1.
Victory ship
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The Victory ship was a class of cargo ship produced in large numbers by North American shipyards during World War II to replace losses caused by German submarines. A total of 531 Victory ships were built, one of the first acts of the United States War Shipping Administration upon its formation in February 1942 was to commission the design of what came to be known as the Victory class. The design was an enhancement of the Liberty ship, which had successfully produced in extraordinary numbers. Victory ships were larger than Liberty ships,14 feet longer at 455 feet,6 feet wider at 62 ft. Displacement was up just under 1,000 tons, to 15,200, with a raised forecastle and a more sophisticated hull shape to help achieve the higher speed, they had a quite different appearance from Liberty ships. To make them vulnerable to U-boat attacks, Victory ships made 15 to 17 knots,4 to 6 knots faster than the Libertys. The extra speed was achieved through more modern, efficient engines, most used steam turbines, which had been in short supply earlier in the war and reserved for warships. All were oil-fired, but for a handful of Canadian vessels completed with both coal bunkers and oil tanks, another improvement was electrically powered auxiliary equipment, rather than steam-driven machinery. To prevent the hull fractures that a few Liberty ships developed and these were manned by United States Navy Armed Guard personnel. The VC2-S-AP5 Haskell-class attack transports were armed with the 5-inch stern gun, one quad 40 mm Bofors cannon, four dual 40 mm Bofors cannon, the Haskells were operated and crewed exclusively by U. S. Navy personnel. The Victory ship was noted for good proportion of cubic between holds for a ship of its day. A Victory ships cargo hold one, two and five hatches are a single rigged with a capacity of 70,400,76,700, and 69,500 bale cubic feet respectively. Victory ships hold three and four hatches are double rigged with a capacity of 136,100 and 100,300 bale cubic feet respectively. Victory ship have built in mast, booms and derrick cranes, the first vessel was SS United Victory launched at Oregon Shipbuilding Corporation on 12 January 1944 and completed on 28 February 1944, making her maiden voyage a month later. American vessels frequently had a name incorporating the word Victory, the British and Canadians used Fort and Park respectively. Although initial deliveries were slow—only 15 had been delivered by May 1944—by the end of the war 531 had been constructed, because the Atlantic battle had been won by the time that the first of the Victory ships appeared none were sunk by U-boats. Three were sunk by Japanese kamikaze attack in April of 1945, many Victory ships were converted to troopship to bring US soldiers home at the end of World War II as part of Operation Magic Carpet. A total of 97 Victory ships were converted to carry up to 1,600 soldiers
2.
Steam turbine
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A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Sir Charles Parsons in 1884, in 1551, Taqi al-Din in Ottoman Egypt described a steam turbine with the practical application of rotating a spit. Steam turbines were described by the Italian Giovanni Branca and John Wilkins in England. The devices described by Taqi al-Din and Wilkins are today known as steam jacks, in 1672 an impulse steam turbine driven car was designed by Ferdinand Verbiest. A more modern version of car was produced some time in the late 18th century by an unknown German mechanic. The modern steam turbine was invented in 1884 by Sir Charles Parsons, the invention of Parsons steam turbine made cheap and plentiful electricity possible and revolutionized marine transport and naval warfare. Parsons design was a reaction type and his patent was licensed and the turbine scaled-up shortly after by an American, George Westinghouse. The Parsons turbine also turned out to be easy to scale up. Parsons had the satisfaction of seeing his invention adopted for all major world power stations, a number of other variations of turbines have been developed that work effectively with steam. The de Laval turbine accelerated the steam to full speed before running it against a turbine blade, De Lavals impulse turbine is simpler, less expensive and does not need to be pressure-proof. It can operate with any pressure of steam, but is less efficient. He taught at the École des mines de Saint-Étienne for a decade until 1897, one of the founders of the modern theory of steam and gas turbines was Aurel Stodola, a Slovak physicist and engineer and professor at the Swiss Polytechnical Institute in Zurich. His work Die Dampfturbinen und ihre Aussichten als Wärmekraftmaschinen was published in Berlin in 1903, a further book Dampf und Gas-Turbinen was published in 1922. It was used in John Brown-engined merchant ships and warships, including liners, the present-day manufacturing industry for steam turbines is dominated by Chinese power equipment makers. Other manufacturers with minor market share include Bhel, Siemens, Alstom, GE, Doosan Škoda Power, Mitsubishi Heavy Industries, the consulting firm Frost & Sullivan projects that manufacturing of steam turbines will become more consolidated by 2020 as Chinese power manufacturers win increasing business outside of China. There are several classifications for modern steam turbines, Turbine blades are of two basic types, blades and nozzles. Blades move entirely due to the impact of steam on them and this results in a steam velocity drop and essentially no pressure drop as steam moves through the blades. A turbine composed of alternating with fixed nozzles is called an impulse turbine, Curtis turbine, Rateau turbine
3.
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
4.
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
5.
Oerlikon 20 mm cannon
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The Oerlikon 20 mm cannon is a series of autocannons, based on an original German 20 mm Becker design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II, and many still in use today. During World War I, the German Reinhold Becker developed a 20 mm caliber cannon and this used a 20x70 RB cartridge and had a cyclic rate of fire of 300 rpm. It was used on a scale as an aircraft gun on Luftstreitkräfte warplanes. Because the Treaty of Versailles banned further production of weapons in Germany. SEMAG continued development of the weapon, and in 1924 had produced the SEMAG L, the Oerlikon firm, named after the Zürich suburb where it was based, then acquired all rights to the weapon, plus the manufacturing equipment and the employees of SEMAG. In 1927 the Oerlikon S was added to the product line. This fired a larger cartridge to achieve a muzzle velocity of 830 m/s, at the cost of increased weight. The purpose of development was to improve the performance of the gun as an anti-tank and anti-aircraft weapon. An improved version known as the 1S followed in 1930, three sizes of gun with their different ammunition and barrel length, but very similar mechanisms, continued to be developed in parallel. In 1930 Oerlikon reconsidered the application of its gun in aircraft and introduced the AF and AL, designed to be used in flexible mounts, the 15-round box magazine used by earlier versions of the gun was replaced by drum magazine holding 15 or 30 rounds. In 1935 it made an important step by introducing a series of guns designed to be mounted in or on the wings of fighter aircraft, designated with FF for Flügelfest meaning wing-mounted, these weapons were again available in the three sizes, with designations FF, FFL and FFS. The FF fired a larger cartridge than the AF, 20x72RB. The FF weighed 24 kg and achieved a velocity of 550 to 600 m/s with a rate of fire of 520 rpm. The FFL of 30 kg fired a projectile at a velocity of 675 m/s with a rate of fire of 500 rpm. And the FFS, which weighed 39 kg, delivered a high velocity of 830 m/s at a rate of fire of 470 rpm. Apart from changes to the design of the guns for wing-mounting and remote control, for the FF series drum sizes of 45,60,75 and 100 rounds were available, but most users chose the 60-round drum. The 1930s were a period of global re-armament, and a number of foreign firms took licenses for the Oerlikon family of aircraft cannon
6.
Atlantic Ocean
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The Atlantic Ocean is the second largest of the worlds oceans with a total area of about 106,460,000 square kilometres. It covers approximately 20 percent of the Earths surface and about 29 percent of its surface area. It separates the Old World from the New World, the Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Eurasia and Africa to the east, and the Americas to the west. The Equatorial Counter Current subdivides it into the North Atlantic Ocean, in contrast, the term Atlantic originally referred specifically to the Atlas Mountains in Morocco and the sea off the Strait of Gibraltar and the North African coast. The Greek word thalassa has been reused by scientists for the huge Panthalassa ocean that surrounded the supercontinent Pangaea hundreds of years ago. The term Aethiopian Ocean, derived from Ancient Ethiopia, was applied to the Southern Atlantic as late as the mid-19th century, many Irish or British people refer to the United States and Canada as across the pond, and vice versa. The Black Atlantic refers to the role of ocean in shaping black peoples history. Irish migration to the US is meant when the term The Green Atlantic is used, the term Red Atlantic has been used in reference to the Marxian concept of an Atlantic working class, as well as to the Atlantic experience of indigenous Americans. Correspondingly, the extent and number of oceans and seas varies, the Atlantic Ocean is bounded on the west by North and South America. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea, to the east, the boundaries of the ocean proper are Europe, the Strait of Gibraltar and Africa. In the southeast, the Atlantic merges into the Indian Ocean, the 20° East meridian, running south from Cape Agulhas to Antarctica defines its border. In the 1953 definition it extends south to Antarctica, while in later maps it is bounded at the 60° parallel by the Southern Ocean, the Atlantic has irregular coasts indented by numerous bays, gulfs, and seas. Including these marginal seas the coast line of the Atlantic measures 111,866 km compared to 135,663 km for the Pacific. Including its marginal seas, the Atlantic covers an area of 106,460,000 km2 or 23. 5% of the ocean and has a volume of 310,410,900 km3 or 23. 3%. Excluding its marginal seas, the Atlantic covers 81,760,000 km2 and has a volume of 305,811,900 km3, the North Atlantic covers 41,490,000 km2 and the South Atlantic 40,270,000 km2. The average depth is 3,646 m and the maximum depth, the bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge. It runs from 87°N or 300 km south of the North Pole to the subantarctic Bouvet Island at 42°S, the MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above 2000 m along most of its length, the MAR is a barrier for bottom water, but at these two transform faults deep water currents can pass from one side to the other
7.
Maryland
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The states largest city is Baltimore, and its capital is Annapolis. Among its occasional nicknames are Old Line State, the Free State, the state is named after Henrietta Maria of France, the wife of Charles I of England. George Calvert was the first Lord of Baltimore and the first English proprietor of the colonial grant. Maryland was the state to ratify the United States Constitution. Maryland is one of the smallest U. S. states in terms of area, as well as one of the most densely populated, Maryland has an area of 12,406.68 square miles and is comparable in overall area with Belgium. It is the 42nd largest and 9th smallest state and is closest in size to the state of Hawaii, the next largest state, its neighbor West Virginia, is almost twice the size of Maryland. Maryland possesses a variety of topography within its borders, contributing to its nickname America in Miniature. The mid-portion of this border is interrupted by Washington, D. C. which sits on land that was part of Montgomery and Prince Georges counties and including the town of Georgetown. This land was ceded to the United States Federal Government in 1790 to form the District of Columbia, the Chesapeake Bay nearly bisects the state and the counties east of the bay are known collectively as the Eastern Shore. Close to the town of Hancock, in western Maryland, about two-thirds of the way across the state. This geographical curiosity makes Maryland the narrowest state, bordered by the Mason–Dixon line to the north, portions of Maryland are included in various official and unofficial geographic regions. Much of the Baltimore–Washington corridor lies just south of the Piedmont in the Coastal Plain, earthquakes in Maryland are infrequent and small due to the states distance from seismic/earthquake zones. The M5.8 Virginia earthquake in 2011 was felt moderately throughout Maryland, buildings in the state are not well-designed for earthquakes and can suffer damage easily. The lack of any glacial history accounts for the scarcity of Marylands natural lakes, laurel Oxbow Lake is an over one-hundred-year-old 55-acre natural lake two miles north of Maryland City and adjacent to Russett. Chews Lake is a natural lake two miles south-southeast of Upper Marlboro. There are numerous lakes, the largest of them being the Deep Creek Lake. Maryland has shale formations containing natural gas, where fracking is theoretically possible, as is typical of states on the East Coast, Marylands plant life is abundant and healthy. Middle Atlantic coastal forests, typical of the southeastern Atlantic coastal plain, grow around Chesapeake Bay, moving west, a mixture of Northeastern coastal forests and Southeastern mixed forests cover the central part of the state
8.
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
9.
Tanker (ship)
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A tanker is a merchant vessel designed to transport liquids or gases in bulk. Major types of tankship include the oil tanker, the chemical tanker, in the United States Navy and Military Sealift Command, any type of tanker used to refuel other ships is called an oiler. Tankers can range in size of capacity from several hundred tons, besides ocean- or seagoing tankers there are also specialized inland-waterway tankers which operate on rivers and canals with an average cargo capacity up to some thousand tons. Before this, technology had not supported the idea of carrying bulk liquids. The market was not geared towards transporting or selling cargo in bulk, therefore most ships carried a wide range of different products in different holds. Liquids were usually loaded in casks—hence the term tonnage, which refers to the volume of the holds in terms of how many tuns or casks of wine could be carried, even potable water, vital for the survival of the crew, was stowed in casks. Carrying bulk liquids in earlier ships posed several problems, The holds, on ships the holds were not sufficiently water. The development of iron and steel hulls solved this problem, loading and discharging, Bulk liquids must be pumped - the development of efficient pumps and piping systems was vital to the development of the tanker. Steam engines were developed as prime-movers for early pumping systems, dedicated cargo handling facilities were now required ashore too - as was a market for receiving a product in that quantity. Casks could be unloaded using ordinary cranes, and the nature of the casks meant that the volume of liquid was always relatively small - therefore keeping the market more stable. The effect was negligible in casks, but could cause capsizing if the tank extended the width of the ship, tankers were first used by the oil industry to transfer refined fuel in bulk from refineries to customers. This would then be stored in tanks ashore, and subdivided for delivery to individual locations. The use of tankers caught on other liquids were also cheaper to transport in bulk, store in dedicated terminals. Even the Guinness brewery used tankers to transport the stout across the Irish Sea, among oil tankers, supertankers are designed for transporting oil around the Horn of Africa from the Middle East. The supertanker Seawise Giant, scrapped in 2010, was 458 meters in length and 69 meters wide, supertankers are one of the three preferred methods for transporting large quantities of oil, along with pipeline transport and rail. Despite being highly regulated, tankers have been involved in environmental disasters resulting from oil spills, see Amoco Cadiz, Braer, Erika, Exxon Valdez, Prestige oil spill and Torrey Canyon for examples of coastal accidents. Many modern tankers are designed for a cargo and a specific route. Draft is typically limited by the depth of water in loading and unloading harbors, cargoes with high vapor pressure at ambient temperatures may require pressurized tanks or vapor recovery systems
10.
Virginia
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Virginia is a state located in the Mid-Atlantic region of the United States, as well as in the historic Southeast. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, the capital of the Commonwealth is Richmond, Virginia Beach is the most populous city, and Fairfax County is the most populous political subdivision. The Commonwealths estimated population as of 2014 is over 8.3 million, the areas history begins with several indigenous groups, including the Powhatan. In 1607 the London Company established the Colony of Virginia as the first permanent New World English colony, slave labor and the land acquired from displaced Native American tribes each played a significant role in the colonys early politics and plantation economy. Although the Commonwealth was under one-party rule for nearly a century following Reconstruction, the Virginia General Assembly is the oldest continuous law-making body in the New World. The state government was ranked most effective by the Pew Center on the States in both 2005 and 2008 and it is unique in how it treats cities and counties equally, manages local roads, and prohibits its governors from serving consecutive terms. Virginias economy changed from agricultural to industrial during the 1960s and 1970s. Virginia has an area of 42,774.2 square miles, including 3,180.13 square miles of water. Virginias boundary with Maryland and Washington, D. C. extends to the mark of the south shore of the Potomac River. The southern border is defined as the 36° 30′ parallel north, the border with Tennessee was not settled until 1893, when their dispute was brought to the U. S. Supreme Court. The Chesapeake Bay separates the portion of the Commonwealth from the two-county peninsula of Virginias Eastern Shore. The bay was formed from the river valleys of the Susquehanna River. Many of Virginias rivers flow into the Chesapeake Bay, including the Potomac, Rappahannock, York, and James, the Tidewater is a coastal plain between the Atlantic coast and the fall line. It includes the Eastern Shore and major estuaries of Chesapeake Bay, the Piedmont is a series of sedimentary and igneous rock-based foothills east of the mountains which were formed in the Mesozoic era. The region, known for its clay soil, includes the Southwest Mountains around Charlottesville. The Blue Ridge Mountains are a province of the Appalachian Mountains with the highest points in the state. The Ridge and Valley region is west of the mountains and includes the Great Appalachian Valley, the region is carbonate rock based and includes Massanutten Mountain. The Cumberland Plateau and the Cumberland Mountains are in the southwest corner of Virginia, in this region, rivers flow northwest, with a dendritic drainage system, into the Ohio River basin
11.
Convoy
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A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support and it may also be used in a non-military sense, for example when driving through remote areas. Arriving at the scene of an emergency with a well-ordered unit. Naval convoys have been in use for centuries, with examples of merchant ships traveling under naval protection dating to the 12th century, the use of organized naval convoys dates from when ships began to be separated into specialist classes and national navies were established. By the French Revolutionary Wars of the late 18th century, effective naval tactics had been developed to ward off pirates. Some convoys contained several hundred merchant ships, the most enduring system of convoys were the Spanish treasure fleets, that sailed from the 1520s until 1790. When merchant ships sailed independently, a privateer could cruise a shipping lane, ships sailing in convoy presented a much smaller target, a convoy was as hard to find as a single ship. As a result of the convoy systems effectiveness, wartime insurance premiums were consistently lower for ships that sailed in convoys, losses of ships travelling out of convoy however were so high that no merchant ship was allowed to sail unescorted. In the early 20th century, the changed the balance of power in convoy battles. Steaming faster than merchant ships and firing at long ranges, a battleship could destroy many ships in a convoy before the others could scatter over the horizon. To protect a convoy against a ship required providing it with an escort of another capital ship. Battleships were the reason that the British Admiralty did not adopt convoy tactics at the start of the first Battle of the Atlantic in World War I. But the German capital ships had been bottled up in the North Sea, the Admiralty took a long time to respond to this change in the tactical position, and in April 1917 convoy was trialled, before being officially introduced in the Atlantic in September 1917. Other arguments against convoy were raised, further, large convoys were thought to overload port resources. Actual analysis of shipping losses in World War I disproved all these arguments, at least so far as they applied to transatlantic, ships sailing in convoys were far less likely to be sunk, even when not provided with any escort at all. The loss of productivity due to delays was small compared with the loss of productivity due to ships being sunk. Ports could deal more easily with convoys because they tended to arrive on schedule, Convoy duty also exposes the escorting warships to the sometimes hazardous conditions of the North Atlantic, with only rare occurrences of visible achievement. The British adopted a system, initially voluntary and later compulsory for almost all merchant ships
12.
New York City
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The City of New York, often called New York City or simply New York, is the most populous city in the United States. With an estimated 2015 population of 8,550,405 distributed over an area of about 302.6 square miles. Located at the tip of the state of New York. Home to the headquarters of the United Nations, New York is an important center for international diplomacy and has described as the cultural and financial capital of the world. Situated on one of the worlds largest natural harbors, New York City consists of five boroughs, the five boroughs – Brooklyn, Queens, Manhattan, The Bronx, and Staten Island – were consolidated into a single city in 1898. In 2013, the MSA produced a gross metropolitan product of nearly US$1.39 trillion, in 2012, the CSA generated a GMP of over US$1.55 trillion. NYCs MSA and CSA GDP are higher than all but 11 and 12 countries, New York City traces its origin to its 1624 founding in Lower Manhattan as a trading post by colonists of the Dutch Republic and was named New Amsterdam in 1626. The city and its surroundings came under English control in 1664 and were renamed New York after King Charles II of England granted the lands to his brother, New York served as the capital of the United States from 1785 until 1790. It has been the countrys largest city since 1790, the Statue of Liberty greeted millions of immigrants as they came to the Americas by ship in the late 19th and early 20th centuries and is a symbol of the United States and its democracy. In the 21st century, New York has emerged as a node of creativity and entrepreneurship, social tolerance. Several sources have ranked New York the most photographed city in the world, the names of many of the citys bridges, tapered skyscrapers, and parks are known around the world. Manhattans real estate market is among the most expensive in the world, Manhattans Chinatown incorporates the highest concentration of Chinese people in the Western Hemisphere, with multiple signature Chinatowns developing across the city. Providing continuous 24/7 service, the New York City Subway is one of the most extensive metro systems worldwide, with 472 stations in operation. Over 120 colleges and universities are located in New York City, including Columbia University, New York University, and Rockefeller University, during the Wisconsinan glaciation, the New York City region was situated at the edge of a large ice sheet over 1,000 feet in depth. The ice sheet scraped away large amounts of soil, leaving the bedrock that serves as the foundation for much of New York City today. Later on, movement of the ice sheet would contribute to the separation of what are now Long Island and Staten Island. The first documented visit by a European was in 1524 by Giovanni da Verrazzano, a Florentine explorer in the service of the French crown and he claimed the area for France and named it Nouvelle Angoulême. Heavy ice kept him from further exploration, and he returned to Spain in August and he proceeded to sail up what the Dutch would name the North River, named first by Hudson as the Mauritius after Maurice, Prince of Orange
US
