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122-509: The General Electric LM2500 is an industrial and marine gas turbine produced by GE Aviation . The LM2500 is a derivative of the General Electric CF6 aircraft engine. As of 2004, the U.S. Navy and at least 29 other navies had used a total of more than one thousand LM2500/LM2500+ gas turbines to power warships . Other uses include hydrofoils , hovercraft and fast ferries . In 2012, GE developed an FPSO version to serve
244-1274: A COGAS cycle (actually COGES, as the turbines generate electricity rather than driving the shafts directly). The LM2500 is license-built in India by Hindustan Aeronautics Limited ; in Italy by Avio Aero ; and in Japan by IHI Corporation . (Subsequent to the February 2024 reporting of an IHI company whistleblower ; On April 24, 2024, IHI announced that investigation was underway by Japan's Ministry of Land, Infrastructure, Transport and Tourism of its subsidiary, IHI Power Systems Co., which had falsified its engine data since 2003, impacting over 4,000 engines globally.) The LM2500/LM2500+ can often be found as turbine part of CODAG , CODOG , CODLAG propulsion systems or in pairs as powerplants for COGAG systems. Aircraft carrier : Amphibious assault ship : Cruiser : Destroyer : Frigate : Fast Combat Support Ship : Maritime Prepositioning Force : Littoral combat ship : Corvette : Maritime Security Cutter, Large : Fast Attack Patrol boat Passenger Ship : The LM2500
366-415: A turbojet , driving the fan of a turbofan , rotor or accessory of a turboshaft , and gear reduction and propeller of a turboprop . If the engine has a power turbine added to drive an industrial generator or a helicopter rotor, the exit pressure will be as close to the entry pressure as possible with only enough energy left to overcome the pressure losses in the exhaust ducting and expel the exhaust. For
488-409: A turboprop engine there will be a particular balance between propeller power and jet thrust which gives the most economical operation. In a turbojet engine only enough pressure and energy is extracted from the flow to drive the compressor and other components. The remaining high-pressure gases are accelerated through a nozzle to provide a jet to propel an aircraft. The smaller the engine, the higher
610-420: A turbopump to permit the use of lightweight, low-pressure tanks, reducing the empty weight of the rocket. A turboprop engine is a turbine engine that drives an aircraft propeller using a reduction gear to translate high turbine section operating speed (often in the 10s of thousands) into low thousands necessary for efficient propeller operation. The benefit of using the turboprop engine is to take advantage of
732-452: A turboshaft design. They supply: Industrial gas turbines differ from aeronautical designs in that the frames, bearings, and blading are of heavier construction. They are also much more closely integrated with the devices they power—often an electric generator —and the secondary-energy equipment that is used to recover residual energy (largely heat). They range in size from portable mobile plants to large, complex systems weighing more than
854-489: A "heavy" cruiser was one with guns of more than 6.1-inch (155 mm) calibre. The Second London Naval Treaty attempted to reduce the tonnage of new cruisers to 8,000 or less, but this had little effect; Japan and Germany were not signatories, and some navies had already begun to evade treaty limitations on warships. The first London treaty did touch off a period of the major powers building 6-inch or 6.1-inch gunned cruisers, nominally of 10,000 tons and with up to fifteen guns,
976-413: A buildup on the outside of the blades. Nickel-based superalloys boast improved strength and creep resistance due to their composition and resultant microstructure . The gamma (γ) FCC nickel is alloyed with aluminum and titanium in order to precipitate a uniform dispersion of the coherent Ni 3 (Al,Ti) gamma-prime (γ') phases. The finely dispersed γ' precipitates impede dislocation motion and introduce
1098-517: A combination of those materials, remained popular until towards the end of the 19th century. The ironclad's armor often meant that they were limited to short range under steam, and many ironclads were unsuited to long-range missions or for work in distant colonies. The unarmored cruiser—often a screw sloop or screw frigate —could continue in this role. Even though mid- to late-19th century cruisers typically carried up-to-date guns firing explosive shells , they were unable to face ironclads in combat. This
1220-726: A cruiser as a surface combatant displacing at least 9750 tonnes; with respect to vessels in service as of the early 2020s it includes the Type 055, the Sejong the Great from South Korea , the Atago and Maya from Japan and the Ticonderoga and Zumwalt from the US. The term "cruiser" or "cruizer" was first commonly used in the 17th century to refer to an independent warship. "Cruiser" meant
1342-737: A displacement of less than 3,000 tons. During the two following decades, this cruiser type came to be the inspiration for combining heavy artillery, high speed and low displacement. The torpedo cruiser (known in the Royal Navy as the torpedo gunboat ) was a smaller unarmored cruiser, which emerged in the 1880s–1890s. These ships could reach speeds up to 20 knots (37 km/h) and were armed with medium to small calibre guns as well as torpedoes. These ships were tasked with guard and reconnaissance duties, to repeat signals and all other fleet duties for which smaller vessels were suited. These ships could also function as flagships of torpedo boat flotillas. After
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#17327799131991464-517: A few dozen hours per year—depending on the electricity demand and the generating capacity of the region. In areas with a shortage of base-load and load following power plant capacity or with low fuel costs, a gas turbine powerplant may regularly operate most hours of the day. A large single-cycle gas turbine typically produces 100 to 400 megawatts of electric power and has 35–40% thermodynamic efficiency . Industrial gas turbines that are used solely for mechanical drive or used in collaboration with
1586-421: A fleet of fast unprotected steel cruisers were ideal for commerce raiding , while the torpedo boat would be able to destroy an enemy battleship fleet. Steel also offered the cruiser a way of acquiring the protection needed to survive in combat. Steel armor was considerably stronger, for the same weight, than iron. By putting a relatively thin layer of steel armor above the vital parts of the ship, and by placing
1708-421: A fleet of large, fast, powerfully armed vessels which would be able to hunt down and mop up enemy cruisers and armored cruisers with overwhelming fire superiority was needed. They were equipped with the same gun types as battleships, though usually with fewer guns, and were intended to engage enemy capital ships as well. This type of vessel came to be known as the battlecruiser , and the first were commissioned into
1830-579: A gas turbine engine is its power to weight ratio. Since significant useful work can be generated by a relatively lightweight engine, gas turbines are perfectly suited for aircraft propulsion. Thrust bearings and journal bearings are a critical part of a design. They are hydrodynamic oil bearings or oil-cooled rolling-element bearings . Foil bearings are used in some small machines such as micro turbines and also have strong potential for use in small gas turbines/ auxiliary power units A major challenge facing turbine design, especially turbine blades ,
1952-437: A group of protected cruisers produced in the same yard and known as the "Elswick cruisers". Her forecastle , poop deck and the wooden board deck had been removed, replaced with an armored deck. Esmeralda ' s armament consisted of fore and aft 10-inch (25.4 cm) guns and 6-inch (15.2 cm) guns in the midships positions. It could reach a speed of 18 knots (33 km/h), and was propelled by steam alone. It also had
2074-496: A heavy cruiser, their 280 mm (11 in) main armament was heavier than the 203 mm (8 in) guns of other nations' heavy cruisers, and the latter two members of the class also had tall conning towers resembling battleships. The Panzerschiffe were listed as Ersatz replacements for retiring Reichsmarine coastal defense battleships, which added to their propaganda status in the Kriegsmarine as Ersatz battleships; within
2196-490: A hundred tonnes housed in purpose-built buildings. When the gas turbine is used solely for shaft power, its thermal efficiency is about 30%. However, it may be cheaper to buy electricity than to generate it. Therefore, many engines are used in CHP (Combined Heat and Power) configurations that can be small enough to be integrated into portable container configurations. Gas turbines can be particularly efficient when waste heat from
2318-418: A lesser extent, on cars, buses, and motorcycles. A key advantage of jets and turboprops for airplane propulsion – their superior performance at high altitude compared to piston engines, particularly naturally aspirated ones – is irrelevant in most automobile applications. Their power-to-weight advantage, though less critical than for aircraft, is still important. Gas turbines offer a high-powered engine in
2440-683: A maximum range of 13,500 metres (14,800 yd) at 26.5 knots (49.1 km/h; 30.5 mph), still well below the "Long Lance". The Japanese were able to keep the Type 93's performance and oxygen power secret until the Allies recovered one in early 1943, thus the Allies faced a great threat they were not aware of in 1942. The Type 93 was also fitted to Japanese post-1930 light cruisers and the majority of their World War II destroyers. Heavy cruisers continued in use until after World War II, with some converted to guided-missile cruisers for air defense or strategic attack and some used for shore bombardment by
2562-602: A range of more than 20 nautical miles. They were mainly used to attack enemy surface ships and shore-based targets. In addition, there were 10–16 secondary guns with a caliber of less than 130 mm (5.1 in). Also, dozens of automatic antiaircraft guns were installed to fight aircraft and small vessels such as torpedo boats. For example, in World War II, American Alaska-class cruisers were more than 30,000 tons, equipped with nine 12 in (305 mm) guns. Some cruisers could also carry three or four seaplanes to correct
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#17327799131992684-532: A recovery steam generator differ from power generating sets in that they are often smaller and feature a dual shaft design as opposed to a single shaft. The power range varies from 1 megawatt up to 50 megawatts. These engines are connected directly or via a gearbox to either a pump or compressor assembly. The majority of installations are used within the oil and gas industries. Mechanical drive applications increase efficiency by around 2%. Oil and gas platforms require these engines to drive compressors to inject gas into
2806-518: A scaled-up heavy cruiser design. Their hull classification symbol of CB (cruiser, big) reflected this. A precursor to the anti-aircraft cruiser was the Romanian British-built protected cruiser Elisabeta . After the start of World War I, her four 120 mm main guns were landed and her four 75 mm (12-pounder) secondary guns were modified for anti-aircraft fire. The development of the anti-aircraft cruiser began in 1935 when
2928-461: A second, independent turbine (known as a power turbine ) that can be connected to a fan, propeller, or electrical generator. The purpose of the gas turbine determines the design so that the most desirable split of energy between the thrust and the shaft work is achieved. The fourth step of the Brayton cycle (cooling of the working fluid) is omitted, as gas turbines are open systems that do not reuse
3050-569: A threshold stress, increasing the stress required for the onset of creep. Furthermore, γ' is an ordered L1 2 phase that makes it harder for dislocations to shear past it. Further Refractory elements such as rhenium and ruthenium can be added in solid solution to improve creep strength. The addition of these elements reduces the diffusion of the gamma prime phase, thus preserving the fatigue resistance, strength, and creep resistance. The development of single crystal superalloys has led to significant improvements in creep resistance as well. Due to
3172-550: A very small and light package. However, they are not as responsive and efficient as small piston engines over the wide range of RPMs and powers needed in vehicle applications. In series hybrid vehicles, as the driving electric motors are mechanically detached from the electricity generating engine, the responsiveness, poor performance at low speed and low efficiency at low output problems are much less important. The turbine can be run at optimum speed for its power output, and batteries and ultracapacitors can supply power as needed, with
3294-612: A widespread classification following the London Naval Treaty in 1930. The heavy cruiser's immediate precursors were the light cruiser designs of the 1910s and 1920s; the US lightly armored 8-inch "treaty cruisers" of the 1920s (built under the Washington Naval Treaty) were originally classed as light cruisers until the London Treaty forced their redesignation. Initially, all cruisers built under
3416-425: Is also required to drive a helicopter rotor or land-vehicle transmission ( turboshaft ), marine propeller or electrical generator (power turbine). Greater thrust-to-weight ratio for flight is achieved with the addition of an afterburner . The basic operation of the gas turbine is a Brayton cycle with air as the working fluid : atmospheric air flows through the compressor that brings it to higher pressure; energy
3538-504: Is available in 3 different versions: The basic LM2500 has a single shaft gas generator derived from the CF6, comprising a 16 stage compressor driven by a two stage air-cooled HP turbine. The combustion chamber is annular. Shaft power is generated by a 6-stage power turbine mounted in the gas generator exhaust stream Additional power is obtained from the LM2500+ by the addition of a zero stage to
3660-463: Is distinguished from the Otto cycle , in that all the processes (compression, ignition combustion, exhaust), occur at the same time, continuously. In a real gas turbine, mechanical energy is changed irreversibly (due to internal friction and turbulence) into pressure and thermal energy when the gas is compressed (in either a centrifugal or axial compressor ). Heat is added in the combustion chamber and
3782-677: Is reducing the creep that is induced by the high temperatures and stresses that are experienced during operation. Higher operating temperatures are continuously sought in order to increase efficiency, but come at the cost of higher creep rates. Several methods have therefore been employed in an attempt to achieve optimal performance while limiting creep, with the most successful ones being high performance coatings and single crystal superalloys . These technologies work by limiting deformation that occurs by mechanisms that can be broadly classified as dislocation glide, dislocation climb and diffusional flow. Protective coatings provide thermal insulation of
General Electric LM2500 - Misplaced Pages Continue
3904-412: Is then added by spraying fuel into the air and igniting it so that the combustion generates a high-temperature flow; this high-temperature pressurized gas enters a turbine, producing a shaft work output in the process, used to drive the compressor; the unused energy comes out in the exhaust gases that can be repurposed for external work, such as directly producing thrust in a turbojet engine , or rotating
4026-419: Is then ducted into the combustor section which can be of a annular , can , or can-annular design. In the combustor section, roughly 70% of the air from the compressor is ducted around the combustor itself for cooling purposes. The remaining roughly 30% the air is mixed with fuel and ignited by the already burning air-fuel mixture , which then expands producing power across the turbine . This expansion of
4148-475: Is used, it is possible to use exhaust air from the turbine as the primary combustion air. This effectively reduces global heat losses, although heat losses associated with the combustion exhaust remain inevitable. Closed-cycle gas turbines based on helium or supercritical carbon dioxide also hold promise for use with future high temperature solar and nuclear power generation. Gas turbines are often used on ships , locomotives , helicopters , tanks , and to
4270-457: The 1937 Coronation Fleet Review . The British press referred to the vessels as pocket battleships, in reference to the heavy firepower contained in the relatively small vessels; they were considerably smaller than contemporary battleships, though at 28 knots were slower than battlecruisers. At up to 16,000 tons at full load, they were not treaty compliant 10,000 ton cruisers. And although their displacement and scale of armor protection were that of
4392-457: The Age of Sail , the term cruising referred to certain kinds of missions—independent scouting, commerce protection, or raiding—usually fulfilled by frigates or sloops-of-war , which functioned as the cruising warships of a fleet. In the middle of the 19th century, cruiser came to be a classification of the ships intended for cruising distant waters, for commerce raiding , and for scouting for
4514-968: The Airbus A400M transport, Lockheed AC-130 and the 60-year-old Tupolev Tu-95 strategic bomber. While military turboprop engines can vary, in the civilian market there are two primary engines to be found: the Pratt & Whitney Canada PT6 , a free-turbine turboshaft engine, and the Honeywell TPE331 , a fixed turbine engine (formerly designated as the Garrett AiResearch 331). Aeroderivative gas turbines are generally based on existing aircraft gas turbine engines and are smaller and lighter than industrial gas turbines. Aeroderivatives are used in electrical power generation due to their ability to be shut down and handle load changes more quickly than industrial machines. They are also used in
4636-528: The BMW 801 . This, however, also translated into poor efficiency and reliability. More advanced gas turbines (such as those found in modern jet engines or combined cycle power plants) may have 2 or 3 shafts (spools), hundreds of compressor and turbine blades, movable stator blades, and extensive external tubing for fuel, oil and air systems; they use temperature resistant alloys, and are made with tight specifications requiring precision manufacture. All this often makes
4758-668: The German "pocket battleship" Admiral Graf Spee (which was on a commerce raiding mission) in the Battle of the River Plate ; German cruiser Admiral Graf Spee then took refuge in neutral Montevideo , Uruguay . By broadcasting messages indicating capital ships were in the area, the British caused Admiral Graf Spee ' s captain to think he faced a hopeless situation while low on ammunition and order his ship scuttled. On 8 June 1940
4880-618: The London Naval Treaty allowed large light cruisers to be built, with the same tonnage as heavy cruisers and armed with up to fifteen 155 mm (6.1 in) guns. The Japanese Mogami class were built to this treaty's limit, the Americans and British also built similar ships. However, in 1939 the Mogami s were refitted as heavy cruisers with ten 203 mm (8.0 in) guns. In December 1939, three British cruisers engaged
5002-504: The Mogami and Tone classes as heavy cruisers by replacing their 6.1 in (155 mm) triple turrets with 8 in (203 mm) twin turrets. Torpedo refits were also made to most heavy cruisers, resulting in up to sixteen 24 in (610 mm) tubes per ship, plus a set of reloads. In 1941 the 1920s light cruisers Ōi and Kitakami were converted to torpedo cruisers with four 5.5 in (140 mm) guns and forty 24 in (610 mm) torpedo tubes. In 1944 Kitakami
General Electric LM2500 - Misplaced Pages Continue
5124-553: The Type 93 torpedo for these ships, eventually nicknamed "Long Lance" by the Allies. This type used compressed oxygen instead of compressed air, allowing it to achieve ranges and speeds unmatched by other torpedoes. It could achieve a range of 22,000 metres (24,000 yd) at 50 knots (93 km/h; 58 mph), compared with the US Mark 15 torpedo with 5,500 metres (6,000 yd) at 45 knots (83 km/h; 52 mph). The Mark 15 had
5246-666: The short-range air defense role. By the end of the Cold War the line between cruisers and destroyers had blurred, with the Ticonderoga -class cruiser using the hull of the Spruance -class destroyer but receiving the cruiser designation due to their enhanced mission and combat systems. As of 2023 , only three countries operated active duty vessels formally classed as cruisers: the United States , Russia and Italy . These cruisers are primarily armed with guided missiles, with
5368-413: The specific volume of the gas increases, accompanied by a slight loss in pressure. During expansion through the stator and rotor passages in the turbine, irreversible energy transformation once again occurs. Fresh air is taken in, in place of the heat rejection. Air is taken in by a compressor, called a gas generator , with either an axial or centrifugal design, or a combination of the two. This air
5490-414: The 1900s, these ships were usually traded for faster ships with better sea going qualities. Steel also affected the construction and role of armored cruisers. Steel meant that new designs of battleship, later known as pre-dreadnought battleships , would be able to combine firepower and armor with better endurance and speed than ever before. The armored cruisers of the 1890s and early 1900s greatly resembled
5612-402: The 1920s had displacements of less than 10,000 tons and a speed of up to 35 knots. They were equipped with 6–12 main guns with a caliber of 127–133 mm (5–5.5 inches). In addition, they were equipped with 8–12 secondary guns under 127 mm (5 in) and dozens of small caliber cannons, as well as torpedoes and mines. Some ships also carried 2–4 seaplanes, mainly for reconnaissance. In 1930
5734-458: The 1930 London Naval Treaty created a divide of two cruiser types, heavy cruisers having 6.1 inches to 8 inch guns, while those with guns of 6.1 inches or less were light cruisers . Each type were limited in total and individual tonnage which shaped cruiser design until the collapse of the treaty system just prior to the start of World War II. Some variations on the Treaty cruiser design included
5856-547: The 1930s the US developed a series of new guns firing "super-heavy" armor piercing ammunition; these included the 6-inch (152 mm)/47 caliber gun Mark 16 introduced with the 15-gun Brooklyn -class cruisers in 1936, and the 8-inch (203 mm)/55 caliber gun Mark 12 introduced with USS Wichita in 1937. The heavy cruiser was a type of cruiser designed for long range, high speed and an armament of naval guns around 203 mm (8 in) in calibre. The first heavy cruisers were built in 1915, although it only became
5978-679: The CLAA designation until 1949. The concept of the quick-firing dual-purpose gun anti-aircraft cruiser was embraced in several designs completed too late to see combat, including: USS Worcester , completed in 1948; USS Roanoke , completed in 1949; two Tre Kronor -class cruisers, completed in 1947; two De Zeven Provinciën -class cruisers, completed in 1953; De Grasse , completed in 1955; Colbert , completed in 1959; and HMS Tiger , HMS Lion and HMS Blake , all completed between 1959 and 1961. Most post-World War II cruisers were tasked with air defense roles. In
6100-685: The German Deutschland -class "pocket battleships", which had heavier armament at the expense of speed compared to standard heavy cruisers, and the American Alaska class , which was a scaled-up heavy cruiser design designated as a "cruiser-killer". In the later 20th century, the obsolescence of the battleship left the cruiser as the largest and most powerful surface combatant ships (aircraft carriers not being considered surface combatants, as their attack capability comes from their air wings rather than on-board weapons). The role of
6222-565: The German capital ships Scharnhorst and Gneisenau , classed as battleships but with large cruiser armament, sank the aircraft carrier HMS Glorious with gunfire. From October 1940 through March 1941 the German heavy cruiser (also known as "pocket battleship", see above) Admiral Scheer conducted a successful commerce-raiding voyage in the Atlantic and Indian Oceans. On 27 May 1941, HMS Dorsetshire attempted to finish off
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#17327799131996344-534: The Kriegsmarine, the Panzerschiffe had the propaganda value of capital ships: heavy cruisers with battleship guns, torpedoes, and scout aircraft. The similar Swedish Panzerschiffe were tactically used as centers of battlefleets and not as cruisers. They were deployed by Nazi Germany in support of the German interests in the Spanish Civil War. Panzerschiff Admiral Graf Spee represented Germany in
6466-575: The LM2500 from their ships. The LM2500+ is an evolution of the LM2500, delivering up to 40,200 shp (30,000 kW) or 28.6 MW of electric energy when combined with an electrical generator . Two of such turbo-generators have been installed in the superstructure near the funnel of Queen Mary 2 , the world's largest transatlantic ocean liner, for additional electric energy for the liner to reach higher sea speeds.. Celebrity Cruises uses two LM2500+ engines in their Millennium -class cruise ships in
6588-745: The Royal Navy in 1907. The British battlecruisers sacrificed protection for speed, as they were intended to "choose their range" (to the enemy) with superior speed and only engage the enemy at long range. When engaged at moderate ranges, the lack of protection combined with unsafe ammunition handling practices became tragic with the loss of three of them at the Battle of Jutland . Germany and eventually Japan followed suit to build these vessels, replacing armored cruisers in most frontline roles. German battlecruisers were generally better protected but slower than British battlecruisers. Battlecruisers were in many cases larger and more expensive than contemporary battleships, due to their much larger propulsion plants. At around
6710-521: The Royal Navy re-armed HMS Coventry and HMS Curlew . Torpedo tubes and 6-inch (152 mm) low-angle guns were removed from these World War I light cruisers and replaced with ten 4-inch (102 mm) high-angle guns, with appropriate fire-control equipment to provide larger warships with protection against high-altitude bombers. A tactical shortcoming was recognised after completing six additional conversions of C-class cruisers . Having sacrificed anti-ship weapons for anti-aircraft armament,
6832-432: The Royal Navy, only battlecruisers HMS Hood , HMS Repulse and HMS Renown were capable of both outrunning and outgunning the Panzerschiffe. They were seen in the 1930s as a new and serious threat by both Britain and France. While the Kriegsmarine reclassified them as heavy cruisers in 1940, Deutschland -class ships continued to be called pocket battleships in the popular press. The American Alaska class represented
6954-738: The United States in the Korean War and the Vietnam War . The German Deutschland class was a series of three Panzerschiffe ("armored ships"), a form of heavily armed cruiser, designed and built by the German Reichsmarine in nominal accordance with restrictions imposed by the Treaty of Versailles . All three ships were launched between 1931 and 1934, and served with Germany's Kriegsmarine during World War II . Within
7076-704: The Washington treaty had torpedo tubes, regardless of nationality. However, in 1930, results of war games caused the US Naval War College to conclude that only perhaps half of cruisers would use their torpedoes in action. In a surface engagement, long-range gunfire and destroyer torpedoes would decide the issue, and under air attack numerous cruisers would be lost before getting within torpedo range. Thus, beginning with USS New Orleans launched in 1933, new cruisers were built without torpedoes, and torpedoes were removed from older heavy cruisers due to
7198-675: The World War I era that succeeded armored cruisers were now classified, along with dreadnought battleships, as capital ships . By the early 20th century, after World War I, the direct successors to protected cruisers could be placed on a consistent scale of warship size, smaller than a battleship but larger than a destroyer . In 1922, the Washington Naval Treaty placed a formal limit on these cruisers, which were defined as warships of up to 10,000 tons displacement carrying guns no larger than 8 inches in calibre ; whilst
7320-532: The accuracy of gunfire and perform reconnaissance. Together with battleships, these heavy cruisers formed powerful naval task forces, which dominated the world's oceans for more than a century. After the signing of the Washington Treaty on Arms Limitation in 1922, the tonnage and quantity of battleships, aircraft carriers and cruisers were severely restricted. In order not to violate the treaty, countries began to develop light cruisers. Light cruisers of
7442-456: The active species (typically vacancies) within the alloy and reducing dislocation and vacancy creep. It has been found that a coating of 1–200 μm can decrease blade temperatures by up to 200 °C (392 °F). Bond coats are directly applied onto the surface of the substrate using pack carburization and serve the dual purpose of providing improved adherence for the TBC and oxidation resistance for
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#17327799131997564-510: The addition of a ducted fan are called turbofans or (rarely) fan-jets. These engines produce nearly 80% of their thrust by the ducted fan, which can be seen from the front of the engine. They come in two types, low-bypass turbofan and high bypass , the difference being the amount of air moved by the fan, called "bypass air". These engines offer the benefit of more thrust without extra fuel consumption. Gas turbines are also used in many liquid-fuel rockets , where gas turbines are used to power
7686-429: The battle fleet. Cruisers came in a wide variety of sizes, from the medium-sized protected cruiser to large armored cruisers that were nearly as big (although not as powerful or as well-armored) as a pre-dreadnought battleship . With the advent of the dreadnought battleship before World War I , the armored cruiser evolved into a vessel of similar scale known as the battlecruiser . The very large battlecruisers of
7808-497: The battlecruiser squadrons were required to operate with the battle fleet. Some light cruisers were built specifically to act as the leaders of flotillas of destroyers. These vessels were essentially large coastal patrol boats armed with multiple light guns. One such warship was Grivița of the Romanian Navy . She displaced 110 tons, measured 60 meters in length and was armed with four light guns. The auxiliary cruiser
7930-440: The battleships of the day; they tended to carry slightly smaller main armament (7.5-to-10-inch (190 to 250 mm) rather than 12-inch) and have somewhat thinner armor in exchange for a faster speed (perhaps 21 to 23 knots (39 to 43 km/h) rather than 18). Because of their similarity, the lines between battleships and armored cruisers became blurred. Shortly after the turn of the 20th century there were difficult questions about
8052-401: The blade and offer oxidation and corrosion resistance. Thermal barrier coatings (TBCs) are often stabilized zirconium dioxide -based ceramics and oxidation/corrosion resistant coatings (bond coats) typically consist of aluminides or MCrAlY (where M is typically Fe and/or Cr) alloys. Using TBCs limits the temperature exposure of the superalloy substrate, thereby decreasing the diffusivity of
8174-420: The closely related form of the turbocharger . The turbocharger is basically a compact and simple free shaft radial gas turbine which is driven by the piston engine's exhaust gas . The centripetal turbine wheel drives a centrifugal compressor wheel through a common rotating shaft. This wheel supercharges the engine air intake to a degree that can be controlled by means of a wastegate or by dynamically modifying
8296-559: The coal bunkers where they might stop shellfire, a useful degree of protection could be achieved without slowing the ship too much. Protected cruisers generally had an armored deck with sloped sides, providing similar protection to a light armored belt at less weight and expense. The first protected cruiser was the Chilean ship Esmeralda , launched in 1883. Produced by a shipyard at Elswick , in Britain, owned by Armstrong , she inspired
8418-473: The compressor and the turbine with a compressed air store. In a conventional turbine, up to half the generated power is used driving the compressor. In a compressed air energy storage configuration, power is used to drive the compressor, and the compressed air is released to operate the turbine when required. Turboshaft engines are used to drive compressors in gas pumping stations and natural gas liquefaction plants. They are also used in aviation to power all but
8540-431: The compressor, making 17 stages in all. Specifications for three models of LM2500 series gas turbine engines: Related development Comparable engines Related lists Gas turbine A gas turbine or gas turbine engine is a type of continuous flow internal combustion engine . The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in
8662-513: The compressor/shaft/turbine rotor assembly, with other moving parts in the fuel system. This, in turn, can translate into price. For instance, costing 10,000 ℛℳ for materials, the Jumo 004 proved cheaper than the Junkers 213 piston engine, which was 35,000 ℛℳ , and needed only 375 hours of lower-skill labor to complete (including manufacture, assembly, and shipping), compared to 1,400 for
8784-444: The construction of a simple gas turbine more complicated than a piston engine. Moreover, to reach optimum performance in modern gas turbine power plants the gas needs to be prepared to exact fuel specifications. Fuel gas conditioning systems treat the natural gas to reach the exact fuel specification prior to entering the turbine in terms of pressure, temperature, gas composition, and the related Wobbe index . The primary advantage of
8906-412: The construction of experimental steam-powered frigates and sloops. By the middle of the 1850s, the British and U.S. Navies were both building steam frigates with very long hulls and a heavy gun armament, for instance USS Merrimack or Mersey . The 1860s saw the introduction of the ironclad . The first ironclads were frigates, in the sense of having one gun deck; however, they were also clearly
9028-407: The converted anti-aircraft cruisers might themselves need protection against surface units. New construction was undertaken to create cruisers of similar speed and displacement with dual-purpose guns , which offered good anti-aircraft protection with anti-surface capability for the traditional light cruiser role of defending capital ships from destroyers. The first purpose built anti-aircraft cruiser
9150-768: The cruiser varied according to ship and navy, often including air defense and shore bombardment . During the Cold War the Soviet Navy 's cruisers had heavy anti-ship missile armament designed to sink NATO carrier task-forces via saturation attack . The U.S. Navy built guided-missile cruisers upon destroyer-style hulls (some called " destroyer leaders " or "frigates" prior to the 1975 reclassification ) primarily designed to provide air defense while often adding anti-submarine capabilities , being larger and having longer-range surface-to-air missiles (SAMs) than early Charles F. Adams guided-missile destroyers tasked with
9272-425: The design of future cruisers. Modern armored cruisers, almost as powerful as battleships, were also fast enough to outrun older protected and unarmored cruisers. In the Royal Navy, Jackie Fisher cut back hugely on older vessels, including many cruisers of different sorts, calling them "a miser's hoard of useless junk" that any modern cruiser would sweep from the seas. The scout cruiser also appeared in this era; this
9394-537: The direction of flow: Additional components have to be added to the gas generator to suit its application. Common to all is an air inlet but with different configurations to suit the requirements of marine use, land use or flight at speeds varying from stationary to supersonic. A propelling nozzle is added to produce thrust for flight. An extra turbine is added to drive a propeller ( turboprop ) or ducted fan ( turbofan ) to reduce fuel consumption (by increasing propulsive efficiency) at subsonic flight speeds. An extra turbine
9516-472: The early 1950s, advances in aviation technology forced the move from anti-aircraft artillery to anti-aircraft missiles. Therefore, most modern cruisers are equipped with surface-to-air missiles as their main armament. Today's equivalent of the anti-aircraft cruiser is the guided-missile cruiser (CAG/CLG/CG/CGN). Cruisers participated in a number of surface engagements in the early part of World War II, along with escorting carrier and battleship groups throughout
9638-425: The early 2020s. In March 2018, GE Power achieved a 63.08% gross efficiency for its 7HA turbine. Aeroderivative gas turbines can also be used in combined cycles, leading to a higher efficiency, but it will not be as high as a specifically designed industrial gas turbine. They can also be run in a cogeneration configuration: the exhaust is used for space or water heating, or drives an absorption chiller for cooling
9760-450: The early 20th century. The Washington Naval Treaty of 1922 placed limits on the construction of ships with a standard displacement of more than 10,000 tons and an armament of guns larger than 8-inch (203 mm). A number of navies commissioned classes of cruisers at the top end of this limit, known as " treaty cruisers ". The London Naval Treaty in 1930 then formalised the distinction between these "heavy" cruisers and light cruisers:
9882-684: The embargo. The LM2500 was uprated to 26,500 shp (19,800 kW) for the Arleigh Burke -class destroyers , which were initiated in the 1980s and started to see service in the early 1990s, and the T-AOE-6 class of fast combat tanker. In 2001 the LM2500 (20 MW) was installed in a sound-proof capsule in the South African Navy Valour class (Meko A-200 SAN) frigates as part of a CODAG propulsion system with two MTU 16V 1163 TB93 Propulsion Diesels. The current generation
10004-435: The engine cycled on and off to run it only at high efficiency. The emergence of the continuously variable transmission may also alleviate the responsiveness problem. Turbines have historically been more expensive to produce than piston engines, though this is partly because piston engines have been mass-produced in huge quantities for decades, while small gas turbine engines are rarities; however, turbines are mass-produced in
10126-604: The engine's crankshaft instead of to a centrifugal compressor, thus providing additional power instead of boost. While the turbocharger is a pressure turbine, a power recovery turbine is a velocity one. Cruiser A cruiser is a type of warship . Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships , and can usually perform several operational roles from search-and-destroy to ocean escort to sea denial . The term "cruiser", which has been in use for several hundred years, has changed its meaning over time. During
10248-533: The entire engine from raw materials, including the fabrication of a centrifugal compressor wheel from plywood, epoxy and wrapped carbon fibre strands. Several small companies now manufacture small turbines and parts for the amateur. Most turbojet-powered model aircraft are now using these commercial and semi-commercial microturbines, rather than a Schreckling-like home-build. Small gas turbines are used as auxiliary power units (APUs) to supply auxiliary power to larger, mobile, machines such as an aircraft , and are
10370-620: The exceptions of the aircraft cruisers Admiral Kuznetsov and Giuseppe Garibaldi . BAP Almirante Grau was the last gun cruiser in service, serving with the Peruvian Navy until 2017. Nevertheless, other classes in addition to the above may be considered cruisers due to differing classification systems. The US/NATO system includes the Type 055 from China and the Kirov and Slava from Russia. International Institute for Strategic Studies ' "The Military Balance" defines
10492-407: The exhaust gases, or from ducted fans connected to the gas turbines. Jet engines that produce thrust from the direct impulse of exhaust gases are often called turbojets . While still in service with many militaries and civilian operators, turbojets have mostly been phased out in favor of the turbofan engine due to the turbojet's low fuel efficiency, and high noise. Those that generate thrust with
10614-400: The frigate became the preeminent type of cruiser. A frigate was a small, fast, long range, lightly armed (single gun-deck) ship used for scouting, carrying dispatches, and disrupting enemy trade. The other principal type of cruiser was the sloop, but many other miscellaneous types of ship were used as well. During the 19th century, navies began to use steam power for their fleets. The 1840s saw
10736-550: The hobby of engine collecting. In its most extreme form, amateurs have even rebuilt engines beyond professional repair and then used them to compete for the land speed record. The simplest form of self-constructed gas turbine employs an automotive turbocharger as the core component. A combustion chamber is fabricated and plumbed between the compressor and turbine sections. More sophisticated turbojets are also built, where their thrust and light weight are sufficient to power large model aircraft. The Schreckling design constructs
10858-435: The inlet air and increase the power output, technology known as turbine inlet air cooling . Another significant advantage is their ability to be turned on and off within minutes, supplying power during peak, or unscheduled, demand. Since single cycle (gas turbine only) power plants are less efficient than combined cycle plants, they are usually used as peaking power plants , which operate anywhere from several hours per day to
10980-617: The lack of grain boundaries, single crystals eliminate Coble creep and consequently deform by fewer modes – decreasing the creep rate. Although single crystals have lower creep at high temperatures, they have significantly lower yield stresses at room temperature where strength is determined by the Hall-Petch relationship. Care needs to be taken in order to optimize the design parameters to limit high temperature creep while not decreasing low temperature yield strength. Airbreathing jet engines are gas turbines optimized to produce thrust from
11102-550: The marine industry to reduce weight. Common types include the General Electric LM2500 , General Electric LM6000 , and aeroderivative versions of the Pratt & Whitney PW4000 , Pratt & Whitney FT4 and Rolls-Royce RB211 . Increasing numbers of gas turbines are being used or even constructed by amateurs. In its most straightforward form, these are commercial turbines acquired through military surplus or scrapyard sales, then operated for display as part of
11224-400: The mixture then leaves the combustor section and has its velocity increased across the turbine section to strike the turbine blades, spinning the disc they are attached to, thus creating useful power. Of the power produced, 60-70% is solely used to power the gas generator. The remaining power is used to power what the engine is being used for, typically an aviation application, being thrust in
11346-491: The most powerful ships in the navy, and were principally to serve in the line of battle. In spite of their great speed, they would have been wasted in a cruising role. The French constructed a number of smaller ironclads for overseas cruising duties, starting with the Belliqueuse , commissioned 1865. These "station ironclads" were the beginning of the development of the armored cruisers, a type of ironclad specifically for
11468-525: The oil and gas industry's demand for a lighter, more compact version to generate electricity and drive compressors to send natural gas through pipelines. The LM2500 was first used on the US Navy GTS ; Admiral W. M. Callaghan in 1969, after the original FT-4 gas turbines experienced many technical problems. Later, they were used in US Navy warships in the Spruance class of destroyers and
11590-482: The perceived hazard of their being exploded by shell fire. The Japanese took exactly the opposite approach with cruiser torpedoes, and this proved crucial to their tactical victories in most of the numerous cruiser actions of 1942. Beginning with the Furutaka class launched in 1925, every Japanese heavy cruiser was armed with 24-inch (610 mm) torpedoes, larger than any other cruisers'. By 1933 Japan had developed
11712-467: The pioneer of modern Micro-Jets, Kurt Schreckling , produced one of the world's first Micro-Turbines, the FD3/67. This engine can produce up to 22 newtons of thrust, and can be built by most mechanically minded people with basic engineering tools, such as a metal lathe . Evolved from piston engine turbochargers , aircraft APUs or small jet engines , microturbines are 25 to 500 kilowatt turbines
11834-474: The purpose of using pulverized coal or finely ground biomass (such as sawdust) as a fuel. In the indirect system, a heat exchanger is used and only clean air with no combustion products travels through the power turbine. The thermal efficiency is lower in the indirect type of external combustion; however, the turbine blades are not subjected to combustion products and much lower quality (and therefore cheaper) fuels are able to be used. When external combustion
11956-513: The purpose or mission of a ship, rather than a category of vessel. However, the term was nonetheless used to mean a smaller, faster warship suitable for such a role. In the 17th century, the ship of the line was generally too large, inflexible, and expensive to be dispatched on long-range missions (for instance, to the Americas), and too strategically important to be put at risk of fouling and foundering by continual patrol duties. The Dutch navy
12078-471: The related Kidd class , which were constructed from 1970. In this configuration it was rated to 21,500 shp (16,000 kW). This configuration was subsequently used into the 1980s in the Oliver Hazard Perry -class frigates , and Ticonderoga -class cruisers . It was also used by one of People's Republic of China's Type 052 Luhu Class Missile Destroyer (Harbin 112) acquired before
12200-670: The rotation rate of the shaft must be to attain the required blade tip speed. Blade-tip speed determines the maximum pressure ratios that can be obtained by the turbine and the compressor. This, in turn, limits the maximum power and efficiency that can be obtained by the engine. In order for tip speed to remain constant, if the diameter of a rotor is reduced by half, the rotational speed must double. For example, large jet engines operate around 10,000–25,000 rpm, while micro turbines spin as fast as 500,000 rpm. Mechanically, gas turbines can be considerably less complex than Reciprocating engines . Simple turbines might have one main moving part,
12322-483: The same air. Gas turbines are used to power aircraft, trains, ships, electrical generators, pumps, gas compressors, and tanks . In an ideal gas turbine, gases undergo four thermodynamic processes: an isentropic compression, an isobaric (constant pressure) combustion, an isentropic expansion and isobaric heat rejection. Together, these make up the Brayton cycle , also known as the "constant pressure cycle" . It
12444-488: The same time as the battlecruiser was developed, the distinction between the armored and the unarmored cruiser finally disappeared. By the British Town class , the first of which was launched in 1909, it was possible for a small, fast cruiser to carry both belt and deck armor, particularly when turbine engines were adopted. These light armored cruisers began to occupy the traditional cruiser role once it became clear that
12566-606: The same way. In British service these were known as Armed Merchant Cruisers (AMC). The Germans and French used them in World War I as raiders because of their high speed (around 30 knots (56 km/h)), and they were used again as raiders early in World War II by the Germans and Japanese. In both the First World War and in the early part of the Second, they were used as convoy escorts by the British. Cruisers were one of
12688-545: The size of a refrigerator . Microturbines have around 15% efficiencies without a recuperator , 20 to 30% with one and they can reach 85% combined thermal-electrical efficiency in cogeneration . Most gas turbines are internal combustion engines but it is also possible to manufacture an external combustion gas turbine which is, effectively, a turbine version of a hot air engine . Those systems are usually indicated as EFGT (Externally Fired Gas Turbine) or IFGT (Indirectly Fired Gas Turbine). External combustion has been used for
12810-503: The smallest modern helicopters, and function as an auxiliary power unit in large commercial aircraft. A primary shaft carries the compressor and its turbine which, together with a combustor, is called a Gas Generator . A separately spinning power-turbine is usually used to drive the rotor on helicopters. Allowing the gas generator and power turbine/rotor to spin at their own speeds allows more flexibility in their design. Also known as miniature gas turbines or micro-jets. With this in mind
12932-511: The substrate. The Al from the bond coats forms Al 2 O 3 on the TBC-bond coat interface which provides the oxidation resistance, but also results in the formation of an undesirable interdiffusion (ID) zone between itself and the substrate. The oxidation resistance outweighs the drawbacks associated with the ID zone as it increases the lifetime of the blade and limits the efficiency losses caused by
13054-589: The supersized cruiser design. Due to the German pocket battleships , the Scharnhorst class , and rumored Japanese "super cruisers", all of which carried guns larger than the standard heavy cruiser's 8-inch size dictated by naval treaty limitations, the Alaska s were intended to be "cruiser-killers". While superficially appearing similar to a battleship/battlecruiser and mounting three triple turrets of 12-inch guns , their actual protection scheme and design resembled
13176-577: The traditional cruiser missions of fast, independent raiding and patrol. The first true armored cruiser was the Russian General-Admiral , completed in 1874, and followed by the British Shannon a few years later. Until the 1890s armored cruisers were still built with masts for a full sailing rig, to enable them to operate far from friendly coaling stations. Unarmored cruising warships, built out of wood, iron, steel or
13298-573: The treaty limit. Thus, most light cruisers ordered after 1930 were the size of heavy cruisers but with more and smaller guns. The Imperial Japanese Navy began this new race with the Mogami class , launched in 1934. After building smaller light cruisers with six or eight 6-inch guns launched 1931–35, the British Royal Navy followed with the 12-gun Southampton class in 1936. To match foreign developments and potential treaty violations, in
13420-595: The turbine engines high power-to-weight ratio to drive a propeller, thus allowing a more powerful, but also smaller engine to be used. Turboprop engines are used on a wide range of business aircraft such as the Pilatus PC-12 , commuter aircraft such as the Beechcraft 1900 , and small cargo aircraft such as the Cessna 208 Caravan or De Havilland Canada Dash 8 , and large aircraft (typically military) such as
13542-463: The turbine housing's geometry (as in a variable geometry turbocharger ). It mainly serves as a power recovery device which converts a great deal of otherwise wasted thermal and kinetic energy into engine boost. Turbo-compound engines (actually employed on some semi-trailer trucks ) are fitted with blow down turbines which are similar in design and appearance to a turbocharger except for the turbine shaft being mechanically or hydraulically connected to
13664-480: The turbine is recovered by a heat recovery steam generator (HRSG) to power a conventional steam turbine in a combined cycle configuration. The 605 MW General Electric 9HA achieved a 62.22% efficiency rate with temperatures as high as 1,540 °C (2,800 °F). For 2018, GE offers its 826 MW HA at over 64% efficiency in combined cycle due to advances in additive manufacturing and combustion breakthroughs, up from 63.7% in 2017 orders and on track to achieve 65% by
13786-542: The war. In the later part of the war, Allied cruisers primarily provided anti-aircraft (AA) escort for carrier groups and performed shore bombardment. Japanese cruisers similarly escorted carrier and battleship groups in the later part of the war, notably in the disastrous Battle of the Philippine Sea and Battle of Leyte Gulf . In 1937–41 the Japanese, having withdrawn from all naval treaties, upgraded or completed
13908-498: The wells to force oil up via another bore, or to compress the gas for transportation. They are also often used to provide power for the platform. These platforms do not need to use the engine in collaboration with a CHP system due to getting the gas at an extremely reduced cost (often free from burn off gas). The same companies use pump sets to drive the fluids to land and across pipelines in various intervals. One modern development seeks to improve efficiency in another way, by separating
14030-480: The workhorse types of warship during World War I . By the time of World War I, cruisers had accelerated their development and improved their quality significantly, with drainage volume reaching 3000–4000 tons, a speed of 25–30 knots and a calibre of 127–152 mm. Naval construction in the 1920s and 1930s was limited by international treaties designed to prevent the repetition of the Dreadnought arms race of
14152-461: Was a merchant ship hastily armed with small guns on the outbreak of war. Auxiliary cruisers were used to fill gaps in their long-range lines or provide escort for other cargo ships, although they generally proved to be useless in this role because of their low speed, feeble firepower and lack of armor. In both world wars the Germans also used small merchant ships armed with cruiser guns to surprise Allied merchant ships. Some large liners were armed in
14274-532: Was a small, fast, lightly armed and armored type designed primarily for reconnaissance. The Royal Navy and the Italian Navy were the primary developers of this type. The growing size and power of the armored cruiser resulted in the battlecruiser, with an armament and size similar to the revolutionary new dreadnought battleship; the brainchild of British admiral Jackie Fisher. He believed that to ensure British naval dominance in its overseas colonial possessions,
14396-542: Was evidenced by the clash between HMS Shah , a modern British cruiser, and the Peruvian monitor Huáscar . Even though the Peruvian vessel was obsolete by the time of the encounter, it stood up well to roughly 50 hits from British shells. In the 1880s, naval engineers began to use steel as a material for construction and armament. A steel cruiser could be lighter and faster than one built of iron or wood. The Jeune Ecole school of naval doctrine suggested that
14518-458: Was further converted to carry up to eight Kaiten human torpedoes in place of ordinary torpedoes. Before World War II, cruisers were mainly divided into three types: heavy cruisers, light cruisers and auxiliary cruisers. Heavy cruiser tonnage reached 20–30,000 tons, speed 32–34 knots, endurance of more than 10,000 nautical miles, armor thickness of 127–203 mm. Heavy cruisers were equipped with eight or nine 8 in (203 mm) guns with
14640-582: Was noted for its cruisers in the 17th century, while the Royal Navy —and later French and Spanish navies—subsequently caught up in terms of their numbers and deployment. The British Cruiser and Convoy Acts were an attempt by mercantile interests in Parliament to focus the Navy on commerce defence and raiding with cruisers, rather than the more scarce and expensive ships of the line. During the 18th century
14762-536: Was the British Dido class , completed in 1940–42. The US Navy's Atlanta -class cruisers (CLAA: light cruiser with anti-aircraft capability) were designed to match the capabilities of the Royal Navy. Both Dido and Atlanta cruisers initially carried torpedo tubes; the Atlanta cruisers at least were originally designed as destroyer leaders, were originally designated CL ( light cruiser ), and did not receive
14884-467: Was uprated in the late 1990s to over 30,000 shp (22,000 kW). LM2500 installations place the engine inside a metal container for sound and heat isolation from the rest of the machinery spaces. This container is very near the size of a standard 40-foot (12 m) intermodal shipping container – but not the same, the engine size very slightly exceeds those dimensions. The air intake ducting may be designed and shaped appropriately for easy removal of
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