123-697: The Clyde Arc (known locally as the Squinty Bridge ) is a road bridge spanning the River Clyde in Glasgow , Scotland, connecting Finnieston near the SEC Armadillo and SEC with Pacific Quay and Glasgow Science Centre in Govan . Prominent features of the bridge are its innovative curved design, and that it crosses the river at an angle. The Arc is the first city centre traffic crossing over
246-549: A river source heat pump scheme in the area called Queens Quay. It is the first large heat pump scheme in Britain to deliver at 80 °C. The heat pumps were supplied by Star Refrigeration Ltd, who manufactured them in their Glasgow factory. The project was delivered by Vital Energi. Steel Steel is an alloy of iron and carbon with improved strength and fracture resistance compared to other forms of iron. Because of its high tensile strength and low cost, steel
369-557: A 46-ton cutter, was built by Scotts of Greenock in 1803. The pre-eminent Scottish yacht designer William Fyfe did not start designing yachts until 1807. The first yacht club on the Clyde was the Northern Yacht Club , which was established in 1824 and received its royal charter in 1831. The club was founded to organise and encourage the sport of yacht racing. By 1825, Scottish and Irish clubs were racing against each other on
492-412: A BOS process is manufactured in one-twelfth the time. Today, electric arc furnaces (EAF) are a common method of reprocessing scrap metal to create new steel. They can also be used for converting pig iron to steel, but they use a lot of electrical energy (about 440 kWh per metric ton), and are thus generally only economical when there is a plentiful supply of cheap electricity. The steel industry
615-530: A Celtic language—most likely Old British . But there is more than one old Celtic word that the river's name could plausibly derive from. One possible root is the Common Brittonic Clywwd , meaning 'loud' or 'loudly'. More likely, the river was named after a local Celtic goddess, Clōta . The goddess's name in turn derives from an older, Proto-Celtic word meaning 'the strongly flowing one' or 'the holy cleanser'. Humans have settled along
738-478: A brief closure the bridge would have to remain closed for six months. In addition traffic on the river below was also halted. In March Nuttall began installing five temporary saddle frames atop the bridge's arch; these allowed the weight of the bridge to be supported without the hangers. This allowed them to replace defective fork connectors at the top and bottom of each hanger. The bridge recommenced on 28 June 2008 with just two of its four lanes in use, having had all
861-713: A carbon-intermediate steel by the 1st century AD. There is evidence that carbon steel was made in Western Tanzania by the ancestors of the Haya people as early as 2,000 years ago by a complex process of "pre-heating" allowing temperatures inside a furnace to reach 1300 to 1400 °C. Evidence of the earliest production of high carbon steel in South Asia is found in Kodumanal in Tamil Nadu ,
984-444: A change of volume. In this case, expansion occurs. Internal stresses from this expansion generally take the form of compression on the crystals of martensite and tension on the remaining ferrite, with a fair amount of shear on both constituents. If quenching is done improperly, the internal stresses can cause a part to shatter as it cools. At the very least, they cause internal work hardening and other microscopic imperfections. It
1107-428: A ferrite BCC crystal form, but at higher carbon content it takes a body-centred tetragonal (BCT) structure. There is no thermal activation energy for the transformation from austenite to martensite. There is no compositional change so the atoms generally retain their same neighbours. Martensite has a lower density (it expands during the cooling) than does austenite, so that the transformation between them results in
1230-651: A few miles from the river, was constructed later by the Romans as a means of defending the area against invasion by the Picts . Despite the strategic location and flat terrain of Glasgow and the surrounding Clyde basin, no Roman civilian settlement was ever constructed. Instead, the region may have functioned as a frontier zone between the Roman province known as Britannia Inferior and the Caledonians , an indigenous group that
1353-445: A hard but brittle martensitic structure. The steel is then tempered, which is just a specialized type of annealing, to reduce brittleness. In this application the annealing (tempering) process transforms some of the martensite into cementite, or spheroidite and hence it reduces the internal stresses and defects. The result is a more ductile and fracture-resistant steel. When iron is smelted from its ore, it contains more carbon than
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#17327878805511476-457: A heat source. The flow rate downstream alone is around 50 m /s. Reducing this temperature by 3 °C would enable river heat pumps to extract 188.1 MW of heat. Since river heat pumps typically have an efficiency of 3.0, the heat deliverable is 1.5 times the river component. As a result, the estuary could deliver 282 MW of heat. The temperature of industrial heat pump delivery is typically 80 °C. In 2020, West Dunbartonshire Council deployed
1599-454: A long but declining history of coal usage and, beginning around the 1950s, an increasing reliance on petroleum fuels. The decline of hydrocarbon pollution was followed by the appearance of PCB concentrations in the 1950s. Total PCB concentration levels peaked in the period 1965 to 1977, and declined beginning in the 1990s. The Polmadie Burn , which flows into the Clyde at Richmond Park , remains heavily contaminated by hexavalent chromium , to
1722-412: A narrow range of concentrations of mixtures of carbon and iron that make steel, several different metallurgical structures, with very different properties can form. Understanding such properties is essential to making quality steel. At room temperature , the most stable form of pure iron is the body-centred cubic (BCC) structure called alpha iron or α-iron. It is a fairly soft metal that can dissolve only
1845-597: A naval defence contractor, BAE Systems Surface Ships , which specialises in the design and construction of technologically advanced warships for the Royal Navy and other navies around the world. The two yards are the former Yarrow yard at Scotstoun , and Fairfields at Govan. In addition, the King George V Dock is operated by the Clyde Port Authority . Ferguson Shipbuilders , at Port Glasgow on
1968-534: A small concentration of carbon, no more than 0.005% at 0 °C (32 °F) and 0.021 wt% at 723 °C (1,333 °F). The inclusion of carbon in alpha iron is called ferrite . At 910 °C, pure iron transforms into a face-centred cubic (FCC) structure, called gamma iron or γ-iron. The inclusion of carbon in gamma iron is called austenite. The more open FCC structure of austenite can dissolve considerably more carbon, as much as 2.1%, (38 times that of ferrite) carbon at 1,148 °C (2,098 °F), which reflects
2091-478: A small workshop at Sandbank in 1876, and went on to become one of the foremost wooden boat builders on the Clyde. The 'golden years' of Robertson's yard were in the early 20th century, when they started building classic 12-and-15-metre (39 and 49 ft) racing yachts. More than 55 boats were built by Robertson's in preparation for World War I, and the yard remained busy even during the Great Depression in
2214-453: A steel's final rolling, it is heat treated for strength; however, this is relatively rare. Steel was known in antiquity and was produced in bloomeries and crucibles . The earliest known production of steel is seen in pieces of ironware excavated from an archaeological site in Anatolia ( Kaman-Kalehöyük ) which are nearly 4,000 years old, dating from 1800 BC. Wootz steel
2337-428: A time for repair and maintenance without affecting its operation. However, our number one priority is public safety and until we are completely satisfied the bridge is safe to use, it will remain closed. A detailed inspection on 24 January found a stress fracture in a second support cable stay, like the one which had failed previously. Engineers determined that all of these connectors would have to be replaced; rather than
2460-672: Is continuously cast into long slabs, cut and shaped into bars and extrusions and heat treated to produce a final product. Today, approximately 96% of steel is continuously cast, while only 4% is produced as ingots. The ingots are then heated in a soaking pit and hot rolled into slabs, billets , or blooms . Slabs are hot or cold rolled into sheet metal or plates. Billets are hot or cold rolled into bars, rods, and wire. Blooms are hot or cold rolled into structural steel , such as I-beams and rails . In modern steel mills these processes often occur in one assembly line , with ore coming in and finished steel products coming out. Sometimes after
2583-550: Is 5.4 m (18 ft). It was officially opened on 18 September 2006 by Glasgow City Council leader Steven Purcell , although pedestrians were allowed to walk across it the previous two days as part of Glasgow's annual " Doors Open " Weekend. The bridge connects Finnieston Street on the north bank of the river to Govan Road on the southern bank. The bridge takes four lanes of traffic, two of which are dedicated to public transport and two for private and commercial traffic. There are also pedestrian and cycle paths. The new bridge
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#17327878805512706-414: Is around half a mile distant from the Clyde. It is said to have constructed over 500 vessels, many of which were assembled and then 'knocked down' to kit form for despatch to a remote location, such as Chauncy Maples . Clyde shipbuilding reached its peak in the years just before World War I: It is estimated that, in the year 1913 alone, over 370 ships were completed. The first recorded Clyde racing yacht,
2829-403: Is common for quench cracks to form when steel is water quenched, although they may not always be visible. There are many types of heat treating processes available to steel. The most common are annealing , quenching , and tempering . Annealing is the process of heating the steel to a sufficiently high temperature to relieve local internal stresses. It does not create a general softening of
2952-411: Is designed to last 120 years. The bridge has a main span of 96 m (315 ft) with two end spans of 36.5 m (120 ft), resulting in a total span of 169 m (554 ft). The design of the main span features a steel arch. The supports for the main span are located within the river with the abutments located behind the existing quay walls. The central navigation height at mean water height
3075-403: Is desirable. To become steel, it must be reprocessed to reduce the carbon to the correct amount, at which point other elements can be added. In the past, steel facilities would cast the raw steel product into ingots which would be stored until use in further refinement processes that resulted in the finished product. In modern facilities, the initial product is close to the final composition and
3198-453: Is distinguishable from wrought iron (now largely obsolete), which may contain a small amount of carbon but large amounts of slag . Iron is commonly found in the Earth's crust in the form of an ore , usually an iron oxide, such as magnetite or hematite . Iron is extracted from iron ore by removing the oxygen through its combination with a preferred chemical partner such as carbon which
3321-408: Is heat treated to contain both a ferritic and martensitic microstructure to produce a formable, high strength steel. Transformation Induced Plasticity (TRIP) steel involves special alloying and heat treatments to stabilize amounts of austenite at room temperature in normally austenite-free low-alloy ferritic steels. By applying strain, the austenite undergoes a phase transition to martensite without
3444-535: Is known as stainless steel . Tungsten slows the formation of cementite , keeping carbon in the iron matrix and allowing martensite to preferentially form at slower quench rates, resulting in high-speed steel . The addition of lead and sulphur decrease grain size, thereby making the steel easier to turn , but also more brittle and prone to corrosion. Such alloys are nevertheless frequently used for components such as nuts, bolts, and washers in applications where toughness and corrosion resistance are not paramount. For
3567-691: Is often considered an indicator of economic progress, because of the critical role played by steel in infrastructural and overall economic development . In 1980, there were more than 500,000 U.S. steelworkers. By 2000, the number of steelworkers had fallen to 224,000. The economic boom in China and India caused a massive increase in the demand for steel. Between 2000 and 2005, world steel demand increased by 6%. Since 2000, several Indian and Chinese steel firms have expanded to meet demand, such as Tata Steel (which bought Corus Group in 2007), Baosteel Group and Shagang Group . As of 2017 , though, ArcelorMittal
3690-514: Is one of the largest manufacturing industries in the world, but also one of the most energy and greenhouse gas emission intense industries, contributing 8% of global emissions. However, steel is also very reusable: it is one of the world's most-recycled materials, with a recycling rate of over 60% globally . The noun steel originates from the Proto-Germanic adjective * * stahliją or * * stakhlijan 'made of steel', which
3813-463: Is one of the most commonly manufactured materials in the world. Steel is used in buildings, as concrete reinforcing rods, in bridges, infrastructure, tools, ships, trains, cars, bicycles, machines, electrical appliances, furniture, and weapons. Iron is always the main element in steel, but many other elements may be present or added. Stainless steels , which are resistant to corrosion and oxidation , typically need an additional 11% chromium . Iron
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3936-551: Is one of the world's most-recycled materials, with a recycling rate of over 60% globally; in the United States alone, over 82,000,000 metric tons (81,000,000 long tons; 90,000,000 short tons) were recycled in the year 2008, for an overall recycling rate of 83%. As more steel is produced than is scrapped, the amount of recycled raw materials is about 40% of the total of steel produced - in 2016, 1,628,000,000 tonnes (1.602 × 10 long tons; 1.795 × 10 short tons) of crude steel
4059-520: Is possible only by reducing iron's ductility. Steel was produced in bloomery furnaces for thousands of years, but its large-scale, industrial use began only after more efficient production methods were devised in the 17th century, with the introduction of the blast furnace and production of crucible steel . This was followed by the Bessemer process in England in the mid-19th century, and then by
4182-434: Is possible to make very high-carbon (and other alloy material) steels, but such are not common. Cast iron is not malleable even when hot, but it can be formed by casting as it has a lower melting point than steel and good castability properties. Certain compositions of cast iron, while retaining the economies of melting and casting, can be heat treated after casting to make malleable iron or ductile iron objects. Steel
4305-400: Is quite ductile , or soft and easily formed. In steel, small amounts of carbon, other elements, and inclusions within the iron act as hardening agents that prevent the movement of dislocations . The carbon in typical steel alloys may contribute up to 2.14% of its weight. Varying the amount of carbon and many other alloying elements, as well as controlling their chemical and physical makeup in
4428-457: Is related to * * stahlaz or * * stahliją 'standing firm'. The carbon content of steel is between 0.02% and 2.14% by weight for plain carbon steel ( iron - carbon alloys ). Too little carbon content leaves (pure) iron quite soft, ductile, and weak. Carbon contents higher than those of steel make a brittle alloy commonly called pig iron . Alloy steel is steel to which other alloying elements have been intentionally added to modify
4551-441: Is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic . The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron
4674-547: Is the world's largest steel producer . In 2005, the British Geological Survey stated China was the top steel producer with about one-third of the world share; Japan , Russia , and the United States were second, third, and fourth, respectively, according to the survey. The large production capacity of steel results also in a significant amount of carbon dioxide emissions inherent related to
4797-498: Is then lost to the atmosphere as carbon dioxide. This process, known as smelting , was first applied to metals with lower melting points, such as tin , which melts at about 250 °C (482 °F), and copper , which melts at about 1,100 °C (2,010 °F), and the combination, bronze, which has a melting point lower than 1,083 °C (1,981 °F). In comparison, cast iron melts at about 1,375 °C (2,507 °F). Small quantities of iron were smelted in ancient times, in
4920-571: The Clyde Navigation Consolidation Act 1858 ( 21 & 22 Vict. c. cxlix). The Clyde Port Authority Confirmation Act 1965 (c. xlv) replaced the Clyde Navigation Trust with the Clyde Port Authority from 1 January 1966, which has since been renamed to 'Clydeport', and was privatisated in 1992. In 2003 it was acquired by Peel Holdings . The Clyde is formed by the confluence of two streams,
5043-505: The 7th century , Saint Mungo established a new Christian community on the banks of the Clyde, potentially replacing Cathures if this is assumed to have occupied the same locus. This community was the beginnings of what would become the city of Glasgow. Several villages along the Clyde that were founded in or before this period have endured to this day, and have grown to become towns, including Llanerc ( Lanark ), Cadzow ( Hamilton ), and Rhynfrwd ( Renfrew ). The fortress of Altclut fell in
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5166-715: The Daer Water (the headwaters of which are dammed to form the Daer Reservoir ) and the Potrail Water. The Southern Upland Way crosses both streams before they meet at Watermeetings ( grid reference NS953131 ) to form the River Clyde proper. At this point, the Clyde is only 10 km (6 mi) from Tweed's Well, the source of the River Tweed , and is about the same distance from Annanhead Hill ,
5289-463: The Gare Loch , within half a mile of each other. McGruers built over 700 boats. Both yards built many widely-known and classic yachts, some of which are still sailing today. The Glasgow Humane Society is responsible for the safety and preservation of life on Glasgow's waterways. Founded in 1790, it is the oldest lifesaving organisation in the world. During and immediately after World War II ,
5412-655: The Golconda area in Andhra Pradesh and Karnataka , regions of India , as well as in Samanalawewa and Dehigaha Alakanda, regions of Sri Lanka . This came to be known as wootz steel , produced in South India by about the sixth century BC and exported globally. The steel technology existed prior to 326 BC in the region as they are mentioned in literature of Sangam Tamil , Arabic, and Latin as
5535-628: The Industrial Revolution was due to the location of Glasgow, as a port facing the Americas. Tobacco and cotton trade began to drive this economic engine in the early 18th century. However, an obstacle to further economic growth soon became evident: the Clyde was too shallow for the largest ocean-going ships to navigate into it, so cargo had to be transferred, at Greenock or Port Glasgow , to smaller ships that could sail upstream into Glasgow itself. In 1768, John Golborne advised that
5658-597: The River Cart , by many boatyards, including those at Maryhill and Kirkintilloch on the Forth & Clyde Canal , and Blackhill on the Monkland Canal . Over the same time period, it is estimated that more than 300 firms have engaged in shipbuilding on Clydeside, although probably at most 30 to 40 firms were operating at any given time. The shipbuilding firms became household names on Clydeside, and even around
5781-645: The River Tay and the River Spey . It runs through the city of Glasgow . The River Clyde estuary has an upper tidal limit located at the tidal weir next to Glasgow Green . Historically, it was important to the British Empire because of its role in shipbuilding and trade. To the Romans , it was Clota , and in the early medieval Cumbric language , it was known as Clud or Clut . It
5904-601: The Scottish Government . Piling works for the bridge were carried out from a large floating barge on the Clyde, whilst the bridge superstructure was fabricated offsite. The bridge-deck concrete-slab units were cast at an onsite pre-casting yard. Planning permission was granted in 2003 and construction of the bridge began in May 2005. It was structurally completed in April 2006. The bridge project cost an estimated £20.3M and
6027-575: The Siege of Dumbarton of 870 AD, when a force of Norse-Irish raiders from the Kingdom of Dublin sacked it. After that, the kingdom, now politically weakened, possibly moved its capital to Govan . However, it never fully recovered, and in the 11th century it was annexed by the Kingdom of Alba . It did however retain some autonomy under the Church of Glasgow, which became the secular successors of much of
6150-599: The cementation process was described in a treatise published in Prague in 1574 and was in use in Nuremberg from 1601. A similar process for case hardening armour and files was described in a book published in Naples in 1589. The process was introduced to England in about 1614 and used to produce such steel by Sir Basil Brooke at Coalbrookdale during the 1610s. The raw material for this process were bars of iron. During
6273-546: The early modern period onwards, the Clyde began to be used commercially as a trade route; trade between Glasgow and the rest of Europe became commonplace. In the centuries that followed, the Clyde became increasingly vital to both Scotland and Britain as a major trade route for exporting and importing resources. The Clyde Navigation Trust was initially formed in 1840 by the Clyde Navigation Act 1840 ( 3 & 4 Vict. c. cxviii), and then reconstituted under
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#17327878805516396-541: The legions of the Roman Empire arrived in southern Scotland, the river and the area surrounding it had been settled by the Brythonic-speaking Damnonii tribe. It has been suggested that a Damnonii town called Cathures was located there and was the precursor to modern Glasgow. The Damnonii tribe originally likely distributed power among individual chiefdoms, but at some point before 500 AD
6519-607: The open-hearth furnace . With the invention of the Bessemer process, a new era of mass-produced steel began. Mild steel replaced wrought iron . The German states were the major steel producers in Europe in the 19th century. American steel production was centred in Pittsburgh , Bethlehem, Pennsylvania , and Cleveland until the late 20th century. Currently, world steel production is centered in China, which produced 54% of
6642-445: The 17th century, it was realized that the best steel came from oregrounds iron of a region north of Stockholm , Sweden. This was still the usual raw material source in the 19th century, almost as long as the process was used. Crucible steel is steel that has been melted in a crucible rather than having been forged , with the result that it is more homogeneous. Most previous furnaces could not reach high enough temperatures to melt
6765-475: The 17th century, the first step in European steel production has been the smelting of iron ore into pig iron in a blast furnace . Originally employing charcoal, modern methods use coke , which has proven more economical. In these processes, pig iron made from raw iron ore was refined (fined) in a finery forge to produce bar iron , which was then used in steel-making. The production of steel by
6888-559: The 1930s, as many wealthy businessmen developed a passion for yacht racing on the Clyde. During World War II, the yard was devoted to Admiralty work, producing large, high-speed Fairmile Marine motor boats (motor torpedo boats and motor gun boats). After the war, the yard built the successful one-class Loch Longs and two 12 m (39 ft) challengers for the America's Cup , designed by David Boyd: Sceptre (1958) and Sovereign (1964). Because of difficult business conditions in 1965,
7011-458: The 1970s, and completed eastward in 2005, is a foot-and mountain-bike path that follows the course of the Clyde between Glasgow and New Lanark . Scottish Natural Heritage has designated it one of Scotland's Great Trails . The British Geological Survey has identified and evaluated organic chemical pollutants in the sediment of the Clyde estuary. Surface sediments from the Glasgow reaches of
7134-608: The Arabs from Persia, who took it from India. It was originally created from several different materials including various trace elements , apparently ultimately from the writings of Zosimos of Panopolis . In 327 BC, Alexander the Great was rewarded by the defeated King Porus , not with gold or silver but with 30 pounds of steel. A recent study has speculated that carbon nanotubes were included in its structure, which might explain some of its legendary qualities, though, given
7257-540: The Clyde and Cuningar to Milton , were previously found to contain polyaromatic hydrocarbons (PAH) from 630 μg/kg to 23,711 μg/kg and polychlorinated biphenyl (PCB) in the range of 5 to 130.5 μg/kg, which puts these sediments in the range classified as "non-toxic." However, a later study showed PCB concentrations as high as 5,797 μg/kg, which is above published threshold levels for such chlorinated compounds. A comparison between individual PAH compounds that have different thermal stabilities shows that
7380-470: The Clyde since the Paleolithic era. Artifacts dating from 12,000 BC have been found near Biggar , a rural town close to the river. Biggar is home to an archeological site at which Britain's most ancient artifacts have been unearthed. Prehistoric canoes , used by ancient peoples for transport or trade, have been found in the river. There are a number of Mesolithic sites along the Clyde, especially in
7503-542: The Clyde's importance as a major industrial centre rapidly declined. During the war, the Luftwaffe singled out Clydebank for bombing , and its buildings sustained heavy damage. In the immediate postwar period, the sharp reduction in warship orders was initially balanced by a prolonged boom in merchant shipbuilding. But by the end of the 1950s, other countries had begun to establish well-capitalised and highly productive shipbuilding centres that were able to outcompete many of
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#17327878805517626-407: The Clyde. By the mid-19th century, yachting and yacht building had become widely popular. The Clyde became famous worldwide for its significant contribution to yachting and yachtbuilding, and was the home of many notable designers: William Fife III , Alfred Mylne , G. L. Watson , E. McGruer, and David Boyd. It was also home to many famous yacht yards. Robertson's Yard started repairing boats in
7749-516: The European shipbuilding yards. Several Clydeside yards booked a series of loss-making contracts in the hope of weathering the storm, but their unprofitable circumstances continued for too long, and by the mid-1960s they faced potential collapse. Harland and Wolff 's Linthouse yard went under, and Fairfields of Govan faced bankruptcy. The government tried to limit the decline by creating the Upper Clyde Shipbuilders consortium, but
7872-644: The Glasgow Garden Festival 1988 as part of the re-use of city docklands and associated industrial uses led by the Scottish Development Agency in the 1980s and early 90s. The Clyde Waterfront Regeneration project from 2008 aims to continue this approach of finding new uses and attracting new investment, from Glasgow Green to Dumbarton. Residents and tourists come back to the riverside, especially in Glasgow, where vast former docklands have given way to housing and amenities on
7995-470: The Linz-Donawitz process of basic oxygen steelmaking (BOS), developed in 1952, and other oxygen steel making methods. Basic oxygen steelmaking is superior to previous steelmaking methods because the oxygen pumped into the furnace limited impurities, primarily nitrogen, that previously had entered from the air used, and because, with respect to the open hearth process, the same quantity of steel from
8118-516: The Lower Clyde, is now owned by the Scottish government. It is the last survivor of the many shipyards that once dominated Port Glasgow and Greenock. Its core business is now the construction of car ferries . Major regeneration schemes include those in the 1970s of forming Strathclyde Country Park , lying between Hamilton and Motherwell, as part of motorway developments; the establishment of
8241-568: The Upper Clyde Valley. Permanent settlements and structures, including what is believed to be a temple to moon gods in Govan , were constructed in the area during the Neolithic and Bronze Ages . Celtic art, language, and other aspects of culture began spreading to the area from the south during this period, and prehistoric artifacts suggest that, by around 1000 BCE, they had become the dominant cultural influences there. Before
8364-468: The amounts of PBDE compounds revealed a decline in certain compounds, in line with the European ban on production of mixtures containing environmentally harmful PBDE with eight and nine bromine atoms. At the same time, there was an increase in the amounts of the less harmful mixture, composed of ten bromine atoms. The River Clyde, or more accurately the Clyde Estuary, has significant potential as
8487-436: The austenite grain boundaries until the percentage of carbon in the grains has decreased to the eutectoid composition (0.8% carbon), at which point the pearlite structure forms. For steels that have less than 0.8% carbon (hypoeutectoid), ferrite will first form within the grains until the remaining composition rises to 0.8% of carbon, at which point the pearlite structure will form. No large inclusions of cementite will form at
8610-471: The austenite is for it to precipitate out of solution as cementite , leaving behind a surrounding phase of BCC iron called ferrite with a small percentage of carbon in solution. The two, cementite and ferrite, precipitate simultaneously producing a layered structure called pearlite , named for its resemblance to mother of pearl . In a hypereutectoid composition (greater than 0.8% carbon), the carbon will first precipitate out as large inclusions of cementite at
8733-684: The banks in the city. Examples of public amenities and attractions include the Scottish Exhibition and Conference Centre , the Glasgow Science Centre , and the Riverside Museum . Merchant shipping has largely moved west, closer to deeper water at Greenock, and 20 miles beyond that, south, to Hunterston. The river's water is increasingly used for recreation now that industrial uses have diminished. The Clyde Walkway , originating at Glasgow's Custom House Quay in
8856-494: The boundaries in hypoeutectoid steel. The above assumes that the cooling process is very slow, allowing enough time for the carbon to migrate. As the rate of cooling is increased the carbon will have less time to migrate to form carbide at the grain boundaries but will have increasingly large amounts of pearlite of a finer and finer structure within the grains; hence the carbide is more widely dispersed and acts to prevent slip of defects within those grains, resulting in hardening of
8979-523: The cast steel connectors replaced with milled steel connectors. Once reopened, Glasgow City Council estimated that 6,500 crossings will be made every day using the bridge. New Civil Engineer reported subcontractor Watson Steel Structures was suing Macalloy , the supplier of the failed connectors, for £1.8 million. Watson alleged components obtained from Macalloy did not meet British Standards or their own specifications; parts were inadequately manufactured, and did not tally with test certificates provided by
9102-521: The characteristics of steel. Common alloying elements include: manganese , nickel , chromium , molybdenum , boron , titanium , vanadium , tungsten , cobalt , and niobium . Additional elements, most frequently considered undesirable, are also important in steel: phosphorus , sulphur , silicon , and traces of oxygen , nitrogen , and copper . Plain carbon-iron alloys with a higher than 2.1% carbon content are known as cast iron . With modern steelmaking techniques such as powder metal forming, it
9225-403: The connecting fork on one of the bridge's 14 hangers (supporting cables that transfer the weight of the roadway to the bridge's arch) snapped; Strathclyde Police quickly closed the bridge to traffic. Robert Booth, a spokesman for Glasgow City Council said: We don't believe the integrity of the bridge is affected. The Clyde Arc is designed to allow for the removal of one of the bridge supports at
9348-537: The consortium became mired in controversy and collapsed in 1971. After that, James Callaghan 's Labour government implemented the Aircraft and Shipbuilding Industries Act 1977 (c. 3), which nationalised most of the Clyde's shipyards and grouped them with other major British shipyards, such as the firm British Shipbuilders . Today, two major shipyards on the Upper Clyde remain in operation. They are both owned by
9471-422: The desired properties. Nickel and manganese in steel add to its tensile strength and make the austenite form of the iron-carbon solution more stable, chromium increases hardness and melting temperature, and vanadium also increases hardness while making it less prone to metal fatigue . To inhibit corrosion, at least 11% chromium can be added to steel so that a hard oxide forms on the metal surface; this
9594-425: The exchange of military information. The Romans did, however, construct several forts ( castra ) in the area, notably on the banks of the Clyde. These include Castledykes, Bothwellhaugh , and Old Kilpatrick and Bishopton . The Romans also constructed several roads along the river, both small ones and larger ones designed to be used as trade routes and to carry entire legions. The Antonine Wall , which lies only
9717-528: The extent it turned bright green in 2019, and yellow in 2021. Although pollution from heavy industry and power generation has been decreasing, there is evidence that human-made pollution from new synthetic compounds in electrical products and textiles has been increasing. The amounts of 16 polybrominated diphenyl ether (PBDE) compounds used as flame retardants in televisions, computers, and furniture upholstery were measured in sediment cores collected from six sites between Princes Dock and Greenock. Comparison of
9840-413: The final steel (either as solute elements, or as precipitated phases), impedes the movement of the dislocations that make pure iron ductile, and thus controls and enhances its qualities. These qualities include the hardness , quenching behaviour , need for annealing , tempering behaviour , yield strength , and tensile strength of the resulting steel. The increase in steel's strength compared to pure iron
9963-596: The finest steel in the world exported to the Roman, Egyptian, Chinese and Arab worlds at that time – what they called Seric Iron . A 200 BC Tamil trade guild in Tissamaharama , in the South East of Sri Lanka, brought with them some of the oldest iron and steel artifacts and production processes to the island from the classical period . The Chinese and locals in Anuradhapura , Sri Lanka had also adopted
10086-603: The firm. Macalloy denied the claim and countered Watson Steel Structures Ltd had only specified minimum yield stress for the components. River Clyde The River Clyde ( Scottish Gaelic : Abhainn Chluaidh , pronounced [ˈavɪɲ ˈxl̪ˠuəj] ) is a river that flows into the Firth of Clyde , in the west of Scotland. It is the ninth-longest river in the United Kingdom, and the third longest in Scotland after
10209-513: The form of charcoal) in a crucible, was produced in Merv by the 9th to 10th century AD. In the 11th century, there is evidence of the production of steel in Song China using two techniques: a "berganesque" method that produced inferior, inhomogeneous steel, and a precursor to the modern Bessemer process that used partial decarburization via repeated forging under a cold blast . Since
10332-599: The hardenability of thick sections. High strength low alloy steel has small additions (usually < 2% by weight) of other elements, typically 1.5% manganese, to provide additional strength for a modest price increase. Recent corporate average fuel economy (CAFE) regulations have given rise to a new variety of steel known as Advanced High Strength Steel (AHSS). This material is both strong and ductile so that vehicle structures can maintain their current safety levels while using less material. There are several commercially available grades of AHSS, such as dual-phase steel , which
10455-466: The increased flow of the newly constrained water wore away the river bottom. In other cases, dredging was required to deepen the river. In the mid-19th century, engineers took on the task of dredging the Clyde much more extensively. They removed millions of cubic feet of silt to deepen and widen the channel. The major stumbling block encountered by that project was a massive geological intrusion known as Elderslie Rock . Because that rock increased
10578-518: The machinery needed to drive these vessels, including the boilers, pumps, and steering gear, including Rankin & Blackmore , Hastie's and Kincaid 's of Greenock, Rowan's of Finnieston, Weir's of Cathcart, Howden's of Tradeston, and Babcock & Wilcox of Renfrew. One shipyard that was known as a 'Clyde' shipyard was not actually located on any of the Clyde's waterways: Alley & MacLellan 's Sentinel Works in Jessie Street at Polmadie
10701-439: The main production route. At the end of 2008, the steel industry faced a sharp downturn that led to many cut-backs. In 2021, it was estimated that around 7% of the global greenhouse gas emissions resulted from the steel industry. Reduction of these emissions are expected to come from a shift in the main production route using cokes, more recycling of steel and the application of carbon capture and storage technology. Steel
10824-450: The most part, however, p-block elements such as sulphur, nitrogen , phosphorus , and lead are considered contaminants that make steel more brittle and are therefore removed from steel during the melting processing. The density of steel varies based on the alloying constituents but usually ranges between 7,750 and 8,050 kg/m (484 and 503 lb/cu ft), or 7.75 and 8.05 g/cm (4.48 and 4.65 oz/cu in). Even in
10947-489: The open sea. Shipping and shipbuilding grow in Glasgow and its neighbouring industrial burghs of Govan and Partick ; with the Clyde, including is lower reaches, becoming the centre of world shipbuilding. The river then flows west, out of Glasgow, past Renfrew , under the Erskine Bridge , and past Dumbarton on the northern shore and the sandbank at Ardmore Point between Cardross and Helensburgh . Opposite, on
11070-436: The oxidation rate of iron increases rapidly beyond 800 °C (1,470 °F), it is important that smelting take place in a low-oxygen environment. Smelting, using carbon to reduce iron oxides, results in an alloy ( pig iron ) that retains too much carbon to be called steel. The excess carbon and other impurities are removed in a subsequent step. Other materials are often added to the iron/carbon mixture to produce steel with
11193-480: The political framework was a British culture of Welsh speakers that was politically unified and formed a centralised kingdom known as Alt Clut, representing the power centre at Dunbarton Rock. None of the documentary or archaeological evidence from the period when the Roman legions arrived suggests that battles took place in the area. Therefore the Roman legions and Damnonii tribespeople are assumed to have been on good terms and to have co-operated by means of trade and
11316-471: The power of the Falls of Clyde , the most spectacular of which is Cora Linn. A hydroelectric power station still generates 11MW of electricity there today, although the mills have now become a museum and World Heritage Site . The river then makes its way northwest, past the towns of Wishaw to the east of it and Larkhall to the west of it. The river's surroundings here become increasingly suburban. Between
11439-579: The problem, so in 1773, a training wall called the Lang Dyke was built on the Dumbuck shoal to stop water flowing over into the southern channel of the river. In the late 18th and early 19th centuries, hundreds of jetties were built out from the banks of the river between Dumbuck and the Broomielaw quay in Glasgow proper. In some cases, this construction had the effect of deepening the river, because
11562-449: The product but only locally relieves strains and stresses locked up within the material. Annealing goes through three phases: recovery , recrystallization , and grain growth . The temperature required to anneal a particular steel depends on the type of annealing to be achieved and the alloying constituents. Quenching involves heating the steel to create the austenite phase then quenching it in water or oil . This rapid cooling results in
11685-759: The production methods of creating wootz steel from the Chera Dynasty Tamils of South India by the 5th century AD. In Sri Lanka, this early steel-making method employed a unique wind furnace, driven by the monsoon winds, capable of producing high-carbon steel. Since the technology was acquired from the Tamilians from South India, the origin of steel technology in India can be conservatively estimated at 400–500 BC. The manufacture of wootz steel and Damascus steel , famous for its durability and ability to hold an edge, may have been taken by
11808-399: The project's difficulty, the work was not completed until the 1880s. Around this time, the Clyde became an important source of inspiration for artists, such as John Atkinson Grimshaw and James Kay , who were interested in painting scenes that depicted the new industrial era and the modern world. The completion of the dredging was well-timed, because the channel finally became navigable all
11931-475: The river built since the Kingston Bridge was opened to traffic in 1970. The bridge was named the "Clyde Arc" upon its official opening on 18 September 2006. It had been previously known as the "Finnieston Bridge", or the "Squinty Bridge". The Clyde Arc was designed by Halcrow Group and built by BAM Nuttall . Glasgow City Council instigated the project in conjunction with Scottish Enterprise and
12054-510: The river should be made narrower and the scour increased by constructing rubble jetties and dredging sandbanks and shoals . Another obstacle to navigation that had to be solved was that the river divided into two shallow channels by the Dumbuck shoal near Dumbarton . After James Watt 's 1769 report describing this problem, a jetty was constructed at Longhaugh Point to block off the southern channel. This turned out to be insufficient to solve
12177-589: The river's shipyards were given contracts to build prestigious ocean-going liners, as well as warships. The Queen Mary and, in later years, the Queen Elizabeth 2 were built in the town of Clydebank . Between 1712, when the Scott family's shipyard was built at Greenock, and the present day, over 25,000 ships have been built on the River Clyde, its firth, and its tributaries , the River Kelvin and
12300-477: The solid-state, by heating the ore in a charcoal fire and then welding the clumps together with a hammer and in the process squeezing out the impurities. With care, the carbon content could be controlled by moving it around in the fire. Unlike copper and tin, liquid or solid iron dissolves carbon quite readily. All of these temperatures could be reached with ancient methods used since the Bronze Age . Since
12423-595: The source of PAH pollution in the Clyde is different in different parts of the river. PAH in the inner Clyde (Cuningar to Milton) are from combustion sources (vehicle exhaust, coal burning), whereas PAH in the outer Clyde are from petroleum spills. The amount and type of sedimentary pollution in the Clyde reflects the area's industrial history. In order to assess how the nature of the pollutants has changed over time, from 1750 to 2002, seven sediment cores of one metre's depth were collected, and dated using lead concentrations and changing lead isotope ratios. The sediments showed
12546-458: The source of the River Annan . From there, it meanders northeastward before turning to the west, where its flood plain serve as the site of many major roads in the area, then reaches the town of Lanark , where the late 17th- and early 18th-century industrialists David Dale and Robert Owen built mills and the model settlement of New Lanark on the banks of the Clyde. The mills harnessed
12669-459: The southeastern part of Glasgow, the river begins to widen, meandering through Cambuslang , Rutherglen , and Dalmarnock , and past Glasgow Green . From the Tidal Weir westwards, the river is tidal : a mix of fresh and salt water. Over three centuries the river has been engineered and widened where it passes through Glasgow city centre and onwards towards Dumbarton and Greenock and
12792-509: The southern shore, is the last remaining Lower Clyde shipyard, at Port Glasgow . The river continues on to Greenock , where it reaches the Tail of the Bank as the river merges into the Firth of Clyde . Here at the mouth of the Clyde, there is currently a significant ecological problem of oxygen depletion in the water column. The economic prosperity that the Clyde made possible at the beginning of
12915-401: The steel. At the very high cooling rates produced by quenching, the carbon has no time to migrate but is locked within the face-centred austenite and forms martensite . Martensite is a highly strained and stressed, supersaturated form of carbon and iron and is exceedingly hard but brittle. Depending on the carbon content, the martensitic phase takes different forms. Below 0.2% carbon, it takes on
13038-561: The steel. The early modern crucible steel industry resulted from the invention of Benjamin Huntsman in the 1740s. Blister steel (made as above) was melted in a crucible or in a furnace, and cast (usually) into ingots. The modern era in steelmaking began with the introduction of Henry Bessemer 's process in 1855, the raw material for which was pig iron. His method let him produce steel in large quantities cheaply, thus mild steel came to be used for most purposes for which wrought iron
13161-561: The technology of that time, such qualities were produced by chance rather than by design. Natural wind was used where the soil containing iron was heated by the use of wood. The ancient Sinhalese managed to extract a ton of steel for every 2 tons of soil, a remarkable feat at the time. One such furnace was found in Samanalawewa and archaeologists were able to produce steel as the ancients did. Crucible steel , formed by slowly heating and cooling pure iron and carbon (typically in
13284-607: The territory when it was treated as a Principality of the Scottish Crown. In the 13th century, Glasgow, then still a small town, built its first bridge over the river Clyde. This was an important step in its ability to eventually grow into a city. The establishment, in the 15th century, of both the University of Glasgow and the Archdiocese of Glasgow , vastly increased the importance of the town within Scotland. From
13407-482: The towns of Motherwell and Hamilton , the course of the river has been altered to create an artificial loch within Strathclyde Park . Part of the original course can still be seen: It lies between the island and the eastern shore of the loch. The river then flows through Blantyre and Bothwell , where the ruined Bothwell Castle stands on a defensible promontory . As it flows past Uddingston and into
13530-525: The upper carbon content of steel, beyond which is cast iron. When carbon moves out of solution with iron, it forms a very hard, but brittle material called cementite (Fe 3 C). When steels with exactly 0.8% carbon (known as a eutectoid steel), are cooled, the austenitic phase (FCC) of the mixture attempts to revert to the ferrite phase (BCC). The carbon no longer fits within the FCC austenite structure, resulting in an excess of carbon. One way for carbon to leave
13653-475: The way from Greenock to Glasgow just when the steelwork industry had begun to grow in the city. Shipbuilding replaced trade as the major activity on the river, and shipbuilding companies started rapidly establishing themselves there. The Clyde soon gained a reputation for being the best location for shipbuilding in the British Empire , and grew to become the world's pre-eminent shipbuilding centre. The term Clydebuilt became an industry symbol of high quality, and
13776-418: The world to some extent. These included, among many others, John Brown & Company of Clydebank, Denny of Dumbarton, Scott of Greenock, Lithgows of Port Glasgow, Simon and Lobnitz of Renfrew, Alexander Stephen & Sons of Linthouse, Fairfield of Govan, Inglis of Pointhouse, Barclay Curle of Whiteinch, Connell and Yarrow of Scotstoun. Almost as famous were the engineering firms that supplied
13899-428: The world's steel in 2023. Further refinements in the process, such as basic oxygen steelmaking (BOS), largely replaced earlier methods by further lowering the cost of production and increasing the quality of the final product. Today more than 1.6 billion tons of steel is produced annually. Modern steel is generally identified by various grades defined by assorted standards organizations . The modern steel industry
14022-465: The yard turned to doing GRP production work (mainly building Pipers and Etchells), and it closed in 1980. During its 104-year history, Robertson's Yard built 500 boats, many of which are still sailing today. Two other notable boatyards on the Clyde were Silvers, which operated from 1910 to 1970, and McGruers, which operated from 1910 to 1973. They were situated on the Rosneath peninsula on the banks of
14145-477: Was built to provide better access to Pacific Quay and allow better access to regeneration areas on both banks of the Clyde. The bridge has been designed to cope with a possible light rapid transit system (light railway scheme) or even a tram system. The bridge is the first part of several development projects planned to regenerate Glasgow. The £40M Tradeston Bridge was also completed (a further proposed pedestrian bridge linking Springfield Quay with Lancefield Quay
14268-527: Was central to the Kingdom of Strathclyde ( Teyrnas Ystrad Clut ). The exact etymology of the river's name is unclear, though it is known that the name is ancient. In 50AD, the Egyptian mathematician, astronomer and geographer Claudius Ptolemy wrote of the river as "Klōta", It was called Clut or Clud by the Britons and Clota by the Romans. It is therefore likely that the name comes from
14391-718: Was developed in Southern India and Sri Lanka in the 1st millennium BCE. Metal production sites in Sri Lanka employed wind furnaces driven by the monsoon winds, capable of producing high-carbon steel. Large-scale wootz steel production in India using crucibles occurred by the sixth century BC, the pioneering precursor to modern steel production and metallurgy. High-carbon steel was produced in Britain at Broxmouth Hillfort from 490–375 BC, and ultrahigh-carbon steel
14514-509: Was formerly used. The Gilchrist-Thomas process (or basic Bessemer process ) was an improvement to the Bessemer process, made by lining the converter with a basic material to remove phosphorus. Another 19th-century steelmaking process was the Siemens-Martin process , which complemented the Bessemer process. It consisted of co-melting bar iron (or steel scrap) with pig iron. These methods of steel production were rendered obsolete by
14637-467: Was hostile to the Romans. Strathclyde was founded as an independent unified British kingdom, quite some centuries after the Roman occupation of Britain . The kingdom's core territory and much of its arable land was located around the Clyde basin in the area traditionally associated with Alt Clut. The kingdom was ruled from its original capital, the near impenetrable Alt Clut fortress (Dumbarton Rock), which
14760-420: Was not). The canting basin and Govan Graving Docks next to Pacific Quay are subject to development along with Tradeston and Laurieston . A derelict area of Dalmarnock was used as the 'athletes' village' for the 2014 Commonwealth Games in Glasgow. The bridge was closed between 14 January and 28 June 2008 due to the failure of one support hanger, and cracks found in a second. On the night of 14 January 2008
14883-438: Was produced globally, with 630,000,000 tonnes (620,000,000 long tons; 690,000,000 short tons) recycled. Modern steels are made with varying combinations of alloy metals to fulfil many purposes. Carbon steel , composed simply of iron and carbon, accounts for 90% of steel production. Low alloy steel is alloyed with other elements, usually molybdenum , manganese, chromium, or nickel, in amounts of up to 10% by weight to improve
15006-706: Was produced in the Netherlands from the 2nd-4th centuries AD. The Roman author Horace identifies steel weapons such as the falcata in the Iberian Peninsula , while Noric steel was used by the Roman military . The Chinese of the Warring States period (403–221 BC) had quench-hardened steel, while Chinese of the Han dynasty (202 BC—AD 220) created steel by melting together wrought iron with cast iron, thus producing
15129-558: Was situated on the river and overlooked much of the estuary. This fortress was noteworthy enough to have been referred to at the time in several letters and poems about Sub-Roman Britain , written by Gildas and others. Strathclyde remained a powerful kingdom during the early medieval period in Britain. It was also a reservoir of native Welsh culture : Its territory expanded along the Clyde Vae Southern Uplands and Ayrshire, and eventually southwards into Cumbria. In
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