Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea. The term monsoon is used to refer to the rainy phase of a seasonally changing pattern, although technically there is a dry phase; the term is sometimes incorrectly used for locally heavy but short-term rains, although these rains meet the dictionary definition of monsoon. The major monsoon systems of the world consist of the West Asia-Australian monsoons; the inclusion of the North and South American monsoons with incomplete wind reversal has been debated. The term was first used in English in British India and neighbouring countries to refer to the big seasonal winds blowing from the Bay of Bengal and Arabian Sea in the southwest bringing heavy rainfall to the area; the English monsoon came from Portuguese monção from Arabic mawsim, "perhaps via early modern Dutch monson."
Strengthening of the Asian monsoon has been linked to the uplift of the Tibetan Plateau after the collision of the Indian sub-continent and Asia around 50 million years ago. Because of studies of records from the Arabian Sea and that of the wind-blown dust in the Loess Plateau of China, many geologists believe the monsoon first became strong around 8 million years ago. More studies of plant fossils in China and new long-duration sediment records from the South China Sea led to a timing of the monsoon beginning 15–20 million years ago and linked to early Tibetan uplift. Testing of this hypothesis awaits deep ocean sampling by the Integrated Ocean Drilling Program; the monsoon has varied in strength since this time linked to global climate change the cycle of the Pleistocene ice ages. A study of marine plankton suggested that the Indian Monsoon strengthened around 5 million years ago. During ice periods, the sea level fell and the Indonesian Seaway closed; when this happened, cold waters in the Pacific were impeded from flowing into the Indian Ocean.
It is believed that the resulting increase in sea surface temperatures in the Indian Ocean increased the intensity of monsoons. Five episodes during the Quaternary at 2.22 Ma, 1.83 Ma, 0.68 Ma, 0.45 Ma and 0.04 Ma were identified which showed a weakening of Leeuwin Current. The weakening of the LC would have an effect on the sea surface temperature field in the Indian Ocean, as the Indonesian through flow warms the Indian Ocean, thus these five intervals could be those of considerable lowering of SST in the Indian Ocean and would have influenced Indian monsoon intensity. During the weak LC, there is the possibility of reduced intensity of the Indian winter monsoon and strong summer monsoon, because of change in the Indian Ocean dipole due to reduction in net heat input to the Indian Ocean through the Indonesian through flow, thus a better understanding of the possible links between El Niño, Western Pacific Warm Pool, Indonesian Throughflow, wind pattern off western Australia, ice volume expansion and contraction can be obtained by studying the behaviour of the LC during Quaternary at close stratigraphic intervals.
The impact of monsoon on the local weather is different from place to place. In some places there is just a likelihood of having a little less rain. In other places, quasi semi-deserts are turned into vivid green grasslands where all sorts of plants and crops can flourish; the Indian Monsoon turns large parts of India from a kind of semi-desert into green lands. See photos only taken 3 months apart in the Western Ghats. In places like this it is crucial for farmers to have the right timing for putting the seeds on the fields, as it is essential to use all the rain, available for growing crops. Monsoons are large-scale sea breezes which occur when the temperature on land is warmer or cooler than the temperature of the ocean; these temperature imbalances happen. Over oceans, the air temperature remains stable for two reasons: water has a high heat capacity, because both conduction and convection will equilibrate a hot or cold surface with deeper water. In contrast, dirt and rocks have lower heat capacities, they can only transmit heat into the earth by conduction and not by convection.
Therefore, bodies of water stay at a more temperature, while land temperature are more variable. During warmer months sunlight heats the surfaces of both land and oceans, but land temperatures rise more quickly; as the land's surface becomes warmer, the air above it expands and an area of low pressure develops. Meanwhile, the ocean remains at a lower temperature than the land, the air above it retains a higher pressure; this difference in pressure causes sea breezes to blow from the ocean to the land, bringing moist air inland. This moist air rises to a higher altitude over land and it flows back toward the ocean. However, when the air rises, while it is still over the land, the air cools; this decreases the air's ability to hold water, this causes precipitation over the land. This is. In the colder months, the cycle is reversed; the land cools faster than the oceans and the air over the land has higher pressure than air over the ocean. This causes the air over the land to flow to the ocean; when humid air rises over the ocean, it cools, this causes precipitation over the oceans.
(The cool air flows towards the land to complete the cy
South Vietnam the Republic of Vietnam, was a country that existed from 1955 to 1975, the period when the southern portion of Vietnam was a member of the Western Bloc during part of the Cold War. It received international recognition in 1949 as the "State of Vietnam", a constitutional monarchy; this became the "Republic of Vietnam" in 1955. Its capital was Saigon. South Vietnam was bordered by North Vietnam to the north, Laos to the northwest, Cambodia to the southwest, Thailand across the Gulf of Thailand to the southwest, the Philippines, Malaysia and Indonesia across the South China Sea to the east and southeast; the Republic of Vietnam was proclaimed on 26 October 1955, with Ngô Đình Diệm as its first president, after having served as premier under Emperor Bao Dai, exiled. Its sovereignty was recognized by the United States and 87 other nations, it had membership in several special committees of the United Nations, but its application for full membership was rejected in 1957 because of a Soviet veto.
South Vietnam's origins can be traced to the French colony of Cochinchina, which consisted of the southern third of Vietnam, Cochinchina, a subdivision of French Indochina, the southern half of Central Vietnam or Annam, a French protectorate. After the Second World War, the anti-Japanese Viet Minh guerrilla forces, led by Ho Chi Minh, proclaimed the establishment of a Democratic Republic of Vietnam in Hanoi in September 1945, issuing a Declaration of Independence modeled on the U. S. one from 1776. In 1949, anti-communist Vietnamese politicians formed a rival government in Saigon led by former emperor Bảo Đại. Bảo Đại was deposed by Prime Minister Ngô Đình Diệm in 1955, who proclaimed himself president after a referendum. Diệm was killed in a military coup led by general Dương Văn Minh in 1963, a series of short-lived military governments followed. General Nguyễn Văn Thiệu led the country after a U. S.-encouraged civilian presidential election from 1967 until 1975. The beginnings of the Vietnam War occurred in 1959 with an uprising by the newly organized National Liberation Front for South Vietnam and supported by the northern Democratic Republic of Vietnam, with other assistance rendered by the Soviet Union and its Warsaw Pact communist satellites, along with neighboring People's Republic of China and North Korea.
Larger escalation of the insurgency occurred in 1965 with the landing of United States regular forces of Marines, followed by Army units to supplement the cadre of military advisors guiding ARVN southern forces. A regular bombing campaign over North Vietnam was conducted by offshore U. S. Navy airplanes and aircraft carriers joined by Air Force squadrons through 1966 and 1967. Fighting peaked up to that point during the Tet Offensive of February 1968, when there were over a million South Vietnamese soldiers and 500,000 U. S. soldiers in South Vietnam. On the war turned into a more conventional fight as the balance of power became equalized. An larger, armored invasion commenced during the Easter Offensive following US ground-forces withdrawal, had nearly overran some major northern cities until beaten back. Despite a truce agreement under the Paris Peace Accords, concluded in January 1973, after a torturous five years of on and off negotiations, fighting continued immediately afterwards; the North Vietnamese regular army and Viet Cong launched a major second combined-arms invasion in 1975, termed the Spring Offensive.
Communist forces overran Saigon on 30 April 1975. On the day President Duong Van Minh declared RVN cease to exist, five ARVN generals, one Saigon police chief, numbers of ARVN soldiers and officers commit suicide to avoid being humiliated surrender. On July 2, 1976, the Provisional Revolutionary Government of the Republic of South Vietnam and the Democratic Republic of Vietnam merged to form the Socialist Republic of Vietnam; the official name of the South Vietnamese state was Việt Nam Cộng hòa and the French name was referred to as République du Viêt Nam. The North was known as the "Democratic Republic of Vietnam". Việt Nam was the name adopted by Emperor Gia Long in 1804, it is a name used in ancient times. In 1839, Emperor Minh Mạng renamed the country Đại Nam. In 1945, the nation's official name was changed back to "Vietnam"; the name is sometimes rendered as "Viet Nam" in English. The term "South Vietnam" became common usage in 1954, when the Geneva Conference provisionally partitioned Vietnam into communist and non-communist parts.
Other names of this state were used during its existence such as Free Vietnam and the Government of Viet Nam. Before World War II, the southern third of Vietnam was the concession of Cochinchina, administered as part of French Indochina. A French governor-general in Hanoi administered all the five parts of Indochina while Cochinchina was under a French governor, but the difference from the other parts was that most indigenous intellensia and wealthy were naturalized French The northern third of Vietnam (then the colony of Tonkin was under
The M2 Machine Gun or Browning.50 Caliber Machine Gun is a heavy machine gun designed toward the end of World War I by John Browning. Its design is similar to Browning's earlier M1919 Browning machine gun, chambered for the.30-06 cartridge. The M2 uses the much larger and much more powerful.50 BMG cartridge, developed alongside and takes its name from the gun itself. It has been referred to in reference to its M2 nomenclature; the design has had many specific designations. It is effective against infantry, unarmored or armored vehicles and boats, light fortifications and low-flying aircraft; the Browning.50 caliber machine gun has been used extensively as a vehicle weapon and for aircraft armament by the United States from the 1930s to the present. It was used during World War II, the Korean War, the Vietnam War, the Falklands War, the Soviet–Afghan War, the Gulf War, the Iraq War and the War in Afghanistan in the 2000s and 2010s, it is the primary heavy machine gun of NATO countries, has been used by many other countries as well.
The M2 has been in use longer than any other firearm in U. S. inventory except the.45 ACP M1911 pistol designed by John Browning. The current M2HB is manufactured in the U. S. by General Dynamics and U. S. Ordnance for use by the U. S. government, for allies via Foreign Military Sales, as well as foreign manufacturers such as FN Herstal. Machine guns were used in World War I, weapons of larger than rifle caliber began appearing on both sides of the conflict; the larger rounds were needed to defeat the armor, being introduced to the battlefield, both on the ground and in the air. During World War I, the Germans introduced a armored airplane, the Junkers J. I; the armor made aircraft machine guns using conventional rifle ammunition ineffective. The American Expeditionary Force's commander General John J. Pershing asked for a larger caliber machine gun. Pershing asked the Army Ordnance Department to develop a machine gun with a caliber of at least 0.50 inches and a muzzle velocity of at least 2,700 feet per second.
U. S. Col. John Henry Parker, commanding a machine gun school in France, observed the effectiveness of a French 11 mm incendiary armor-piercing round; the Army Ordnance Department ordered eight experimental Colt machine guns rechambered for the French 11 mm cartridge. The French 11 mm round was found to be unsuitable. Pershing wanted a muzzle velocity of 2,700 ft/s. Development with the French round was dropped. Around July 1917, John M. Browning started redesigning his.30-06 M1917 machine gun for a larger and more powerful round. Winchester worked on the cartridge, a scaled-up version of the.30-06. Winchester added a rim to the cartridge because the company wanted to use the cartridge in an anti-tank rifle, but Pershing insisted the cartridge be rimless; the first.50 machine gun underwent trials on 15 October 1918. It fired at less than 500 rounds per minute, the muzzle velocity was only 2,300 ft/s. Cartridge improvements were promised; the gun was heavy, difficult to control, fired too for the anti-personnel role, was not powerful enough against armor.
While the.50 was being developed, some German T Gewehr 1918 anti-tank rifles and ammunition were seized. The German rounds had a muzzle velocity of 2,700 ft/s, an 800 gr bullet, could pierce1 in at 250 yd. Winchester improved the.50 caliber round to have similar performance. The muzzle velocity was 2,750 ft/s. Efforts by John M. Browning and Fred T. Moore resulted in the water-cooled Browning machine gun, caliber.50, M1921. An aircraft version was termed the Browning aircraft machine gun, caliber.50, M1921. These guns were used experimentally from 1921 until 1937, they had the ammunition fed only from the left side. Service trials raised doubts whether the guns would be suitable for aircraft or for anti-aircraft use. A heavy barrel M1921 was considered for ground vehicles. John M. Browning died in 1926. Between 1927 and 1932, S. H. Green studied the design problems of the needs of the armed services; the result was a single receiver design that could be turned into seven types of.50 caliber machine guns by using different jackets and other components.
The new receiver allowed left side feed. In 1933, Colt manufactured several prototype Browning machine guns. With support from the Navy, Colt started manufacturing the M2 in 1933. FN Herstal has manufactured the M2 machine gun since the 1930s. General Dynamics, U. S. Ordnance and Ohio Ordnance Works Inc. are other current manufacturers. A variant without a water jacket, but with a thicker-walled, air-cooled barrel was designated the M2 HB; the added mass and surface area of the heavy barrel compensated somewhat for the loss of water-cooling, while reducing bulk and weight: the M2 weighs 121 lb with a water jacket, but the M2 HB weighs 84 lb. Due to the long procedure for changing the barrel, an improved system was developed called QCB; the lightweight "Army/Navy" prefixed AN/M2 "light-barrel" version of the Browning M2 weighing 60 pounds was developed, became the standard.50-caliber aviation machine gun of the World War II-era for American military aircraft of nearly every type replacing Browning's own air-cooled.30 caliber machine gun design in nearly
The Soviet Union the Union of Soviet Socialist Republics, was a socialist state in Eurasia that existed from 1922 to 1991. Nominally a union of multiple national Soviet republics, its government and economy were centralized; the country was a one-party state, governed by the Communist Party with Moscow as its capital in its largest republic, the Russian Soviet Federative Socialist Republic. Other major urban centres were Leningrad, Minsk, Alma-Ata, Novosibirsk, it spanned over 10,000 kilometres east to west across 11 time zones, over 7,200 kilometres north to south. It had five climate zones: tundra, steppes and mountains; the Soviet Union had its roots in the 1917 October Revolution, when the Bolsheviks, led by Vladimir Lenin, overthrew the Russian Provisional Government which had replaced Tsar Nicholas II during World War I. In 1922, the Soviet Union was formed by a treaty which legalized the unification of the Russian, Transcaucasian and Byelorussian republics that had occurred from 1918. Following Lenin's death in 1924 and a brief power struggle, Joseph Stalin came to power in the mid-1920s.
Stalin committed the state's ideology to Marxism–Leninism and constructed a command economy which led to a period of rapid industrialization and collectivization. During his rule, political paranoia fermented and the Great Purge removed Stalin's opponents within and outside of the party via arbitrary arrests and persecutions of many people, resulting in at least 600,000 deaths. In 1933, a major famine struck the country. Before the start of World War II in 1939, the Soviets signed the Molotov–Ribbentrop Pact, agreeing to non-aggression with Nazi Germany, after which the USSR invaded Poland on 17 September 1939. In June 1941, Germany broke the pact and invaded the Soviet Union, opening the largest and bloodiest theatre of war in history. Soviet war casualties accounted for the highest proportion of the conflict in the effort of acquiring the upper hand over Axis forces at intense battles such as Stalingrad and Kursk; the territories overtaken by the Red Army became satellite states of the Soviet Union.
The post-war division of Europe into capitalist and communist halves would lead to increased tensions with the United States-led Western Bloc, known as the Cold War. Stalin died in 1953 and was succeeded by Nikita Khrushchev, who in 1956 denounced Stalin and began the de-Stalinization; the Cuban Missile Crisis occurred during Khrushchev's rule, among the many factors that led to his downfall in 1964. In the early 1970s, there was a brief détente of relations with the United States, but tensions resumed with the Soviet–Afghan War in 1979. In 1985, the last Soviet premier, Mikhail Gorbachev, sought to reform and liberalize the economy through his policies of glasnost and perestroika, which caused political instability. In 1989, Soviet satellite states in Eastern Europe overthrew their respective communist governments; as part of an attempt to prevent the country's dissolution due to rising nationalist and separatist movements, a referendum was held in March 1991, boycotted by some republics, that resulted in a majority of participating citizens voting in favor of preserving the union as a renewed federation.
Gorbachev's power was diminished after Russian President Boris Yeltsin's high-profile role in facing down a coup d'état attempted by Communist Party hardliners. In late 1991, Gorbachev resigned and the Supreme Soviet of the Soviet Union met and formally dissolved the Soviet Union; the remaining 12 constituent republics emerged as independent post-Soviet states, with the Russian Federation—formerly the Russian SFSR—assuming the Soviet Union's rights and obligations and being recognized as the successor state. The Soviet Union was a powerhouse of many significant technological achievements and innovations of the 20th century, including the world's first human-made satellite, the first humans in space and the first probe to land on another planet, Venus; the country had the largest standing military in the world. The Soviet Union was recognized as one of the five nuclear weapons states and possessed the largest stockpile of weapons of mass destruction, it was a founding permanent member of the United Nations Security Council as well as a member of the Organization for Security and Co-operation in Europe, the World Federation of Trade Unions and the leading member of the Council for Mutual Economic Assistance and the Warsaw Pact.
The word "Soviet" is derived from a Russian word сове́т meaning council, advice, harmony and all deriving from the proto-Slavic verbal stem of vět-iti, related to Slavic věst, English "wise", the root in "ad-vis-or", or the Dutch weten. The word sovietnik means "councillor". A number of organizations in Russian history were called "council". For example, in the Russian Empire the State Council, which functioned from 1810 to 1917, was referred to as a Council of Ministers after the revolt of 1905. During the Georgian Affair, Vladimir Lenin envisioned an expression of Great Russian ethnic chauvinism by Joseph Stalin and his supporters, calling for these nation-states to join Russia as semi-independent parts of a greater union, which he named as the Union of Soviet Republics of Europe and Asia. Stalin resisted the proposal, but accepted it, although with Lenin's agreement changed the name of the newly proposed sta
The Diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel, injected into the combustion chamber, is caused by the elevated temperature of the air in the cylinder due to the mechanical compression. Diesel engines work by compressing only the air; this increases the air temperature inside the cylinder to such a high degree that atomised Diesel fuel injected into the combustion chamber ignites spontaneously. With the fuel being injected into the air just before combustion, the dispersion of the fuel is uneven; the process of mixing air and fuel happens entirely during combustion, the oxygen diffuses into the flame, which means that the Diesel engine operates with a diffusion flame. The torque a Diesel engine produces is controlled by manipulating the air ratio; the Diesel engine has the highest thermal efficiency of any practical internal or external combustion engine due to its high expansion ratio and inherent lean burn which enables heat dissipation by the excess air.
A small efficiency loss is avoided compared with two-stroke non-direct-injection gasoline engines since unburned fuel is not present at valve overlap and therefore no fuel goes directly from the intake/injection to the exhaust. Low-speed Diesel engines can reach effective efficiencies of up to 55%. Diesel engines may be designed as either four-stroke cycles, they were used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in ships. Use in locomotives, heavy equipment and electricity generation plants followed later. In the 1930s, they began to be used in a few automobiles. Since the 1970s, the use of Diesel engines in larger on-road and off-road vehicles in the US has increased. According to Konrad Reif, the EU average for Diesel cars accounts for 50% of the total newly registered; the world's largest Diesel engines put in service are 14-cylinder, two-stroke watercraft Diesel engines. In 1878, Rudolf Diesel, a student at the "Polytechnikum" in Munich, attended the lectures of Carl von Linde.
Linde explained that steam engines are capable of converting just 6-10 % of the heat energy into work, but that the Carnot cycle allows conversion of all the heat energy into work by means of isothermal change in condition. According to Diesel, this ignited the idea of creating a machine that could work on the Carnot cycle. After several years of working on his ideas, Diesel published them in 1893 in the essay Theory and Construction of a Rational Heat Motor. Diesel was criticised for his essay, but only few found the mistake that he made. Diesel's idea was to compress the air so that the temperature of the air would exceed that of combustion. However, such an engine could never perform any usable work. In his 1892 US patent #542846 Diesel describes the compression required for his cycle: "pure atmospheric air is compressed, according to curve 1 2, to such a degree that, before ignition or combustion takes place, the highest pressure of the diagram and the highest temperature are obtained-that is to say, the temperature at which the subsequent combustion has to take place, not the burning or igniting point.
To make this more clear, let it be assumed that the subsequent combustion shall take place at a temperature of 700°. In that case the initial pressure must be sixty-four atmospheres, or for 800° centigrade the pressure must be ninety atmospheres, so on. Into the air thus compressed is gradually introduced from the exterior finely divided fuel, which ignites on introduction, since the air is at a temperature far above the igniting-point of the fuel; the characteristic features of the cycle according to my present invention are therefore, increase of pressure and temperature up to the maximum, not by combustion, but prior to combustion by mechanical compression of air, there upon the subsequent performance of work without increase of pressure and temperature by gradual combustion during a prescribed part of the stroke determined by the cut-oil". By June 1893, Diesel had realised his original cycle would not work and he adopted the constant pressure cycle. Diesel describes the cycle in his 1895 patent application.
Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion. Now it is stated that the compression must be sufficient to trigger ignition. "1. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a supply for compressed air or gas. See US patent # 608845 filed 1895 / granted 1898In 1892, Diesel received patents in Germany, the United Kingdom and the United States for "Method of and Apparatus for Converting Heat into Work". In 1894 and 1895, he filed patents and addenda in various
Essex-class aircraft carrier
The Essex class was a class of aircraft carriers of the United States Navy that constituted the 20th century's most numerous class of capital ships. The class consisted of 24 vessels, which came in "long-hull" versions. Thirty-two ships were ordered, but as World War II wound down, six were canceled before construction, two were canceled after construction had begun. No Essex-class ships were lost to enemy action, despite several vessels sustaining heavy damage; the Essex-class carriers were the backbone of the U. S. Navy's combat strength during World War II from mid-1943 on, along with the addition of the three Midway-class carriers just after the war, continued to be the heart of U. S. naval strength until the supercarriers began to come into the fleet in numbers during the 1960s and 1970s. The preceding Yorktown-class aircraft carriers and the designers' list of trade-offs and limitations forced by arms control treaty obligations shaped the formative basis from which the Essex class was developed — a design formulation sparked into being when the Japanese and Italians repudiated the limitations proposed in the 1936 revision of the Washington Naval Treaty of 1922 — in effect providing a free pass for all five signatories to resume the interrupted naval arms race of the 1920s in early 1937.
At the time of the repudiations, both Italy and Japan had colonial ambitions, intending on or conducting military conquests. With the demise of the treaty limitations and the growing tensions in Europe, naval planners were free to apply both the lessons they had learned operating carriers for fifteen years and those of operating the Yorktown-class carriers to the newer design. Designed to carry a larger air group, unencumbered by the latest in a succession of pre-war naval treaty limits, Essex was over sixty feet longer, nearly ten feet wider in beam, more than a third heavier. A longer, wider flight deck and a deck-edge elevator facilitated more efficient aviation operations, enhancing the ship's offensive and defensive air power. Machinery arrangement and armor protection were improved from previous designs; these features, plus the provision of more anti-aircraft guns, gave the ships much enhanced survivability. In fact, during the war, none of the Essex-class carriers were lost and two, USS Franklin and USS Bunker Hill, came home under their own power and were repaired after receiving heavy damage.
Some ships in the class would serve until well after the end of the Vietnam War, when the class was retired and replaced by newer classes. Debates raged regarding the effect of strength deck location. British designers' comments tended to disparage the use of hangar deck armor, but some historians, such as D. K. Brown in Nelson to Vanguard, see the American arrangement to have been superior. In the late 1930s, locating the strength deck at hangar deck level in the proposed Essex-class ships reduced the weight located high in the ship, resulting in smaller supporting structures and more aircraft capacity for the desired displacement. Subsequently, the larger size of the first supercarriers necessitated a deeper hull and shifted the center of gravity and center of stability lower, enabling moving the strength deck to the flight deck, thus freeing US Naval design architects to move the armor higher and remain within compliance of US Navy stability specifications without imperiling seaworthiness.
One of the design studies prepared for the Essex project, "Design 9G", included an armored flight deck but reduced aircraft capacity, displaced 27,200 tons, or about 1,200 tons more than "Design 9F", which formed the basis of the actual Essex design. After the abrogation of disarmament treaties by Japan in 1936, the U. S. took a realistic look at its naval strength. With the Naval Expansion Act of Congress passed on 17 May 1938, an increase of 40,000 tons in aircraft carriers was authorized; this permitted the building of Hornet, the third Yorktown-class carrier, Essex, the lead ship of a new class. CV-9 was to be the prototype of the 27,000-ton aircraft carrier larger than Enterprise, yet smaller than Saratoga; the Navy ordered the first three of the new design, CV-9, CV-10 and CV-11, from Newport News Shipbuilding & Drydock on 3 July 1940. These were to become known as Essex-class carriers. Under the terms of the Two-Ocean Navy Act, ten more of these carriers were programmed. Eight were ordered on 9 September, CV-12 through CV−15 from Newport News, CV-16 through −19 from Bethlehem Steel's Fore River Shipyard.
After the US declaration of war, Congress appropriated funds for nineteen more Essexes. Ten were ordered in August 1942 and three more in June 1943. Only two of these were completed in time to see active World War II service. Six ships ordered in 1944 were canceled; the Essex-class carriers combined the policy of naming aircraft carriers after historic battles begun with the Lexington class with the policy of naming them for historic navy ships followed for the Yorktown class. The first eight hulls were assigned names from historic Navy ships (Essex, Bon Homme Richard, Kearsarge, Hanc