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Rubis-class Submarine
The ''Rubis'' class is a series of nuclear-powered attack submarines operated by the French Navy. The class comprises six vessels, the first entering service in 1983 and the last in 1993, with another two being cancelled. All six submarines of the ''Rubis'' class are based at Toulon and are part of the ''Escadrille de sous-marins nucléaires d'attaque''. Smaller than contemporary designs of other major world navies, the ''Rubis'' class shares many of its system designs with the conventionally-powered . In the late 1980s, the ''Rubis'' class was proposed as an export to Canada in their plan to acquire nuclear-powered submarines. The submarines of the class were built in two batches, with the final two built to an improved standard to reduce noise emissions that plagued the original design. Dubbed the AMÉTHYSTE rebuild, the first four hulls were refitted to its standard until they were practically indistinguishable from the final two hulls. Four of the submarines have had signifi ...
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DCNS (company)
Naval Group is a major French industrial group specialized in naval defense design, development and construction. Its headquarters are located in Paris. Heir to the French naval dockyards initiated in 1631 by Cardinal Richelieu and to the Direction des Constructions et Armes Navales (''DCAN''), which became Direction des Constructions Navales (''DCN'') in 1991 and then DCNS in 2007, the company was rebranded ''Naval Group'' in 2017. Its two main shareholders are the French State (62.49%) and Thales Group (35%). Naval Group employs nearly 16,000 people across 18 countries. History Naval Group has a heritage of almost 400 years. Major shipyards were built in France in Brest (1631), Nantes-Indret (1771), Lorient (1778) and, subsequently, in Cherbourg (1813). Others were to follow. As early as 1926, what we know as Naval Group today already had all the facilities now owned by the group in mainland France. The birth of the naval dockyards In 1624, Cardinal Richelieu, who was King ...
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Turbo-electric Drive
A turbine–electric transmission system includes a turboshaft gas turbine connected to an electrical generator, creating electricity that powers electric traction motors. No clutch is required. Turbine–electric transmissions are used to drive both gas turbine locomotives (rarely) and warships. Locomotive applications A handful of experimental locomotives from the 1930s and 1940s used gas turbines as prime movers. These turbines were based on stationary practice, with single large reverse-flow combustors, heat exchangers and using low-cost heavy oil bunker fuel. In the 1960s the idea re-emerged, using developments in light weight engines developed for helicopters and using lighter kerosene fuels. As these turbines were compact and lightweight, the vehicles were produced as railcars rather than separate locomotives. Naval applications Gas and steam turbines are most efficient at thousands of revolutions per minute. This is a major drawback because of the need for heavy gears, w ...
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Anti-ship Missile
An anti-ship missile (AShM) is a guided missile that is designed for use against ships and large boats. Most anti-ship missiles are of the sea skimming variety, and many use a combination of inertial guidance and active radar homing. A good number of other anti-ship missiles use infrared homing to follow the heat that is emitted by a ship; it is also possible for anti-ship missiles to be guided by radio command all the way. The first anti-ship missiles, which were developed and built by Nazi Germany, used radio command guidance.https://airandspace.si.edu/collection-objects/bomb-guided-fritz-x-x-1/nasm_A19840794000#:~:text=The%20Fritz%20X%2C%20also%20known,the%20Henschel%20Hs%20293%20missile. These saw some success in the Mediterranean Theatre during 1943–44, sinking or heavily damaging at least 31 ships with the Henschel Hs 293 and more than seven with the ''Fritz X'', including the Italian battleship ''Roma'' and the light cruiser . A variant of the HS 293 had a TV ca ...
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Diesel Generator
A diesel generator (DG) (also known as a diesel Genset) is the combination of a diesel engine with an electric generator (often an alternator) to generate electrical energy. This is a specific case of engine generator. A diesel compression-ignition engine is usually designed to run on diesel fuel, but some types are adapted for other liquid fuels or natural gas. Diesel generating sets are used in places without connection to a power grid, or as an emergency power supply if the grid fails, as well as for more complex applications such as peak-lopping, grid support, and export to the power grid. Diesel generator size is crucial to minimize low load or power shortages. Sizing is complicated by the characteristics of modern electronics, specifically non-linear loads. In size ranges around 50 MW and above, an open cycle gas turbine is more efficient at full load than an array of diesel engines, and far more compact, with comparable capital costs; but for regular part-loading, ...
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SEMT-Pielstick
SEMT Pielstick was a French company that designed and built large diesel engines. Its full name was (Company of Thermal Machines Studies). Founded in 1948, SEMT was bought by MAN Diesel in 2006 During its existence as an independent company, SEMT manufactured engines for locomotives, naval vessels, Power station, power plants, and merchant ships. Its customers included France, the United States, Russia, India and other countries. History SEMT. was created in 1946 by France's ministry for Industrial engineering, industrial production by combining five national companies: * (Saint-Nazaire), * (La Courneuve) * (Le Havre) * (Nantes) * (Denain) The aim of the new company was to develop new engines in France that could be licensed internationally. In 1948, the first licenses were supplied to licensed engine building companies worldwide. In 1951, after its relocation at La Courneuve, the was equipped with the first Testbed, test beds. The equipment, which enabled th ...
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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 (ship), 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 ...
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Turbo-alternator
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.Gordon R. Selmon, ''Magnetoelectric Devices'', John Wiley and Sons, 1966 no ISBN pp. 391-393 Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually the term refers to small rotating machines driven by automotive and other internal combustion engines. An alternator that uses a permanent magnet for its magnetic field is called a magneto. Alternators in power stations driven by steam turbines are called turbo-alternators. Large 50 or 60 Hz three-phase alternators in power plants generate most of the world's electric power, which is distributed by electric power grids. History Alternating current generating syst ...
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Kilowatt
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Watt (1736–1819), an 18th-century Scottish inventor, mechanical engineer, and chemist who improved the Newcomen engine with his own steam engine in 1776. Watt's invention was fundamental for the Industrial Revolution. Overview When an object's velocity is held constant at one metre per second against a constant opposing force of one newton, the rate at which work is done is one watt. : \mathrm In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V), meaning the watt is equivalent to the volt-ampere (the latter unit, however, is used for a different quantity from the real power of an electrical circuit). : ...
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Megawatt
The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units, International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Energy transformation, energy transfer. The watt is named after James Watt (1736–1819), an 18th-century Scottish people, Scottish invention, inventor, mechanical engineer, and chemist who improved the Newcomen steam engine, Newcomen engine with his own Watt steam engine, steam engine in 1776. Watt's invention was fundamental for the Industrial Revolution. Overview When an object's velocity is held constant at one metre per second against a constant opposing force of one Newton (unit), newton, the rate at which Work (physics), work is done is one watt. : \mathrm In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potentia ...
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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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Displacement (ship)
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed (known as "lightweight tonnage") to its maximum load. Numerous specific terms are used to describe varying levels of load and trim, detailed below. Ship displacement should not be confused with measurements of volume or capacity typically used for commercial vessels and measured by tonnage: net tonnage and gross tonnage. Calculation The process of determining a vessel's displacement begins with measuring its draft.George, 2005. p.5. This is accomplished by means of its "draft marks" (or "load lines"). A mer ...
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Draft (hull)
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water. The more heavily a vessel is loaded, the deeper it sinks into the water, and the greater its draft. After construction, the shipyard creates a table showing how much water the vessel displaces based on its draft and the density of the water (salt or fresh). The draft can also be used to determine the weight of cargo on board by calculating the total displacement of water, accounting for the content of the ship's bunkers, and using Archimedes' principle. The closely related term "trim" is defined as the difference between the forward and aft ...
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