|
ASW Weapons
An anti-submarine weapon (ASW) is any one of a number of devices that are intended to act against a submarine and its crew, to destroy (sink) the vessel or reduce its capability as a weapon of war. In its simplest sense, an anti-submarine weapon is usually a projectile, missile or bomb that is optimized to destroy submarines. History Before World War I Prior to about 1890, naval weapons were only used against surface shipping. With the rise of the military submarine after this time, countermeasures were considered for use against them. The first submarine installation of torpedo tubes was in 1885 and the first ship was sunk by a submarine-launched torpedo in 1887. There were only two ways of countering the military submarine initially: ramming them or sinking them with gunfire. However, once they were submerged, they were largely immune until they had to surface again. By the start of the First World War there were nearly 300 submarines in service with another 80 in production. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USS Roosevelt (DDG-80) Launches Mk 54 Torpedo In April 2014
Several ships of the United States Navy have borne some version of the name ''Roosevelt'' in honor of members of the Roosevelt family. * , a that saw service during World War II. * , a , launched in 1945 and struck in 1977. * , a patrol vessel in commission from 1918 to 1919, named for President Theodore Roosevelt * , an , launched in 1999 and currently in service. She was named for both President Franklin D. Roosevelt and his wife, Eleanor Roosevelt. Three of the ships have been named United States Ship, USS ''Theodore Roosevelt'', in honor of President Theodore Roosevelt. * , a steamer built in 1906, acquired by the Navy from the Roosevelt Steamship Company sometime in 1918 and fitted out as a troop transport. * , a ballistic missile submarine, launched in 1959 and stricken in 1982. * , a launched in 1984 and currently in active service {{DEFAULTSORT:Roosevelt United States Navy ship names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British R Class Submarine
The R-class submarines were a class of 12 small British diesel-electric submarines built for the Royal Navy during World War I, and were forerunners of the modern attack submarine, in that they were designed specifically to attack and sink enemy submarines, their battery capacity and hull shape being optimized for underwater performance. With a submerged speed of , the class set an underwater speed record not broken until the experimental Japanese Submarine No.71 of 1938, which was capable of more than submerged. Description Ordered in December 1917, the R class were designed to be faster underwater than on the surface, achieving a submerged speed of versus a surfaced speed of . They were well-streamlined, having no external ballast tanks, casing, or deck gun, and a streamlined spindle-shaped hull of circular cross-sectionFitzsimons, p.2170, "''R-1''" (not reproduced until the American USS ''Albacore'') which tapered sharply towards the stern and allowed only for a sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Speed Gradient
In acoustics, the sound speed gradient is the rate of change of the speed of sound with distance, for example with depth in the ocean, or height in the Earth's atmosphere. A sound speed gradient leads to refraction of sound wavefronts in the direction of lower sound speed, causing the sound rays to follow a curved path. The radius of curvature of the sound path is inversely proportional to the gradient. When the sun warms the Earth's surface, there is a negative temperature gradient in atmosphere. The speed of sound decreases with decreasing temperature, so this also creates a negative sound speed gradient. The sound wave front travels faster near the ground, so the sound is refracted upward, away from listeners on the ground, creating an acoustic shadow at some distance from the source. The opposite effect happens when the ground is covered with snow, or in the morning over water, when the sound speed gradient is positive. In this case, sound waves can be refracted from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Battle Of The Atlantic 1939-1945 A31000
''The'' is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pronoun '' the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mark 24 FIDO Torpedo
The Mark 24 mine (also known as FIDO or Fido) is an air-dropped anti-submarine (ASW) acoustic torpedo developed by the United States during World War II; it was called a mine to conceal its capabilities. The torpedo entered service with the Allies in March 1943; the United States Navy (USN) used it until 1948. Approximately 4,000 were produced. Of the 340 deployed during the war, 204 were fired, sinking 37 and damaging 18 Axis submarines. Background The concept of the acoustic torpedo existed by World War I, but was impractical due to the insufficient understanding of underwater acoustics. Germany was developing electrically-driven acoustic torpedoes by 1933; the resulting G7e and G7es anti-ship torpedoes, running at a preset depth, entered service on submarines in 1943. The USN received a similar anti-ship torpedo, the Mark 28, in 1944. ASW torpedoes must detect and respond to greater changes in depth and azimuth than anti-ship torpedoes. FIDO was designed within the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft
An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, in a few cases, direct Powered lift, downward thrust from its engines. Common examples of aircraft include airplanes, rotorcraft (including helicopters), airships (including blimps), Glider (aircraft), gliders, Powered paragliding, paramotors, and hot air balloons. Part 1 (Definitions and Abbreviations) of Subchapter A of Chapter I of Title 14 of the U. S. Code of Federal Regulations states that aircraft "means a device that is used or intended to be used for flight in the air." The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called ''aeronautics.'' Aircrew, Crewed aircraft are flown by an onboard Aircraft pilot, pilot, whereas unmanned aerial vehicles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Explosion
An underwater explosion (also known as an UNDEX) is a explosive material, chemical or nuclear explosive, nuclear explosion that occurs under the surface of a body of water. While useful in anti-ship and submarine warfare, underwater bombs are not as effective against coastal facilities. Properties of water Underwater explosions differ from in-air explosions due to the properties of water: *Mass and compressibility, incompressibility (all explosions) – water has a much higher density than air, which makes water harder to move (higher inertia). It is also relatively hard to compress (increase density) when under pressure in a low range (up to about 100 atmospheres). These two together make water an excellent conductor of shock waves from an explosion. *Effect of neutron exposure on salt water (nuclear explosions only) – most underwater blast scenarios happen in seawater, not fresh or pure water. The water itself is not much affected by neutrons but salt is strongly affected. Whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. As the mortar projectiles employed contact fuzes rather than time or bathymetric (depth) fuzes, detonation occurred directly against a hard surface such as the hull of a submarine making it more deadly than depth charges, which relied on damage caused by hydrostatic shockwaves. During World War II out of 5,174 British depth charge attacks there were 85.5 kills, a ratio of 60.5 to 1. In comparison, the Hedgehog made 268 attacks for 47 kills, a ratio of 5.7 to 1. Development The "Hedgehog", so named because the empty rows of its launcher spigots resembled the spines on the back of a hedgeh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leigh Light
The Leigh Light (L/L) was a British World War II era anti-submarine device used in the Battle of the Atlantic. It was a powerful (22 million candelas) carbon arc searchlight of diameter fitted to a number of the British Royal Air Force's Coastal Command patrol bombers to help them spot surfaced German U-boats at night. Early night operations with the new air-to-surface-vessel (ASV) radar demonstrated that the radar's minimum range of about meant that the target was still invisible when it disappeared off the radar display. Efforts to reduce this minimum were not successful, so Wing Commander Humphrey de Verd Leigh hit upon the idea of using a searchlight that would be switched on just when the target was about to disappear on radar. The U-boat had insufficient time to dive and the bombardier had a clear view of the target. Introduced in June 1942, it was so successful that for a time German submarines were forced to switch to charging their batteries during the day ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of The Atlantic
The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allies of World War II, Allied naval Blockade of Germany (1939–1945), blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counter-blockade. The campaign peaked from mid-1940 to the end of 1943. The Battle of the Atlantic pitted U-boats and other warships of the German (navy) and aircraft of the (air force) against the Royal Navy, Royal Canadian Navy, United States Navy, and Merchant Navy (United Kingdom), Allied merchant shipping. Convoys, coming mainly from North America and predominantly going to the United Kingdom and the Soviet Union, were protected for the most part by the British and Canadian navies and air forces. These forces were aided by ships and aircraft of the United States beginning on 13 September 1941. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total population of over 84 million in an area of , making it the most populous member state of the European Union. It borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The Capital of Germany, nation's capital and List of cities in Germany by population, most populous city is Berlin and its main financial centre is Frankfurt; the largest urban area is the Ruhr. Settlement in the territory of modern Germany began in the Lower Paleolithic, with various tribes inhabiting it from the Neolithic onward, chiefly the Celts. Various Germanic peoples, Germanic tribes have inhabited the northern parts of modern Germany since classical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
