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Bouncing Bomb
A bouncing bomb is a bomb designed to bounce to a target across water in a calculated manner to avoid obstacles such as torpedo nets, and to allow both the bomb's speed on arrival at the target and the timing of its detonation to be pre-determined, in a similar fashion to a regular naval depth charge. The inventor of the first such bomb was the British engineer Barnes Wallis, whose "Upkeep" bouncing bomb was used in the RAF's Operation Chastise of May 1943 to bounce into German dams and explode under water, with effect similar to the underground detonation of the Grand Slam and Tallboy earthquake bombs, both of which he also invented. British bouncing bombs After the outbreak of the Second World War in 1939, Wallis saw strategic bombing as the means to destroy the enemy's ability to wage war and he wrote a paper entitled "A Note on a Method of Attacking the Axis Powers". Referring to the enemy's power supplies, he wrote (as Axiom 3): "If their destruction or paralysis can ...
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Code Name
A code name, call sign or cryptonym is a code word or name used, sometimes clandestinely, to refer to another name, word, project, or person. Code names are often used for military purposes, or in espionage. They may also be used in industrial counter-espionage to protect secret projects and the like from business rivals, or to give names to projects whose marketing name has not yet been determined. Another reason for the use of names and phrases in the military is that they transmit with a lower level of cumulative errors over a walkie-talkie or radio link than actual names. Military origins During World War I, names common to the Allies referring to nations, cities, geographical features, military units, military operations, diplomatic meetings, places, and individual persons were agreed upon, adapting pre-war naming procedures in use by the governments concerned. In the British case names were administered and controlled by the Inter Services Security Board (ISSB) staffed b ...
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Tallboy Bomb
Tallboy or Bomb, Medium Capacity, 12,000 lb was an earthquake bomb developed by the British aeronautical engineer Barnes Wallis and used by the Royal Air Force (RAF) during the Second World War."Medium capacity" refers to the ratio of bomb case to explosive filling; in the case of the Tallboy, this was less than 50 per cent explosive by weight, in contrast to "high capacity" bombs like the Blockbuster bombs, in which up to three-quarters of their weight was the explosive. At , it could be carried only by a modified model of the Avro Lancaster heavy bomber. It proved to be effective against large, fortified structures against which conventional bombing had proved ineffective. History Wallis presented his ideas for a 10-ton bomb in his 1941 paper "A Note on a Method of Attacking the Axis Powers", which showed that a very large bomb exploding deep underground next to a target would transmit the shock into the foundations of the target, particularly since shock waves are transm ...
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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 ...
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Fleet In Being
In naval warfare, a "fleet in being" is a naval force that extends a controlling influence without ever leaving port. Were the fleet to leave port and face the enemy, it might lose in battle and no longer influence the enemy's actions, but while it remains safely in port, the enemy is forced to continually deploy forces to guard against it. A "fleet in being" can be part of a sea denial doctrine, but not one of sea control. Use of the term The term was first used in 1690 when Lord Torrington, commander of the Royal Navy forces in the English Channel, found himself facing a stronger French fleet. He proposed avoiding a sea battle, except under very favourable conditions, until he could be reinforced. By thus keeping his "fleet in being", he could maintain an active threat which would force the enemy to remain in the area and prevent them from taking the initiative elsewhere. Secondary use Rudyard Kipling published a series of articles about the British Channel Fleet under the tit ...
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Allies Of World War II
The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during the Second World War (1939–1945) to oppose the Axis powers, led by Nazi Germany, Imperial Japan, and Fascist Italy. Its principal members by 1941 were the United Kingdom, United States, Soviet Union, and China. Membership in the Allies varied during the course of the war. When the conflict broke out on 1 September 1939, the Allied coalition consisted of the United Kingdom, France, and Poland, as well as their respective dependencies, such as British India. They were soon joined by the independent dominions of the British Commonwealth: Canada, Australia, New Zealand and South Africa. Consequently, the initial alliance resembled that of the First World War. As Axis forces began invading northern Europe and the Balkans, the Allies added the Netherlands, Belgium, Norway, Greece, and Yugoslavia. The Soviet Union, which initially had a nonaggression pa ...
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Battleship
A battleship is a large armored warship with a main battery consisting of large caliber guns. It dominated naval warfare in the late 19th and early 20th centuries. The term ''battleship'' came into use in the late 1880s to describe a type of ironclad warship,Stoll, J. ''Steaming in the Dark?'', Journal of Conflict Resolution Vol. 36 No. 2, June 1992. now referred to by historians as pre-dreadnought battleships. In 1906, the commissioning of into the United Kingdom's Royal Navy heralded a revolution in the field of battleship design. Subsequent battleship designs, influenced by HMS ''Dreadnought'', were referred to as "dreadnoughts", though the term eventually became obsolete as dreadnoughts became the only type of battleship in common use. Battleships were a symbol of naval dominance and national might, and for decades the battleship was a major factor in both diplomacy and military strategy.Sondhaus, L. ''Naval Warfare 1815–1914'', . A global arms race in battleship cons ...
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Torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially a ''fish''. The term ''torpedo'' originally applied to a variety of devices, most of which would today be called naval mine, mines. From about 1900, ''torpedo'' has been used strictly to designate a self-propelled underwater explosive device. While the 19th-century battleship had evolved primarily with a view to engagements between armored warships with naval artillery, large-caliber guns, the invention and refinement of torpedoes from the 1860s onwards allowed small torpedo boats and other lighter surface combatant , surface vessels, submarines/submersibles, even improvised fishing boats or frogmen, and later light aircraft, to destroy large shi ...
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Fjord
In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Germany, Greenland, the Faroe Islands, Iceland, Ireland, Kamchatka, the Kerguelen Islands, Labrador, Newfoundland, New Zealand, Norway, Novaya Zemlya, Nunavut, Quebec, the Patagonia region of Argentina and Chile, Russia, South Georgia Island, Tasmania, United Kingdom, and Washington state. Norway's coastline is estimated to be long with its nearly 1,200 fjords, but only long excluding the fjords. Formation A true fjord is formed when a glacier cuts a U-shaped valley by ice segregation and abrasion of the surrounding bedrock. According to the standard model, glaciers formed in pre-glacial valleys with a gently sloping valley floor. The work of the glacier then left an overdeepened U-shaped valley that ends abruptly at a valley or trough end. Such valleys are fjords wh ...
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Hydroelectricity
Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewable energy, renewable sources combined and also more than nuclear power. Hydropower can provide large amounts of Low-carbon power, low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once a hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel-powered energy plants.
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Underwater Explosion
An underwater explosion (also known as an UNDEX) is a chemical or 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 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. When exposed to neutron radiation during the microsecond of ...
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Axiom
An axiom, postulate, or assumption is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments. The word comes from the Ancient Greek word (), meaning 'that which is thought worthy or fit' or 'that which commends itself as evident'. The term has subtle differences in definition when used in the context of different fields of study. As defined in classic philosophy, an axiom is a statement that is so evident or well-established, that it is accepted without controversy or question. As used in modern logic, an axiom is a premise or starting point for reasoning. As used in mathematics, the term ''axiom'' is used in two related but distinguishable senses: "logical axioms" and "non-logical axioms". Logical axioms are usually statements that are taken to be true within the system of logic they define and are often shown in symbolic form (e.g., (''A'' and ''B'') implies ''A''), while non-logical axioms (e.g., ) are actually ...
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Axis Powers
The Axis powers, ; it, Potenze dell'Asse ; ja, 枢軸国 ''Sūjikukoku'', group=nb originally called the Rome–Berlin Axis, was a military coalition that initiated World War II and fought against the Allies. Its principal members were Nazi Germany, the Kingdom of Italy, and the Empire of Japan. The Axis were united in their opposition to the Allies, but otherwise lacked comparable coordination and ideological cohesion. The Axis grew out of successive diplomatic efforts by Germany, Italy, and Japan to secure their own specific expansionist interests in the mid-1930s. The first step was the protocol signed by Germany and Italy in October 1936, after which Italian leader Benito Mussolini declared that all other European countries would thereafter rotate on the Rome–Berlin axis, thus creating the term "Axis". The following November saw the ratification of the Anti-Comintern Pact, an anti-communist treaty between Germany and Japan; Italy joined the Pact in 1937, follow ...
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