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Clearance Car
A clearance car is a type of railroad car in maintenance of way service. Its purpose is to check the clearances around the tracks and ensure that trains conforming to the railroad's standard loading gauge or ''dynamic envelope'' will not encounter any obstruction. Additionally, by measuring the actual clearances along a route, the railroad can determine whether outsize loads can be accommodated along that route, and the largest size feasible. Design Early clearance cars simply consisted of an outline of the system loading gauge attached to a railroad car, which would be towed along the route to ensure the clearances were still sufficient. Later clearance cars functioned by using physical feelers—rods which extended from the car in all directions which would be deflected back by obstructions. These would be connected to instrumentation which displayed the actual clearance at that point. These feelers have an advantage in that they bounce back and do not break if they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WMATA Rohr 1028 With Locomotive
The Washington Metropolitan Area Transit Authority (WMATA ), commonly referred to as Metro, is a tri-jurisdictional government agency that operates transit service in the Washington metropolitan area. WMATA was created by the United States Congress as an interstate compact between Washington, D.C., the State of Maryland, and the Commonwealth of Virginia. WMATA provides rapid transit service under the Metrorail name, fixed-route bus service under the Metrobus brand, and paratransit service under the MetroAccess brand. In , the system had a ridership of , or about per weekday as of . The authority is also part of a public–private partnership that operates the DC Circulator bus system. WMATA has its own police force, the Metro Transit Police Department. The authority's board of directors consists of two voting representatives each from the District of Columbia, Maryland, Virginia, and the U.S. federal government. Each jurisdiction also appoints two alternate representatives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railroad Car
A railroad car, railcar (American and Canadian English), railway wagon, railway carriage, railway truck, railwagon, railcarriage or railtruck (British English and UIC), also called a train car, train wagon, train carriage or train truck, is a vehicle used for the carrying of cargo or passengers on a rail transport system (a railroad/railway). Such cars, when coupled together and hauled by one or more locomotives, form a train. Alternatively, some passenger cars are self-propelled in which case they may be either single railcars or make up multiple units. The term "car" is commonly used by itself in American English when a rail context is implicit. Indian English sometimes uses "bogie" in the same manner, though the term has other meanings in other variants of English. In American English, "railcar" is a generic term for a railway vehicle; in other countries "railcar" refers specifically to a self-propelled, powered, railway vehicle. Although some cars exist for the railroad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maintenance Of Way
Maintenance of way (commonly abbreviated to MOW) refers to the maintenance, construction, and improvement of rail infrastructure, including tracks, ballast, grade, and lineside infrastructure such as signals and signs. Track The most fundamental maintenance of way task is the construction, repair, and replacement of the track and its supporting ballast and grade. The task was once done entirely by manual labor, but in the 21st century, track maintenance is largely done by specialized machines that are much faster and require fewer people to accomplish the same amount of work. Electrification systems On rail lines, which include electrification by a third rail or an overhead line An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipm ..., maintenance of way work includes repairing an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineering Tolerance
Engineering tolerance is the permissible limit or limits of variation in: # a physical dimension; # a measured value or physical property of a material, manufactured object, system, or service; # other measured values (such as temperature, humidity, etc.); # in engineering and safety, a physical distance or space (tolerance), as in a truck (lorry), train or boat under a bridge as well as a train in a tunnel (see structure gauge and loading gauge); # in mechanical engineering, the space between a bolt and a nut or a hole, etc. Dimensions, properties, or conditions may have some variation without significantly affecting functioning of systems, machines, structures, etc. A variation beyond the tolerance (for example, a temperature that is too hot or too cold) is said to be noncompliant, rejected, or exceeding the tolerance. Considerations when setting tolerances A primary concern is to determine how wide the tolerances may be without affecting other factors or the outcome of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rail Tracks
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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loading Gauge
A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and structures. Classification systems vary between different countries, and gauges may vary across a network, even if the track gauge is uniform. The term loading gauge can also be applied to the maximum size of road vehicles in relation to tunnels, overpasses and bridges, and doors into automobile repair shops, bus garages, filling stations, residential garages, multi-storey car parks and warehouses. A related but separate gauge is the structure gauge, which sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. The difference between these two gauges is called the clearance. The specified amount of clearance makes allowance for wobbling o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Envelope
A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and structures. Classification systems vary between different countries, and gauges may vary across a network, even if the track gauge is uniform. The term loading gauge can also be applied to the maximum size of road vehicles in relation to tunnels, overpasses and bridges, and doors into automobile repair shops, bus garages, filling stations, residential garages, multi-storey car parks and warehouses. A related but separate gauge is the structure gauge, which sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. The difference between these two gauges is called the clearance. The specified amount of clearance makes allowance for wobbling of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loading Gauge Profile Vehicle For South Australian Railways 500 Class Locomotives, 1926 (NRM 17-336-mb-b21-d15)
Loading may refer to: Biology * Carbohydrate loading, a strategy employed by endurance athletes to maximize the storage of glycogen in the muscles * Creatine loading, a phase of use of creatine supplements * Vocal loading, the stress inflicted on the speech organs when speaking for long periods Engineering * Application of a structural load to a system ** Disk loading, the pressure maintained over the swept area of a helicopter's rotor ** Seismic loading, one of the basic concepts of earthquake engineering ** Wing loading, the loaded weight of an aircraft divided by the area of its wing * Loading characteristic, a measure of traffic on a telephone system * Insertion of an electrical load into a circuit ** Use of a loading coil to increase inductance * Loading (computing), the process in which the contents of a file are read into a computer's memory Other uses * Task loading, the number of tasks taken on by a diver * Loading (TV channel), a Brazilian TV Network focused on pop and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light which is ''coherent''. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers and lidar (light detection and ranging). Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum. Alternatively, temporal coherence can be used to produce ultrashort pulses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
York Station
York railway station is on the East Coast Main Line serving the city of York, North Yorkshire, England. It is north of and on the main line it is situated between to the south and to the north. , the station is operated by London North Eastern Railway. York station is a key junction approximately halfway between London and Edinburgh. It is approximately north of the point where the Cross Country and TransPennine Express routes via Leeds join the main line, connecting Scotland and the North East, North West, Midlands and southern England. The junction was historically a major site for rolling stock manufacture, maintenance and repair. In ''Britain's 100 Best Railway Stations'' by Simon Jenkins, the station was one of only ten to be awarded five stars. History The first York railway station was a temporary wooden building on Queen Street outside the walls of the city, opened in 1839 by the York and North Midland Railway. It was succeeded in 1841, inside the walls, by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structure Gauge
A structure gauge, also called the minimum clearance outline, is a diagram or physical structure that sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. It specifies the height and width of platforms, tunnels and bridges, and the width of the doors that allow access to a warehouse from a rail siding. Specifications may include the minimum distance from rail vehicles to railway platforms, buildings, electrical equipment boxes, signal equipment, third rails or supports for overhead lines. A related but separate gauge is the loading gauge: a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. The difference between these two gauges is called the clearance. The specified amount of clearance makes allowance for wobbling of rail vehicles at speed; consequently, in some circumstances a train may be permitted to go past a restricted clearance at very slow speed. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
