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Breather Switch
A breather switch, expansion joint, or adjustment switch is an intentional gap in railway tracks to allow for thermal expansion in long sections of otherwise unbroken rail. They are placed between very long sections of continuous welded rail (CWR) or at the transition between CWR and jointed track, and commonly in the vicinity of bridges, viaducts and tunnels where the infrastructure and track may expand at different rates. The mating sections are tapered diagonally (unlike a butt joint between two lengths of rail), allowing smoother transitions and higher speeds across the gap. Breather switches have two advantages over jointed track: they greatly reduce the small gap between the rails, eliminating or significantly reducing the noise and vibration caused by passing trains, and, where CWR is particularly prone to expansion, they act as relief points to ensure that track does not warp out of shape or result in a sun kink In structural engineering, buckling is the sudden chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railway Track
A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, British English) and ballast (or slab track), plus the underlying subgrade. It enables trains to move by providing a dependable surface for their wheels to roll upon. Early tracks were constructed with wooden or cast iron rails, and wooden or stone sleepers; since the 1870s, rails have almost universally been made from steel. Historical development The first railway in Britain was the Wollaton Wagonway, built in 1603 between Wollaton and Strelley in Nottinghamshire. It used wooden rails and was the first of around 50 wooden-railed tramways built over the next 164 years. These early wooden tramways typically used rails of oak or beech, attached to wooden sleepers with iron or wooden nails. Gravel or small stones were packed around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expansion Joint
An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seismic activity. They are commonly found between sections of buildings, bridges, sidewalks, railway tracks, piping systems, ships, and other structures. Building faces, concrete slabs, and pipelines expand and contract due to warming and cooling from seasonal variation, or due to other heat sources. Before expansion joint gaps were built into these structures, they would crack under the stress induced. Bridge expansion joints Bridge expansion joints are designed to allow for continuous traffic between structures while accommodating movement, shrinkage, and temperature variations on reinforced and prestressed concrete, composite, and steel structures. They stop the bridge from bending out of place in extreme conditions, and also allow enou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railway Track
A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, British English) and ballast (or slab track), plus the underlying subgrade. It enables trains to move by providing a dependable surface for their wheels to roll upon. Early tracks were constructed with wooden or cast iron rails, and wooden or stone sleepers; since the 1870s, rails have almost universally been made from steel. Historical development The first railway in Britain was the Wollaton Wagonway, built in 1603 between Wollaton and Strelley in Nottinghamshire. It used wooden rails and was the first of around 50 wooden-railed tramways built over the next 164 years. These early wooden tramways typically used rails of oak or beech, attached to wooden sleepers with iron or wooden nails. Gravel or small stones were packed around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viaduct
A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide valley, road, river, or other low-lying terrain features and obstacles. The term ''viaduct'' is derived from the Latin ''via'' meaning "road", and ''ducere'' meaning "to lead". It is a 19th-century derivation from an analogy with ancient Roman aqueducts. Like the Roman aqueducts, many early viaducts comprised a series of arches of roughly equal length. Over land The longest in antiquity may have been the Pont Serme which crossed wide marshes in southern France. At its longest point, it measured 2,679 meters with a width of 22 meters. Viaducts are commonly used in many cities that are railroad hubs, such as Chicago, Birmingham, London and Manchester. These viaducts cross the large railroad yards that are needed for freight trains there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butt Joint
A butt joint is a technique in which two pieces of material are joined by simply placing their ends together without any special shaping. The name "butt joint" comes from the way the material is joined. The butt joint is the simplest joint to make since it merely involves cutting the material to the appropriate length and butting them together. It is also the weakest because unless some form of reinforcement is used (see below), it relies upon glue or welding alone to hold it together. Because the orientation of the material usually presents only one end to a long gluing or welding surface, the resulting joint is inherently weak. Nonetheless, it generally provides sufficient strength in most cases, particularly when fasteners are used. The butt joint is widely used in many applications due to its simplicity, notably in rough carpentry and construction. Methods The butt joint is a very simple joint to construct. Members are simply docked (cut off) at the right angle and have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Train
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often known simply as "engines"), though some are self-propelled, such as multiple units. Passengers and cargo are carried in railroad cars, also known as wagons. Trains are designed to a certain gauge, or distance between rails. Most trains operate on steel tracks with steel wheels, the low friction of which makes them more efficient than other forms of transport. Trains have their roots in wagonways, which used railway tracks and were powered by horses or pulled by cables. Following the invention of the steam locomotive in the United Kingdom in 1804, trains rapidly spread around the world, allowing freight and passengers to move over land faster and cheaper than ever possible before. Rapid transit and trams were first built in the lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buckling
In structural engineering, buckling is the sudden change in shape ( deformation) of a structural component under load, such as the bowing of a column under compression or the wrinkling of a plate under shear. If a structure is subjected to a gradually increasing load, when the load reaches a critical level, a member may suddenly change shape and the structure and component is said to have ''buckled''. Euler's critical load and Johnson's parabolic formula are used to determine the buckling stress in slender columns. Buckling may occur even though the stresses that develop in the structure are well below those needed to cause failure in the material of which the structure is composed. Further loading may cause significant and somewhat unpredictable deformations, possibly leading to complete loss of the member's load-carrying capacity. However, if the deformations that occur after buckling do not cause the complete collapse of that member, the member will continue to support ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Williamsburg Bridge
The Williamsburg Bridge is a suspension bridge in New York City across the East River connecting the Lower East Side of Manhattan at Delancey Street with the Williamsburg neighborhood of Brooklyn at Broadway near the Brooklyn-Queens Expressway ( Interstate 278). Completed in 1903, it was the longest suspension bridge span in the world until 1924. The bridge is one of four toll-free vehicular bridges connecting Manhattan Island and Long Island. The others are the Queensboro Bridge to the north, and the Manhattan and Brooklyn Bridges to the south. The Williamsburg Bridge once carried New York State Route 27A and was planned to carry Interstate 78, though the planned I-78 designation was aborted by the cancellation of the Lower Manhattan Expressway and Bushwick Expressway. History Construction Construction on what was then known as the "East River Bridge", the second to span it, began in 1896 after approval by the Governor of New York on May 27, 1895. The new bridge w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City Subway
The New York City Subway is a rapid transit system owned by the government of New York City and leased to the New York City Transit Authority, an affiliate agency of the state-run Metropolitan Transportation Authority (MTA). Opened on October 27, 1904, the New York City Subway is one of the world's oldest public transit systems, one of the most-used, and the one with the most stations, with 472 stations in operation (424 if stations connected by transfers are counted as single stations). Stations are located throughout the boroughs of Manhattan, Brooklyn, Queens, and the Bronx. The system has operated 24/7 service every day of the year throughout most of its history, barring emergencies and disasters. By annual ridership, the New York City Subway is the busiest rapid transit system in both the Western Hemisphere and the Western world, as well as the seventh-busiest rapid transit rail system in the world. In , the subway delivered rides, or about per weekday as of . On Octo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornish Main Line
The Cornish Main Line ( kw, Penn-hyns-horn Kernow) is a railway line in Cornwall and Devon in the United Kingdom. It runs from Penzance to Plymouth, crossing from Cornwall into Devon over the famous Royal Albert Bridge at Saltash. It directly serves Truro, St Austell, Bodmin (by a Parkway station) and Liskeard. It forms the backbone for rail services in Cornwall and there are branches off it which serve St Ives, Falmouth, Newquay and Looe. The main line also carries direct trains to and from London, Birmingham, Cardiff, Manchester, the north of England and Scotland. It is the southernmost railway line in the United Kingdom and the westernmost in England. History The Cornish Main Line was originally built by two separate railway companies, the West Cornwall Railway between Truro and Penzance, opened in 1852, and the Cornwall Railway between Plymouth and a separate station in Truro, opened in 1859. The West Cornwall Railway was itself based on the Hayle Railway, opened i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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