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Track Circuit Interrupter
A track circuit interrupter may be fitted at catch points, trap points or buffer stops to maintain a track circuit in the 'occupied' state in the event of a derailment. The track circuit remains de-energised until the interrupter is replaced. Application At catch or trap points Trap points or catch points are designed to intentionally derail vehicles making an unauthorised movement. When a vehicle derails completely, its wheels cease to shunt the track circuit. Since the vehicle might still be foul of the track, it is important to maintain the track circuit in the 'occupied' state. To achieve this, a cast iron interrupter is fitted to one of the run-off rails such that it will be struck by the wheels of a vehicle that is about to be derailed. Since the track circuit is bonded via the interrupter, it is proved to be intact when the track circuit relay is energised. At buffer stops A track circuit interrupter may be fitted behind a friction buffer stop. In the event of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Track Circuit Interrupter
A track circuit interrupter may be fitted at catch points, trap points or buffer stops to maintain a track circuit in the 'occupied' state in the event of a derailment. The track circuit remains de-energised until the interrupter is replaced. Application At catch or trap points Trap points or catch points are designed to intentionally derail vehicles making an unauthorised movement. When a vehicle derails completely, its wheels cease to shunt the track circuit. Since the vehicle might still be foul of the track, it is important to maintain the track circuit in the 'occupied' state. To achieve this, a cast iron interrupter is fitted to one of the run-off rails such that it will be struck by the wheels of a vehicle that is about to be derailed. Since the track circuit is bonded via the interrupter, it is proved to be intact when the track circuit relay is energised. At buffer stops A track circuit interrupter may be fitted behind a friction buffer stop. In the event of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catch Points
Catch points and trap points are types of turnout which act as railway safety devices. Both work by guiding railway carriages and trucks from a dangerous route onto a separate, safer track. Catch points are used to derail vehicles which are out of control (known as ''runaways'') on steep slopes. Trap points are used to protect main railway lines from unauthorised vehicles moving onto them from sidings or branch lines. Either of these track arrangements may lead the vehicles into a sand drag or safety siding, track arrangements which are used to safely stop them after they have left the main tracks. A derail is another device used for the same purposes as catch and trap points. Trap points ''Trap points'' are found at the exit from a siding or where a secondary track joins a main line. A facing turnout is used to prevent any unauthorised movement that may otherwise obstruct the main line. The trap points also prevent any damage that may be done by a vehicle passin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffer Stops
A buffer stop, bumper, bumping post, bumper block or stopblock (US), is a device to prevent railway vehicles from going past the end of a physical section of track. The design of the buffer stop is dependent, in part, on the kind of couplings that the railway uses, since the coupling gear is the first part of the vehicle that the buffer stop touches. The term "buffer stop" is of British origin, since railways in Great Britain principally use buffer-and-screw couplings between vehicles. Types Several different types of buffer stop have been developed. They differ depending on the type of coupler used and on the intended application. * Buffer stops with anticlimbers. These are particularly important for passenger railway applications, because the anticlimbers reduce the likelihood of telescoping of the railroad cars during a head-on impact. * Buffer stops for a knuckle coupler or an SA3 coupler (centrally positioned between the two rails) * Buffer stops with traditional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Track Circuit
A track circuit is an electrical device used to prove the absence of a train on rail tracks to signallers and control relevant signals. An alternative to track circuits are axle counters. Principles and operation The basic principle behind the track circuit lies in the connection of the two rails by the wheels and axle of locomotives and rolling stock to short an electrical circuit. This circuit is monitored by electrical equipment to detect the absence of the trains. Since this is a safety appliance, fail-safe operation is crucial. Hence the circuit is designed to indicate the presence of a train when failures occur. On the other hand, false occupancy readings are disruptive to railway operations and must be minimized. Track circuits allow railway signalling systems to operate semi-automatically, by displaying signals for trains to slow or stop in the presence of occupied track ahead of them. They help prevent Train dispatcher, dispatchers and Manual block, operators from ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shunt (electrical)
In electronics, a shunt is a device that creates a low- resistance path for electric current, to allow it to pass around another point in the circuit.Rudolf F. Graf, ''Modern dictionary of Electronics'', Mc-Graw Hill, 1968 Library of Congress 68-13873 ''Shunt'' page 454. The origin of the term is in the verb 'to shunt' meaning to turn away or follow a different path. Defective device bypass One example is in miniature Christmas lights which are wired in series. When the filament burns out in one of the incandescent light bulbs, the full line voltage appears across the burnt out bulb. A shunt resistor, which has been connected in parallel across the filament before it burnt out, will then short out to bypass the burnt filament and allow the rest of the string to light. If too many lights burn out however, a shunt will also burn out, requiring the use of a multimeter to find the point of failure. Photovoltaics In photovoltaics, the term is widely used to describe an ''unwan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cast Iron
Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing. Carbon (C), ranging from 1.8 to 4 wt%, and silicon (Si), 1–3 wt%, are the main alloying elements of cast iron. Iron alloys with lower carbon content are known as steel. Cast iron tends to be brittle, except for malleable cast irons. With its relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast irons have become an engineering material with a wide range of applications and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Track Circuit Interrupter - Diagram B
Track or Tracks may refer to: Routes or imprints * Ancient trackway, any track or trail whose origin is lost in antiquity * Animal track, imprints left on surfaces that an animal walks across * Desire path, a line worn by people taking the shortest/most convenient route across fields, parks or woods * Forest track, a track (unpaved road) or trail through a forest * Fossil trackway, a type of trace fossil, usually preserving a line of animal footprints * Trackway, an ancient route of travel or track used by animals * Trail * Vineyard track, a land estate (defined by law) meant for the growing of vine grapes Arts, entertainment, and media Films * ''Tracks'' (1976 film), an American film starring Dennis Hopper * ''Tracks'' (2003 film), a 2003 animated short film * ''Tracks'' (2013 film), an Australian film starring Mia Wasikowska * ''The Track'' (film), a 1975 French thriller–drama film Literature * ''Tracks'' (novel), written by Native American author Louise Erdrich * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rail Freight Transport
Rail freight transport is the use of railroads and trains to transport cargo as opposed to human passengers. A freight train, cargo train, or goods train is a group of freight cars (US) or goods wagons (International Union of Railways) hauled by one or more locomotives on a railway, transporting cargo all or some of the way between the shipper and the intended destination as part of the logistics chain. Trains may haul bulk material, intermodal containers, general freight or specialized freight in purpose-designed cars. Rail freight practices and economics vary by country and region. When considered in terms of ton-miles or tonne-kilometers hauled per unit of energy consumed, rail transport can be more efficient than other means of transportation. Maximum economies are typically realized with bulk commodities (e.g., coal), especially when hauled over long distances. However, shipment by rail is not as flexible as by the highway, which has resulted in much freight being haul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treadle (railway)
In railway signalling, a treadle is a mechanical or electrical device that detects that a train wheel has passed a particular location. They are used where a track circuit requires reinforcing with additional information about a train's location, such as around an automatic level crossing, or in an annunciator circuit, which sounds a warning that a train has passed an exact point. They also serve as a critical backup in the case of track circuit failure. The important difference between a treadle and a track circuit is that while a track circuit detects a train over a distance as long as several kilometres, a treadle provides detection at a single fixed location. Types Mechanical In situations where track circuits are unreliable due to rusty rails, for example adjacent to buffer stops and catch points, a long treadle bar is used. When this is depressed, the signaller gains indication (if they have not already done so) of a train in a section. Electro-Mechanical An electro-mec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
