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German Submarine U-757
German submarine ''U-757'' was a Type VIIC U-boat built for Nazi Germany's ''Kriegsmarine'' for service during World War II. Laid down as yard number 140 at the Kriegsmarinewerft (KMW) in Wilhelmshaven, ''U-757'' served with 6th U-boat Flotilla from 28 February 1942 until 8 January 1944 under the command of '' Korvettenkapitän'' Friedrich Deetz. Design German Type VIIC submarines were preceded by the shorter Type VIIB submarines. ''U-757'' had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two Garbe, Lahmeyer & Co. RP 137/c double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to . The submarine ... [...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] |
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] |
Displacement (ship)
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed (known as "lightweight tonnage") to its maximum load. Numerous specific terms are used to describe varying levels of load and trim, detailed below. Ship displacement should not be confused with measurements of volume or capacity typically used for commercial vessels and measured by tonnage: net tonnage and gross tonnage. Calculation The process of determining a vessel's displacement begins with measuring its draft.George, 2005. p.5. This is accomplished by means of its "draft marks" (or "load lines"). A mer ... [...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] |
Convoy HX 228
HX 228 was a North Atlantic convoy of the HX series which ran during the Battle of the Atlantic in World War II. It was one of a series of four convoy battles that occurred during the crisis month of March 1943 and is notable for the loss of the Escort Group leader Commander AA "Harry" Tait. Prelude HX 228 was an east-bound convoy of 60 ships, plus local contingents, which sailed from New York on 28 February 1943 bound for Liverpool and carrying war materials. The Mid-Ocean Escort Force group B3 joined the convoy from St Johns. The escort group was led by Commander AA Tait of HMS ''Harvester''; the other ships of this group were the destroyers HMS ''Escapade'', ORP ''Burza'' and ORP ''Garland'' and the corvettes HMS ''Narcissus'' and FNFL ships '' Aconit'', ''Renoncule'' and ''Roselys''. The group was backed by the escort carrier and two destroyers which sailed from Argentia on 5 March. Arrayed against them in the North Atlantic were three U-boat patrol lines, ' ... [...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] |
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