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Thetis (decoy)
Thetis was the name of a floating radar decoy used by German U-boats during the Second World War. The device was stored dismantled in the bow compartment as a pole about two metres long. Assembly usually took place in the U-boat's conning tower, and could be assembled in about four minutes (''FuMT 2 - Thetis IIC''). Later versions could be launched from a standard torpedo tube (''FuMT 4 - Thetis US''). When deployed, it was extended to a total length of eight metres, half of which was submerged. The upper half had a series of reflectors that were tuned to Allied anti-submarine radar wavelengths to give the same return signal as a U-boat. The number of Thetis decoys carried varied between different U-boats: * carried approximately 12 units during her 10th and last patrol between 16 January 1944 and 6 May; all were used in the Bay of Biscay. * carried 16 units during her 6th and last patrol between 25 January 1944 and 25 February. * carried an unknown number of units during her 21st a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thetis Radar Decoy
Thetis (; grc-gre, Θέτις ), is a figure from Greek mythology with varying mythological roles. She mainly appears as a sea nymph, a goddess of water, or one of the 50 Nereids, daughters of the ancient sea god Nereus. When described as a Nereid in Classical myths, Thetis was the daughter of Nereus and Doris, and a granddaughter of Tethys with whom she sometimes shares characteristics. Often she seems to lead the Nereids as they attend to her tasks. Sometimes she also is identified with Metis. Some sources argue that she was one of the earliest of deities worshipped in Archaic Greece, the oral traditions and records of which are lost. Only one written record, a fragment, exists attesting to her worship and an early Alcman hymn exists that identifies Thetis as the creator of the universe. Worship of Thetis as the goddess is documented to have persisted in some regions by historical writers such as Pausanias. In the Trojan War cycle of myth, the wedding of Thetis and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...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 kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bay Of Biscay
The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and the northern coast of Spain west to Cape Ortegal. The south area of the Bay of Biscay that washes over the northern coast of Spain is known locally as the Cantabrian Sea. The average depth is and the greatest depth is . Name The Bay of Biscay is named (for English speakers) after Biscay on the northern Spanish coast, probably standing for the western Basque districts (''Biscay'' up to the early 19th century). Its name in other languages is: * ast, Mar Cantábricu * eu, Bizkaiko golkoa * br, pleg-mor Gwaskogn * french: golfe de Gascogne (named after Gascony, France) * gl, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Overlord
Operation Overlord was the codename for the Battle of Normandy, the Allies of World War II, Allied operation that launched the successful invasion of German-occupied Western Front (World War II), Western Europe during World War II. The operation was launched on 6 June 1944 (D-Day) with the Normandy landings. A 1,200-plane Airborne forces, airborne assault preceded an amphibious warfare, amphibious assault involving more than 5,000 vessels. Nearly 160,000 troops crossed the English Channel on 6 June, and more than two million Allied troops were in France by the end of August. The decision to undertake a cross-channel invasion in 1944 was taken at the Washington Conference (1943), Trident Conference in Washington, D.C., Washington in May 1943. General Dwight D. Eisenhower was appointed commander of Supreme Headquarters Allied Expeditionary Force, and General Bernard Montgomery was named commander of the 21st Army Group, which comprised all the land forces involved in the invasio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bold (decoy)
Bold (a term derived from kobold) was a German sonar decoy, used by U-boats during the Second World War from 1942 onwards. It consisted of a metal canister about in diameter filled with calcium hydride. It was launched by an ejector system colloquially referred to as ''Pillenwerfer'' (English: "pill thrower"). When mixed with seawater, the calcium hydride produced large quantities of hydrogen which bubbled out of the container, creating a false sonar target. A valve opened and closed, holding the device at a depth of about . The device lasted 20 to 25 minutes. The Royal Navy called it SBT (Submarine Bubble Target). See also * Sieglinde (decoy) Sieglinde was a sonar decoy used during the Second World War by German U-boats. ''Sieglinde'' was installed in chambers on the sides of the U-boat. It could be ejected to a considerable distance from the boat when attempting to hide from a seeker' ... External links Sonar decoys at uboataces.com Sonar decoys Weapons countermeasures S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
