The Nordenfelt gun was a multiple barrel organ gun that had a row of up to twelve barrels. It was fired by pulling a lever back and forth and ammunition was gravity fed through chutes for each barrel, it was produced in a number of different calibres from rifle up to 25 mm. Larger calibres were used, but for these calibres the design permitted rapid manual loading rather than true automatic fire; this article covers the anti-personnel rifle-calibre gun. The weapon was designed by Helge Palmcrantz, he created a mechanism to load and fire a multiple barreled gun by moving a single lever backwards and forwards. It was patented in 1873. Production of the weapon was funded by a Swedish steel producer and banker named Thorsten Nordenfelt, working in London; the name of the weapon was changed to the Nordenfelt gun. A plant producing the weapon was set up in England, with sales offices in London, long demonstrations were conducted at several exhibitions; the weapon was adopted by the British Royal Navy, as an addition to their Gardner guns.
During a demonstration held at Portsmouth a ten-barrelled version of the weapon, firing rifle calibre cartridges fired 3,000 rounds of ammunition in 3 minutes and 3 seconds without stoppage or failure. However, with the development of the Maxim gun the weapon was outclassed. Nordenfelt merged in 1888 with the Maxim Gun Company to become Maxim Nordenfelt Guns and Ammunition Company Limited. At least one Nordenfelt was re-activated for the 1966 film Khartoum and can be seen firing in the river boat sequence. Argentina Australia Austria-Hungary Brazil Chile China France Philippine Republic Portugal Spain Turkey United Kingdom United States Uruguay 1-inch Nordenfelt gun Gardner gun: similar hand-cranked machine gun George M. Chinn, The Machine Gun. History and Development of Manual and Airborne Repeating Weapons, Volume I, Washington, 1951. C. Sleeman, "The Development of Machine Guns", The North American review, Volume 139, Issue 335, October 1884 Ellis, John. 1975. The Social History of the Machine Gun.
New York: Pantheon Books. Handbook for Gardner and Nordenfelt rifle calibre machine guns. 1889, 1891 Handbook of the 0.45 inch 5 barrel Nordenfelt guns, marks I and II, 1888 at State Library of Victoria Handbook of the 0.45 inch, 5-barrel Nordenfelt guns, Marks I and II 1894 at State Library of Victoria Handbook for the 0.303" Nordenfelt 3-barrel, Gardner 2-barrel, converted from 0.4 and 0.45" M. H. chamber: mounted on carriages, machine gun and carriage, machine gun. London: H. M. S. O. 1900 Animations and technical descriptions of 2, 4 and 5-barrel Machine Guns Nordenfelt Video—video of Nordenfelt machine gun firing video of mechanism
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1868 until 1945, when it was dissolved following Japan's surrender in World War II. The Japan Maritime Self-Defense Force was formed after the dissolution of the IJN; the Imperial Japanese Navy was the third largest navy in the world by 1920, behind the Royal Navy and the United States Navy. It was supported by the Imperial Japanese Navy Air Service for aircraft and airstrike operation from the fleet, it was the primary opponent of the Western Allies in the Pacific War. The origins of the Imperial Japanese Navy go back to early interactions with nations on the Asian continent, beginning in the early medieval period and reaching a peak of activity during the 16th and 17th centuries at a time of cultural exchange with European powers during the Age of Discovery. After two centuries of stagnation during the country's ensuing seclusion policy under the shōgun of the Edo period, Japan's navy was comparatively backward when the country was forced open to trade by American intervention in 1854.
This led to the Meiji Restoration. Accompanying the re-ascendance of the Emperor came a period of frantic modernization and industrialization; the navy had several successes, sometimes against much more powerful enemies such as in the Sino-Japanese War and the Russo-Japanese War, before being destroyed in World War II. Japan has a long history of naval interaction with the Asian continent, involving transportation of troops between Korea and Japan, starting at least with the beginning of the Kofun period in the 3rd century. Following the attempts at Mongol invasions of Japan by Kubilai Khan in 1274 and 1281, Japanese wakō became active in plundering the coast of China. Japan undertook major naval building efforts in the 16th century, during the Warring States period, when feudal rulers vying for supremacy built vast coastal navies of several hundred ships. Around that time Japan may have developed one of the first ironclad warships when Oda Nobunaga, a daimyō, had six iron-covered Oatakebune made in 1576.
In 1588 Toyotomi Hideyoshi issued a ban on Wakō piracy. Japan built her first large ocean-going warships in the beginning of the 17th century, following contacts with the Western nations during the Nanban trade period. In 1613, the daimyō of Sendai, in agreement with the Tokugawa Bakufu, built Date Maru, a 500-ton galleon-type ship that transported the Japanese embassy of Hasekura Tsunenaga to the Americas, which continued to Europe. From 1604 the Bakufu commissioned about 350 Red seal ships armed and incorporating some Western technologies for Southeast Asian trade. For more than 200 years, beginning in the 1640s, the Japanese policy of seclusion forbade contacts with the outside world and prohibited the construction of ocean-going ships on pain of death. Contacts were maintained, with the Dutch through the port of Nagasaki, the Chinese through Nagasaki and the Ryukyus and Korea through intermediaries with Tsushima; the study of Western sciences, called "rangaku" through the Dutch enclave of Dejima in Nagasaki led to the transfer of knowledge related to the Western technological and scientific revolution which allowed Japan to remain aware of naval sciences, such as cartography and mechanical sciences.
Seclusion, led to loss of any naval and maritime traditions the nation possessed. Apart from Dutch trade ships no other Western vessels were allowed to enter Japanese ports. A notable exception was during the Napoleonic wars. Frictions with foreign ships, started from the beginning of the 19th century; the Nagasaki Harbour Incident involving HMS Phaeton in 1808, other subsequent incidents in the following decades, led the shogunate to enact an Edict to Repel Foreign Vessels. Western ships, which were increasing their presence around Japan due to whaling and the trade with China, began to challenge the seclusion policy; the Morrison Incident in 1837 and news of China's defeat during the Opium War led the shogunate to repeal the law to execute foreigners, instead to adopt the Order for the Provision of Firewood and Water. The shogunate began to strengthen the nation's coastal defenses. Many Japanese realized that traditional ways would not be sufficient to repel further intrusions, western knowledge was utilized through the Dutch at Dejima to reinforce Japan's capability to repel the foreigners.
Numerous attempts to open Japan ended in failure, in part to Japanese resistance, until the early 1850s. During 1853 and 1854, American warships under the command of Commodore Matthew Perry entered Edo Bay and made demonstrations of force requesting trade negotiations. After two hundred years of seclusion, the 1854 Convention of Kanagawa led to the opening of Japan to international trade and interaction; this was soon followed by treaties with other powers. As soon as Japan opened up to foreign influences, the Tokugawa shogunate recognized the vulnerability of the country from the sea and initiated an active policy of assimilation and adoption of Western naval technologies. In 1855, with Dutch assistance, the shogunate acquired its first steam warship, Kankō Maru, began using it for training, establishing a Naval Training Center at Nagasaki. Samurai such as the future Admiral Enomoto Takeaki were sent by the shogunate to study in the Netherlands for several years. In 1859 the
A boiler is a closed vessel in which fluid is heated. The fluid does not boil; the heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central heating, boiler-based power generation and sanitation. In a fossil fuel power plant using a steam cycle for power generation, the primary heat source will be combustion of coal, oil, or natural gas. In some cases byproduct fuel such as the carbon-monoxide rich offgasses of a coke battery can be burned to heat a boiler. In a nuclear power plant, boilers called steam generators are heated by the heat produced by nuclear fission. Where a large volume of hot gas is available from some process, a heat recovery steam generator or recovery boiler can use the heat to produce steam, with little or no extra fuel consumed. In all cases the combustion product waste gases are separate from the working fluid of the steam cycle, making these systems examples of External combustion engines; the pressure vessel of a boiler is made of steel, or of wrought iron.
Stainless steel of the austenitic types, is not used in wetted parts of boilers due to corrosion and stress corrosion cracking. However, ferritic stainless steel is used in superheater sections that will not be exposed to boiling water, electrically-heated stainless steel shell boilers are allowed under the European "Pressure Equipment Directive" for production of steam for sterilizers and disinfectors. In live steam models, copper or brass is used because it is more fabricated in smaller size boilers. Copper was used for fireboxes, because of its better formability and higher thermal conductivity. For much of the Victorian "age of steam", the only material used for boilermaking was the highest grade of wrought iron, with assembly by riveting; this iron was obtained from specialist ironworks, such as those in the Cleator Moor area, noted for the high quality of their rolled plate, suitable for use in critical applications such as high-pressure boilers. In the 20th century, design practice moved towards the use of steel, with welded construction, stronger and cheaper, can be fabricated more and with less labour.
Wrought iron boilers corrode far more than their modern-day steel counterparts, are less susceptible to localized pitting and stress-corrosion. That makes the longevity of older wrought-iron boilers far superior to that of welded steel boilers. Cast iron may be used for the heating vessel of domestic water heaters. Although such heaters are termed "boilers" in some countries, their purpose is to produce hot water, not steam, so they run at low pressure and try to avoid boiling; the brittleness of cast iron makes it impractical for high-pressure steam boilers. The source of heat for a boiler is combustion of any of several fuels, such as wood, oil, or natural gas. Electric steam boilers use resistance- or immersion-type heating elements. Nuclear fission is used as a heat source for generating steam, either directly or, in most cases, in specialised heat exchangers called "steam generators". Heat recovery steam generators use. There are two methods to measure the boiler efficiency: Direct method Indirect methodDirect method: Direct method of boiler efficiency test is more usable or more common.
Boiler efficiency = power out / power in = / * 100%Q = rate of steam flow in kg/h Hg = enthalpy of saturated steam in kcal/kg Hf = enthalpy of feed water in kcal/kg q = rate of fuel use in kg/h GCV = gross calorific value in kcal/kg Indirect method: To measure the boiler efficiency in indirect method, we need a following parameter like: Ultimate analysis of fuel Percentage of O2 or CO2 at flue gas Flue gas temperature at outlet Ambient temperature in deg c and humidity of air in kg/kg GCV of fuel in kcal/kg Ash percentage in combustible fuel GCV of ash in kcal/kg Boilers can be classified into the following configurations: Pot boiler or Haycock boiler/Haystack boiler: A primitive "kettle" where a fire heats a filled water container from below. 18th century Haycock boilers produced and stored large volumes of low-pressure steam hardly above that of the atmosphere. These could burn wood or most coal. Efficiency was low. Flued boiler with one or two large flues—an early type or forerunner of fire-tube boiler.
Fire-tube boiler: Here, water fills a boiler barrel with a small volume left above to accommodate the steam. This is the type of boiler used in nearly all steam locomotives; the heat source is inside a furnace or firebox that has to be kept permanently surrounded by the water in order to maintain the temperature of the heating surface below the boiling point. The furnace can be situated at one end of a fire-tube which lengthens the path of the hot gases, thus augmenting the heating surface which can be further increased by making the gases reverse direction through a second parallel tube or a bundle of multiple tubes. In case of a locomotive-type boiler, a boiler
The Pacific Ocean is the largest and deepest of Earth's oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bounded by Asia and Australia in the west and the Americas in the east. At 165,250,000 square kilometers in area, this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth's water surface and about one-third of its total surface area, making it larger than all of Earth's land area combined; the centers of both the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean. The equator subdivides it into the North Pacific Ocean and South Pacific Ocean, with two exceptions: the Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific, its mean depth is 4,000 meters. The Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 meters; the western Pacific has many peripheral seas. Though the peoples of Asia and Oceania have traveled the Pacific Ocean since prehistoric times, the eastern Pacific was first sighted by Europeans in the early 16th century when Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and discovered the great "southern sea" which he named Mar del Sur.
The ocean's current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favorable winds on reaching the ocean. He called it Mar Pacífico, which in both Portuguese and Spanish means "peaceful sea". Important human migrations occurred in the Pacific in prehistoric times. About 3000 BC, the Austronesian peoples on the island of Taiwan mastered the art of long-distance canoe travel and spread themselves and their languages south to the Philippines and maritime Southeast Asia. Long-distance trade developed all along the coast from Mozambique to Japan. Trade, therefore knowledge, extended to the Indonesian islands but not Australia. By at least 878 when there was a significant Islamic settlement in Canton much of this trade was controlled by Arabs or Muslims. In 219 BC Xu Fu sailed out into the Pacific searching for the elixir of immortality. From 1404 to 1433 Zheng He led expeditions into the Indian Ocean; the first contact of European navigators with the western edge of the Pacific Ocean was made by the Portuguese expeditions of António de Abreu and Francisco Serrão, via the Lesser Sunda Islands, to the Maluku Islands, in 1512, with Jorge Álvares's expedition to southern China in 1513, both ordered by Afonso de Albuquerque from Malacca.
The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and reached a new ocean. He named it Mar del Sur because the ocean was to the south of the coast of the isthmus where he first observed the Pacific. In 1519, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Spanish expedition to the Spice Islands that would result in the first world circumnavigation. Magellan called the ocean Pacífico because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters; the ocean was called the Sea of Magellan in his honor until the eighteenth century. Although Magellan himself died in the Philippines in 1521, Spanish Basque navigator Juan Sebastián Elcano led the remains of the expedition back to Spain across the Indian Ocean and round the Cape of Good Hope, completing the first world circumnavigation in a single expedition in 1522. Sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, Papua New Guinea.
In 1542–43 the Portuguese reached Japan. In 1564, five Spanish ships carrying 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi, sailed to the Philippines and Mariana Islands. For the remainder of the 16th century, Spanish influence was paramount, with ships sailing from Mexico and Peru across the Pacific Ocean to the Philippines via Guam, establishing the Spanish East Indies; the Manila galleons operated for two and a half centuries, linking Manila and Acapulco, in one of the longest trade routes in history. Spanish expeditions discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, the Admiralty Islands in the South Pacific. In the quest for Terra Australis, Spanish explorations in the 17th century, such as the expedition led by the Portuguese navigator Pedro Fernandes de Queirós, discovered the Pitcairn and Vanuatu archipelagos, sailed the Torres Strait between Australia and New Guinea, named after navigator Luís Vaz de Torres. Dutch explorers, sailing around southern Africa engaged in discovery and trade.
In the 16th and 17th centuries Spain considered the Pacific Ocean a mare clausum—a sea closed to other naval powers. As the only known entrance from the Atlantic, the Strait of Magellan was at times patrolled by fleets sent to prevent entrance of non-Spanish ships. On the western side of the Pacific Ocean the Dutch threatened the Spanish Philippines; the 18th cen
Yokosuka Naval Arsenal
Yokosuka Naval Arsenal was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy, was located at Yokosuka, Kanagawa prefecture on Tokyo Bay, south of Yokohama. In 1866, the Tokugawa shogunate government established the Yokosuka Seisakusho, a military arsenal and naval base, with the help of foreign engineers, including the French naval architect Léonce Verny; the new facility was intended to produce modern, western-style warships and equipment for the Tokugawa navy. The construction of the arsenal was an important first step for the modernization of Japan's industry. Modern buildings, an aqueduct, brick factories, technical schools to train Japanese technicians were established. After the Boshin War and the Meiji Restoration, the new Meiji government took over control of the facility in 1871, renaming it the Yokosuka Zosenjo; the first dry dock was opened in 1871, is still in operation today. Japan's first domestically produced warship, was completed the same year.
The Yokosuka Naval District was established at Yokosuka, Kanagawa in 1884, as the first of the naval districts responsible for the defense of the Japanese home islands, the Yokosuka Shipyards was renamed the Yokosuka Naval Arsenal in 1903. Japan had purchased five submarines from the American Electric Boat Company during the Russo-Japanese War of 1904–1905; these Holland Type VII submarines were built by Arthur Leopold Busch as he traveled to Japan during this time. Mr. Busch was a naval architect and shipbuilder who represented the newly organized company now located at the Quincy Massachusett's shipyard known as the Fore River Ship and Engine Company; these first five submarines became Japan's initial entry into the theater of underwater warfare that began nearly the same time as the outbreak of the war. Another representative of Electric Boat, Frank Cable, an electrician working for Isaac L. Rice's company trained two Japanese crews in the operation of such craft. Arthur Busch was the man responsible for building the United States Navy's first submarine some five or so years before this time for the Holland Torpedo Boat Company.
This was America's first commissioned craft type. Two additional Holland designed submarines were built for Japan by 1906 "under contract" and a licensing "agreement" with Holland's company back in 1905; these pioneering submarines progressively got larger and larger as time went on, climaxing by the end of the Cold War. In 1909, Japan's first domestically designed and produced battleship, Satsuma was launched. Yokosuka became one of the main shipyards of the Imperial Japanese Navy in the 20th century, building numerous battleships such as Yamashiro, aircraft carriers such as Hiryu and Shokaku. Naval aircraft were designed at the nearby Yokosuka Naval Air Technical Arsenal. During the Pacific War, the Yokosuka Naval Arsenal was attacked by one bomber during the Doolittle Raid on 18 April 1942 and by a large force of carrier aircraft during the Attack on Yokosuka on 18 July 1945; the facilities were seized by the Allied forces at the end of World War II, on 15 October 1945 the Yokosuka Naval Arsenal was abolished.
However, the facilities continued to be used in the post-World War II period, by the United States Navy as the Yokosuka Ship Repair Facility and its former property is now under the control of the United States Fleet Activities Yokosuka. A steam hammer from the former Yokosuka Naval Arsenal is on display at the Verny Commemorative Museum in Yokosuka. Satsuma, Satsuma-class semi-dreadnought Yamashiro, Fusō-class battleship Owari, Kii-class battleship Kurama, Ibuki-class armoured cruiser Hiei, Kongō-class battlecruiser Amagi, Amagi-class battlecruiser Fleet carrier Hiryū Shōkaku, Shōkaku-class fleet carrier Unryū, Unryū-class fleet carrier Myōkō, Myōkō-class Heavy cruiser Suzuya, Mogami-class Heavy cruiser Tenryū, Tenryū-class Light cruiser Noshiro, Agano-class Light cruiser Shōhō, Zuihō-class Light carrier Converted carrier Ryūhō Harusame-class: 4 ships Kamikaze-class: 8 ships Matsu/Tachibana-class: 26 ships Type B: 9 ships Type D: 6 ships Kaidai: 6 ships Kaichū: 5 ships Jansen, Marius B..
The Making of Modern Japan. Harvard University Press. ISBN 0-674-00991-6. ISBN 9780674003347. Yokosuka, Base of an Empire. Presidio Press. ISBN 0-89141-088-0. Teratani, Takeaki. Kindai Nihon no zosen to kaigun: Yokohama, Yokosuka no kaijishi. Seizando Shoten. ISBN 4-425-30131-5
Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for either a source of parts, which can be sold for re-use, or for the extraction of raw materials, chiefly scrap. It may be known as ship dismantling, ship cracking, or ship recycling. Modern ships have a lifespan of 25 to 30 years before corrosion, metal fatigue and a lack of parts render them uneconomical to run. Ship breaking allows the materials from the ship steel, to be recycled and made into new products; this reduces energy use in the steelmaking process. Equipment on board the vessel can be reused. While ship breaking is sustainable, there are concerns about the use of poorer countries without stringent environmental legislation, it is considered one of the world's most dangerous industries and labour-intensive. In 2012 1,250 ocean ships were broken down, their average age was 26 years. In 2013, the world total of demolished ships amounted to 29,052,000 tonnes, 92% of which were demolished in Asia.
India, Bangladesh and Pakistan have the highest market share and are global centres of ship breaking, with Chittagong Ship Breaking Yard in Bangladesh, Alang in India and Gadani in Pakistan being the largest ships' graveyards in the world. The largest sources of ships are states of China and Germany although there is a greater variation in the source of carriers versus their disposal; the ship breaking yards of India, Bangladesh and Pakistan employ 225,000 workers as well as providing a large number of indirect jobs. In Bangladesh, the recycled steel covers 20% of the country's needs and in India it is 10%; as an alternative to ship breaking, ships may be sunk to create artificial reefs after legally-mandated removal of hazardous materials, or sunk in deep ocean waters. Storage is a viable temporary option, whether on land or afloat, though all ships will be scrapped, sunk, or preserved for museums. Wooden-hulled ships were set on fire or'conveniently sunk'. In Tudor times, ships were dismantled and the timber re-used.
This procedure was no longer applicable with the advent of metal-hulled boats. The navy vessel HMS Temeraire had her masts and guns removed and her crew paid off, she was sold by Dutch auction on 16 August 1838 to John Beatson, a shipbreaker based at Rotherhithe for £5,530. Beatson was faced with the task of transporting the ship 55 miles from Sheerness to Rotherhithe, the largest ship to have attempted this voyage. To accomplish this he hired two steam tugs from the Thames Steam Towing Company and employed a Rotherhithe pilot named William Scott and twenty five men to sail her up the Thames, at a cost of £58; the shipbreakers undertook a thorough dismantling, removing all the copper sheathing, rudder pintles and gudgeons, copper bolts and other fastenings to be sold back to the Admiralty. The timber was sold to house builders and shipyard owners, though some was retained for working into specialist commemorative furniture; the ship's final voyage was immortalised by William Turner's painting The Fighting ‘Temeraire’, Tugged to her Last Berth to be Broken Up, 1838.
In 1880, Denny Brothers of Dumbarton used scrap maritime steel in their shipbuilding. Many other nations began to purchase British ships for scrap by the late 19th century, including Germany, the Netherlands and Japan; the Italian industry started in 1892, the Japanese after an 1896 law had been passed to subsidise native shipbuilding. After being damaged or involved in a disaster, liner operators did not want the name of the broken ship to tarnish the brand of their passenger services; the final voyage of many Victorian ships was with the final letter of their name chipped off. In the 1930s, it became cheaper to run her ashore as opposed to using a dry dock; the ship would have to run ashore at full speed. Dismantling operations required a 10 feet rise of close proximity to a steel-works. Electric shears, a wrecking ball and oxy-acetylene torches were used; the technique of the time is identical to that of developing countries today. Thos W Ward Ltd. one of the largest breakers in the United Kingdom in the 1930s, would recondition and sell all furniture and machinery.
Many historical artifacts were sold at public auctions: the Cunarder Mauretania received high bids for her fittings worldwide. However with obsolete technology, any weapons and military information were removed; until the late 20th century, ship breaking took place in port cities of industrialized countries such as the United Kingdom and the United States. Those dismantlers that still remain in the United States work on government surplus vessels. In the mid 20th century, low-cost East Asian countries began to dominate ship breaking, with countries such as Japan Korea and Taiwan and China increasing their world share. For example, in 1977 Taiwan dominated the industry with more than half the market share, followed by Spain and Pakistan. Bangladesh had no capacity at all. However, the sector is volatile and fluctuates wildly, Taiwan processed just 2 ships 13 years as wages across East Asia rose. In 1960, after a severe cyclone, the Greek ship M D Alpine was stranded on the shores of Sitakunda, Chittagong.
It could not be re-floated and so remained there for several years. In 1965, the in East Pakistan, Chittagong Steel House bought the ship and had it scrapped, it took years to scrap the vessel. Until 1980 the Gadani ship-breaking yard of Pakistan was the largest ship-breaking yard in the world. Tightening environmental regulations resulted in increased costs of hazardo
The displacement or displacement tonnage of a ship is its weight based on the amount of water its hull displaces at varying loads. It is measured indirectly using Archimedes' principle by first calculating the volume of water displaced by the ship converting that value into weight displaced. Traditionally, various measurement rules have been in use. Today, metric tonnes are more used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed to its maximum load. Numerous specific terms are detailed below. Ship displacement should not be confused with measurements of volume or capacity used for commercial vessels, such as net tonnage, gross tonnage, or deadweight tonnage; the process of determining a vessel's displacement begins with measuring its draft This is accomplished by means of its "draft marks". A merchant vessel has three matching sets: one mark each on the port and starboard sides forward and astern; these marks allow a ship's displacement to be determined to an accuracy of 0.5%.
The draft observed at each set of marks is averaged to find a mean draft. The ship's hydrostatic tables show the corresponding volume displaced. To calculate the weight of the displaced water, it is necessary to know its density. Seawater is more dense than fresh water; the density of water varies with temperature. Devices akin to slide rules have been available, it is done today with computers. Displacement is measured in units of tonnes or long tons. There are terms for the displacement of a vessel under specified conditions: Loaded displacement is the weight of the ship including cargo, fuel, stores and such other items necessary for use on a voyage; these bring the ship down to its "load draft", colloquially known as the "waterline". Full load displacement and loaded displacement have identical definitions. Full load is defined as the displacement of a vessel when floating at its greatest allowable draft as established by a classification society. Warships have arbitrary full load condition established.
Deep load condition means stores, with most available fuel capacity used. Light displacement is defined as the weight of the ship excluding cargo, water, stores, crew, but with water in boilers to steaming level. Normal displacement is the ship's displacement "with all outfit, two-thirds supply of stores, etc. on board." Standard displacement known as "Washington displacement", is a specific term defined by the Washington Naval Treaty of 1922. It is the displacement of the ship complete manned and equipped ready for sea, including all armament and ammunition, outfit and fresh water for crew, miscellaneous stores, implements of every description that are intended to be carried in war, but without fuel or reserve boiler feed water on board. Naval architecture Hull Hydrodynamics Tonnage Dear, I. C. B.. Oxford Companion to Ships and the Sea. Oxford: Oxford University Press. ISBN 0-19-920568-X. George, William E.. Stability & Trim for the Ship's Officer. Centreville, Md: Cornell Maritime Press. ISBN 0-87033-564-2.
Hayler, William B.. American Merchant Seaman's Manual. Cambridge, Md: Cornell Maritime Press. ISBN 0-87033-549-9.. Turpin, Edward A.. Merchant Marine Officers' Handbook. Centreville, MD: Cornell Maritime Press. ISBN 0-87033-056-X. Navy Department. "Nomenclature of Naval Vessels". History.navy.mil. United States Navy. Retrieved 2008-03-24. Military Sealift Command. "Definitions and Equivalents". MSC Ship Inventory. United States Navy. Retrieved 2008-03-24. MLCPAC Naval Engineering Division. "Trim and Stability Information for Drydocking Calculations". United States Coast Guard. Retrieved 2008-03-24. United States of America. "Conference on the Limitation of Armament, 1922". Papers Relating to the Foreign Relations of the United States: 1922. 1. Pp. 247–266. United States Naval Institute. Proceedings of the United States Naval Institute. United States Naval Institute. Retrieved 2008-03-24