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90-469: The Low Moor Ironworks was a wrought iron foundry established in 1791 in the village of Low Moor about 3 miles (4.8 km) south of Bradford in Yorkshire, England. The works were built to exploit the high-quality iron ore and low-sulphur coal found in the area. Low Moor made wrought iron products from 1801 until 1957 for export around the world. At one time it was the largest ironworks in Yorkshire,

180-524: A bar, expelling slag in the process. During the Middle Ages , water-power was applied to the process, probably initially for powering bellows, and only later to hammers for forging the blooms. However, while it is certain that water-power was used, the details remain uncertain. That was the culmination of the direct process of ironmaking. It survived in Spain and southern France as Catalan Forges to

270-582: A carbon content of less than 0.008 wt% . Bar iron is a generic term sometimes used to distinguish it from cast iron. It is the equivalent of an ingot of cast metal, in a convenient form for handling, storage, shipping and further working into a finished product. The bars were the usual product of the finery forge , but not necessarily made by that process: Wrought iron is a form of commercial iron containing less than 0.10% of carbon, less than 0.25% of impurities total of sulfur, phosphorus, silicon and manganese, and less than 2% slag by weight. Wrought iron

360-470: A final product. Sometimes European ironworks would skip the shingling process completely and roll the puddle balls. The only drawback to that is that the edges of the rough bars were not as well compressed. When the rough bar was reheated, the edges might separate and be lost into the furnace. The bloom was passed through rollers and to produce bars. The bars of wrought iron were of poor quality, called muck bars or puddle bars. To improve their quality,

450-463: A high silky luster and fibrous appearance. Wrought iron lacks the carbon content necessary for hardening through heat treatment , but in areas where steel was uncommon or unknown, tools were sometimes cold-worked (hence cold iron ) to harden them. An advantage of its low carbon content is its excellent weldability. Furthermore, sheet wrought iron cannot bend as much as steel sheet metal when cold worked. Wrought iron can be melted and cast; however,

540-434: A low scale to supply the steel to the artisan swordmakers. Osmond iron consisted of balls of wrought iron, produced by melting pig iron and catching the droplets on a staff, which was spun in front of a blast of air so as to expose as much of it as possible to the air and oxidise its carbon content. The resultant ball was often forged into bar iron in a hammer mill. In the 15th century, the blast furnace spread into what

630-449: A lower melting point than iron or steel. Cast and especially pig iron have excess slag which must be at least partially removed to produce quality wrought iron. At foundries it was common to blend scrap wrought iron with cast iron to improve the physical properties of castings. For several years after the introduction of Bessemer and open hearth steel, there were different opinions as to what differentiated iron from steel; some believed it

720-412: A major complex of mines, piles of coal and ore, kilns, blast furnaces, forges and slag heaps connected by railway lines. The surrounding countryside was littered with waste, and smoke from the furnaces and machinery blackened the sky. Today Low Moor is still industrial, but the pollution has been mostly eliminated. The ironworks depended on the excellent resources of high-quality coal and iron ore found in

810-459: A modest amount of wrought iron was refined into steel , which was used mainly to produce swords , cutlery , chisels , axes , and other edged tools, as well as springs and files. The demand for wrought iron reached its peak in the 1860s, being in high demand for ironclad warships and railway use. However, as properties such as brittleness of mild steel improved with better ferrous metallurgy and as steel became less costly to make thanks to

900-422: A new company called Robert Heath And Low Moor Ltd. Efforts were made to reduce costs, although this affected quality. Attempts to use high-sulphur coal created serious problems and destroyed the reputation of the works as a supplier of high quality iron, while a slump in heavy industry in the 1920s further reduced demand. The company poured money into attempts to diversify the operations, but did not succeed. In 1928

990-603: A number of patented processes for that, which are referred to today as potting and stamping . The earliest were developed by John Wood of Wednesbury and his brother Charles Wood of Low Mill at Egremont , patented in 1763. Another was developed for the Coalbrookdale Company by the Cranage brothers . Another important one was that of John Wright and Joseph Jesson of West Bromwich . A number of processes for making wrought iron without charcoal were devised as

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1080-410: A process for manufacturing wrought iron quickly and economically. It involved taking molten steel from a Bessemer converter and pouring it into cooler liquid slag. The temperature of the steel is about 1500 °C and the liquid slag is maintained at approximately 1200 °C. The molten steel contains a large amount of dissolved gases so when the liquid steel hit the cooler surfaces of the liquid slag

1170-410: A refinery where raw coal was used to remove silicon and convert carbon within the raw material, found in the form of graphite, to a combination with iron called cementite. In the fully developed process (of Hall), this metal was placed into the hearth of the puddling furnace where it was melted. The hearth was lined with oxidizing agents such as haematite and iron oxide. The mixture was subjected to

1260-409: A second steam hammer with an 8-ton ram was installed for heavy forgings. In 1871 a third steam hammer of 7 tons was installed. New rolling mills were also built to meet demand for iron plates in shipbuilding, supplied by slabs forged in the works. By 1867 there were about 4,000 employees. A description of the works at that time said The accumulation of cinders and calcined shale actually overspreads

1350-481: A single hearth for all stages. The introduction of coke for use in the blast furnace by Abraham Darby in 1709 (or perhaps others a little earlier) initially had little effect on wrought iron production. Only in the 1750s was coke pig iron used on any significant scale as the feedstock of finery forges. However, charcoal continued to be the fuel for the finery. From the late 1750s, ironmasters began to develop processes for making bar iron without charcoal. There were

1440-412: A strong current of air and stirred with long bars, called puddling bars or rabbles, through working doors. The air, the stirring, and the "boiling" action of the metal helped the oxidizing agents to oxidize the impurities and carbon out of the pig iron. As the impurities oxidize, they formed a molten slag or drifted off as gas, while the remaining iron solidified into spongy wrought iron that floated to

1530-424: Is redshort or hot short if it contains sulfur in excess quantity. It has sufficient tenacity when cold, but cracks when bent or finished at a red heat. Hot short iron was considered unmarketable. Cold short iron, also known as coldshear , colshire , contains excessive phosphorus. It is very brittle when cold and cracks if bent. It may, however, be worked at high temperature. Historically, coldshort iron

1620-547: Is a valley , or dale , in North Yorkshire and West Yorkshire , England . It is named after the River Aire , which flows through it. The upper valley, from Malham Cove to Airton , is known as Malhamdale , named after the village of Malham. At Airton the valley widens and becomes Airedale proper. The river flows past Skipton on to Keighley , Bingley , Shipley , and Leeds . Airedale, in conjunction with

1710-414: Is a more important measure of the quality of wrought iron. In tensile testing, the best irons are able to undergo considerable elongation before failure. Higher tensile wrought iron is brittle. Because of the large number of boiler explosions on steamboats in the early 1800s, the U.S. Congress passed legislation in 1830 which approved funds for correcting the problem. The treasury awarded a $ 1500 contract to

1800-520: Is an archaic past participle of the verb "to work", and so "wrought iron" literally means "worked iron". Wrought iron is a general term for the commodity, but is also used more specifically for finished iron goods, as manufactured by a blacksmith . It was used in that narrower sense in British Customs records, such manufactured iron was subject to a higher rate of duty than what might be called "unwrought" iron. Cast iron , unlike wrought iron,

1890-435: Is brittle and cannot be worked either hot or cold. In the 17th, 18th, and 19th centuries, wrought iron went by a wide variety of terms according to its form, origin, or quality. While the bloomery process produced wrought iron directly from ore, cast iron or pig iron were the starting materials used in the finery forge and puddling furnace . Pig iron and cast iron have higher carbon content than wrought iron, but have

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1980-451: Is damned up to supply the works, and every drop is carefully economised. The great furnaces, with broad, flaring flames rising from them, of course attract attention as the works are approached. In form they resemble an ordinary lime-kiln, and, on the summit, in the midst of the eager flames, are strange-looking wheels–appendages of the machinery by means of which the ironstone and other matters are dragged up an inclined plane on iron waggons to

2070-491: Is deceptive. Most of the manganese, sulfur, phosphorus, and silicon in the wrought iron are incorporated into the slag fibers, making wrought iron purer than plain carbon steel. Amongst its other properties, wrought iron becomes soft at red heat and can be easily forged and forge welded . It can be used to form temporary magnets , but it cannot be magnetized permanently, and is ductile , malleable , and tough . For most purposes, ductility rather than tensile strength

2160-467: Is highly refined, with a small amount of silicate slag forged out into fibers. It comprises around 99.4% iron by mass. The presence of slag can be beneficial for blacksmithing operations, such as forge welding, since the silicate inclusions act as a flux and give the material its unique, fibrous structure. The silicate filaments in the slag also protect the iron from corrosion and diminish the effect of fatigue caused by shock and vibration. Historically,

2250-435: Is largely upfaulted Carboniferous limestone . The middle section between Skipton and Knottingley is peat and gritstone, with steep valley walls crested with moorland prevalent between Skipton and Shipley. The sandstone deposits between Skipton and Leeds have characterised the buildings within this part of Airedale, whilst the deposits of Limestone, Coal , Fireclay and Ironstone fuelled industrial developments. Airedale

2340-407: Is no longer manufactured commercially. Wrought iron was originally produced by a variety of smelting processes, all described today as "bloomeries". Different forms of bloomery were used at different places and times. The bloomery was charged with charcoal and iron ore and then lit. Air was blown in through a tuyere to heat the bloomery to a temperature somewhat below the melting point of iron. In

2430-450: Is no longer produced on a commercial scale. Many products described as wrought iron, such as guard rails , garden furniture , and gates are made of mild steel. They are described as "wrought iron" only because they have been made to resemble objects which in the past were wrought (worked) by hand by a blacksmith (although many decorative iron objects, including fences and gates, were often cast rather than wrought). The word "wrought"

2520-682: Is notable for several tourist sites and the World Heritage Site of Saltaire village. Other attractions include the Keighley and Worth Valley Railway , Bingley Five Rise Locks , the Shipley Glen Tramway , East Riddlesden Hall , Rodley Nature Reserve , Kirkstall Abbey , the Royal Armouries (Leeds) , St Aidan's Nature Reserve and Fairburn Ings Nature Reserve . Many of the former woollen and cotton mills of

2610-628: Is now Belgium where it was improved. From there, it spread via the Pays de Bray on the boundary of Normandy and then to the Weald in England. With it, the finery forge spread. Those remelted the pig iron and (in effect) burnt out the carbon, producing a bloom, which was then forged into bar iron. If rod iron was required, a slitting mill was used. The finery process existed in two slightly different forms. In Great Britain, France, and parts of Sweden, only

2700-555: The Bessemer process and the Siemens–Martin process , the use of wrought iron declined. Many items, before they came to be made of mild steel , were produced from wrought iron, including rivets , nails , wire , chains , rails , railway couplings , water and steam pipes , nuts , bolts , horseshoes , handrails , wagon tires, straps for timber roof trusses , and ornamental ironwork , among many other things. Wrought iron

2790-660: The Crimean War (1853–56) and the Indian Mutiny (1857–58). The arms business declined after this, as the government increasingly took charge of weapons production. The works turned to making weldless railway tyres, steam engine boilers, sugar pans for refineries in the West Indies, water pipes and heavy iron components for industrial purposes. By 1863 there were 3,600 employees at the works including 1,993 miners, 420 furnacemen, 770 forgemen and 323 engineers. In 1864

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2880-481: The Industrial Revolution began during the latter half of the 18th century. The most successful of those was puddling, using a puddling furnace (a variety of the reverberatory furnace ), which was invented by Henry Cort in 1784. It was later improved by others including Joseph Hall , who was the first to add iron oxide to the charge. In that type of furnace, the metal does not come into contact with

2970-682: The Iron Age . The peoples that occupied the Aire Valley (and much of north eastern England) were called Brigantes by the Romans . Transport improved in the 18th and 19th centuries with the building of the Aire and Calder Navigation and the Leeds and Liverpool Canal . The railways arrived from the 1830s onwards and during the twentieth century the roads were vastly improved in the valley. Airedale

3060-599: The Ribble Valley , provides low-altitude passes from Yorkshire to Lancashire through the Aire Gap . It is therefore an important transport route and was a strategically important area historically. The upper Aire valley was formed 12,000 years ago by a retreating glacier. A moraine formed in the Cononley area and the lake stretched as far north as Gargrave . Colonisation by man developed later on, especially during

3150-609: The Walloon process was used. That employed two different hearths, a finery hearth for finishing the iron and a chafery hearth for reheating it in the course of drawing the bloom out into a bar. The finery always burnt charcoal, but the chafery could be fired with mineral coal , since its impurities would not harm the iron when it was in the solid state. On the other hand, the German process, used in Germany, Russia, and most of Sweden used

3240-524: The bloomery ever being used in China. The fining process involved liquifying cast iron in a fining hearth and removing carbon from the molten cast iron through oxidation . Wagner writes that in addition to the Han dynasty hearths believed to be fining hearths, there is also pictorial evidence of the fining hearth from a Shandong tomb mural dated 1st to 2nd century AD, as well as a hint of written evidence in

3330-413: The finery forge at least by the 2nd century BC, the earliest specimens of cast and pig iron fined into wrought iron and steel found at the early Han dynasty site at Tieshengguo. Pigott speculates that the finery forge existed in the previous Warring States period (403–221 BC), due to the fact that there are wrought iron items from China dating to that period and there is no documented evidence of

3420-701: The 1960s, the price of steel production was dropping due to recycling, and even using the Aston process, wrought iron production was labor-intensive. It has been estimated that the production of wrought iron is approximately twice as expensive as that of low-carbon steel. In the United States, the last plant closed in 1969. The last in the world was the Atlas Forge of Thomas Walmsley and Sons in Bolton , Great Britain, which closed in 1973. Its 1860s-era equipment

3510-418: The 4th century AD Daoist text Taiping Jing . Wrought iron has been used for many centuries, and is the "iron" that is referred to throughout Western history. The other form of iron, cast iron , was in use in China since ancient times but was not introduced into Western Europe until the 15th century; even then, due to its brittleness, it could be used for only a limited number of purposes. Throughout much of

3600-455: The Aire Valley from the city centre up to junction 45 of the M1 (known as Gateway 45 ). This houses several manufacturing and food companies. The names Aire and Airedale are associated with many things and areas. Most notable in the valley are Airedale General Hospital , Aireborough (a region comprising mostly Wharfedale towns) and Airedale , a suburb of Castleford. The area gives its name to

3690-662: The Crystal Palace in London the ironworks exhibited an enormous cannon. The company also provided samples of ore, coal, pig iron and wrought iron, a smaller gun, a sugar cane mill, an olive mill and an elliptograph. The Low Moor company bought the Bierley Ironworks in 1854. By 1855 Low Moor was producing 21,840 tons of iron per year, and was the largest ironworks in Yorkshire. The foundries at Low Moor produced quantities of guns, shells and shot for troops fighting in

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3780-575: The Franklin Institute to conduct a study. As part of the study, Walter R. Johnson and Benjamin Reeves conducted strength tests on boiler iron using a tester they had built in 1832 based on a design by Lagerhjelm in Sweden. Because of misunderstandings about tensile strength and ductility, their work did little to reduce failures. The importance of ductility was recognized by some very early in

3870-542: The Middle Ages, iron was produced by the direct reduction of ore in manually operated bloomeries , although water power had begun to be employed by 1104. The raw material produced by all indirect processes is pig iron. It has a high carbon content and as a consequence, it is brittle and cannot be used to make hardware. The osmond process was the first of the indirect processes, developed by 1203, but bloomery production continued in many places. The process depended on

3960-681: The areas adjacent to the River Aire and its tributaries. The Aire Catchment Flood Management Plan (CFMP), which takes into account all the becks and streams that feed the river, lists the Worth Valley and most of Bradford City as part of Airedale. Similarly, the Airedale Partnership's Masterplan, which is sponsored by Bradford Council, shows the same boundaries as the Aire CFMP. The upper section between Malham and Skipton

4050-451: The bars were cut up, piled and tied together by wires, a process known as faggoting or piling. They were then reheated to a welding state, forge welded, and rolled again into bars. The process could be repeated several times to produce wrought iron of desired quality. Wrought iron that has been rolled multiple times is called merchant bar or merchant iron. The advantage of puddling was that it used coal, not charcoal as fuel. However, that

4140-505: The blast engine. Smalley called on Thomas Woodcock to prepare plans for the furnaces, casting houses and other works. Woodcock moved to Low Moor, and was to be architect and general manager until his death in 1833. Construction of the plant began in June 1790, including blast furnaces and casting shops. The furnaces had square bases, tapering as they rose to about 50 feet (15 m) in height. The two furnaces were blown in on 13 August 1791 and

4230-461: The blast furnaces were sold for use in road-making. Robert Wilson , Works Manager at James Nasmyth 's Bridgewater foundry in Patricroft near Manchester, had improved Nasmyth's 1842 design for a steam hammer , inventing the self-acting motion that made it possible to adjust the force of the blow delivered by the hammer – a critically important improvement. Nasmyth's steam hammers could now vary

4320-431: The blast furnaces. Apart from the heaviest machines, steam drives were replaced by electrical drives. The outbreak of World War I (1914–1918) caused a temporary surge in demand for shell casings and drop forgings, including shoes for the tracks of the first tanks. After the war it was clear that future demand for wrought iron was uncertain. The company was taken over by Robert Heath & Sons of Staffordshire , creating

4410-513: The coal mines. About 1780 a wooden railway was built from the Low Moor mines to the coal yard in the centre of Bradford, from where the coal could be carried via the Leeds and Liverpool Canal . Soon after, Leeds went bankrupt. The property was twice offered for sale by auction, in December 1786 and October 1787, but no suitable offer was made. Leeds committed suicide in 1787. In 1788 the estate

4500-443: The company installed a new mill to roll iron plate for engine boilers. In 1843 four pairs of forge hammers were installed, driven by steam engines, and in 1844 the company decided to install one of James Nasmyth 's newly invented steam hammers . The process to convert ore into pig iron and then into wrought iron involved first converting the coal to coke to remove water and sulphur, a process that took 48 hours if done in piles in

4590-736: The company opened the Barnby Furnace Colliery on land leased from Walter Spencer Stanhope . This mine worked the "Silkstone Seam". In 1802 the Low Moor Furnace Waggonway was constructed connecting the colliery to Barnby Basin on the Barnsley Canal . The colliery had closed by May 1807. The waggonway was replaced in 1809 by the Silkstone Waggonway which ran over much of its trackbed, and operated until 1870. The ironworks were owned by

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4680-435: The company was declared bankrupt, and the Low Moor assets bought by Thos. W. Ward Ltd. Many of the mines, tracks and plant were closed or dismantled. Some buildings were sold or leased to other companies, and some plant was modernised. Wrought iron production finally ended in 1957. As of 1971 new owners were producing alloy steel, making about 350 tons per week. Notes Citations Sources Wrought iron Before

4770-470: The country, and will soon rival in cubic bulk the mass of the Pyramids. In some cases the hillocks of rubbish have been levelled, and covered with soil brought from a distance... Iron plates, bars and railway tires, sent to Russia, America, India, and, in fact, all over the world, are the principal manufactures here; but guns (from 32 to 68-pounders) are also made here... Every runlet of water for miles around

4860-413: The course of the smelt, slag would melt and run out, and carbon monoxide from the charcoal would reduce the ore to iron, which formed a spongy mass (called a "bloom") containing iron and also molten silicate minerals (slag) from the ore. The iron remained in the solid state. If the bloomery were allowed to become hot enough to melt the iron, carbon would dissolve into it and form pig or cast iron, but that

4950-629: The dale have been demolished or converted into housing. The heavy industry east of Leeds is still in existence and two of the three coal fired powers stations in the lower section take their water from the River Aire. Industry that lies alongside the Aire includes Ferrybridge , Eggborough and Drax power stations, Eggborough Saint Gobain glassworks, Stolze and Allied Glass in Knottingley and Kellingley Colliery . Leeds City Council have an enterprise zone that covers 400 acres of regenerated land along

5040-498: The development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron. It was given the name wrought because it was hammered, rolled, or otherwise worked while hot enough to expel molten slag. The modern functional equivalent of wrought iron is mild steel , also called low-carbon steel. Neither wrought iron nor mild steel contain enough carbon to be hardened by heating and quenching. Wrought iron

5130-593: The development of the blast furnace, of which medieval examples have been discovered at Lapphyttan , Sweden and in Germany . The bloomery and osmond processes were gradually replaced from the 15th century by finery processes, of which there were two versions, the German and Walloon. They were in turn replaced from the late 18th century by puddling , with certain variants such as the Swedish Lancashire process . Those, too, are now obsolete, and wrought iron

5220-466: The development of tube boilers, evidenced by Thurston's comment: If made of such good iron as the makers claimed to have put into them "which worked like lead," they would, as also claimed, when ruptured, open by tearing, and discharge their contents without producing the usual disastrous consequences of a boiler explosion. Airedale 53°52′55″N 1°54′17″W  /  53.8819°N 1.9048°W  / 53.8819; -1.9048 Airedale

5310-577: The families of the founders throughout the 19th century, with the addition of the Wickhams, who married into the Hirds. The annually employed capital grew from £52,000 in 1793 to £250,000 in 1818. The company started to produce wrought iron in 1801, at first using imported iron but by 1803 using Low Moor pig iron. In 1803 a regiment of volunteers was formed at Low Moor ready to repel the expected French invasion. The works were gradually mechanised. By 1805 there

5400-521: The first casting was made by the forgemen three days later. At first the works produced domestic goods, but soon began producing industrial products including parts for steam engines. In 1795 the company won contracts to provide guns, shot and shells to the government, which had been at war with revolutionary France since 1793. By 1799 the works were producing about 2,000 tons of pig iron per year, from which iron goods were made that ranged from columns used in mill construction to garden furniture. In 1800,

5490-602: The force of the blow across a wide range. Nasmyth's first steam hammer was built for the Low Moor Works. They rejected the machine, but on 18 August 1843 accepted an improved version with a self-acting gear. From 1845 to 1856 Robert Wilson was employed by the Low Moor Ironworks. While at Low Moor he improved the steam hammer with the "circular balanced valve". In the Great Exhibition of 1851 at

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5580-432: The fuel, and so is not contaminated by its impurities. The heat of the combustion products passes over the surface of the puddle and the roof of the furnace reverberates (reflects) the heat onto the metal puddle on the fire bridge of the furnace. Unless the raw material used is white cast iron, the pig iron or other raw product of the puddling first had to be refined into refined iron , or finers metal. That would be done in

5670-401: The gases were liberated. The molten steel then froze to yield a spongy mass having a temperature of about 1370 °C. The spongy mass would then be finished by being shingled and rolled as described under puddling (above). Three to four tons could be converted per batch with the method. Steel began to replace iron for railroad rails as soon as the Bessemer process for its manufacture

5760-430: The iron. The included slag in wrought iron also imparts corrosion resistance. Antique music wire , manufactured at a time when mass-produced carbon-steels were available, was found to have low carbon and high phosphorus; iron with high phosphorus content, normally causing brittleness when worked cold, was easily drawn into music wires. Although at the time phosphorus was not an easily identified component of iron, it

5850-514: The mid 19th century, in Austria as the stuckofen to 1775, and near Garstang in England until about 1770; it was still in use with hot blast in New York in the 1880s. In Japan the last of the old tatara bloomeries used in production of traditional tamahagane steel, mainly used in swordmaking, was extinguished only in 1925, though in the late 20th century the production resumed on

5940-461: The mines. The company also employed about 800 miners in collieries to the east at Beeston , Churwell , Osmondthorpe and Potternewton , near Leeds . Minerals were carried to the works by horse-drawn wagons or by wagons on tramways drawn by stationary engines. The Low Moor mines produced about 60,000 tons of ore yearly by 1876. The iron was prized for its uniform and brilliant grain, commanding premium prices. The quality seemed to be due in part to

6030-524: The mouths of the furnaces, which waggons, self-acting, where no living power could perform the office, turn topsy-turvy, and there unload their contents. In 1868 617,628 tons of Low Moor ironstone were raised, the peak production. In 1876 about 2,000 coal miners were employed in pits ranging in depth from 30 to 150 yards (27 to 137 m) in the surrounding townships of North Bierley, Tong , Bowling, Shelf , Wyke , Clifton , Hipperholme and Cleckheaton . Thirteen pumping engines were used to drain water from

6120-408: The nature of the ore and coal and in part to the manufacturing process. Production came at the cost of aesthetics. An 1876 description said "the natural effect of the perpetual smoke-canopy under which the vegetation of the district exists is to give to it a dinginess not pleasant to look upon... The appearance created by the works themselves and their surroundings has been not inaptly likened to that in

6210-666: The product is no longer wrought iron, since the slag stringers characteristic of wrought iron disappear on melting, so the product resembles impure, cast, Bessemer steel. There is no engineering advantage to melting and casting wrought iron, as compared to using cast iron or steel, both of which are cheaper. Due to the variations in iron ore origin and iron manufacture, wrought iron can be inferior or superior in corrosion resistance, compared to other iron alloys. There are many mechanisms behind its corrosion resistance. Chilton and Evans found that nickel enrichment bands reduce corrosion. They also found that in puddled, forged, and piled iron,

6300-531: The same manner as mild steel, but the presence of oxide or inclusions will give defective results. The material has a rough surface, so it can hold platings and coatings better than smooth steel. For instance, a galvanic zinc finish applied to wrought iron is approximately 25–40% thicker than the same finish on steel. In Table 1, the chemical composition of wrought iron is compared to that of pig iron and carbon steel . Although it appears that wrought iron and plain carbon steel have similar chemical compositions, that

6390-454: The sun the metal runs, For horse-shoe nails, or thund'ring guns ... No pen can write, no mind can soar To tell the wonders of Low Moor. By 1835 the works were handling a growing volume of orders. There was no room to expand in the original site, which was crowded by industrial works, offices and workers houses. Construction started on a new site to the southeast, and in 1836 two oven-topped blast furnaces came into operation there. In 1842

6480-477: The time the ironworks were developed recent technological advances had made it practical to smelt iron using coal rather than charcoal and to use steam engines to power the steps in production of iron goods. Most of the land occupied by the iron works was part of the Royds Hall estate. Operation of a coal mine on the estate is mentioned in 1673. In 1744 the owner, Edward Rookes Leeds, began to actively develop

6570-465: The top of the puddle and was fished out of the melt as puddle balls, using puddle bars. There was still some slag left in the puddle balls, so while they were still hot they would be shingled to remove the remaining slag and cinder. That was achieved by forging the balls under a hammer, or by squeezing the bloom in a machine. The material obtained at the end of shingling is known as bloom. The blooms are not useful in that form, so they were rolled into

6660-420: The vicinity of the crater of some volcano." The company began to run into difficulty in the late 1880s. Its mines were increasingly scattered and expensive. The rail network had a variety of gauges and used a mix of stationary engines and locomotives. Some of the plant was obsolete and operations were generally inefficient. However, there was continued demand for "Best Yorkshire Iron" for applications where safety

6750-399: The vicinity. The "better bed" coal came from a seam about 18 to 28 inches (460 to 710 mm) thick resting on hard sandstone. This coal is particularly low in sulphur. About 120 feet (37 m) above this coal seam there is a layer of "black bed" coal. The ironstone lies above this layer, holding about 32% iron. The Halifax coal beds lie about 230 yards (210 m) below the better bed. At

6840-417: The war with France in 1814 the works were producing 33 tons of pig iron weekly. Prices fell for a while as demand slackened after the war, but demand for gas pipes and street lights began to pick up in 1822. The Airedale poet John Nicholson wrote in 1829, When first the shapeless sable ore Is laid in heaps around Low Moor, The roaring blast, the quiv'ring flame, Give to the mass another name: White as

6930-560: The working-over of the metal spread out copper, nickel, and tin impurities that produce electrochemical conditions that slow down corrosion. The slag inclusions have been shown to disperse corrosion to an even film, enabling the iron to resist pitting. Another study has shown that slag inclusions are pathways to corrosion. Other studies show that sulfur in the wrought iron decreases corrosion resistance, while phosphorus increases corrosion resistance. Chloride ions also decrease wrought iron's corrosion resistance. Wrought iron may be welded in

7020-458: The yard, or 24 hours if done in ovens. About 32% of the better bed coal would be lost in coking. The ironstone was allowed to weather for some time to free it from shale. Limestone was brought from Skipton to help separate clay from the iron ore. In 1832 it took 9,750 pounds (4,420 kg) of coal, 2,800 pounds (1,300 kg) of limestone and 8,500 pounds (3,900 kg) of ironstone to make 2,240 pounds (1,020 kg) of pig iron. The ironstone

7110-402: Was a self-tipping inclined railway to charge the furnaces, a nail slitting mill, two nose-helve hammers and a plate-rolling mill. As the iron works grew, the company built workers' cottages in the district that took the name of North Brierley and a hostel for the boys who worked in the pits. The boys were given free clothing and schooling. The company also ran several public houses. By the end of

7200-479: Was adopted (1865 on). Iron remained dominant for structural applications until the 1880s, because of problems with brittle steel, caused by introduced nitrogen, high carbon, excess phosphorus, or excessive temperature during or too-rapid rolling. By 1890 steel had largely replaced iron for structural applications. Sheet iron (Armco 99.97% pure iron) had good properties for use in appliances, being well-suited for enamelling and welding, and being rust-resistant. In

7290-503: Was baked with coke and limestone in a kiln, then emptied into a furnace, from which it came out as ore. This was cast into pigs with crystalline or granular structure, and then refined by cold blast, coming out flaky. There were four blast furnaces , with the air delivered by powerful steam engines. The iron was then puddled , becoming granular and malleable. The steam hammers forged the glowing iron into malleable slabs, which were rolled into wrought iron plates. Large quantities of slag from

7380-490: Was considered sufficient for nails . Phosphorus is not necessarily detrimental to iron. Ancient Near Eastern smiths did not add lime to their furnaces. The absence of calcium oxide in the slag, and the deliberate use of wood with high phosphorus content during the smelting, induces a higher phosphorus content (typically <0.3%) than in modern iron (<0.02–0.03%). Analysis of the Iron Pillar of Delhi gives 0.11% in

7470-474: Was critically important. In 1888 Low Moor was converted to a limited liability company, although descendants of the founders retained control. The directors planned two new blast furnaces at the New Works, each 70 feet (21 m) high, with capacities of 340 and 240 tons per week. The first came into operation in 1892. In 1905 an electrical power station was built at the New Works, with boilers fired by gas from

7560-515: Was hypothesized that the type of iron had been rejected for conversion to steel but excelled when tested for drawing ability. During the Han dynasty (202 BC – 220 AD), new iron smelting processes led to the manufacture of new wrought iron implements for use in agriculture, such as the multi-tube seed drill and iron plough . In addition to accidental lumps of low-carbon wrought iron produced by excessive injected air in ancient Chinese cupola furnaces . The ancient Chinese created wrought iron by using

7650-477: Was moved to the Blists Hill site of Ironbridge Gorge Museum for preservation. Some wrought iron is still being produced for heritage restoration purposes, but only by recycling scrap. The slag inclusions, or stringers , in wrought iron give it properties not found in other forms of ferrous metal. There are approximately 250,000 inclusions per square inch. A fresh fracture shows a clear bluish color with

7740-445: Was not the intention. However, the design of a bloomery made it difficult to reach the melting point of iron and also prevented the concentration of carbon monoxide from becoming high. After smelting was complete, the bloom was removed, and the process could then be started again. It was thus a batch process, rather than a continuous one such as a blast furnace. The bloom had to be forged mechanically to consolidate it and shape it into

7830-541: Was of little advantage in Sweden, which lacked coal. Gustaf Ekman observed charcoal fineries at Ulverston , which were quite different from any in Sweden. After his return to Sweden in the 1830s, he experimented and developed a process similar to puddling but used firewood and charcoal, which was widely adopted in the Bergslagen in the following decades. In 1925, James Aston of the United States developed

7920-486: Was sold to a partnership of Richard Hird, a country gentleman, John Preston and John Jarratt for £34,000. After some sales of shares the partners were Richard Hird, Joseph Dawson, a minister, and John Hardy, a solicitor. Dawson was interested in metallurgy and chemistry and was a close friend of Dr. Joseph Priestley . He seems to have been the prime mover in the enterprise. The partners planned to found an ironworks, and engaged an engineer from Wigan named Smalley to build

8010-473: Was the chemical composition and others that it was whether the iron heated sufficiently to melt and "fuse". Fusion eventually became generally accepted as relatively more important than composition below a given low carbon concentration. Another difference is that steel can be hardened by heat treating . Historically, wrought iron was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require

8100-557: Was wholly within the West Riding of Yorkshire until the reform of local government in 1974. The upper valley is within the Yorkshire Dales and Yorkshire Dales National Park . From Aire Springs the river flows past Skipton and Keighley, through Bingley, Saltaire , Shipley and into Leeds. Until this point the river is essentially swift flowing and fed by streams and becks . The broad definition of Airedale includes all

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