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Old Iron Bridge, Merthyr Tydfil
The Old Iron Bridge of 1800, originally known simply as Merthyr Bridge before 1809, in Merthyr Tydfil, South Wales, was a cast-iron bridge across the River Taff. Although an important early example of iron bridge-building and well known as a local landmark within living memory, the bridge has largely disappeared from engineering history. Early iron bridges The Iron Bridge across the Severn near Coalbrookdale opened in 1781 and is generally regarded as the world's first cast-iron bridge. It had little immediate influence on bridge design and few other important iron bridges were built as a result. However a flood in 1795 washed away many bridges on the Severn, but the Iron Bridge survived. This survival had more influence on bridge design, as did the completion of Wearmouth Bridge the following year. Cast iron was now established as a viable material for bridges and a number were produced in the years immediately afterwards. Earlier bridges in Merthyr Richard Crawshay's Cy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Merthyr Tydfil
Merthyr Tydfil ( cy, Merthyr Tudful) is the main town in Merthyr Tydfil County Borough, Wales, administered by Merthyr Tydfil County Borough Council. It is about north of Cardiff. Often called just Merthyr, it is said to be named after Tydfil, daughter of King Brychan of Brycheiniog, who according to legend was slain at Merthyr by pagans about 480 CE. generally means "martyr" in modern Welsh, but here closer to the Latin : a place of worship built over a martyr's relics. Similar place names in south Wales are Merthyr Cynog, Merthyr Dyfan and Merthyr Mawr. Noted for its industrial past, Merthyr was known as the 'Iron Capital of the World' in the early 19th century, due to the scale of its iron production. The world's first steam-powered railway journey happened in Merthyr in 1804, travelling from the ironworks at Penydarren to the Glamorganshire Canal on the Merthyr Tramroad. The 1851 census found Wales to be the world's first industrialised nation, as more people were emplo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riser (casting)
A riser, also known as a feeder, is a reservoir built into a metal casting mold to prevent cavities due to shrinkage. Most metals are less dense as a liquid than as a solid so castings shrink upon cooling, which can leave a void at the last point to solidify. Risers prevent this by providing molten metal to the casting as it solidifies, so that the cavity forms in the riser and not the casting.. Risers are not effective on materials that have a large freezing range, because directional solidification is not possible. They are also not needed for casting processes that utilized pressure to fill the mold cavity. Theory Risers are only effective if three conditions are met: the riser cools after the casting, the riser has enough material to compensate for the casting shrinkage, and the casting directionally solidifies towards the riser. For the riser to cool after the casting the riser must cool more slowly than the casting. Chvorinov's rule briefly states that the slowest cooli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runner (casting)
In metalworking and jewelry making, casting is a process in which a liquid metal is delivered into a mold (usually by a crucible) that contains a negative impression (i.e., a three-dimensional negative image) of the intended shape. The metal is poured into the mold through a hollow channel called a sprue. The metal and mold are then cooled, and the metal part (the ''casting'') is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods. Casting processes have been known for thousands of years, and have been widely used for sculpture (especially in bronze), jewelry in precious metals, and weapons and tools. Highly engineered castings are found in 90 percent of durable goods, including cars, trucks, aerospace, trains, mining and construction equipment, oil wells, appliances, pipes, hydrants, wind turbines, nuclear plants, medical devices, defense products, toys, and more. Traditional techniques include lost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand Casting
Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. The term "sand casting" can also refer to an object produced via the sand casting process. Sand castings are produced in specialized factories called foundries. Over 60% of all metal castings are produced via sand casting process. Molds made of sand are relatively cheap, and sufficiently refractory even for steel foundry use. In addition to the sand, a suitable bonding agent (usually clay) is mixed or occurs with the sand. The mixture is moistened, typically with water, but sometimes with other substances, to develop the strength and plasticity of the clay and to make the aggregate suitable for molding. The sand is typically contained in a system of frames or mold boxes known as a flask. The mold cavities and gate system are created by compacting the sand around models called patterns, by carving directly into the sand, or by 3D printing. Basic pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobblestone
Cobblestone is a natural building material based on cobble-sized stones, and is used for pavement roads, streets, and buildings. Setts, also called Belgian blocks, are often casually referred to as "cobbles", although a sett is distinct from a cobblestone by being quarried or shaped to a regular form, whereas cobblestone is generally of a naturally occurring form and is less uniform in size. Use in roading Cobblestones are typically either set in sand or similar material, or are bound together with mortar. Paving with cobblestones allows a road to be heavily used all year long. It prevents the build-up of ruts often found in dirt roads. It has the additional advantage of immediately draining water, and not getting muddy in wet weather or dusty in dry weather. Shod horses are also able to get better traction on stone cobbles, pitches or setts than tarmac or asphalt. The fact that carriage wheels, horse hooves and even modern automobiles make a lot of noise when rolling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sett (paving)
A sett, also known as a block or Belgian block, is a broadly rectangular quarried stone used in paving roads and walkways. Formerly in widespread use, particularly on steeper streets because setts provided horses' hooves with better grip than a smooth surface, they are now encountered rather as decorative stone paving in landscape architecture. Setts are often referred to as "cobblestones", although a sett is distinct from a cobblestone in that it is quarried or worked to a regular shape, whereas the latter is generally a small, naturally-rounded rock. Setts are usually made of granite. Places Europe Places paved with setts include many streets in Rome and elsewhere in Italy (where blocks are called '' sampietrini'' or ''bolognini''), since the technique was first used by Romans. In Aberdeen (Scotland), and much of Edinburgh's Old Town and New Town, a large number of streets retain the original setts. Silloth on Solway, a seaside town in Cumbria, still has setts (origina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parapet
A parapet is a barrier that is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure. The word comes ultimately from the Italian ''parapetto'' (''parare'' 'to cover/defend' and ''petto'' 'chest/breast'). Where extending above a roof, a parapet may simply be the portion of an exterior wall that continues above the edge line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a fire wall or party wall. Parapets were originally used to defend buildings from military attack, but today they are primarily used as guard rails, to conceal rooftop equipment, reduce wind loads on the roof, and to prevent the spread of fires. In the Bible the Hebrews are obligated to build a parapet on the roof of their houses to prevent people falling (Deuteronomy 22:8). Parapet types Parapets may be plain, embattled, perforated or panelled, which are not mutually exclusive terms. *Plain parapets are upward extensions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wrought Ironwork
Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which give it a wood-like "grain" that is visible when it is etched, rusted, or bent to failure. Wrought iron is tough, malleable, ductile, corrosion resistant, and easily forge welded, but is more difficult to weld electrically. Before 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 hardenable by heating and quenching. Wrought iron is highly refined, with a small amount of silic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolt (fastener)
A bolt is a form of threaded fastener with an external male thread requiring a matching pre-formed female thread such as a nut. Bolts are very closely related to screws. Bolts vs. screws The distinction between a bolt and a screw is poorly-defined. The academic distinction, per '' Machinery's Handbook'', is in their intended design: bolts are designed to pass through an unthreaded hole in a component and be fastened with the aid of a nut, although such a fastener can be used without a nut to tighten into a threaded component such as a nut-plate or tapped housing. Screws in contrast are used in components which contain their own thread, or to cut its own internal thread into them. This definition allows ambiguity in the description of a fastener depending on the application it is actually used for, and the terms screw and bolt are widely used by different people or in different countries to apply to the same or varying fastener. Bolts are often used to make a bolted join ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batter (walls)
In architecture, batter is a receding slope of a wall, structure, or earthwork. A wall sloping in the opposite direction is said to ''overhang''. When used in fortifications it may be called a talus. The term is used with buildings and non-building structures to identify when a wall or element is intentionally built with an inward slope. A battered corner is an architectural feature using batters. A batter is sometimes used in foundations, retaining walls, dry stone walls, dams, lighthouses, and fortifications. Other terms that may be used to describe battered walls are "tapered" and "flared". Typically in a battered wall, the taper provides a wide base to carry the weight of the wall above, with the top gradually resulting in the thinnest part as to ease the weight of wall below. The ''batter angle'' is typically described as a ratio of the offset and height or a degree angle that is dependent on the building materials and application. For example, typical dry-stone constru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balustrade
A baluster is an upright support, often a vertical moulded shaft, square, or lathe-turned form found in stairways, parapets, and other architectural features. In furniture construction it is known as a spindle. Common materials used in its construction are wood, stone, and less frequently metal and ceramic. A group of balusters supporting a handrail, coping, or ornamental detail are known as a balustrade. The term baluster shaft is used to describe forms such as a candlestick, upright furniture support, and the stem of a brass chandelier. The term banister (also bannister) refers to a baluster or to the system of balusters and handrail of a stairway. It may be used to include its supporting structures, such as a supporting newel post. Etymology According to the ''Oxford English Dictionary'', "baluster" is derived through the french: balustre, from it, balaustro, from ''balaustra'', "pomegranate flower" rom a resemblance to the swelling form of the half-open flower (''ill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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