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German Submarine U-71 (1940)
German submarine ''U-71'' was a type VII C submarine of Nazi Germany's '' Kriegsmarine'' during the Second World War. Ordered on 25 January 1939, her keel was laid down as yard number 618 on 21 December that year. She was launched on 31 October 1940 and commissioned on 14 December. She entered the 7th U-boat Flotilla as a training submarine (commissioning until 31 May 1941), then served as a front (operational) boat between 1 June 1941 and 31 May 1943. During that time she carried out ten war patrols, but had to return to port following damage after colliding with in the North Atlantic on 17 April 1943. After that, she moved to the 24th U-boat Flotilla as a training submarine (1 June 1943 – 30 June 1944), then to the 22nd flotilla also as a training boat from 1 July 1944 until 27 February 1945. She was a member of 17 wolfpacks. She sank five ships and was scuttled on 2 May 1945 at Wilhelmshaven, six days before the German surrender. Design German Type VIIC submarines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was the German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a dictatorship. Under Hitler's rule, Germany quickly became a totalitarian state where nearly all aspects of life were controlled by the government. The Third Reich, meaning "Third Realm" or "Third Empire", alluded to the Nazi claim that Nazi Germany was the successor to the earlier Holy Roman Empire (800–1806) and German Empire (1871–1918). The Third Reich, which Hitler and the Nazis referred to as the Thousand-Year Reich, ended in May 1945 after just 12 years when the Allies defeated Germany, ending World War II in Europe. On 30 January 1933, Hitler was appointed chancellor of Germany, the head of gove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
22nd U-boat Flotilla
22nd U-boat Flotilla ("22. Unterseebootsflottille") was formed in January 1941 in Gotenhafen under the command of ''Korvettenkapitän'' Wilhelm Ambrosius German submarine ''U-43'' was a Type IXA U-boat of Nazi Germany's '' Kriegsmarine'' during World War II. The keel for ''U-43'' was laid down in August 1938 at Bremen; she was launched in May 1939 and commissioned in August. Between Novemb .... The flotilla was disbanded in May 1945. Flotilla commanders References * 22 Military units and formations established in 1941 Military units and formations disestablished in 1945 {{Germany-mil-unit-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are specially shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft (ship), propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor–generator
A motor–generator (an M–G set) is a device for converting electrical power to another form. Motor–generator sets are used to convert frequency, voltage, or phase of power. They may also be used to isolate electrical loads from the electrical power supply line. Large motor–generators were widely used to convert industrial amounts of power while smaller motor–generators (such as the one shown in the picture) were used to convert battery power to higher DC voltages. While a motor–generator set may consist of distinct motor and generator machines coupled together, a single unit dynamotor (for dynamo–motor) has the motor coils and the generator coils wound around a single rotor; both the motor and generator therefore share the same outer field coils or magnets.Radio Amateur's Handbook 1976, pub. |
Supercharged
In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induction that is mechanically powered (usually by a belt from the engine's crankshaft), as opposed to a turbocharger, which is powered by the kinetic energy of the exhaust gasses. However, up until the mid-20th century, a turbocharger was called a "turbosupercharger" and was considered a type of supercharger. The first supercharged engine was built in 1878, with usage in aircraft engines beginning in the 1910s and usage in car engines beginning in the 1920s. In piston engines used by aircraft, supercharging was often used to compensate for the lower air density at high altitudes. Supercharging is less commonly used in the 21st century, as manufacturers have shifted to turbochargers to reduce fuel consumption and/or increase power outputs. Des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draught (ship)
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water. The more heavily a vessel is loaded, the deeper it sinks into the water, and the greater its draft. After construction, the shipyard creates a table showing how much water the vessel displaces based on its draft and the density of the water (salt or fresh). The draft can also be used to determine the weight of cargo on board by calculating the total displacement of water, accounting for the content of the ship's bunkers, and using Archimedes' principle. The closely related term "trim" is defined as the difference between the forward and aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam (nautical)
The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water. Generally speaking, the wider the beam of a ship (or boat), the more initial stability it has, at the expense of secondary stability in the event of a capsize, where more energy is required to right the vessel from its inverted position. A ship that heels on her ''beam ends'' has her deck beams nearly vertical. Typical values Typical length-to-beam ratios ( aspect ratios) for small sailboats are from 2:1 (dinghies to trailerable sailboats around ) to 5:1 (racing sailboats over ). Large ships have widely varying beam ratios, some as large as 20:1. Rowing shells designed for flatwater racing may have length to beam ratios as high as 30:1, while a cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelmshaven
Wilhelmshaven (, ''Wilhelm's Harbour''; Northern Low Saxon: ''Willemshaven'') is a coastal town in Lower Saxony, Germany. It is situated on the western side of the Jade Bight, a bay of the North Sea, and has a population of 76,089. Wilhelmshaven is the centre of the "Jade Bay" business region (which has around 330,000 inhabitants) and is Germany's main military port. The adjacent Lower Saxony Wadden Sea National Park (part of the Wattenmeer UNESCO World Natural Heritage Site) provides the basis for the major tourism industry in the region. History The , built before 1383, operated as a pirate stronghold; the Hanseatic League destroyed it in 1433. Four centuries later, the Kingdom of Prussia planned a fleet and a harbour on the North Sea. In 1853, Prince Adalbert of Prussia, a cousin of the Prussian King Frederick William IV of Prussia, Frederick William IV, arranged the Jade Treaty (''Jade-Vertrag'') with the Grand Duchy of Oldenburg, in which Prussia and the Grand Duchy ente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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. In the Pacific the American submarine force was able to devastate Japan’s merchant marine, though this was not solely due to the wolfpack tactic. Wolfpacks fell out of use during the Cold War as the role of the submarine changed and as convoys became rare. World War I During the (German war on trade) Allied ships travelled independently prior to the introduction of the convoy system and were vulnerable to attacks by U-boats operating as 'lone wolves'. By gathering up merchant ships into con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Commissioning
Ship commissioning is the act or ceremony of placing a ship in active service and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to placing a warship in active duty with its country's military forces. The ceremonies involved are often rooted in centuries-old naval tradition. Ship naming and launching endow a ship hull with her identity, but many milestones remain before she is completed and considered ready to be designated a commissioned ship. The engineering plant, weapon and electronic systems, galley, and other equipment required to transform the new hull into an operating and habitable warship are installed and tested. The prospective commanding officer, ship's officers, the petty officers, and seamen who will form the crew report for training and familiarization with their new ship. Before commissioning, the new ship undergoes sea trials to identify any deficiencies needing corre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceremonial Ship Launching
Ceremonial ship launching involves the performance of ceremonies associated with the process of transferring a vessel to the water. It is a nautical tradition in many cultures, dating back thousands of years, to accompany the physical process with ceremonies which have been observed as public celebration and a solemn blessing, usually but not always, in association with the launch itself. Ship launching imposes stresses on the ship not met during normal operation and, in addition to the size and weight of the vessel, represents a considerable engineering challenge as well as a public spectacle. The process also involves many traditions intended to invite good luck, such as christening by breaking a sacrificial bottle of champagne over the bow as the ship is named aloud and launched. Methods There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching". The oldest, most familiar, and most widely used is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keel Laying
Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship. Keel laying is one of the four specially celebrated events in the life of a ship; the others are launching, commissioning and decommissioning. In earlier times, the event recognized as the keel laying was the initial placement of the central timber making up the backbone of a vessel, called the keel. As steel ships replaced wooden ones, the central timber gave way to a central steel beam. Modern ships are most commonly built in a series of pre-fabricated, complete hull sections rather than around a single keel. The event recognized as the keel laying is the first joining of modular components, or the lowering of the first module into place in the building dock. It is now often called "keel authentication", and is the ceremonial beginning of the ship's life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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