Type 052 destroyer
The Type 052 Luhu-class is one of the first modern multi-role guided missile destroyers built by China. There are currently two units in service with the Peoples Liberation Army Navy Surface Force. It was succeeded by the Type 051B, designed by the China Warship Design Institute, both ships were built at Jiangnan Shipyard - No.112 Harbin was the first Luhu destroyer followed by No.113 Qingdao. The chief designer was academician Mr. Pan Jingfu, the class is said to be the first indigenous Chinese warship design approaching modern standards, a significant improvement over the earlier Luda class. The Luhu class made use of foreign technologies that were accessible to the PRC prior to the Tiananmen Square incident of 1989. These included French-made radars and fire-control systems and the General Electric LM2500 gas turbine engines from the US, the Type 052 became the first Chinese destroyer design to use gas turbine engines, and the first equipped with a integrated combat system. Even with incorporation of Western technology, the lack of adequate shipborne air defense systems has had great impact on PLAN operations.
The HQ-7 SAM system is reported to be equipped with 8 ready to fire missiles, the same system is used on the upgraded 051G Luda Destroyer. In spite of the advances, the 052 Luhu-class destroyers still suffer in some such as electronic warfare. The operational capability of the Luhu-class destroyers has been called into question by naval analysts, ship visits in 1997 allowed US Naval officers to board and inspect Luhu Destroyer No.112 Harbin and to take numerous photographs. The Chinese attempted to address problems with the introduction of an improved Luhu design. This follow-on, essentially an enlarged Luhu, features some improved electronics from foreign suppliers as well as more advanced weapons, however, in some cases, the designers appear to have opted for less capable indigenous designs to ease the system integration issues suffered by the Luhu-class destroyers. The PLAN was reportedly unhappy with the design of the Luhai-class destroyers, the second unit had French Thomson-CSF DUBV 23/43 HMS/VDS, which were subsequently replaced by domestic copy SJD-9 sonar system.
The combat data systems for the first unit was ZKJ-3, a Chinese equivalent of the Italian IPN-10 combat data system, ZKJ-3 is developed from the export version of IPN-10, SADOC2. SADOC2 was sold to China in 1985 and it differs from IPN-10 in that it lacks the data link the latter has, incorporation of a domestic data link is the main improvement of Chinese ZKJ-3, making it the Chinese equivalent of IPN-10. These combat data systems were replaced by more advanced follow-on equipment such as ZKJ-4A/B series during upgrades. Experience gained in handling these foreign systems has helped subsequent development of similar Chinese systems, both of the Type 052 destroyers were upgraded in 2011. The four Type 76A guns were replaced by two Type 730 CIWS on top of the helicopter hangar, the Crotale/HHQ-7 short-range SAM may have been replaced by the newer model which provides better interception against sea-skimming AShMs
A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability, the term most commonly refers to a large, crewed vessel. It is used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine. The noun submarine evolved as a form of submarine boat, by naval tradition, submarines are usually referred to as boats rather than as ships. Although experimental submarines had been built before, submarine design took off during the 19th century, Submarines were first widely used during World War I, and now figure in many navies large and small. Civilian uses for submarines include marine science, salvage and facility inspection, Submarines can be modified to perform more specialized functions such as search-and-rescue missions or undersea cable repair. Submarines are used in tourism, and for undersea archaeology, most large submarines consist of a cylindrical body with hemispherical ends and a vertical structure, usually located amidships, which houses communications and sensing devices as well as periscopes.
In modern submarines, this structure is the sail in American usage, a conning tower was a feature of earlier designs, a separate pressure hull above the main body of the boat that allowed the use of shorter periscopes. There is a propeller at the rear, and various hydrodynamic control fins, deep-diving and specialty submarines may deviate significantly from this traditional layout. Submarines use diving planes and change the amount of water, Submarines have one of the widest ranges of types and capabilities of any vessel. Submarines can work at greater depths than are survivable or practical for human divers, modern deep-diving submarines derive from the bathyscaphe, which in turn evolved from the diving bell. In 1578, the English mathematician William Bourne recorded in his book Inventions or Devises one of the first plans for an underwater navigation vehicle and its unclear whether he ever carried out his idea. The first submersible of whose construction there exists reliable information was designed and built in 1620 by Cornelis Drebbel and it was propelled by means of oars.
By the mid-18th century, over a dozen patents for submarines/submersible boats had been granted in England, in 1747, Nathaniel Symons patented and built the first known working example of the use of a ballast tank for submersion. His design used leather bags that could fill with water to submerge the craft, a mechanism was used to twist the water out of the bags and cause the boat to resurface. In 1749, the Gentlemens Magazine reported that a design had initially been proposed by Giovanni Borelli in 1680. By this point of development, further improvement in design stagnated for over a century, until new industrial technologies for propulsion. The first military submarine was the Turtle, a hand-powered acorn-shaped device designed by the American David Bushnell to accommodate a single person and it was the first verified submarine capable of independent underwater operation and movement, and the first to use screws for propulsion
The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers in this system are represented by combinations of letters from the Latin alphabet, Roman numerals, as used today, are based on seven symbols, The use of Roman numerals continued long after the decline of the Roman Empire. The numbers 1 to 10 are usually expressed in Roman numerals as follows, I, II, III, IV, V, VI, VII, VIII, IX, Numbers are formed by combining symbols and adding the values, so II is two and XIII is thirteen. Symbols are placed left to right in order of value. Named after the year of its release,2014 as MMXIV, the year of the games of the XXII Olympic Winter Games The standard forms described above reflect typical modern usage rather than a universally accepted convention. Usage in ancient Rome varied greatly and remained inconsistent in medieval, Roman inscriptions, especially in official contexts, seem to show a preference for additive forms such as IIII and VIIII instead of subtractive forms such as IV and IX.
Both methods appear in documents from the Roman era, even within the same document, double subtractives occur, such as XIIX or even IIXX instead of XVIII. Sometimes V and L are not used, with such as IIIIII. Such variation and inconsistency continued through the period and into modern times. Clock faces that use Roman numerals normally show IIII for four o’clock but IX for nine o’clock, this is far from universal, for example, the clock on the Palace of Westminster in London uses IV. Similarly, at the beginning of the 20th century, different representations of 900 appeared in several inscribed dates. For instance,1910 is shown on Admiralty Arch, London, as MDCCCCX rather than MCMX, although Roman numerals came to be written with letters of the Roman alphabet, they were originally independent symbols. The Etruscans, for example, used
People's Liberation Army Navy Submarine Force
The Peoples Liberation Army Navy Submarine Force is the submarine service of the Peoples Liberation Army Navy. It consists of all types of submarines in operational service organized into three fleets, the North Sea Fleet, the East Sea Fleet, and the South Sea Fleet, currently, PLANSF operates a fleet of 68 submarines which include nuclear as well as conventional submarines. Its surface branch counterpart is the Peoples Liberation Army Navy Surface Force, the PLAN currently operates two classes of ballistic missile submarines, with a further class under development, Type 096 submarine - In development. Type 094 submarine -4 in active service, Type 092 submarine - 1in service Chinas first ballistic missile submarine, Type 092 submarine, was laid down in 1978, launched in 1981 and commissioned by 1983. Its primary weapon is the JL-1 SLBM, with 12 launch tubes, the JL-1 missile was not ready until the first successful test launch of the missile from the Xia in 1988. Previous launch attempts from 1985 had failed, the missiles short range only permits the 092 to launch its missiles against regional targets.
Striking targets far away require the submarine to travel closer to enemy waters. The Type 094 submarine is believed to have influenced by Russian assistance. It features 12 launch tubes for the longer ranged JL-2 missile, the 094 would be permitted to patrol nearer Chinese waters, with the ability to launch its missiles against continental US targets. China was the first Asian country and the 5th globally to design, build. The PLAN understands the value of nuclear submarines and the doctrine surrounding them, the PLAN currently has two types of nuclear-powered attack submarines in service, Type 095 submarine -1 completed to enter service. Type 093 submarine -2 in active service, Type 091 submarine -3 in active service. Nuclear submarines have been envisaged in the PLAN since the 1950s, despite ambition and a long history of development, the acquisition of nuclear submarines has been a difficult process. The Cultural Revolution greatly disrupted nuclear submarine development, the Sino-Soviet split prevented any Soviet assistance in nuclear propulsion, and these propulsion problems have been troublesome to this day.
The first Chinese nuclear-powered submarine was laid down in 1967 but not completed until 1974, the Han-class experienced more than 20 years of development, with the last of the class not being commissioned until 1990. Since their commission the class has gone through major upgrades and numerous refits with the remaining boats having been refitted with new sonars. The Han-class has mostly operated in local waters, but since the 1990s, a Han-class shadowed a US carrier battle group in the mid-1990s, and more recently, operated around Japanese waters, prompting a Japanese task force to chase the submarine out of its territory. A new class of submarine has been in development since the 1980s, little information has emerged about the Type 093 submarine, but it is believed to have some Russian influence
The Kilo class is the NATO reporting name for a naval diesel-electric submarine that is made in Russia. The original version of the vessels were designated Project 877 Paltus in Soviet Union, there is a more advanced version, designated as Improved Kilo-class submarine in the West, and Project 636 Varshavyanka in Russia. These attack submarines are intended for anti-shipping and anti-submarine operations in relatively shallow waters. Original Project 877 boats are equipped with Rubikon MGK-400 sonar system, newer Project 636 boats are equipped with improved MGK-400EM, with MG-519 Arfa upgraded to MG-519EM. The improved sonar systems have reduced the number of operators needed by sharing the same console via automation, anechoic tiles are fitted on casings and fins to absorb the sound waves of active sonar, which results in a reduction and distortion of the return signal. These tiles help attenuate sounds that are emitted from the submarine, the Kilo class was to have been succeeded by the Lada class.
In November 2011, the Russian Navy announced that the Lada class will not enter service because trials with the boat of the new class. Construction of two boats was suspended. On 27 July 2012, the Russian Navy commander-in-chief announced that construction of the Lada-class submarines will resume, one Kilo-class submarine, B-871, was equipped with pump-jet propulsion. The version Kilo 636MV contains a GE2-01 radar and an improved MGK 400E sonar, in this version, the submarine is able to operate in more weather conditions than the original Kilo-class submarines. The first submarine entered service in the Soviet Navy in 1980, as of September 2011,17 vessels were believed to still be in active service with the Russian Navy, while 7 vessels were thought to be in reserve. 40 vessels have been exported to countries, Algeria,2 Original Kilo,4 Improved Kilo. Peoples Republic of China,2 Original Kilo,10 Improved Kilo, india,10 Original Kilo,1 sustained major casualty, – Designated as the Sindhughosh class Poland,1 Original Kilo – ORP Orzeł.
Romania,1 Original Kilo – Delfinul, Russia,22 Original Kilo,6 Improved Kilo +6 Improved Kilo on order for Pacific fleet to be delivered 2019-2021. The government of Venezuela expressed interest in buying 3 Project 636 Kilo-class submarines The government of Indonesia in 2007-2008 planned to acquire at least 2 Kilo-class submarines. In October 2013, the ministry of defence of Indonesia reported the possibility of a grant from the Russian government involving up to ten ex-Russian navy Kilo-class submarines. Army General Moeldoko, Indonesian Armed Forces chief of staff, announced that a team will be sent to Russia last month to inspect the condition of future submarines, the Philippine Navy has shown its interest on the Kilo-class submarine as part of its modernization program. Defense Secretary Delfin Lorenzana said that the country is now evaluating the Russian offer, there are several variants of the Kilo class
JSTOR is a digital library founded in 1995. Originally containing digitized back issues of journals, it now includes books and primary sources. It provides full-text searches of almost 2,000 journals, more than 8,000 institutions in more than 160 countries have access to JSTOR, most access is by subscription, but some older public domain content is freely available to anyone. William G. Bowen, president of Princeton University from 1972 to 1988, JSTOR originally was conceived as a solution to one of the problems faced by libraries, especially research and university libraries, due to the increasing number of academic journals in existence. Most libraries found it prohibitively expensive in terms of cost and space to maintain a collection of journals. By digitizing many journal titles, JSTOR allowed libraries to outsource the storage of journals with the confidence that they would remain available long-term, online access and full-text search ability improved access dramatically. Bowen initially considered using CD-ROMs for distribution, JSTOR was initiated in 1995 at seven different library sites, and originally encompassed ten economics and history journals. JSTOR access improved based on feedback from its sites.
Special software was put in place to make pictures and graphs clear, with the success of this limited project and Kevin Guthrie, then-president of JSTOR, wanted to expand the number of participating journals. They met with representatives of the Royal Society of London and an agreement was made to digitize the Philosophical Transactions of the Royal Society dating from its beginning in 1665, the work of adding these volumes to JSTOR was completed by December 2000. The Andrew W. Mellon Foundation funded JSTOR initially, until January 2009 JSTOR operated as an independent, self-sustaining nonprofit organization with offices in New York City and in Ann Arbor, Michigan. JSTOR content is provided by more than 900 publishers, the database contains more than 1,900 journal titles, in more than 50 disciplines. Each object is identified by an integer value, starting at 1. In addition to the site, the JSTOR labs group operates an open service that allows access to the contents of the archives for the purposes of corpus analysis at its Data for Research service.
This site offers a facility with graphical indication of the article coverage. Users may create focused sets of articles and request a dataset containing word and n-gram frequencies and they are notified when the dataset is ready and may download it in either XML or CSV formats. The service does not offer full-text, although academics may request that from JSTOR, JSTOR Plant Science is available in addition to the main site. The materials on JSTOR Plant Science are contributed through the Global Plants Initiative and are only to JSTOR
Type 052D destroyer
The Type 052D destroyer is a class of guided missile destroyers being deployed by the Chinese Peoples Liberation Army Navy Surface Force. Currently it is being built at two different Chinese ship yards, after the Type 052C destroyer, two new hulls were spotted under construction at Changxingdao-Jiangnan Shipyard in August 2012. According to imagery, they were armed with a new 130 mm main gun, altogether six vessels of this class are now fitting out or under construction, one vessel is on sea trial and four vessels are active. Nearing the completion of the first 12 Type 052D ships, the PLAN will shift production to the newer Type 055 destroyer. The layout of the Type 052D is similar to the earlier Type 052C, the helicopter hangar on the Type 052D is moved to the center, as opposed to being on the left like on the Type 052C. A pair of enclosed boat/raft launching systems similar to that of the Type 054A frigate is added, the Type 517HA VHF radar mast is moved toward the stern of the ship. There are several mounting sites for a new single barrel 30 mm stealthy gun mount that is fully automated.
Due to the angle of superstructure slope, more space was made available for the active phased array radar. It is believed that this new APAR is a development of Type 348 Radar mounted on the Type 052C, one of the main differences is that the size of the new array is larger, so presumably there are more transceivers on each array. The VLS system on Type 052D differs from that on Type 052C, the circular-shaped VLS system on Type 052C is replaced by the VLS with rectangular cells on Type 052D. Moreover, this box-like VLS looks different from the VLS system of Type 054A, photos show that Type 052Ds VLS system does not contain the shared exhaust vents between the rows of launching tubes, which is the common feature of Type 054As VLS. Instead, the VLS on Type 052D looks more similar to the American Mk 41 VLS and it is reported that chief designers of Chinese CCL VLS included Professor Yuan Zenfeng, Professor Miao Peiyun and professor Liang Shijie. Similar to U. S. Navys MK41, a launching module includes 8 launching tubes, each launching model has a launching control unit, which can simultaneously launch up to 4 missiles of different kind.
The launching control unit must have built-in test/diagnostic function, another improvement of the Type 052D is that the Type H/PJ87 100mm gun on the Type 052C is replaced by a new single barrel 130 mm gun, designated as the Type H/PJ38 CIWS. Based on photos, Type 052D destroyers starting with the 9th hull will be fitted with the H/PJ-11 CIWS instead of the previous smaller H/PJ-12 currently fitted on existing hulls. Compared to the seven-barreled H/PJ-12, the H/PJ-11 is an eleven-barreled 30 mm CIWS that was so far exclusively fitted on the Liaoning aircraft carrier and the latest few Type 054A frigates. Designated as JSIDLS, this is the Chinese equivalent of Link 16, more than 300 establishments and 8000 people were involved in the development of JSIDLS, and it won State Science and Technology Prizes after completion. Chinas state-run media informally designate the Type 052D as Chinese Aegis, the new destroyer is equipped with a flat-array AESA radar, a 64-cell VLS and modern long-range anti-air missiles
Naval War College Review
The Naval War College Review is a quarterly peer-reviewed academic journal published by the United States Navys Naval War College. It covers public policy matters of interest to the services and was established in 1948. In a separate, but related initiative in 1948, the Chief of Naval Personnel, in response to this suggestion and with further authorization from the Navy Department, Spruance initiated publication of a periodical. Initially entitled Information Service for Officers, it first appeared in October 1948 with a lecture by Vice Admiral Robert B, carneys Naval War College lecture, Logistical Planning for War, as its lead article. It was initially classified as Restricted and issued only to officers in the grades of lieutenant commander, major. The first issue had a circulation of 3,000 copies, in its fifth year of publication, Information Service for Officers had reached a circulation of 6,000 copies and was being distributed to major commands. Further changes in policy that allowed the journal to publish articles by civilian academics did not occur until the editorship of Commander Robert M.
From that point forward, the journal had a range of submitted articles. The following persons have been editors-in-chief, Summer 1967-March 1970, Colonel T. C, caswell, Jr. Nov/Dec 1981-Sept/Oct 1985, Frank Uhlig, Jr. Nov/Dec 1985-Summer 1988, Robert M. Laske Autumn 1988-Autumn 1993, Frank Uhlig, Jr. Grassey Spring 2003–Summer/Autumn 2004, Catherine McArdle Kelleher Winter 2005-Autumn 2005, Peter Dombrowski Winter 2006-present, Carnes Lord Official website
Sonar is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels. Two types of technology share the name sonar, passive sonar is essentially listening for the sound made by vessels, active sonar is emitting pulses of sounds, Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of targets in the water. Acoustic location in air was used before the introduction of radar, Sonar may be used in air for robot navigation, and SODAR is used for atmospheric investigations. The term sonar is used for the equipment used to generate. The acoustic frequencies used in sonar systems vary from low to extremely high. The study of sound is known as underwater acoustics or hydroacoustics. In the 19th century a bell was used as an ancillary to lighthouses to provide warning of hazards. The use of sound to locate underwater in the same way as bats use sound for aerial navigation seems to have been prompted by the Titanic disaster of 1912. S.
Revenue Cutter Miami on the Grand Banks off Newfoundland Canada, in that test, Fessenden demonstrated depth sounding, underwater communications and echo ranging. The so-called Fessenden oscillator, at ca.500 Hz frequency, was unable to determine the bearing of the due to the 3 metre wavelength. The ten Montreal-built British H class submarines launched in 1915 were equipped with a Fessenden oscillator, during World War I the need to detect submarines prompted more research into the use of sound. Although piezoelectric and magnetostrictive transducers superseded the electrostatic transducers they used, lightweight sound-sensitive plastic film and fibre optics have been used for hydrophones, while Terfenol-D and PMN have been developed for projectors. By 1918, both France and Britain had built prototype active systems, the British tested their ASDIC on HMS Antrim in 1920, and started production in 1922. The 6th Destroyer Flotilla had ASDIC-equipped vessels in 1923, an anti-submarine school, HMS Osprey, and a training flotilla of four vessels were established on Portland in 1924.
The US Sonar QB set arrived in 1931, by the outbreak of World War II, the Royal Navy had five sets for different surface ship classes, and others for submarines, incorporated into a complete anti-submarine attack system. The effectiveness of early ASDIC was hamstrung by the use of the charge as an anti-submarine weapon. This required a vessel to pass over a submerged contact before dropping charges over the stern. The hunter was effectively firing blind, during which time a commander could take evasive action
Type 039A submarine
The Government of Pakistan approved the construction of new next-generation AIP submarines for the Pakistani Navy. Eight boats have been ordered,4 of which will be built in China, Pakistani Navy officials have confirmed that air independent propulsion will be implemented on the submarines. The type of AIP system has not been disclosed, in mid-2006, the Navy announced its requirement of three new fast-attack submarines to replace the two Agosta-70 submarines and expand its submarine fleet. The French defence consortium, the DCN, offered its latest export design— the Marlin class submarine— which uses technology from the Barracuda nuclear attack submarine, the Navy chose the Type 214 submarine from Germanys HDW. In 2009, it was reported that the Navy had canceled its plans with HDW, since 2011 the Pakistan Navy had been negotiating with China for six submarines equipped with air-independent propulsion systems. In April 2015 the Government of Pakistan reportedly announced that it had approved the procurement of eight such submarines, list of active Pakistan Navy ships Air-independent propulsion