much the same way as an aircraft's elevator. As the planes are a long distance fore-and-aft from the hull's centre of buoyancy, they introduce a pitching moment. Ballast tanks within the submarine adjust buoyancy to be neutral, making the boat controllable. The position of the planes controls the pitch of the boat and, with the forward motion of the boat, this controls depth. If not carefully controlled, this could lead to a 'porpoising' motion whereby the planesman continually hunts for a stable combination of depth and pitch. For easier berth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Source
Operation Source was a series of attacks to neutralise the heavy German warships – ''Tirpitz'', ''Scharnhorst'' and ''Lützow'' – based in northern Norway, using X-class midget submarines. The attacks took place in September 1943 at Kaafjord and succeeded in keeping ''Tirpitz'' out of action for at least six months. The concept for the attack was developed by Commander Cromwell-Varley, with support of Max Horton, Flag Officer Submarines, and Prime Minister Winston Churchill. The operation was directed from HMS ''Varbel'', located in Port Bannatyne on the Isle of Bute. ''Varbel'' (named after Commanders Varley and Bell, designers of the X-Craft prototype) was the on-shore headquarters for the 12th Submarine Flotilla (midget submarines). It had been a luxury 88-bedroom hotel (the Kyles Hydropathic Hotel) requisitioned by the Admiralty to serve as the flotilla’s headquarters. All X-craft training and preparation for X-craft attacks (including that on ''Tirpitz'') was c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiel
Kiel () is the capital and most populous city in the northern Germany, German state of Schleswig-Holstein, with a population of 246,243 (2021). Kiel lies approximately north of Hamburg. Due to its geographic location in the southeast of the Jutland peninsula on the southwestern shore of the Baltic Sea, Kiel has become one of Germany's major maritime centres, known for a variety of international sailing events, including the annual Kiel Week, which is the biggest sailing event in the world. Kiel is also known for the Kiel mutiny, Kiel Mutiny, when sailors refused to board their vessels in protest against Germany's further participation in World War I, resulting in the abdication of the Wilhelm II, German Emperor, Kaiser and the formation of the Weimar Republic. The Olympic sailing competitions of the 1936 Summer Olympics, 1936 and the 1972 Summer Olympics#Venues, 1972 Summer Olympics were held in the Bay of Kiel. Kiel has also been one of the traditional homes of the German Nav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Class Submarine
The X class was a World War II midget submarine class built for the Royal Navy during 1943–44. It was substantially larger than the original Chariot manned torpedo. Known individually as X-Craft, the vessels were designed to be towed to their intended area of operations by a full-size "mother" submarine – usually one of the T class or S class – with a passage crew on board, the operational crew being transferred from the towing submarine to the X-Craft by dinghy when the operational area was reached, and the passage crew returning with the dinghy to the towing submarine. Once the attack was over, the X-Craft would rendezvous with the towing submarine and then be towed home. Range was limited primarily by the endurance and determination of their crews, but was thought to be up to 14 days in the craft or 1,200 miles (1931 km) distance after suitable training. Actual range of the X-Craft itself was surfaced and at submerged. Specification The craft was about long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
