The Phalanx CIWS is a close-in weapon system for defense against anti-ship missiles, etc. It was manufactured by the General Dynamics Corporation, Pomona Division. Consisting of a radar-guided 20 mm Vulcan cannon mounted on a swiveling base, the Phalanx has been used by multiple navies around the world, notably the U. S. Navy on every class of surface combat ship with the exception of the San Antonio-class LPD, by the Canadian Royal Canadian Navy, the British Royal Navy, by the U. S. Coast Guard aboard its Hamilton and Legend-class cutters; the Phalanx is used by 15 other allied nations. A land variant, known as the LPWS, part of the C-RAM system, has been deployed in a short range missile defense role, to counter incoming rockets and mortar fire; because of their distinctive barrel-shaped radome and their automated nature of operation, Phalanx CIWS units are sometimes nicknamed "R2-D2" after the famous droid character from the Star Wars films. The Phalanx Close-In Weapons System was developed as the last line of automated weapons defense against antiship missiles and attacking aircraft, including high-g and maneuvering sea-skimmers.
The first prototype system was offered to the U. S. Navy for evaluation on the destroyer leader USS King in 1973 and it was determined that additional improvements were required to improve performance and reliability. Subsequently, the Phalanx Operational Suitability Model completed its Operational Test and Evaluation on board the destroyer USS Bigelow in 1977; the model exceeded operational maintenance and availability specifications. Another evaluation followed, the weapon system was approved for production in 1978. Phalanx production started with orders for 14 foreign military systems; the first ship fitted out was the aircraft carrier USS Coral Sea in 1980. The Navy began placing CIWS systems on non-combatant vessels in 1984; the basis of the system is the 20 mm M61 Vulcan Gatling gun autocannon, used since 1959 by the United States military on various tactical aircraft, linked to a Ku band fire control radar system for acquiring and tracking targets. This proven system was combined with a purpose-made mounting, capable of fast elevation and traverse speeds, to track incoming targets.
An self-contained unit, the mounting houses the gun, an automated fire-control system and all other major components, enabling it to automatically search for, track and confirm kills using its computer-controlled radar system. Due to this self-contained nature, Phalanx is ideal for support ships, which lack integrated targeting systems and have limited sensors; the entire unit has a mass between 12,400 to 13,500 lb. Due to the evolution of threats and computer technology, the Phalanx system has been developed through several configurations; the basic style is the Block 0, equipped with first-generation, solid-state electronics and with marginal capability against surface targets. The Block 1 upgrade offered various improvements in radar, computing power, rate of fire, an increase in maximum engagement elevation to +70 degrees; these improvements were intended to increase the system's capability against emerging Russian supersonic antiship missiles. Block 1A introduced a new computer system to counter more maneuverable targets.
The Block 1B PSuM adds a forward-looking infrared sensor to make the weapon effective against surface targets. This addition was developed to provide ship defense against small vessel threats and other "floaters" in littoral waters and to improve the weapon's performance against slower low-flying aircraft; the FLIR's capability is of use against low-observability missiles and can be linked with the RIM-116 Rolling Airframe Missile system to increase RAM engagement range and accuracy. The Block 1B allows for an operator to visually identify and target threats; as the system model manager, the U. S. Navy is in the process of upgrading all their Phalanx systems to the Block 1B configuration. All U. S Navy Phalanx systems are scheduled for upgrade to Block 1B by the end of FY 2015. In addition to the FLIR sensor, the Block 1B incorporates an automatic acquisition video tracker, optimized gun barrels, Enhanced Lethality Cartridges for additional capabilities against asymmetric threats such as small maneuvering surface craft, slow-flying fixed and rotary-winged aircraft, unmanned aerial vehicles.
The FLIR sensor improves performance against antiship cruise missiles, while the OGB and ELC provide tighter dispersion and increased "first-hit" range. Another system upgrade is the Phalanx 1B Baseline 2 radar to improve detection performance, increase reliability, reduce maintenance, it has a surface mode to track and destroy threats closer to the water's surface, increasing the ability to defend against fast-attack boats and low-flying missiles. S. Navy Phalanx system-equipped vessels by FY 2019; the Block 1B is used by other navies, such as Canada, Japan, Egypt and the UK. In April 2017, Raytheon tested a new electric gun for the Phalanx allowing the system to fire at varying rates to conserve ammunition; the new design replaces the pneumatic motor and storage tanks, reducing system weight by 180 lb while increasing reliability and reducing operating costs. The CIWS is designed to be the last
Mark 13 missile launcher
The Mark 13 guided missile launching system is a single-arm missile launcher designed for use on frigates and other military vessels. Because of its distinctive single-armed design, the Mark 13 is referred to as the "one-armed bandit." The Mark 13 is equipped to fire the RIM-66 Standard, RGM-84 Harpoon, RIM-24 Tartar missiles for anti-air and anti-ship defense, is capable of firing the Standard at a rate of one every eight seconds. Its 40-round magazine consists of two concentric rings of vertically stored missiles, 24 in the outer ring and 16 in the inner. Total capacity was reduced by 1 due to a requirement to carry a Guided Missile Training Round in order to test system functionality. In case of a fire, the system is equipped with magazine sprinkling, CO2 suppression and booster suppression, it is equipped with a dud jettison function to eject a round overboard if it fails to fire. In the United States Navy, the Mark 13 launcher was most employed as part of the Mark 74 Guided Missile Launch System, or the Mark 92 Fire Control System.
Though the launcher was original armament on U. S. Navy Perry-class frigates, in order to save costs on an obsolete system, by 2004 all active U. S. Navy vessels have had the system removed, it was fitted on the French Cassard-class frigates, as well as the two Mitscher-class destroyers converted to DDGs, the last ten American Charles F. Adams-class destroyers, the American California-class cruisers, the German Lütjens-class destroyers and Australian Perth-class destroyers and Adelaide-class frigates, Dutch Tromp-class frigates and Jacob van Heemskerck-class frigates, Italian Durand de la Penne-class destroyers; the Mark 22 guided missile launching system is a variation of the Mark 13 launcher which has only the inner 16 round storage ring of the Mark 13 launcher. It was deployed on US-designed, Baleares-class Spanish frigates. and US Navy Brooke class frigates. Another major difference is; the launcher rotates over the desired missile and it is hoisted onto the rail. On the Mark 13 the magazine rotates under the launcher.
List of United States Navy Guided Missile Launching Systems Tartar Guided Missile Fire Control System M-11 Shtorm Russian counterpart NAVEDTRA 14909 Gunner’s Mate 3 & 2 – Chapters 7 through 8 via alternatewars.com FAS Mk 13 GMLS
Naval Station Norfolk
Naval Station Norfolk, is a United States Navy base in Norfolk, Virginia. It supports naval forces in the United States Fleet Forces Command, those operating in the Atlantic Ocean, Mediterranean Sea, the Indian Ocean; the installation occupies about 4 miles of waterfront space and 11 miles of pier and wharf space of the Hampton Roads peninsula known as Sewell's Point. It is the world's largest naval station, with the largest concentration of U. S. Navy forces through 75 ships alongside 14 piers and with 134 aircraft and 11 aircraft hangars at the adjacently operated Chambers Field and Port Services controls more than 3,100 ships' movements annually as they arrive and depart their berths. Air Operations conducts over 100,000 flight operations each year, an average of 275 flights per day or one every six minutes. Over 150,000 passengers and 264,000 tons of mail and cargo depart annually on Air Mobility Command aircraft and other AMC-chartered flights from the airfield's AMC Terminal; the area where the base is located was the site of the original 1907 Jamestown Exposition.
In 1915 the Headquarters of the 5th Naval District was manned. In April 1917, not long after the United States entered World War I, a bill was passed for the purchase of the land, money was set aside in the amount of $1.6 million for the development of the base. The Naval Operating Base and other facilities were established. By 1918, there were 34,000 enlisted men at the base. However, by the war's end, the base was reduced in personnel and put into a "standby mode." When World War II began in Europe in 1939, the base became more active again. New facilities were built, including new runways for part of Naval Air Station Norfolk, it had ramps built to be used by seaplanes to be operated by the Navy during the war. About 400 acres was acquired and, by 1943, the air station had become a central airfield for operations. Due to the expansion, it contributed to ending the war due because of the training it provided to naval air units. In March 1946, the Chief of Naval Operations ordered the Commandant of the 5th Naval District to place NOB Norfolk and NAS Norfolk as separate installations under the command of Commandant Naval Base, whose title was soon changed to Commander, Navy Region, Mid-Atlantic.
On 1 January 1953, the name of the naval base was changed to Naval Station Norfolk, after being known as the NOB. In 1968, the Naval Air Station was given a major role in John F. Kennedy's vision of putting a man on the moon; the air station became Recovery Control Center Atlantic, which provided command and communications for the ships and aircraft that participated in the recovery operations of Apollo 7. Due to the end of the Cold War, a drawdown began in the 1990s, the Navy began reducing shore installations to help with operating costs. Due to this, the Navy merged the separate Naval Station Norfolk and Naval Air Station Norfolk into a single installation to be called Naval Station Norfolk, which became official on 5 February 1999. Following the attack on USS Cole and 11 September 2001 terrorist attacks, the base had some major upgrades to its security gates, costing more than $12.5 million. On 26 January 2017, NS Norfolk celebrated its centennial at the Pennsylvania House, a historical building built for the Jamestown Exposition, located on the base.
On Easter of 1988, members of the anti-nuclear group Plowshares boarded the battleship USS Iowa with visitors for a ship's tour and left their group to do symbolic damage to the ship's empty Tomahawk missile launchers, using hammers and their own blood. On March 24, 2014, a shooting at NS Norfolk resulted in the death of a civilian; the shooting occurred around 11:20 p.m. EDT aboard USS Mahan. Security forces shot and killed the civilian who had shot the sailor aboard the vessel; the base was closed for a short time after the shooting on USS Mahan. Naval Station Norfolk is home port of their assigned ships. In addition, the Naval Station plays host to several Military Sealift Command ships, as well as the submarines of the Atlantic Fleet; as of June 2017, the following operational units are headquartered or homeported at Naval Station Norfolk: In addition to the several operational units, Naval Station Norfolk is headquarters to a number of shore activities that provided administrative and specialty support to regional operational assets, in some cases, the entire Navy.
As of February 2017, these included: Navy Warfare Development Command Navy Region Mid-Atlantic Navy Expeditionary Combat Command Naval Reserve Force Navy Fleet Readiness Centers Naval Surface Force Atlantic Naval Computer and Telecommunications Area Master Station Atlantic Navy Exchange Command Naval Safety Center Naval Criminal Investigative Service, Norfolk Field Office headquarters and NCIS Resident Agency Norfolk, a subordinate component of the Norfolk Field Office. Commodore Levy Chapel This article incorporates public domain material from websites or documents of the United States Navy. Official website Flagship - military-authorized newspaper of NAS Norfolk and Commander Navy Region Mid-Atlantic NS Norfolk at GlobalSecurity.org Navy Lodge Norfolk FAA Airport Diagram, effective March 28, 2019 FAA Terminal Procedures for NGU, effective March 28, 2019 Resources for this U. S. military airport: FAA airport information for NGU AirNav airport information for KNGU ASN accident history for NGU NOAA/NWS latest weather observations SkyVector aeronautical chart for KNGU
Oliver Hazard Perry-class frigate
The Oliver Hazard Perry class is a class of guided missile frigates named after the U. S. Commodore Oliver Hazard Perry, the hero of the naval Battle of Lake Erie. Known as the Perry or FFG-7 class, the warships were designed in the United States in the mid-1970s as general-purpose escort vessels inexpensive enough to be bought in large quantities to replace World War II-era destroyers and complement 1960s-era Knox-class frigates. In Admiral Elmo Zumwalt's "high low fleet plan", the FFG-7s were the low capability ships with the Spruance-class destroyers serving as the high capability ships. Intended to protect amphibious landing forces and replenishment groups, merchant convoys from aircraft and submarines, they were later part of battleship-centred surface action groups and aircraft carrier battle groups/strike groups. Fifty-five ships were built in the United States: 51 for the United States Navy and four for the Royal Australian Navy. In addition, eight were built in Taiwan, six in Spain, two in Australia for their navies.
Former U. S. Navy warships of this class have been sold or donated to the navies of Bahrain, Poland, Pakistan and Turkey; the first of the 51 U. S. Navy built Oliver Hazard Perry frigates entered into service in 1977, the last remaining in active service, USS Simpson, was decommissioned on 29 September 2015; the retired vessels were either transferred to other navies for continued service. Some of the U. S. Navy's frigates, such as USS Duncan had short careers, while a few lasted as long as 30+ years in active U. S. service, with some lasting longer after being sold or donated to other navies. The ships were designed by the Bath Iron Works shipyard in Maine in partnership with the New York-based naval architects Gibbs & Cox; the design process was notable as the initial design was accomplished with the help of computers in 18 hours by Raye Montague, a United States Naval Engineer. The Oliver Hazard Perry-class ships were produced in 445-foot long "short-hull" and 453-foot long "long-hull" variants.
The long-hull ships carry the larger SH-60 Seahawk LAMPS III helicopters, while the short-hulled warships carry the smaller and less-capable SH-2 Seasprite LAMPS I. Aside from the lengths of their hulls, the principal difference between the versions is the location of the aft capstan: on long-hull ships, it sits a step below the level of the flight deck in order to provide clearance for the tail rotor of the longer Seahawk helicopters; the long-hull ships carry the RAST system for the Seahawk, a hook and winch system that can reel in a Seahawk from a hovering flight, expanding the ship's pitch-and-roll range in which flight operations are permitted. The FFG 8, 29, 32, 33 were built as "short-hull" warships but were modified into "long-hull" warships. Oliver Hazard Perry-class frigates were the second class of surface ship in the US Navy to be built with gas turbine propulsion; the gas turbine propulsion plant was more automated than other Navy propulsion plants at the time and could be centrally monitored and controlled from a remote engineering control center away from the engines.
The gas turbine propulsion plants allowed the ship's speed to be controlled directly from the bridge via a throttle control, a first for the US Navy. American shipyards constructed Oliver Hazard Perry-class ships for the U. S. Navy and the Royal Australian Navy. Early American-built Australian ships were built as the "short-hull" version, but they were modified during the 1980s to the "long-hull" design. Shipyards in Australia and Taiwan have produced several warships of the "long-hull" design for their navies. Although the per-ship costs rose over the period of production, all 51 ships planned for the U. S. Navy were built. During the design phase of the Oliver Hazard Perry class, head of the Royal Corps of Naval Constructors, R. J. Daniels, was invited by an old friend, US Chief of the Bureau of Ships, Adm Robert C Gooding, to advise upon the use of variable-pitch propellers in the class. During the course of this conversation, Daniels warned Gooding against the use of aluminium in the superstructure of the FFG-7 class as he believed it would lead to structural weaknesses.
A number of ships subsequently developed structural cracks, including a 40 ft fissure in USS Duncan, before the problems were remedied. The Oliver Hazard Perry-class frigates were designed as anti-aircraft and anti-submarine warfare guided-missile warships intended to provide open-ocean escort of amphibious warfare ships and merchant ship convoys in moderate threat environments in a potential war with the Soviet Union and the Warsaw Pact countries, they could provide air defense against 1970s- and 1980s-era aircraft and anti-ship missiles. These warships are equipped to escort and protect aircraft carrier battle groups, amphibious landing groups, underway replenishment groups, merchant ship convoys, they can conduct independent operations to perform such tasks as surveillance of illegal drug smugglers, maritime interception operations, exercises with other nations. The addition of the Naval Tactical Data System, LAMPS helicopters, the Tactical Towed Array System gave these warships a combat capability far beyond the original expectations.
They are well suited to operations in littoral regions, for most war-at-sea scenarios. Oliver Hazard Perry-class frigates made worldwide news during the 1980s. Despite being small, these frigates were shown to be d
Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, spacecraft, guided missiles, motor vehicles, weather formations, terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna and a receiver and processor to determine properties of the object. Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed. Radar was developed secretly for military use by several nations in the period before and during World War II. A key development was the cavity magnetron in the UK, which allowed the creation of small systems with sub-meter resolution; the term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging The term radar has since entered English and other languages as a common noun, losing all capitalization.
The modern uses of radar are diverse, including air and terrestrial traffic control, radar astronomy, air-defense systems, antimissile systems, marine radars to locate landmarks and other ships, aircraft anticollision systems, ocean surveillance systems, outer space surveillance and rendezvous systems, meteorological precipitation monitoring and flight control systems, guided missile target locating systems, ground-penetrating radar for geological observations, range-controlled radar for public health surveillance. High tech radar systems are associated with digital signal processing, machine learning and are capable of extracting useful information from high noise levels. Radar is a key technology that the self-driving systems are designed to use, along with sonar and other sensors. Other systems similar to radar make use of other parts of the electromagnetic spectrum. One example is "lidar". With the emergence of driverless vehicles, Radar is expected to assist the automated platform to monitor its environment, thus preventing unwanted incidents.
As early as 1886, German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects. In 1895, Alexander Popov, a physics instructor at the Imperial Russian Navy school in Kronstadt, developed an apparatus using a coherer tube for detecting distant lightning strikes; the next year, he added a spark-gap transmitter. In 1897, while testing this equipment for communicating between two ships in the Baltic Sea, he took note of an interference beat caused by the passage of a third vessel. In his report, Popov wrote that this phenomenon might be used for detecting objects, but he did nothing more with this observation; the German inventor Christian Hülsmeyer was the first to use radio waves to detect "the presence of distant metallic objects". In 1904, he demonstrated the feasibility of detecting a ship in dense fog, but not its distance from the transmitter, he obtained a patent for his detection device in April 1904 and a patent for a related amendment for estimating the distance to the ship.
He got a British patent on September 23, 1904 for a full radar system, that he called a telemobiloscope. It operated on a 50 cm wavelength and the pulsed radar signal was created via a spark-gap, his system used the classic antenna setup of horn antenna with parabolic reflector and was presented to German military officials in practical tests in Cologne and Rotterdam harbour but was rejected. In 1915, Robert Watson-Watt used radio technology to provide advance warning to airmen and during the 1920s went on to lead the U. K. research establishment to make many advances using radio techniques, including the probing of the ionosphere and the detection of lightning at long distances. Through his lightning experiments, Watson-Watt became an expert on the use of radio direction finding before turning his inquiry to shortwave transmission. Requiring a suitable receiver for such studies, he told the "new boy" Arnold Frederic Wilkins to conduct an extensive review of available shortwave units. Wilkins would select a General Post Office model after noting its manual's description of a "fading" effect when aircraft flew overhead.
Across the Atlantic in 1922, after placing a transmitter and receiver on opposite sides of the Potomac River, U. S. Navy researchers A. Hoyt Taylor and Leo C. Young discovered that ships passing through the beam path caused the received signal to fade in and out. Taylor submitted a report, suggesting that this phenomenon might be used to detect the presence of ships in low visibility, but the Navy did not continue the work. Eight years Lawrence A. Hyland at the Naval Research Laboratory observed similar fading effects from passing aircraft. Before the Second World War, researchers in the United Kingdom, Germany, Japan, the Netherlands, the Soviet Union, the United States, independently and in great secrecy, developed technologies that led to the modern version of radar. Australia, New Zealand, South Africa followed prewar Great Britain's radar development, Hungary generated its radar technology during the war. In France in 1934, following systematic studies on the split-anode magnetron, the research branch of the Compagnie Générale de Télégraphie Sans Fil headed by Maurice Ponte with Henri Gutton, Sylvain Berline and M. Hugon, began developing an obstacle-locatin
An azimuth thruster is a configuration of marine propellers placed in pods that can be rotated to any horizontal angle, making a rudder unnecessary. These give ships better maneuverability than a fixed rudder system. There are two major variants, based on the location of the motor: Mechanical transmission, which connects a motor inside the ship to the outboard unit by gearing; the motor may be diesel-electric. Depending on the shaft arrangement, mechanical azimuth thrusters are divided into L-drive and Z-drive. An L-drive thruster has a vertical input shaft and a horizontal output shaft with one right-angle gear. A Z-drive thruster has a horizontal input shaft, a vertical shaft in the rotating column and a horizontal output shaft, with two right-angle gears. Electrical transmission, more called pods, where an electric motor is fitted in the pod itself, connected directly to the propeller without gears; the electricity is produced by an onboard engine diesel or gas turbine. Invented in 1955 by Friedrich W. Pleuger and Friedrich Busmann, ABB Group's Azipod was the first product using this technology.
The most powerful podded thrusters in use are the four 21.5 MW Rolls-Royce Mermaid units fitted to Queen Mary 2. Mechanical azimuth thrusters can be fixed retractable or underwater-mountable, they may have fixed pitch propellers or controllable pitch propellers. Fixed installed thrusters are used for tugboats and supply-boats. Retractable thrusters are used as auxiliary propulsion for dynamically positioned vessels and take-home propulsion for military vessels. Underwater-mountable thrusters are used as dynamic positioning propulsion for large vessels such as semi-submersible drilling rigs and drillships. Primary advantages are maneuverability, electrical efficiency, better use of ship space, lower maintenance costs. Ships with azimuth thrusters do not need tugboats to dock, though they may still require tugs to maneuver in difficult places. English inventor Francis Ronalds described what he called a “Propelling Rudder” in 1859 that combined the propulsion and steering mechanisms of a boat in a single apparatus.
The propeller was placed in a frame having an outer profile similar to a rudder and attached to a vertical shaft that allowed the device to rotate in plane while spin was transmitted to the propeller. The modern azimuth thruster using the Z-drive transmission was invented in 1950 by Joseph Becker, the founder of Schottel in Germany, marketed as the Ruderpropeller. Becker was awarded the 2004 Elmer A. Sperry Award for the invention; this kind of propulsion was first patented in 1955 by Pleuger. In the late 1980s, ABB Group developed the Azipod thruster with the motor located in the pod itself. Pleuger rudder Voith-Schneider Saildrive Z-drive Voith Turbo Marine, Voith Radial Propeller Rolls-Royce plc, including videos of operation Azimuth Thrusters Types and Configurations, Thrustmaster Flowserve Thruster - promotional video showing L-drive type azimuth thruster operation
Philadelphia, sometimes known colloquially as Philly, is the largest city in the U. S. state and Commonwealth of Pennsylvania, the sixth-most populous U. S. city, with a 2017 census-estimated population of 1,580,863. Since 1854, the city has been coterminous with Philadelphia County, the most populous county in Pennsylvania and the urban core of the eighth-largest U. S. metropolitan statistical area, with over 6 million residents as of 2017. Philadelphia is the economic and cultural anchor of the greater Delaware Valley, located along the lower Delaware and Schuylkill Rivers, within the Northeast megalopolis; the Delaware Valley's population of 7.2 million ranks it as the eighth-largest combined statistical area in the United States. William Penn, an English Quaker, founded the city in 1682 to serve as capital of the Pennsylvania Colony. Philadelphia played an instrumental role in the American Revolution as a meeting place for the Founding Fathers of the United States, who signed the Declaration of Independence in 1776 at the Second Continental Congress, the Constitution at the Philadelphia Convention of 1787.
Several other key events occurred in Philadelphia during the Revolutionary War including the First Continental Congress, the preservation of the Liberty Bell, the Battle of Germantown, the Siege of Fort Mifflin. Philadelphia was one of the nation's capitals during the revolution, served as temporary U. S. capital while Washington, D. C. was under construction. In the 19th century, Philadelphia became a railroad hub; the city grew from an influx of European immigrants, most of whom came from Ireland and Germany—the three largest reported ancestry groups in the city as of 2015. In the early 20th century, Philadelphia became a prime destination for African Americans during the Great Migration after the Civil War, as well as Puerto Ricans; the city's population doubled from one million to two million people between 1890 and 1950. The Philadelphia area's many universities and colleges make it a top study destination, as the city has evolved into an educational and economic hub. According to the Bureau of Economic Analysis, the Philadelphia area had a gross domestic product of US$445 billion in 2017, the eighth-largest metropolitan economy in the United States.
Philadelphia is the center of economic activity in Pennsylvania and is home to five Fortune 1000 companies. The Philadelphia skyline is expanding, with a market of 81,900 commercial properties in 2016, including several nationally prominent skyscrapers. Philadelphia has more outdoor murals than any other American city. Fairmount Park, when combined with the adjacent Wissahickon Valley Park in the same watershed, is one of the largest contiguous urban park areas in the United States; the city is known for its arts, culture and colonial history, attracting 42 million domestic tourists in 2016 who spent US$6.8 billion, generating an estimated $11 billion in total economic impact in the city and surrounding four counties of Pennsylvania. Philadelphia has emerged as a biotechnology hub. Philadelphia is the birthplace of the United States Marine Corps, is the home of many U. S. firsts, including the first library, medical school, national capital, stock exchange and business school. Philadelphia contains 67 National Historic Landmarks and the World Heritage Site of Independence Hall.
The city became a member of the Organization of World Heritage Cities in 2015, as the first World Heritage City in the United States. Although Philadelphia is undergoing gentrification, the city maintains mitigation strategies to minimize displacement of homeowners in gentrifying neighborhoods. Before Europeans arrived, the Philadelphia area was home to the Lenape Indians in the village of Shackamaxon; the Lenape are a Native American tribe and First Nations band government. They are called Delaware Indians, their historical territory was along the Delaware River watershed, western Long Island, the Lower Hudson Valley. Most Lenape were pushed out of their Delaware homeland during the 18th century by expanding European colonies, exacerbated by losses from intertribal conflicts. Lenape communities were weakened by newly introduced diseases smallpox, violent conflict with Europeans. Iroquois people fought the Lenape. Surviving Lenape moved west into the upper Ohio River basin; the American Revolutionary War and United States' independence pushed them further west.
In the 1860s, the United States government sent most Lenape remaining in the eastern United States to the Indian Territory under the Indian removal policy. In the 21st century, most Lenape reside in Oklahoma, with some communities living in Wisconsin, in their traditional homelands. Europeans came to the Delaware Valley in the early 17th century, with the first settlements founded by the Dutch, who in 1623 built Fort Nassau on the Delaware River opposite the Schuylkill River in what is now Brooklawn, New Jersey; the Dutch considered the entire Delaware River valley to be part of their New Netherland colony. In 1638, Swedish settlers led by renegade Dutch established the colony of New Sweden at Fort Christina and spread out in the valley. In 1644, New Sweden supported the Susquehannocks in their military defeat of the English colony of Maryland. In 1648, the Dutch built Fort Beversreede on the west bank of the Delaware, south of the Schuylkill near the present-day Eastwick neighborhood, to reassert their dominion over the area.
The Swedes responded by building Fort Nya Korsholm, or New Korsholm, named after a town in Finland with a Swedish majority. In 1655, a