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U-744
German submarine ''U-744'' was a type VIIC U-boat, launched on 11 March 1943, commanded by '' Oberleutnant zur See'' Heinz Blischke. Design German Type VIIC submarines were preceded by the shorter Type VIIB submarines. ''U-744'' 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 AEG GU 460/8–27 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 had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . ''U-744'' was fitted with five torpedo tubes (four fitted at the bow and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-boat
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role (commerce raiding) and enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, and from the United States, to the United Kingdom and (during the Second World War) to the Soviet Union and the Allied territories in the Mediterranean. German submarines also destroyed Brazilian merchant ships during World War II, causing Brazil to declare war on both Germany and Italy on 22 August 1942. The term is an anglicised version of the German word ''U-Boot'' , a shortening of ''Unterseeboot'' ('under-sea-boat'), though the German term refers to any submarine. Austro-Hungarian Navy submarines were also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS Hero (H99)
HMS ''Hero'' was an H-class destroyer built for the Royal Navy in the mid-1930s. During the Spanish Civil War of 1936–1939 the ship enforced the arms blockade imposed by Britain and France on both sides as part of the Mediterranean Fleet. During the first few months of World War II, ''Hero'' searched for German commerce raiders in the Atlantic Ocean and participated in the Second Battle of Narvik during the Norwegian Campaign of April–June 1940 before she was transferred to the Mediterranean Fleet in May where she escorted a number of convoys to Malta. The ship took part in the Battle of Cape Spada in July 1940, Operation Abstention in February 1941, and the evacuations of Greece and Crete in April–May 1941. The ship covered an amphibious landing during the Syria–Lebanon Campaign of June 1941 and began escorting supply convoys in June to Tobruk, Libya shortly afterwards. She was damaged by German dive bombers while rescuing survivors from the minelayer in Octobe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landing Ship Tank
Landing Ship, Tank (LST), or tank landing ship, is the naval designation for ships first developed during World War II (1939–1945) to support amphibious operations by carrying tanks, vehicles, cargo, and landing troops directly onto shore with no docks or piers. This enabled amphibious assaults on almost any beach. The LST had a highly specialized design that enabled ocean crossings as well as shore groundings. The bow had a large door that could open, deploy a ramp and unload vehicles. The LST had a flat keel that allowed the ship to be beached and stay upright. The twin propellers and rudders had protection from grounding. The LSTs served across the globe during World War II including in the Pacific War and in the European theatre. The first tank-landing ships were built to British requirements by converting existing ships; the UK and the US then collaborated upon a joint design. The British ships were used in late 1942 during the Allied invasion of Algeria, by 194 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
9th U-boat Flotilla
The 9th U-boat Flotilla (German ''9. Unterseebootsflottille'') was formed in October 1941 in Brest. It became operational in April 1942, after the first combat ready U-boat, , reached the Brest base on 20 March 1942. The flotilla operated mostly various marks of the Type VII U-boat and it concentrated its efforts mainly in the North Atlantic, against convoys to and from Great Britain. The flotilla served from Brest until the base was threatened with being captured by American forces. The last of the flotilla's U-boats, the left Brest on 4 September 1944 for Bergen, Norway, and this marked the end of the 9th Flotilla. All its surviving boats were reassigned to the 11th U-boat Flotilla in Bergen. The symbol of the 9th Flotilla, ''Der lachende Schwertfisch'' or the "laughing Swordfish" became the unit symbol after Lehmann-Willenbrock assumed command. It has previously been the conning tower emblem on his previous command, of "''Das Boot ''Das Boot'' (, English: "The Boat") i ... [...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 (ship), 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 widel ... [...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] |
North Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe and Asia from the "New World" of the Americas in the European perception of the World. The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to the east, and North and South America to the west. As one component of the interconnected World Ocean, it is connected in the north to the Arctic Ocean, to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south (other definitions describe the Atlantic as extending southward to Antarctica). The Atlantic Ocean is divided in two parts, by the Equatorial Counter Current, with the North(ern) Atlantic Ocean and the South(ern) Atlantic Ocean split at about 8°N. Scientific explorations of the Atlan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frigate
A frigate () is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied somewhat. The name frigate in the 17th to early 18th centuries was given to any full-rigged ship built for speed and maneuverability, intended to be used in scouting, escort and patrol roles. The term was applied loosely to ships varying greatly in design. In the second quarter of the 18th century, the 'true frigate' was developed in France. This type of vessel was characterised by possessing only one armed deck, with an unarmed deck below it used for berthing the crew. Late in the 19th century (British and French prototypes were constructed in 1858), armoured frigates were developed as powerful ironclad warships, the term frigate was used because of their single gun deck. Later developments in ironclad ships rendered the frigate designation obsolete and the term fell out of favour. During the Second World War the name 'frigate' was reintroduced to ... [...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 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 blade to the water at t ... [...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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
