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115-520: The museum originates from the St. Petersburg Model Chamber, used to store models and drawings related to shipbuilding . The Model Chamber was first mentioned in records on 24 January 1709, the date now used as the birthday of the museum. The Model Chamber's collection became the basis for a "Maritime Museum", which was created in 1805. In August 1939 the Central Naval Museum was relocated to

230-434: A body-centered cubic (bcc) crystal structure . As it cools further to 1394 °C, it changes to its γ-iron allotrope, a face-centered cubic (fcc) crystal structure, or austenite . At 912 °C and below, the crystal structure again becomes the bcc α-iron allotrope. The physical properties of iron at very high pressures and temperatures have also been studied extensively, because of their relevance to theories about

345-430: A nuclear spin (− 1 ⁄ 2 ). The nuclide Fe theoretically can undergo double electron capture to Cr, but the process has never been observed and only a lower limit on the half-life of 4.4×10 years has been established. Fe is an extinct radionuclide of long half-life (2.6 million years). It is not found on Earth, but its ultimate decay product is its granddaughter, the stable nuclide Ni . Much of

460-615: A solar barque . Early Egyptians also knew how to fasten the planks of this ship together with mortise and tenon joints. The oldest known tidal dock in the world was built around 2500 BC during the Harappan civilisation at Lothal near the present day Mangrol harbour on the Gujarat coast in India . Other ports were probably at Balakot and Dwarka . However, it is probable that many small-scale ports, and not massive ports, were used for

575-499: A supernova for their formation, involving rapid neutron capture by starting Fe nuclei. In the far future of the universe, assuming that proton decay does not occur, cold fusion occurring via quantum tunnelling would cause the light nuclei in ordinary matter to fuse into Fe nuclei. Fission and alpha-particle emission would then make heavy nuclei decay into iron, converting all stellar-mass objects to cold spheres of pure iron. Iron's abundance in rocky planets like Earth

690-426: A broad beam and heavily curved at both ends. Another important ship type was the galley, which was constructed with both sails and oars. The first extant treatise on shipbuilding was written c.  1436 by Michael of Rhodes, a man who began his career as an oarsman on a Venetian galley in 1401 and worked his way up into officer positions. He wrote and illustrated a book that contains a treatise on shipbuilding,

805-410: A curved, progressive joint could not be achieved. One study finds that there were considerable improvements in ship speed from 1750 to 1850: "we find that average sailing speeds of British ships in moderate to strong winds rose by nearly a third. Driving this steady progress seems to be the continuous evolution of sails and rigging, and improved hulls that allowed a greater area of sail to be set safely in

920-454: A distorted sodium chloride structure. The binary ferrous and ferric halides are well-known. The ferrous halides typically arise from treating iron metal with the corresponding hydrohalic acid to give the corresponding hydrated salts. Iron reacts with fluorine, chlorine, and bromine to give the corresponding ferric halides, ferric chloride being the most common. Ferric iodide is an exception, being thermodynamically unstable due to

1035-407: A fore and aft sail on the mizzen. Ship-building then saw a steady improvement in design techniques and introduction of new materials. Iron was used for more than fastenings ( nails and bolts ) as structural components such as iron knees were introduced, with examples existing in the mid-18th century and from the mid-19th century onwards. This was partly led by the shortage of "compass timber",

1150-589: A given wind. By contrast, looking at every voyage between the Netherlands and East Indies undertaken by the Dutch East India Company from 1595 to 1795, we find that journey time fell only by 10 percent, with no improvement in the heavy mortality, averaging six percent per voyage, of those aboard." Initially copying wooden construction traditions with a frame over which the hull was fastened, Isambard Kingdom Brunel 's Great Britain of 1843

1265-551: A group of 14 ships discovered in Abydos that were constructed of wooden planks which were "sewn" together. Discovered by Egyptologist David O'Connor of New York University , woven straps were found to have been used to lash the planks together, and reeds or grass stuffed between the planks helped to seal the seams. Because the ships are all buried together and near a mortuary belonging to Pharaoh Khasekhemwy , originally they were all thought to have belonged to him, but one of

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1380-508: A high degree of commercialization and an increase in trade. Large numbers of ships were built to meet the demand. The Ming voyages were large in size, numbering as many as 300 ships and 28,000 men. The shipbuilders were brought from different places in China to the shipyard in Nanjing , including Zhejiang , Jiangxi , Fujian , and Huguang (now the provinces of Hubei and Hunan ). One of

1495-553: A macroscopic piece of iron will have a nearly zero overall magnetic field. Application of an external magnetic field causes the domains that are magnetized in the same general direction to grow at the expense of adjacent ones that point in other directions, reinforcing the external field. This effect is exploited in devices that need to channel magnetic fields to fulfill design function, such as electrical transformers , magnetic recording heads, and electric motors . Impurities, lattice defects , or grain and particle boundaries can "pin"

1610-475: A mixture of O 2 /Ar. Iron(IV) is a common intermediate in many biochemical oxidation reactions. Numerous organoiron compounds contain formal oxidation states of +1, 0, −1, or even −2. The oxidation states and other bonding properties are often assessed using the technique of Mössbauer spectroscopy . Many mixed valence compounds contain both iron(II) and iron(III) centers, such as magnetite and Prussian blue ( Fe 4 (Fe[CN] 6 ) 3 ). The latter

1725-406: A range of sailing rigs that included the crab claw sail . The origins of this technology is difficult to date, relying largely on linguistics (studying the words for parts of boats), the written comments of people from other cultures, including the observations of European explorers at the time of first contact and the later more systematic ethnographic observations of the types of craft in use. There

1840-471: A result, mercury is traded in standardized 76 pound flasks (34 kg) made of iron. Iron is by far the most reactive element in its group; it is pyrophoric when finely divided and dissolves easily in dilute acids, giving Fe . However, it does not react with concentrated nitric acid and other oxidizing acids due to the formation of an impervious oxide layer, which can nevertheless react with hydrochloric acid . High-purity iron, called electrolytic iron ,

1955-451: A significant number of workers, and generate income as the shipbuilding market is global . Iron Iron is a chemical element ; it has the symbol Fe (from Latin ferrum  'iron') and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table . It is, by mass, the most common element on Earth , forming much of Earth's outer and inner core . It

2070-891: A similar design. Austronesians established the Austronesian maritime trade network at around 1000 to 600 BC, linking Southeast Asia with East Asia, South Asia, the Middle East, and later East Africa. The route later became part of the Spice trade network and the Maritime Silk Road . The naval history of China stems back to the Spring and Autumn period (722 BC–481 BC) of the ancient Chinese Zhou dynasty . The Chinese built large rectangular barges known as "castle ships", which were essentially floating fortresses complete with multiple decks with guarded ramparts . However,

2185-411: A single piece of hollowed-out log. At the sides were two planks, and two horseshoe-shaped wood pieces formed the prow and stern . These were fitted tightly together edge-to-edge with dowels inserted into holes in between, and then lashed to each other with ropes (made from rattan or fiber) wrapped around protruding lugs on the planks. This characteristic and ancient Austronesian boatbuilding practice

2300-526: A treatise on mathematics, much material on astrology, and other materials. His treatise on shipbuilding treats three kinds of galleys and two kinds of round ships. Shipbuilders in the Ming dynasty (1368~1644) were not the same as the shipbuilders in other Chinese dynasties, due to hundreds of years of accumulated experiences and rapid changes in the Ming dynasty. Shipbuilders in the Ming dynasty primarily worked for

2415-455: A type of rock consisting of repeated thin layers of iron oxides alternating with bands of iron-poor shale and chert . The banded iron formations were laid down in the time between 3,700  million years ago and 1,800  million years ago . Materials containing finely ground iron(III) oxides or oxide-hydroxides, such as ochre , have been used as yellow, red, and brown pigments since pre-historical times. They contribute as well to

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2530-435: A very large coordination and organometallic chemistry : indeed, it was the discovery of an iron compound, ferrocene , that revolutionalized the latter field in the 1950s. Iron is sometimes considered as a prototype for the entire block of transition metals, due to its abundance and the immense role it has played in the technological progress of humanity. Its 26 electrons are arranged in the configuration [Ar]3d 4s , of which

2645-467: Is a famous example). Later Great Britain ' s iron hull was sheathed in wood to enable it to carry a copper-based sheathing . Brunel's Great Eastern represented the next great development in shipbuilding. Built-in association with John Scott Russell , it used longitudinal stringers for strength, inner and outer hulls, and bulkheads to form multiple watertight compartments. Steel also supplanted wrought iron when it became readily available in

2760-663: Is a possibility that they may have reached the Americas . After the 11th century, a new type of ship called djong or jong was recorded in Java and Bali. This type of ship was built using wooden dowels and treenails, unlike the kunlun bo which used vegetal fibres for lashings. The empire of Majapahit used jong, built in northern Java, for transporting troops overseas. The jongs were transport ships which could carry 100–2000 tons of cargo and 50–1000 people, 28.99–88.56 meter in length. The exact number of jong fielded by Majapahit

2875-646: Is also rarely found in basalts that have formed from magmas that have come into contact with carbon-rich sedimentary rocks, which have reduced the oxygen fugacity sufficiently for iron to crystallize. This is known as telluric iron and is described from a few localities, such as Disko Island in West Greenland, Yakutia in Russia and Bühl in Germany. Ferropericlase (Mg,Fe)O , a solid solution of periclase (MgO) and wüstite (FeO), makes up about 20% of

2990-407: Is considered to be resistant to rust, due to its oxide layer. Iron forms various oxide and hydroxide compounds ; the most common are iron(II,III) oxide (Fe 3 O 4 ), and iron(III) oxide (Fe 2 O 3 ). Iron(II) oxide also exists, though it is unstable at room temperature. Despite their names, they are actually all non-stoichiometric compounds whose compositions may vary. These oxides are

3105-499: Is due to its abundant production during the runaway fusion and explosion of type Ia supernovae , which scatters the iron into space. Metallic or native iron is rarely found on the surface of the Earth because it tends to oxidize. However, both the Earth's inner and outer core , which together account for 35% of the mass of the whole Earth, are believed to consist largely of an iron alloy, possibly with nickel . Electric currents in

3220-474: Is experimentally well defined for pressures less than 50 GPa. For greater pressures, published data (as of 2007) still varies by tens of gigapascals and over a thousand kelvin. Below its Curie point of 770 °C (1,420 °F; 1,040 K), α-iron changes from paramagnetic to ferromagnetic : the spins of the two unpaired electrons in each atom generally align with the spins of its neighbors, creating an overall magnetic field . This happens because

3335-494: Is in Earth's crust only amounts to about 5% of the overall mass of the crust and is thus only the fourth most abundant element in that layer (after oxygen , silicon , and aluminium ). Most of the iron in the crust is combined with various other elements to form many iron minerals . An important class is the iron oxide minerals such as hematite (Fe 2 O 3 ), magnetite (Fe 3 O 4 ), and siderite (FeCO 3 ), which are

3450-600: Is known as the " lashed-lug " technique. They were commonly caulked with pastes made from various plants as well as tapa bark and fibres which would expand when wet, further tightening joints and making the hull watertight. They formed the shell of the boat, which was then reinforced by horizontal ribs. Shipwrecks of Austronesian ships can be identified from this construction as well as the absence of metal nails. Austronesian ships traditionally had no central rudders but were instead steered using an oar on one side. Austronesians traditionally made their sails from woven mats of

3565-401: Is not like that of Mn with its weak, spin-forbidden d–d bands, because Fe has higher positive charge and is more polarizing, lowering the energy of its ligand-to-metal charge transfer absorptions. Thus, all the above complexes are rather strongly colored, with the single exception of the hexaquo ion – and even that has a spectrum dominated by charge transfer in the near ultraviolet region. On

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3680-571: Is noted in the works of Ibn Jubayr . The ships of Ancient Egypt's Eighteenth Dynasty were typically about 25 meters (80 ft) in length and had a single mast , sometimes consisting of two poles lashed together at the top making an "A" shape. They mounted a single square sail on a yard , with an additional spar along the bottom of the sail. These ships could also be oar propelled. The ocean- and sea-going ships of Ancient Egypt were constructed with cedar wood, most likely hailing from Lebanon. The ships of Phoenicia seem to have been of

3795-499: Is only a small body of archaeological evidence available. Since Island Southeast Asia contained effective maritime transport between its very large number of islands long before Austronesian seafaring, it is argued that Austronesians adopted an existing maritime technology from the existing inhabitants of this region. Austronesian ships varied from simple canoes to large multihull ships. The simplest form of all ancestral Austronesian boats had five parts. The bottom part consists of

3910-407: Is possible, but nonetheless the sequence does effectively end at Ni because conditions in stellar interiors cause the competition between photodisintegration and the alpha process to favor photodisintegration around Ni. This Ni, which has a half-life of about 6 days, is created in quantity in these stars, but soon decays by two successive positron emissions within supernova decay products in

4025-548: Is somewhat different). Pieces of magnetite with natural permanent magnetization ( lodestones ) provided the earliest compasses for navigation. Particles of magnetite were extensively used in magnetic recording media such as core memories , magnetic tapes , floppies , and disks , until they were replaced by cobalt -based materials. Iron has four stable isotopes : Fe (5.845% of natural iron), Fe (91.754%), Fe (2.119%) and Fe (0.282%). Twenty-four artificial isotopes have also been created. Of these stable isotopes, only Fe has

4140-442: Is such a strong oxidizing agent that it oxidizes ammonia to nitrogen (N 2 ) and water to oxygen: The pale-violet hex aquo complex [Fe(H 2 O) 6 ] is an acid such that above pH 0 it is fully hydrolyzed: As pH rises above 0 the above yellow hydrolyzed species form and as it rises above 2–3, reddish-brown hydrous iron(III) oxide precipitates out of solution. Although Fe has a d configuration, its absorption spectrum

4255-502: Is supposed to have an orthorhombic or a double hcp structure. (Confusingly, the term "β-iron" is sometimes also used to refer to α-iron above its Curie point, when it changes from being ferromagnetic to paramagnetic, even though its crystal structure has not changed. ) The inner core of the Earth is generally presumed to consist of an iron- nickel alloy with ε (or β) structure. The melting and boiling points of iron, along with its enthalpy of atomization , are lower than those of

4370-418: Is the construction of ships and other floating vessels . In modern times, it normally takes place in a specialized facility known as a shipyard . Shipbuilders , also called shipwrights , follow a specialized occupation that traces its roots to before recorded history . Until recently, with the development of complex non-maritime technologies, a ship has often represented the most advanced structure that

4485-467: Is the fourth most abundant element in the Earth's crust , being mainly deposited by meteorites in its metallic state. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching 1,500 °C (2,730 °F), about 500 °C (932 °F) higher than that required to smelt copper . Humans started to master that process in Eurasia during the 2nd millennium BC and

4600-418: Is thus very important economically, and iron is the cheapest metal, with a price of a few dollars per kilogram or pound. Pristine and smooth pure iron surfaces are a mirror-like silvery-gray. Iron reacts readily with oxygen and water to produce brown-to-black hydrated iron oxides , commonly known as rust . Unlike the oxides of some other metals that form passivating layers, rust occupies more volume than

4715-411: Is unknown, but the largest number of jong deployed in an expedition is about 400 jongs, when Majapahit attacked Pasai, in 1350. Until recently, Viking longships were seen as marking an advance on traditional clinker -built hulls where leather thongs were used to join plank boards. This consensus has recently been challenged. Haywood has argued that earlier Frankish and Anglo-Saxon nautical practice

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4830-451: Is used as the traditional "blue" in blueprints . Iron is the first of the transition metals that cannot reach its group oxidation state of +8, although its heavier congeners ruthenium and osmium can, with ruthenium having more difficulty than osmium. Ruthenium exhibits an aqueous cationic chemistry in its low oxidation states similar to that of iron, but osmium does not, favoring high oxidation states in which it forms anionic complexes. In

4945-437: Is used in chemical actinometry and along with its sodium salt undergoes photoreduction applied in old-style photographic processes. The dihydrate of iron(II) oxalate has a polymeric structure with co-planar oxalate ions bridging between iron centres with the water of crystallisation located forming the caps of each octahedron, as illustrated below. Iron(III) complexes are quite similar to those of chromium (III) with

5060-589: The ghe mành . Early Egyptians also knew how to assemble planks of wood with treenails to fasten them together, using pitch for caulking the seams. The " Khufu ship ", a 43.6-meter vessel sealed into a pit in the Giza pyramid complex at the foot of the Great Pyramid of Giza in the Fourth Dynasty around 2500 BC, is a full-size surviving example which may have fulfilled the symbolic function of

5175-579: The k'un-lun po or kunlun bo ("ship of the k'un-lun [dark-skinned southern people]"). These ships used two types of sail of their invention, the junk sail and tanja sail . Large ships are about 50–60 metres (164–197 ft) long, had 5.2–7.8 metres (17–26 ft) tall freeboard , each carrying provisions enough for a year, and could carry 200–1000 people. The Chinese recorded that these Southeast Asian ships were hired for passage to South Asia by Chinese Buddhist pilgrims and travelers, because they did not build seaworthy ships of their own until around

5290-724: The Abbasid period. Mughal Empire had a large shipbuilding industry, which was largely centred in the Bengal Subah . Economic historian Indrajit Ray estimates shipbuilding output of Bengal during the sixteenth and seventeenth centuries at 223,250 tons annually, compared with 23,061 tons produced in nineteen colonies in North America from 1769 to 1771. He also assesses ship repairing as very advanced in Bengal. Documents from 1506, for example, refer to watercraft on

5405-547: The Napoleonic Wars were still built more or less to the same basic plan as those of the Spanish Armada of two centuries earlier, although there had been numerous subtle improvements in ship design and construction throughout this period. For instance, the introduction of tumblehome , adjustments to the shapes of sails and hulls, the introduction of the wheel, the introduction of hardened copper fastenings below

5520-469: The Persian Gulf . Evidence from Ancient Egypt shows that the early Egyptians knew how to assemble planks of wood into a ship hull as early as 3100 BC. Egyptian pottery as old as 4000 BC shows designs of early fluvial boats or other means for navigation. The Archaeological Institute of America reports that some of the oldest ships yet unearthed are known as the Abydos boats . These are

5635-459: The Sierra Leone river carrying 120 men. Others refer to Guinea coast peoples using war canoes of varying sizes – some 70 feet in length, 7–8 feet broad, with sharp pointed ends, rowing benches on the side, and quarterdecks or forecastles build of reeds. The watercraft included miscellaneous facilities, such as cooking hearths, and storage spaces for the crew's sleeping mats. From

5750-767: The Stock Exchange building . It opened in its new location in February 1941, but its work was interrupted four months later by the German invasion of the Soviet Union and the beginning of the Great Patriotic War . The museum organizes joint exhibitions with Russian and foreign museums. 59°56′37″N 30°18′16″E  /  59.9435194444°N 30.3045027778°E  / 59.9435194444; 30.3045027778 Shipbuilding Shipbuilding

5865-432: The supernova remnant gas cloud, first to radioactive Co, and then to stable Fe. As such, iron is the most abundant element in the core of red giants , and is the most abundant metal in iron meteorites and in the dense metal cores of planets such as Earth . It is also very common in the universe, relative to other stable metals of approximately the same atomic weight . Iron is the sixth most abundant element in

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5980-491: The trans - chlorohydridobis(bis-1,2-(diphenylphosphino)ethane)iron(II) complex is used as a starting material for compounds with the Fe( dppe ) 2 moiety . The ferrioxalate ion with three oxalate ligands displays helical chirality with its two non-superposable geometries labelled Λ (lambda) for the left-handed screw axis and Δ (delta) for the right-handed screw axis, in line with IUPAC conventions. Potassium ferrioxalate

6095-466: The universe , and the most common refractory element. Although a further tiny energy gain could be extracted by synthesizing Ni , which has a marginally higher binding energy than Fe, conditions in stars are unsuitable for this process. Element production in supernovas greatly favor iron over nickel, and in any case, Fe still has a lower mass per nucleon than Ni due to its higher fraction of lighter protons. Hence, elements heavier than iron require

6210-461: The 14 ships dates to 3000 BC, and the associated pottery jars buried with the vessels also suggest earlier dating. The ship dating to 3000 BC was about 75 feet (23 m) long and is now thought to perhaps have belonged to an earlier pharaoh. According to professor O'Connor, the 5,000-year-old ship may have even belonged to Pharaoh Aha . The Austronesian expansion , which began c.  3000 BC with migration from Taiwan to

6325-536: The 17th century, some kingdoms added brass or iron cannons to their vessels. By the 18th century, however, the use of swivel cannons on war canoes accelerated. The city-state of Lagos , for instance, deployed war canoes armed with swivel cannons. With the development of the carrack , the west moved into a new era of ship construction by building the first regular oceangoing vessels. In a relatively short time, these ships grew to an unprecedented size, complexity, and cost. Shipyards became large industrial complexes, and

6440-570: The 3d and 4s electrons are relatively close in energy, and thus a number of electrons can be ionized. Iron forms compounds mainly in the oxidation states +2 ( iron(II) , "ferrous") and +3 ( iron(III) , "ferric"). Iron also occurs in higher oxidation states , e.g., the purple potassium ferrate (K 2 FeO 4 ), which contains iron in its +6 oxidation state. The anion [FeO 4 ] with iron in its +7 oxidation state, along with an iron(V)-peroxo isomer, has been detected by infrared spectroscopy at 4 K after cocondensation of laser-ablated Fe atoms with

6555-606: The 8–9th century AD. Austronesians (especially from western Island Southeast Asia ) were trading in the Indian Ocean as far as Africa during this period. By around 50 to 500 AD, a group of Austronesians, believed to be from the southeastern coasts of Borneo (possibly a mixed group related to the modern Ma'anyan , Banjar , and/or the Dayak people ) crossed the Indian Ocean and colonized Madagascar . This resulted in

6670-764: The Admiral Zheng He . Six voyages were conducted under the Yongle Emperor's reign, the last of which returned to China in 1422. After the Yongle Emperor's death in 1424, his successor the Hongxi Emperor ordered the suspension of the voyages. The seventh and final voyage began in 1430, sent by the Xuande Emperor . Although the Hongxi and Xuande Emperors did not emphasize sailing as much as the Yongle Emperor, they were not against it. This led to

6785-507: The Chinese vessels during this era were essentially fluvial (riverine). True ocean-going Chinese fleets did not appear until the 10th century Song dynasty . There is considerable knowledge regarding shipbuilding and seafaring in the ancient Mediterranean. Large multi-masted seafaring ships of Southeast Asian Austronesians first started appearing in Chinese records during the Han dynasty as

6900-654: The Chinese, from the Old Javanese parahu , Javanese prau , or Malay perahu – large ship. Southern Chinese junks showed characteristics of Austronesian ships that they are made using timbers of tropical origin, with keeled, V-shaped hull. This is different from northern Chinese junks, which are developed from flat-bottomed riverine boats. The northern Chinese junks were primarily built of pine or fir wood, had flat bottoms with no keel, water-tight bulkheads with no frames, transom (squared) stern and stem, and have their planks fastened with iron nails or clamps. It

7015-603: The Earth's surface. Items made of cold-worked meteoritic iron have been found in various archaeological sites dating from a time when iron smelting had not yet been developed; and the Inuit in Greenland have been reported to use iron from the Cape York meteorite for tools and hunting weapons. About 1 in 20 meteorites consist of the unique iron-nickel minerals taenite (35–80% iron) and kamacite (90–95% iron). Native iron

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7130-570: The Han dynasty junk ship design in the same century. The Chinese were using square sails during the Han dynasty and adopted the Austronesian junk sail later in the 12th century. Iconographic remains show that Chinese ships before the 12th century used square sails, and the junk rig of Chinese ships is believed to be developed from tilted sails . Southern Chinese junks were based on keeled and multi-planked Austronesian ship known as po by

7245-713: The Harappan maritime trade. Ships from the harbour at these ancient port cities established trade with Mesopotamia . Shipbuilding and boatmaking may have been prosperous industries in ancient India. Native labourers may have manufactured the flotilla of boats used by Alexander the Great to navigate across the Hydaspes and even the Indus , under Nearchos . The Indians also exported teak for shipbuilding to ancient Persia . Other references to Indian timber used for shipbuilding

7360-491: The United States in a 15-year period just before the war was a grand total of two. During the war, thousands of Liberty ships and Victory ships were built, many of them in shipyards that did not exist before the war. And, they were built by a workforce consisting largely of women and other inexperienced workers who had never seen a ship before (or even the ocean). After World War II , shipbuilding (which encompasses

7475-527: The bottom planking of cogs . The north-European and Mediterranean traditions merged in the late 15th century, with carvel construction being adopted in the North and the centre-line mounted rudder replacing the quarter rudder of the Mediterranean. These changes broadly coincided with improvements in sailing rigs, with the three masted ship becoming common, with square sails on the fore and main masts, and

7590-450: The brown deposits present in a sizeable number of streams. Due to its electronic structure, iron has a very large coordination and organometallic chemistry. Many coordination compounds of iron are known. A typical six-coordinate anion is hexachloroferrate(III), [FeCl 6 ] , found in the mixed salt tetrakis(methylammonium) hexachloroferrate(III) chloride . Complexes with multiple bidentate ligands have geometric isomers . For example,

7705-709: The color of various rocks and clays , including entire geological formations like the Painted Hills in Oregon and the Buntsandstein ("colored sandstone", British Bunter ). Through Eisensandstein (a jurassic 'iron sandstone', e.g. from Donzdorf in Germany) and Bath stone in the UK, iron compounds are responsible for the yellowish color of many historical buildings and sculptures. The proverbial red color of

7820-464: The cores of the Earth and other planets. Above approximately 10 GPa and temperatures of a few hundred kelvin or less, α-iron changes into another hexagonal close-packed (hcp) structure, which is also known as ε-iron . The higher-temperature γ-phase also changes into ε-iron, but does so at higher pressure. Some controversial experimental evidence exists for a stable β phase at pressures above 50 GPa and temperatures of at least 1500 K. It

7935-581: The development beyond that raft technology occurred in the "nursery" areas of the Mediterranean and in Maritime Southeast Asia . Favoured by warmer waters and a number of inter-visible islands, boats (and, later, ships) with water-tight hulls (unlike the "flow through" structure of a raft) could be developed. The ships of ancient Egypt were built by joining the hull planks together, edge to edge, with tenons set in mortices cut in

8050-401: The domains in the new positions, so that the effect persists even after the external field is removed – thus turning the iron object into a (permanent) magnet . Similar behavior is exhibited by some iron compounds, such as the ferrites including the mineral magnetite , a crystalline form of the mixed iron(II,III) oxide Fe 3 O 4 (although the atomic-scale mechanism, ferrimagnetism ,

8165-479: The earlier 3d elements from scandium to chromium , showing the lessened contribution of the 3d electrons to metallic bonding as they are attracted more and more into the inert core by the nucleus; however, they are higher than the values for the previous element manganese because that element has a half-filled 3d sub-shell and consequently its d-electrons are not easily delocalized. This same trend appears for ruthenium but not osmium . The melting point of iron

8280-500: The end of the Ming dynasty in 1644. During this period, Chinese navigation technology did not make any progress and even declined in some aspect. In the Islamic world, shipbuilding thrived at Basra and Alexandria . The dhow , felucca , baghlah , and the sambuk became symbols of successful maritime trade around the Indian Ocean from the ports of East Africa to Southeast Asia and the ports of Sindh and Hind (India) during

8395-406: The exception of iron(III)'s preference for O -donor instead of N -donor ligands. The latter tend to be rather more unstable than iron(II) complexes and often dissociate in water. Many Fe–O complexes show intense colors and are used as tests for phenols or enols . For example, in the ferric chloride test , used to determine the presence of phenols, iron(III) chloride reacts with a phenol to form

8510-462: The global stock of iron in use in society is 2,200 kg per capita. More-developed countries differ in this respect from less-developed countries (7,000–14,000 vs 2,000 kg per capita). Ocean science demonstrated the role of the iron in the ancient seas in both marine biota and climate. Iron shows the characteristic chemical properties of the transition metals , namely the ability to form variable oxidation states differing by steps of one and

8625-594: The government, under command of the Ministry of Public Works . During the early years of the Ming dynasty, the Ming government maintained an open policy towards sailing. Between 1405 and 1433, the government conducted seven diplomatic Ming treasure voyages to over thirty countries in Southeast Asia, India, the Middle East and Eastern Africa. The voyages were initiated by the Yongle Emperor , and led by

8740-507: The infrastructure required to transport the trees from their point of origin to the shipyards. Shipbuilders were usually divided into different groups and had separate jobs. Some were responsible for fixing old ships; some were responsible for making the keel and some were responsible for building the helm. After 1477, the Ming government reversed its open maritime policies, enacting a series of isolationist policies in response to piracy . The policies, called Haijin (sea ban), lasted until

8855-536: The introduction of outrigger canoe technology to non-Austronesian cultures in the East African coast. The ancient Chinese also built fluvial ramming vessels as in the Greco-Roman tradition of the trireme , although oar-steered ships in China lost favor very early on since it was in the 1st century China that the stern -mounted rudder was first developed. This was dually met with the introduction of

8970-536: The island of Luzon in the Philippines , spread across Island Southeast Asia . Then, between 1500 BC and 1500 AD they settled uninhabited islands of the Pacific, and also sailed westward to Madagascar. This is associated with distinctive maritime technology: lashed lug construction techniques (both in outrigger canoes and in large planked sailing vessels), various types of outrigger and twin-hulled canoes and

9085-491: The keel, the hull was made by overlapping nine strakes on either side with rivets fastening the oaken planks together. It could hold upwards of thirty men. Sometime around the 12th century, northern European ships began to be built with a straight sternpost , enabling the mounting of a rudder, which was much more durable than a steering oar held over the side. Development in the Middle Ages favored "round ships", with

9200-470: The latter half of the 19th century, providing great savings when compared with iron in cost and weight. Wood continued to be favored for the decks. During World War II , the need for cargo ships was so great that construction time for Liberty ships went from initially eight months or longer, down to weeks or even days. They employed production line and prefabrication techniques such as those used in shipyards today. The total number of dry-cargo ships built in

9315-453: The liquid outer core are believed to be the origin of the Earth's magnetic field . The other terrestrial planets ( Mercury , Venus , and Mars ) as well as the Moon are believed to have a metallic core consisting mostly of iron. The M-type asteroids are also believed to be partly or mostly made of metallic iron alloy. The rare iron meteorites are the main form of natural metallic iron on

9430-446: The literature, this mineral phase of the lower mantle is also often called magnesiowüstite. Silicate perovskite may form up to 93% of the lower mantle, and the magnesium iron form, (Mg,Fe)SiO 3 , is considered to be the most abundant mineral in the Earth, making up 38% of its volume. While iron is the most abundant element on Earth, most of this iron is concentrated in the inner and outer cores. The fraction of iron that

9545-407: The major ores of iron . Many igneous rocks also contain the sulfide minerals pyrrhotite and pentlandite . During weathering , iron tends to leach from sulfide deposits as the sulfate and from silicate deposits as the bicarbonate. Both of these are oxidized in aqueous solution and precipitate in even mildly elevated pH as iron(III) oxide . Large deposits of iron are banded iron formations ,

9660-478: The mating edges. A similar technique, but with the tenons being pinned in position by dowels, was used in the Mediterranean for most of classical antiquity . Both these variants are "shell first" techniques, where any reinforcing frames are inserted after assembly of the planking has defined the hull shape. Carvel construction then took over in the Mediterranean. Northern Europe used clinker construction , but with some flush-planked ship-building in, for instance,

9775-775: The metal and thus flakes off, exposing more fresh surfaces for corrosion. Chemically, the most common oxidation states of iron are iron(II) and iron(III) . Iron shares many properties of other transition metals, including the other group 8 elements , ruthenium and osmium . Iron forms compounds in a wide range of oxidation states , −4 to +7. Iron also forms many coordination compounds ; some of them, such as ferrocene , ferrioxalate , and Prussian blue have substantial industrial, medical, or research applications. The body of an adult human contains about 4 grams (0.005% body weight) of iron, mostly in hemoglobin and myoglobin . These two proteins play essential roles in oxygen transport by blood and oxygen storage in muscles . To maintain

9890-612: The meteorites Semarkona and Chervony Kut, a correlation between the concentration of Ni, the granddaughter of Fe, and the abundance of the stable iron isotopes provided evidence for the existence of Fe at the time of formation of the Solar System . Possibly the energy released by the decay of Fe, along with that released by Al , contributed to the remelting and differentiation of asteroids after their formation 4.6 billion years ago. The abundance of Ni present in extraterrestrial material may bring further insight into

10005-568: The most famous shipyards was Long Jiang Shipyard ( zh:龙江船厂 ), located in Nanjing near the Treasure Shipyard where the ocean-going ships were built. The shipbuilders could build 24 models of ships of varying sizes. Several types of ships were built for the voyages, including Shachuan (沙船), Fuchuan (福船) and Baochuan ( treasure ship ) (宝船). Zheng He's treasure ships were regarded as Shachuan types, mainly because they were made in

10120-479: The mould loft . Shipbuilding and ship repairs, both commercial and military, are referred to as naval engineering . The construction of boats is a similar activity called boat building . The dismantling of ships is called ship breaking . The earliest evidence of maritime transport by modern humans is the settlement of Australia between 50,000 and 60,000 years ago. This almost certainly involved rafts , possibly equipped with some sort of sail . Much of

10235-542: The naturally curved timber that meant that shapes could be cut without weaknesses caused by cuts across the grain of the timber. Ultimately, whole ships were made of iron and, later, steel . The earliest known depictions (including paintings and models) of shallow-water sailing boats is from the 6th to 5th millennium BC of the Ubaid period of Mesopotamia . They were made from bundled reeds coated in bitumen and had bipod masts. They sailed in shallow coastal waters of

10350-559: The necessary levels, human iron metabolism requires a minimum of iron in the diet. Iron is also the metal at the active site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants and animals. At least four allotropes of iron (differing atom arrangements in the solid) are known, conventionally denoted α , γ , δ , and ε . The first three forms are observed at ordinary pressures. As molten iron cools past its freezing point of 1538 °C, it crystallizes into its δ allotrope, which has

10465-436: The orbitals of those two electrons (d z and d x − y ) do not point toward neighboring atoms in the lattice, and therefore are not involved in metallic bonding. In the absence of an external source of magnetic field, the atoms get spontaneously partitioned into magnetic domains , about 10 micrometers across, such that the atoms in each domain have parallel spins, but some domains have other orientations. Thus

10580-539: The origin and early history of the Solar System . The most abundant iron isotope Fe is of particular interest to nuclear scientists because it represents the most common endpoint of nucleosynthesis . Since Ni (14 alpha particles ) is easily produced from lighter nuclei in the alpha process in nuclear reactions in supernovae (see silicon burning process ), it is the endpoint of fusion chains inside extremely massive stars . Although adding more alpha particles

10695-444: The other hand, the pale green iron(II) hexaquo ion [Fe(H 2 O) 6 ] does not undergo appreciable hydrolysis. Carbon dioxide is not evolved when carbonate anions are added, which instead results in white iron(II) carbonate being precipitated out. In excess carbon dioxide this forms the slightly soluble bicarbonate, which occurs commonly in groundwater, but it oxidises quickly in air to form iron(III) oxide that accounts for

10810-581: The oxidizing power of Fe and the high reducing power of I : Ferric iodide, a black solid, is not stable in ordinary conditions, but can be prepared through the reaction of iron pentacarbonyl with iodine and carbon monoxide in the presence of hexane and light at the temperature of −20 °C, with oxygen and water excluded. Complexes of ferric iodide with some soft bases are known to be stable compounds. The standard reduction potentials in acidic aqueous solution for some common iron ions are given below: The red-purple tetrahedral ferrate (VI) anion

10925-497: The past work on isotopic composition of iron has focused on the nucleosynthesis of Fe through studies of meteorites and ore formation. In the last decade, advances in mass spectrometry have allowed the detection and quantification of minute, naturally occurring variations in the ratios of the stable isotopes of iron. Much of this work is driven by the Earth and planetary science communities, although applications to biological and industrial systems are emerging. In phases of

11040-414: The principal ores for the production of iron (see bloomery and blast furnace). They are also used in the production of ferrites , useful magnetic storage media in computers, and pigments. The best known sulfide is iron pyrite (FeS 2 ), also known as fool's gold owing to its golden luster. It is not an iron(IV) compound, but is actually an iron(II) polysulfide containing Fe and S 2 ions in

11155-416: The resilient and salt-resistant pandanus leaves. These sails allowed Austronesians to embark on long-distance voyaging. The ancient Champa of Vietnam also uniquely developed basket-hulled boats whose hulls were composed of woven and resin - caulked bamboo, either entirely or in conjunction with plank strakes . They range from small coracles (the o thúng ) to large ocean-going trading ships like

11270-437: The second half of the 3d transition series, vertical similarities down the groups compete with the horizontal similarities of iron with its neighbors cobalt and nickel in the periodic table, which are also ferromagnetic at room temperature and share similar chemistry. As such, iron, cobalt, and nickel are sometimes grouped together as the iron triad . Unlike many other metals, iron does not form amalgams with mercury . As

11385-450: The shipbuilder learned the techniques of shipbuilding from his family and is very likely to earn a higher status in the shipyard. Additionally, the shipbuilder had access to business networking that could help to find clients. If a shipbuilder entered the occupation through an apprenticeship, the shipbuilder was likely a farmer before he was hired as a shipbuilder, or he was previously an experienced shipbuilder. Many shipbuilders working in

11500-429: The ships built were financed by consortia of investors. These considerations led to the documentation of design and construction practices in what had previously been a secretive trade run by master shipwrights and ultimately led to the field of naval architecture , in which professional designers and draftsmen played an increasingly important role. Even so, construction techniques changed only very gradually. The ships of

11615-422: The shipyard were forced into the occupation. The ships built for Zheng He's voyages needed to be waterproof, solid, safe, and have ample room to carry large amounts of trading goods. Therefore, due to the highly commercialized society that was being encouraged by the expeditions, trades, and government policies, the shipbuilders needed to acquire the skills to build ships that fulfil these requirements. Shipbuilding

11730-433: The shipyards, the marine equipment manufacturers, and many related service and knowledge providers) grew as an important and strategic industry in a number of countries around the world. This importance stems from: Historically, the industry has suffered from the absence of global rules and a tendency towards ( state - supported ) over-investment due to the fact that shipyards offer a wide range of technologies, employ

11845-666: The site of Portus in Rome revealed inscriptions in a shipyard constructed during the reign of Trajan (98–117) that indicated the existence of a shipbuilders guild . Roughly at this time is the last migration wave of the Austronesian expansion , when the Polynesian islands spread over vast distances across the Pacific Ocean were being colonized by the (Austronesian) Polynesians from Island Melanesia using double-hulled voyaging catamarans . At its furthest extent, there

11960-503: The society building it could produce. Some key industrial advances were developed to support shipbuilding, for instance the sawing of timbers by mechanical saws propelled by windmills in Dutch shipyards during the first half of the 17th century. The design process saw the early adoption of the logarithm (invented in 1615) to generate the curves used to produce the shape of a hull , especially when scaling up these curves accurately in

12075-482: The stronger flushed deck design derived from Indian designs, and the increasing use of iron reinforcement. The flushed deck originated from the Bengal rice ships, with Bengal being famous for its shipbuilding industry at the time. Iron was gradually adopted in ship construction, initially to provide stronger joints in a wooden hull e.g. as deck knees, hanging knees, knee riders and the other sharp joints, ones in which

12190-564: The surface of Mars is derived from an iron oxide-rich regolith . Significant amounts of iron occur in the iron sulfide mineral pyrite (FeS 2 ), but it is difficult to extract iron from it and it is therefore not exploited. In fact, iron is so common that production generally focuses only on ores with very high quantities of it. According to the International Resource Panel 's Metal Stocks in Society report ,

12305-558: The treasure shipyard in Nanjing. Shachuan , or 'sand-ships', are ships used primarily for inland transport. However, in recent years, some researchers agree that the treasure ships were more of the Fuchuan type. It is said in vol. 176 of San Guo Bei Meng Hui Bian (三朝北盟汇编) that ships made in Fujian are the best ones. Therefore, the best shipbuilders and laborers were brought from these places to support Zheng He's expedition. The shipyard

12420-540: The use of iron tools and weapons began to displace copper alloys – in some regions, only around 1200 BC. That event is considered the transition from the Bronze Age to the Iron Age . In the modern world , iron alloys, such as steel , stainless steel , cast iron and special steels , are by far the most common industrial metals, due to their mechanical properties and low cost. The iron and steel industry

12535-455: The volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite (Mg,Fe)SiO 3 ; it also is the major host for iron in the lower mantle. At the bottom of the transition zone of the mantle, the reaction γ- (Mg,Fe) 2 [SiO 4 ] ↔ (Mg,Fe)[SiO 3 ] + (Mg,Fe)O transforms γ-olivine into a mixture of silicate perovskite and ferropericlase and vice versa. In

12650-612: The waterline, the introduction of copper sheathing as a deterrent to shipworm and fouling, etc. In the early decades of the Industrial Revolution (1760 to 1825) western ship design remained largely based on its traditional pre-industrial designs and materials and yet greatly improved in safety as "the risk of being wrecked for Atlantic shipping fell by one-third, and of foundering by two thirds, reflecting improvements in seaworthiness and navigation respectively." The improvement in seaworthiness has been credited to adopting

12765-540: Was much more accomplished than had been thought and has described the distribution of clinker vs. carvel construction in Western Europe (see map [1] ). An insight into shipbuilding in the North Sea/Baltic areas of the early medieval period was found at Sutton Hoo , England, where a ship was buried with a chieftain. The ship was 26 metres (85 ft) long and 4.3 metres (14 ft) wide. Upward from

12880-549: Was not the sole industry utilising Chinese lumber at that time; the new capital was being built in Beijing from approximately 1407 onwards, which required huge amounts of high-quality wood. These two ambitious projects commissioned by Emperor Yongle would have had enormous environmental and economic effects, even if the ships were half the dimensions given in the History of Ming . Considerable pressure would also have been placed on

12995-444: Was the first radical new design, being built entirely of wrought iron. Despite her success, and the great savings in cost and space provided by the iron hull, compared to a copper-sheathed counterpart, there remained problems with fouling due to the adherence of weeds and barnacles. As a result, composite construction remained the dominant approach where fast ships were required, with wooden timbers laid over an iron frame ( Cutty Sark

13110-426: Was under the command of Ministry of Public Works . The shipbuilders had no control over their lives. The builders, commoner's doctors, cooks and errands had lowest social status. The shipbuilders were forced to move away from their hometown to the shipyards. There were two major ways to enter the shipbuilder occupation: family tradition, or apprenticeship. If a shipbuilder entered the occupation due to family tradition,

13225-414: Was unknown when the Chinese people started adopting Southeast Asian (Austronesian) shipbuilding techniques. They may have been started as early as the 8th century, but the development was gradual and the true ocean-going Chinese junks did not appear suddenly. The word "po" survived in Chinese long after, referring to the large ocean-going junks. In September 2011, archeological investigations done at

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