1.
Cassiopeia (constellation)
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Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopeia was one of the 48 constellations listed by the 2nd-century Greek astronomer Ptolemy and it is easily recognizable due to its distinctive W shape, formed by five bright stars. It is opposite the Big Dipper, in northern locations above 34ºN latitude it is visible year-round and in the tropics it can be seen at its clearest from September to early November. Even in low southern latitudes below 25ºS it can be low in the North. At magnitude 2.2, Alpha Cassiopeiae, or Schedar, is generally the brightest star in Cassiopeia, though is often shaded by Gamma Cassiopeiae, which has brightened to magnitude 1.6 on occasion. The constellation hosts some of the most luminous stars known, including the yellow hypergiants Rho Cassiopeiae and V509 Cassiopeiae, the semiregular variable PZ Cassiopeiae is one of the largest known stars. In 1572, Tycho Brahes supernova flared brightly in Cassiopeia, fourteen star systems have been found to have exoplanets, one of which—HR 8832—is thought to host seven planets. The constellation is named after Cassiopeia, the queen of Aethiopia, Cassiopeia was the wife of King Cepheus of Aethiopia and mother of Princess Andromeda. Cepheus and Cassiopeia were placed next to each other among the stars, Andromeda was then rescued by the hero Perseus, whom she later married. Cassiopeia has been variously portrayed throughout her history as a constellation, in Persia, she was drawn by al-Sufi as a queen holding a staff with a crescent moon in her right hand, wearing a crown, as well as a two-humped camel. In France, she was portrayed as having a marble throne and this depiction is from Augustin Royers 1679 atlas. In the ancient Celtic world Anu was the goddess and considered to be the mother of all the gods. Other references say that she is the earth goddess or the Goddess of fertility. Anu was known, in the Celtic World, by similar names. She still looks down on us from the sky where she appears as Llys Don. In Chinese astronomy, the forming the constellation Cassiopeia are found among three areas, the Purple Forbidden enclosure, the Black Tortoise of the North, and the White Tiger of the West. The Chinese astronomers saw several figures in what is modern-day Cassiopeia, Kappa, Eta, and Mu Cassopeiae formed a constellation called the Bridge of the Kings, when seen along with Alpha and Beta Cassiopeiae, they formed the great chariot Wang-Liang. The charioteers whip was represented by Gamma Cassiopeiae, sometimes called Tsih, in the 1600s, various Biblical figures were depicted in the stars of Cassiopeia
2.
Liberty ship
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The Liberty ship was a class of cargo ship built in the United States during World War II. Though British in conception, the design was adapted by the United States for its simple, mass-produced on an unprecedented scale, the now iconic Liberty ship came to symbolize U. S. wartime industrial output. The class was developed to meet British orders for transports to replace those torpedoed by German U-boats, the vessels were purchased both for the U. S. fleet and lend-lease deliveries of war materiel to Britain and the Soviet Union. Eighteen American shipyards built 2,710 Liberty ships between 1941 and 1945, easily the largest number of ships produced to a single design and their production mirrored on a much larger scale the manufacture of the Hog Islander and similar standardized ship types during World War I. Only three Liberty Ships are preserved, two as operational museum ships. S, the number was doubled in 1939 and again in 1940 to 200 ships a year. Ship types included two tankers and three types of merchant vessel, all to be powered by steam turbines, limited industrial capacity, especially for reduction gears, meant that relatively few of these ships were built. In 1940 the British government ordered 60 Ocean-class freighters from American yards to replace war losses and these were simple but fairly large with a single 2,500 horsepower compound steam engine of obsolete but reliable design. Britain specified coal-fired plants, because it then had extensive coal mines, the order specified an 18-inch increase in draft to boost displacement by 800 long tons to 10,100 long tons. The accommodation, bridge, and main engine were located amidships, the first Ocean-class ship, SS Ocean Vanguard, was launched on 16 August 1941. The design was modified by the United States Maritime Commission, in part to increase conformity to American construction practices, but more importantly to make it even quicker and cheaper to build. The US version was designated EC2-S-C1, EC for Emergency Cargo,2 for a ship between 400 and 450 feet long, S for steam engines, and C1 for design C1. The new design replaced much riveting, which accounted for one-third of the costs, with welding. It was adopted as a Merchant Marine Act design, and production awarded to a conglomerate of West Coast engineering and construction companies headed by Henry J. Kaiser known as the Six Companies. Liberty ships were designed to carry 10,000 long tons of cargo, usually one type per ship, but, during wartime, generally carried loads far exceeding this. On 27 March 1941, the number of ships was increased to 200 by the Defense Aid Supplemental Appropriations Act and increased again in April to 306. By 1941, the turbine was the preferred marine steam engine because of its greater efficiency compared to earlier reciprocating compound steam engines. Eighteen different companies built the engine. It had the advantage of ruggedness and simplicity
3.
Richmond, California
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Richmond is a city in western Contra Costa County, California, United States. The city was incorporated on August 7,1905, under the McLaughlin Administration, Richmond was the largest city in the United States served by a Green Party mayor. As of the 2010 U. S. Census, the population is at 103,710. The largest, Richmond, Virginia, is the namesake of the California city, the Ohlone Indians were the first inhabitants of the Richmond area, settling an estimated 5,000 years ago. The name Richmond appears to predate actual incorporation by more than fifty years, the Atchison, Topeka and Santa Fe Railroad had its terminus at Richmond. The first post office opened in 1900, Richmond was founded and incorporated in 1905, carved out of Rancho San Pablo, from which the nearby town of San Pablo inherited its name. Until the enactment of prohibition in 1919, the city had the largest winery in the world, in the 1920s the Ku Klux Klan was active in the city. In 1930 the Ford Motor Company opened a plant called Richmond Assembly Plant which moved to Milpitas in the 1960s. The old Ford plant has been a National Historic Place since 1988, the city was a small town at that time, until the onset of World War II which brought on a rush of migrants and a boom in the industrial sector. Standard Oil set up here in 1901, including a what is now the Chevron Richmond Refinery and tank farm. There is a pier into San Francisco Bay south of Point Molate for oil tankers, the western terminus of the Santa Fe Railroad was established in Richmond with ferry connections at Ferry Point in the Brickyard Cove area of Point Richmond to San Francisco. Many of these lived in specially constructed houses scattered throughout the San Francisco Bay Area, including Richmond, Berkeley. A specially built rail line, the Shipyard Railway, transported workers to the shipyards, kaisers Richmond shipyards built 747 Victory and Liberty ships for the war effort, more than any other site in the U. S. The city broke many records and even built one Liberty ship in a five days. On average the yards could build a ship in thirty days, the medical system established for the shipyard workers at the Richmond Field Hospital eventually became todays Kaiser Permanente HMO. It remained in operation until 1993 when it was replaced by the modern Richmond Medical Center hospital, Point Richmond was originally the commercial hub of the city, but a new downtown arose in the center of the city. It was populated by many department stores such as Kress, J. C. Penney, Sears, Macys, during the war the population increased dramatically and peaked at around 120,000 by the end of the war. Once the war ended the workers were no longer needed
4.
National Defense Reserve Fleet
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The NDRF is managed by the U. S. Department of Transportations Maritime Administration. It is a different entity from the United States Navy reserve fleets, NDRF vessels are at the fleet sites at James River, Virginia–the James River Reserve Fleet, Beaumont, Texas–the Beaumont Reserve Fleet, and Suisun Bay, California, and at designated outported berths. Former anchorage sites included Stony Point, New York - the Hudson River Reserve Fleet, Wilmington, North Carolina, Mobile, Alabama, Astoria, Oregon, and Olympia, Washington. Through the 2010s, the oldest, most decrepit hulls at Suisun Bay will be stripped of materials, then broken up in Texas. Twenty of the most polluting mothball ships are slated for recycling by 2012, at its peak in 1950, the NDRF had 2,277 ships in lay-up. In July 2007, it held 230 ships, primarily dry cargo ships with some tankers, military auxiliaries, by the end of August,2015, it held 100. The NDRF was established under Section 11 of the Merchant Ship Sales Act of 1946 to serve as a reserve of ships for national defense, NDRF vessels were used in seven wars and crises. During the Korean War,540 vessels were out to move military forces. During a worldwide tonnage shortfall in 1951–53, more than 600 ships were reactivated to carry coal to Northern Europe, from 1955 through 1964, another 600 ships were used to store grain for the Department of Agriculture. Another 223 cargo ships and 29 tankers were activated during a tonnage shortfall after the Suez Canal was closed in 1956, during the Berlin crisis of 1961,18 vessels were activated and remained in service until 1970. Another 172 vessels were activated for the Vietnam War and these are crewed with a reduced crew but kept available for activation within four, five, ten or twenty days. An additional 28 ships are held under United States Maritime Administration custody for other Government agencies on a cost-reimbursable basis. Vessels with military utility or logistic value are held in status and are in a preservation program that is designed to keep them in the same condition as when they enter the fleet. The internal spaces are dehumidified to slow the corrosion of metal, DC power is distributed through anodes to the exterior underwater portions of the hull, creating an electric field that suppresses corrosion and preserves the surface of the hull. External painting and other work is generally deferred since it does not affect the ability to activate and operate the vessel. MARAD is authorized as the government’s disposal agent through the NDRF program for merchant type vessels equal to or greater than 1,500 gross tons. A state agency can file an application to request title to a vessel as-is where-is from the NDRF for the purpose of creating an artificial reef, of the 132 non-retention vessels in the NDRF, there are 117 that are being prepared for disposal. The NDRF program can give and lend historic artifacts to maritime-heritage organizations, battleships, cruisers, and aircraft carriers which have been stricken or those awaiting final disposition may be transferred to MARAD locations for berthing
5.
James River
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The James River is a river in the U. S. state of Virginia. It is 348 miles long, extending to 444 miles if one includes the Jackson River, the James River drains a catchment comprising 10,432 square miles. The watershed includes about 4% open water and an area with a population of 2.5 million people and it is the 12th longest river in the United States that remains entirely within a single state. Tidal waters extend west to Richmond, the capital of Virginia, larger tributaries draining to the tidal portion include the Appomattox River, Chickahominy River, Warwick River, Pagan River, and the Nansemond River. At its mouth near Newport News Point, the Elizabeth River, many boats pass through this river to import and export Virginia products. The navigable portion of the river was the highway of the Colony of Virginia during its first 15 years, facilitating supply ships delivering supplies. However, for the first five years, despite many hopes of gold and riches, in 1612, businessman John Rolfe successfully cultivated a non-native strain of tobacco which proved popular in England. Soon, the became the primary means of exporting the large hogsheads of this cash crop from an ever-growing number of plantations with wharfs along its banks. This development made the efforts of the Virginia Company of London successful financially, spurring even more development, investments. The upper reaches of the river above the head of navigation at the line were explored by fur trading parties sent by Abraham Wood during the late 17th century. Although ocean-going ships were unable to navigate beyond present-day Richmond, portage of products, produce from the Piedmont and Great Valley regions traveled down the river to seaports at Richmond and Manchester through such port towns as Lynchburg, Scottsville, Columbia and Buchanan. The James River was considered as a route for transport of produce from the Ohio Valley, the James River and Kanawha Canal was built for this purpose, to provide a navigable portion of the Kanawha River, a tributary of the Ohio River. For the most mountainous section between the two points, the James River and Kanawha Turnpike was built to provide a link via wagons. However, before the canal could be completed, in the mid-19th century, railroads emerged as a more practical technology. The Chesapeake and Ohio Railway was completed between Richmond and the Ohio River at the new city of Huntington, West Virginia by 1873, dooming the canals economic prospects. In the 1880s, the Richmond and Alleghany Railroad was laid along the portion of the canals towpath. In modern times, this line is used primarily in transporting West Virginia coal to export coal piers at Newport News. The James River contains numerous parks and other recreational attractions, canoeing, fishing, kayaking, hiking, and swimming are some of the activities that people enjoy along the river during the summer
6.
Lee Hall, Virginia
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Lee Hall is a former unincorporated town long located in the former Warwick County. Since 1958, Lee Hall has been a community in the extreme western portion of the independent city of Newport News in the Commonwealth of Virginia. The mansion was used as headquarters for Confederate generals Joseph E. Johnston, magruder during the Peninsula Campaign of the American Civil War in 1862. Nearby is Endview Plantation, a 238-year-old house, Endview was used as a hospital during the Civil War and as a campground during the Revolutionary War, the War of 1812 and the Civil War. The Boxwood Inn was built in 1897, Lee Hall Depot became a very busy railroad station after the establishment nearby of Fort Eustis in 1918, with freight and heavy troop movements. The busy activity resumed during World War II and it was expanded to accommodate this role. East of Lee Hall, a spur leads to the base. With the coming of the automobile as a form of travel in the early 20th century. As part of the Good Roads Movement, the new road which became U. S. Route 60 was routed from Williamsburg through Grove and this routing was chosen rather than following a competing route via Halsteads Point in York County. Earlier, the east-west road which became U. S.60 was State Route 9, SR9 was renumbered as State Route 39 in 1923, and became U. S.60 in the mid-1920s when it was routed through Grove. The village portion of Lee Hall is connected to I-64 via State Route 238, the 26th Balloon Company of the US Army Air Corps had a training school at Lee Hall at least during the summer of 1920 training soldiers for deployment to central and South America service. In the 21st century, Lee Hall Depot is the only surviving C&O structure of its type on the Lower Peninsula. Across the street from the Depot, the Boxwood Inn, a bed and breakfast establishment in an 1896 house, is open and available for overnight visitors and some meals. The citys tourism agency operates several other attractions at Lee Hall Mansion and Endview Plantation, the Lee Hall community is served by exit 247 of Interstate 64. About 1 block from the railroad station, U. S. Route 60. Lee Hall is served by both Hampton Roads Transit and Williamsburg Area Transit Authority, for direct service to the Williamsburg Amtrak and Greyhound/Carolina Trailways station, ride the WATA Grey Line to the Williamsburg Transportation Center. For service to the Newport News Amtrak station, ride the 116 and transfer to the 106 or 107 to get to the Newport News Amtrak station
7.
Cargo ship
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A cargo ship or freighter is any sort of ship or vessel that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the worlds seas and oceans each year, cargo ships are usually specially designed for the task, often being equipped with cranes and other mechanisms to load and unload, and come in all sizes. Today, they are almost always built by welded steel, cargo ships/freighters can be divided into five groups, according to the type of cargo they carry. Tankers carry petroleum products or other liquid cargo, dry bulk carriers carry coal, grain, ore and other similar products in loose form. Multi-purpose vessels, as the name suggests, carry different classes of cargo – e. g. liquid, a Reefer ship is specifically designed and used for shipping perishable commodities which require temperature-controlled, mostly fruits, meat, fish, vegetables, dairy products and other foodstuffs. Specialized types of cargo vessels include ships and bulk carriers. Cargo ships fall into two categories that reflect the services they offer to industry, liner and tramp services. Those on a published schedule and fixed tariff rates are cargo liners. Tramp ships do not have fixed schedules, users charter them to haul loads. Generally, the shipping companies and private individuals operate tramp ships. Cargo liners run on fixed schedules published by the shipping companies, each trip a liner takes is called a voyage. However, some cargo liners may carry passengers also, a cargo liner that carries 12 or more passengers is called a combination or passenger-cum-cargo line. The desire to trade routes over longer distances, and throughout more seasons of the year. Before the middle of the 19th century, the incidence of piracy resulted in most cargo ships being armed, sometimes heavily, as in the case of the Manila galleons. They were also escorted by warships. Piracy is still common in some waters, particularly in the Malacca Straits. In 2004, the governments of three nations agreed to provide better protection for the ships passing through the Straits. The waters off Somalia and Nigeria are also prone to piracy, while smaller vessels are also in danger along parts of the South American, Southeast Asian coasts, the words cargo and freight have become interchangeable in casual usage
8.
Steam engine
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A steam engine is a heat engine that performs mechanical work using steam as its working fluid. Steam engines are combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as power, nuclear power or geothermal energy may be used. The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle, in the cycle, water is heated and transforms into steam within a boiler operating at a high pressure. When expanded through pistons or turbines, mechanical work is done, the reduced-pressure steam is then exhausted to the atmosphere, or condensed and pumped back into the boiler. Specialized devices such as hammers and steam pile drivers are dependent on the steam pressure supplied from a separate boiler. The use of boiling water to mechanical motion goes back over 2000 years. The Spanish inventor Jerónimo de Ayanz y Beaumont obtained the first patent for an engine in 1606. In 1698 Thomas Savery patented a steam pump that used steam in direct contact with the water being pumped, Saverys steam pump used condensing steam to create a vacuum and draw water into a chamber, and then applied pressurized steam to further pump the water. Thomas Newcomens atmospheric engine was the first commercial steam engine using a piston. In 1781 James Watt patented an engine that produced continuous rotary motion. Watts ten-horsepower engines enabled a range of manufacturing machinery to be powered. The engines could be sited anywhere that water and coal or wood fuel could be obtained, by 1883, engines that could provide 10,000 hp had become feasible. The stationary steam engine was a key component of the Industrial Revolution, the aeolipile described by Hero of Alexandria in the 1st century AD is considered to be the first recorded steam engine. Torque was produced by steam jets exiting the turbine, in the Spanish Empire, the great inventor Jerónimo de Ayanz y Beaumont obtained a patent for the first steam engine in history in 1603. Thomas Savery, in 1698, patented the first practical, atmospheric pressure and it had no piston or moving parts, only taps. It was an engine, a kind of thermic syphon, in which steam was admitted to an empty container. The vacuum thus created was used to water from the sump at the bottom of the mine
9.
Propeller
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A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the blade, and a fluid is accelerated behind the blade. Their disadvantages are higher mechanical complexity and higher cost, the principle employed in using a screw propeller is used in sculling. It is part of the skill of propelling a Venetian gondola but was used in a less refined way in parts of Europe. For example, propelling a canoe with a paddle using a pitch stroke or side slipping a canoe with a scull involves a similar technique. In China, sculling, called lu, was used by the 3rd century AD. In sculling, a blade is moved through an arc. The innovation introduced with the propeller was the extension of that arc through more than 360° by attaching the blade to a rotating shaft. Propellers can have a blade, but in practice there are nearly always more than one so as to balance the forces involved. The origin of the screw propeller starts with Archimedes, who used a screw to lift water for irrigation and bailing boats and it was probably an application of spiral movement in space to a hollow segmented water-wheel used for irrigation by Egyptians for centuries. Leonardo da Vinci adopted the principle to drive his theoretical helicopter, in 1784, J. P. Paucton proposed a gyrocopter-like aircraft using similar screws for both lift and propulsion. At about the time, James Watt proposed using screws to propel boats. This was not his own invention, though, Toogood and Hays had patented it a century earlier, by 1827, Czech-Austrian inventor Josef Ressel had invented a screw propeller which had multiple blades fastened around a conical base. He had tested his propeller in February 1826 on a ship that was manually driven. He was successful in using his bronze screw propeller on an adapted steamboat and his ship Civetta with 48 gross register tons, reached a speed of about six knots. This was the first ship successfully driven by an Archimedes screw-type propeller, after a new steam engine had an accident his experiments were banned by the Austro-Hungarian police as dangerous. Josef Ressel was at the time a forestry inspector for the Austrian Empire, but before this he received an Austro-Hungarian patent for his propeller. This new method of propulsion was an improvement over the paddlewheel as it was not so affected by either ship motions or changes in draft as the burned coal
10.
5"/38 caliber gun
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The Mark 12 5/38 caliber gun was a US naval gun. The gun was installed into Single Purpose and Dual Purpose mounts used primarily by the US Navy, the 38 caliber barrel was a mid-length compromise between the previous United States standard 5/51 low-angle gun and 5/25 anti-aircraft gun. The increased barrel length provided greatly improved performance in both anti-aircraft and anti-surface roles compared to the 5/25 gun, however, except for the barrel length and the use of semi-fixed ammunition, the 5/38 gun was derived from the 5/25 gun. Both weapons had power ramming, which enabled rapid fire at high angles against aircraft, the 5/38 entered service on USS Farragut, commissioned in 1934. The base ring mount, which improved the rate of fire, entered service on USS Gridley. Even this advanced system required nearly 100 rounds of ammunition expenditure per aircraft kill, however, the planes were normally killed by shell fragments and not direct hits, barrage fire was used, with many guns firing in the air at the same time. Base ring mounts with integral hoists had a rate of fire of 15 rounds per minute per barrel, however. On pedestal and other mounts lacking integral hoists,12 to 15 rounds per minute was the rate of fire, useful life expectancy was 4600 effective full charges per barrel. The 5/38 cal gun was mounted on a large number of US Navy ships in the World War II era. It was backfitted to many of the World War I-era battleships during their wartime refits and it has left active US Navy service, but it is still on mothballed ships of the United States Navy reserve fleets. It is also used by a number of nations who bought or were given US Navy surplus ships, each mount carries one or two Mk 12 5/38cal Gun Assemblies. The gun assembly shown is used in single mounts, and it is the gun in twin mounts. It is loaded from the left side, the left gun in twin mounts is the mirror image of the right gun, and it is loaded from the right side. The Mk12 gun assembly weighs 3,990 lb, the major Mk12 Gun Assembly characteristics are,158 Semi-automatic During recoil, some of the recoil energy is stored in the counter-recoil system. That stored energy is used during counter-recoil to prepare the gun for the next round, the firing pin is cocked, the breech is opened, the spent powder case is ejected, and the bore is air cleaned. Hand loaded A Projectile-Man and a Powder-Man are stationed at each gun assembly and their job is to move the round, consisting of a projectile and a powder case, from the hoists to the rammer tray, and then start the ram cycle. The hydraulically driven Rammer Spade, called the Power Spade in that picture, is at the back of the Rammer Tray, if the multiple names of the Spade is confusing, look at this footnote. Vertical sliding-wedge breech block The breech block closes the chamber behind the powder case and it also holds the firing pin assembly
11.
3"/50 caliber gun
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For Army 3-inch gun see 3-inch M1918 gun The 3″/50 caliber gun in United States naval gun terminology indicates the gun fired a projectile 3 inches in diameter, and the barrel was 50 calibers long. Different guns of this caliber were used by the U. S. Navy and U. S. Coast Guard from 1890 through the 1990s on a variety of combatant and transport ship classes. The US Navys first 3″/50 caliber gun was a model with a projectile velocity of 2,100 feet per second. Low-angle mountings for this gun had a range of 7000 yards at the elevation of 15 degrees. The gun entered service around 1900 with the Bainbridge-class destroyers, and was fitted to Connecticut-class battleships. By World War II these guns were only on a few Coast Guard cutters. These guns fired the same 2,700 feet per second used by the following dual-purpose Marks. These were built-up guns with a tube, partial-length jacket, hoop, dual-purpose 3″/50 caliber guns first entered service in 1915 as a refit to USS Texas, and were subsequently mounted on many types of ships as the need for anti-aircraft protection was recognized. They also replaced the original low-angle 4/50 caliber guns on flush-deck Wickes and these dual-purpose guns were quick-firing, meaning that they used fixed ammunition, with powder case and projectile permanently attached, and handled as a single unit weighing 34 pounds. Maximum range was 14,600 yards at 45 degrees elevation, useful life expectancy was 4300 effective full charges per barrel. The 3/50 caliber gun Marks 17 and 18 was first used as a deck gun on R-class submarines launched in 1918-1919. At the time it was an improvement on the earlier 3/23 caliber gun, after using larger guns on many other submarines, the 3/50 caliber gun Mark 21 was specified as the standard deck gun on the Porpoise- through Gato-class submarines launched in 1935-1942. The small gun was chosen to remove the temptation to engage enemy vessels on the surface. The gun was mounted aft of the conning tower to reduce submerged drag. Wartime experience showed that larger guns were needed and this need was initially met by transferring 4/50 caliber guns from S-class submarines as they were shifted from combat to training roles from late 1942. Later, the 5/25 caliber gun, initially removed from battleships sunk or damaged in the attack on Pearl Harbor and later manufactured in a submarine version, post-war experimentation with an extended range variant was abandoned as shipboard surface-to-air missiles were developed. The United States Navy considered contemporary 5/38 caliber guns and 5″/54 caliber guns more effective against surface targets, the 3″/50 caliber gun was a semiautomatic anti-aircraft weapon with a power driven automatic loader. These monobloc 3″ guns were fitted to both single and twin mountings, the single was to be exchanged for a twin 40 mm antiaircraft gun mount and the twin for a quadruple 40 mm mount
12.
Bofors 40 mm gun
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The Bofors 40 mm gun, often referred to simply as the Bofors gun, is an anti-aircraft/multi-purpose autocannon designed in the 1930s by the Swedish arms manufacturer AB Bofors. It was one of the most popular medium-weight anti-aircraft systems during World War II, a small number of these weapons remain in service to this day, and saw action as late as the Gulf War. In the post-war era the original design was not suitable for action against jet powered aircraft, so Bofors introduced a new model of more power. In spite of sharing almost nothing with the design other than the calibre and the distinctive conical flash hider. Although not as popular as the original L/60 model, the L/70 remains in service to this day, especially as a weapon for light armored vehicles. Bofors itself has been part of BAE Systems AB since March 2005, the Swedish Navy purchased a number of 2 pounder Pom-Poms from Vickers as anti-aircraft guns in 1922. The Navy approached Bofors about the development of a capable replacement. Bofors signed a contract in late 1928, Bofors produced a gun that was a smaller version of a 57 mm semi-automatic gun developed as an anti-torpedo boat weapon in the late 19th century by Finspong. Their first test gun was a re-barreled Nordenfelt version of the Finspong gun, testing of this gun in 1929 demonstrated that a problem existed feeding the weapon in order to maintain a reasonable rate of fire. A mechanism that was enough to handle the stresses of moving the large round was too heavy to move quickly enough to fire rapidly. One attempt to solve this problem used zinc shell cases that burned up when fired and this proved to leave heavy zinc deposits in the barrel, and had to be abandoned. This seemed to be the solution they needed, improving firing rates to a level. During this period Krupp purchased a share of Bofors. Krupp engineers started the process of updating the Bofors factories to use equipment and metallurgy. The prototype was completed and fired in November 1931, and by the middle of the month it was firing strings of two and three rounds. Changes to the mechanism were all that remained, and by the end of the year it was operating at 130 rounds per minute. Continued development was needed to turn it into a suitable for production. Since acceptance trials had been passed the year before, this known as the 40 mm akan M/32
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United States
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This article incorporates text from this source, which is in the 
