Type 291 Radar
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Type 291 Radar
The Type 291 radar was designed as a search radar for ships destroyer-sized and smaller in 1942. By the end of the Second World War it had been installed in almost every British and Commonwealth destroyer and escort ship as well as many submarines, naval trawlers, and motor torpedo boats. Some sets were furnished to the Soviet Union for their destroyers as a part of Lend-Lease. The initial model of the radar had separate transmitting and receiving antennas, but they were soon combined.Friedman, p. 196 The original Type 291 had a hand-steered antenna and it was replaced by Types 291M, P, and Q with power training and a plan position indicator A plan position indicator (PPI) is a type of radar display that represents the radar antenna in the center of the display, with the distance from it and height above ground drawn as concentric circles. As the radar antenna rotates, a radial tra .... U and W variants with different antennas were produced for coastal craft and submarines res ...
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Conning Tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and ground tackle. It is usually located as high on the ship as practical, to give the conning team good visibility of the entirety of the ship, ocean conditions, and other vessels. The naval term "conn" may derive from the Middle English ''conne'' (study, become acquainted with) or French ''conduire'' from Latin ''conducere'' (conduct). Surface ships On surface ships, the conning tower was a feature of all battleships and armored cruisers from about 1860 to the early years of World War II. Located at the front end of the superstructure, the conning tower was a heavily armored cylinder, with tiny slit windows on three sides providing a reasonable field of view. Designed to shield just enough personnel and devices for navigation during battle ...
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Submarine
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and Autonomous underwater vehicle, robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as ''boats'' rather than ''ships'' irrespective of their size. Although experimental submarines had been built earlier, submarine design took off during the 19th century, and they were adopted by several navies. They were first widely used during World War I (1914–1918), and are now used in many navy, navies, large and small. Military uses include attacking enemy surface ships (merchant and military) or other submarines, and for aircraft carrier protection, Blockade runner, blockade running, Ballistic missile submarine, nuclear deterrence, reconnaissance, conventio ...
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Search Radar
This is a list of different types of radar. Detection and search radars Search radars scan great volumes of space with pulses of short radio waves. They typically scan the volume two to four times a minute. The waves are usually less than a meter long. Ships and planes are metal, and reflect radio waves. The radar measures the distance to the reflector by measuring the time of the roundtrip from emission of a pulse to reception, dividing this by two, and then multiplying by the speed of light. To be accepted, the received pulse has to lie within a period of time called the ''range gate''. The radar determines the direction because the short radio waves behave like a search light when emitted from the reflector of the radar set's antenna. Search * Early Warning (EW) Radar Radar Systems ** Ground Control Intercept (GCI) Radar ** Airborne Early Warning (AEW) ** Airborne ground surveillance (AGS) ** Over-the-Horizon (OTH) Radar *Target Acquisition (TA, TAR) Radar Systems ** Surface ...
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Search Radar
This is a list of different types of radar. Detection and search radars Search radars scan great volumes of space with pulses of short radio waves. They typically scan the volume two to four times a minute. The waves are usually less than a meter long. Ships and planes are metal, and reflect radio waves. The radar measures the distance to the reflector by measuring the time of the roundtrip from emission of a pulse to reception, dividing this by two, and then multiplying by the speed of light. To be accepted, the received pulse has to lie within a period of time called the ''range gate''. The radar determines the direction because the short radio waves behave like a search light when emitted from the reflector of the radar set's antenna. Search * Early Warning (EW) Radar Radar Systems ** Ground Control Intercept (GCI) Radar ** Airborne Early Warning (AEW) ** Airborne ground surveillance (AGS) ** Over-the-Horizon (OTH) Radar *Target Acquisition (TA, TAR) Radar Systems ** Surface ...
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Destroyer
In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in 1885 by Fernando Villaamil for the Spanish NavySmith, Charles Edgar: ''A short history of naval and marine engineering.'' Babcock & Wilcox, ltd. at the University Press, 1937, page 263 as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War. Before World War II, destroyers were light vessels with little endurance for unattended o ...
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Escort Ship
Ocean escort was a type of United States Navy warship. They were an evolution of the World War II destroyer escort types. The ocean escorts were intended as convoy escorts and were designed for mobilization production in wartime or low-cost mass production in peacetime. They were commissioned from 1954 through 1974, serving in the Cold War and the Vietnam War. Designation The ocean escorts' hull classification symbol was DE, a carryover from the World War II era when vessels of similar size and role were classified as destroyer escorts. DEs were ASW vessels; DEGs were ASW and AAW vessels with the short-range Tartar guided missile added. Ships similar or identical to the World War II destroyer escorts and the Cold War ocean escorts were called "frigates" in most other navies. Outside the US Navy, no other navy appears to have used the ship type of "ocean escort". The closest equivalents in type name are the Soviet and classes, built circa 1954–65. These classes' Russian de ...
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Naval Trawler
Naval trawlers are vessels built along the lines of a fishing trawler but fitted out for naval purposes; they were widely used during the First and Second World Wars. Some—known in the Royal Navy as "Admiralty trawlers"— were purpose-built to naval specifications, others adapted from civilian use. Fishing trawlers were particularly suited for many naval requirements because they were robust vessels designed to work heavy trawls in all types of weather, and had large clear working decks. A minesweeper could be created by replacing the trawl with a mine sweep. Adding depth charge racks on the deck, ASDIC sonar below, and a or gun in the bow equipped the trawler for anti-submarine duties. History Armed trawlers were also used to defend fishing groups from enemy aircraft or submarines. The smallest civilian trawlers were converted to danlayers. Contemporary Some nations still use armed trawlers for fisheries protection and patrol. The Indian Navy used naval trawlers for ...
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Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national republics; in practice, both its government and its economy were highly centralized until its final years. It was a one-party state governed by the Communist Party of the Soviet Union, with the city of Moscow serving as its capital as well as that of its largest and most populous republic: the Russian SFSR. Other major cities included Leningrad (Russian SFSR), Kiev (Ukrainian SSR), Minsk ( Byelorussian SSR), Tashkent (Uzbek SSR), Alma-Ata (Kazakh SSR), and Novosibirsk (Russian SFSR). It was the largest country in the world, covering over and spanning eleven time zones. The country's roots lay in the October Revolution of 1917, when the Bolsheviks, under the leadership of Vladimir Lenin, overthrew the Russian Provisional Government ...
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Lend-Lease
Lend-Lease, formally the Lend-Lease Act and introduced as An Act to Promote the Defense of the United States (), was a policy under which the United States supplied the United Kingdom, the Soviet Union and other Allied nations with food, oil, and materiel between 1941 and 1945. It was given on the basis that such help was essential for the defense of the United States; this aid included warships and warplanes, along with other weaponry. It was signed into law on March 11, 1941, and ended on September 20, 1945. In general, the aid was free, although some hardware (such as ships) were returned after the war. Canada, already a belligerent, supplemented its aid to Great Britain with a similar, smaller program called Mutual Aid. A total of $50.1 billion (equivalent to $ in ) worth of supplies was shipped, or 17% of the total war expenditures of the U.S. In all, $31.4 billion went to the United Kingdom, $11.3 billion to the Soviet Union, $3.2 billion to France, $1.6 billion to Chin ...
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Plan Position Indicator
A plan position indicator (PPI) is a type of radar display that represents the radar antenna in the center of the display, with the distance from it and height above ground drawn as concentric circles. As the radar antenna rotates, a radial trace on the PPI sweeps in unison with it about the center point. It is the most common type of radar display. Description The radar antenna sends pulses while rotating 360 degrees around the radar site at a fixed elevation angle. It can then change angle or repeat at the same angle according to the need. Return echoes from targets are received by the antenna and processed by the receiver and the most direct display of those data is the PPI. The height of the echoes increases with the distance to the radar, as represented in the adjacent image. This change is not a straight line but a curve as the surface of the Earth is curved and ''sinks'' below the radar horizon. For fixed-site installations, north is usually represented at the top of ...
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World War II British Electronics
In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique while others talk of a "plurality of worlds". Some treat the world as one simple object while others analyze the world as a complex made up of many parts. In ''scientific cosmology'' the world or universe is commonly defined as " e totality of all space and time; all that is, has been, and will be". '' Theories of modality'', on the other hand, talk of possible worlds as complete and consistent ways how things could have been. ''Phenomenology'', starting from the horizon of co-given objects present in the periphery of every experience, defines the world as the biggest horizon or the "horizon of all horizons". In ''philosophy of mind'', the world is commonly contrasted with the mind as that which is represented by the mind. ''Th ...
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Naval Radars
A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake-borne, riverine, littoral, or ocean-borne combat operations and related functions. It includes anything conducted by surface ships, amphibious ships, submarines, and seaborne aviation, as well as ancillary support, communications, training, and other fields. The strategic offensive role of a navy is projection of force into areas beyond a country's shores (for example, to protect sea-lanes, deter or confront piracy, ferry troops, or attack other navies, ports, or shore installations). The strategic defensive purpose of a navy is to frustrate seaborne projection-of-force by enemies. The strategic task of the navy also may incorporate nuclear deterrence by use of submarine-launched ballistic missiles. Naval operations can be broadly divided between riverine and littoral applications (brown-water navy), open-ocean applications (blue ...
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