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Point Machine
A point machine (also known as a point motor, switch machine or switch motor) is a device for operating railway Railroad switch, turnouts especially at a distance. Overview In the earliest times, points were operated manually by levers. Gradually, these were centralized and came to be operated from a signal box, either by rods, or by double wire arrangements. Since the limitation of mechanical operation restricted the design of track layouts on the one hand, and tended to require more signal boxes, even lightly used ones, on the other hand, there has always been a desire of railway administrations to increase the distance that remote turnouts can be operated. This requires some kind of power operation of points and signals. The principal means of power operation include hydraulic, pneumatic and electric. More recently with the increase in weight of rail, and the introduction of high speed turnouts with finer angles requiring multiple drives, points have become stiffer and beyon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railroad Switch
A railroad switch (), turnout, or ''set ofpoints () is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off. The most common type of switch consists of a pair of linked tapering rails, known as ''points'' (''switch rails'' or ''point blades''), lying between the diverging outer rails (the ''stock rails''). These points can be moved laterally into one of two positions to direct a train coming from the point blades toward the straight path or the diverging path. A train moving from the narrow end toward the point blades (i.e. it will be directed to one of the two paths, depending on the position of the points) is said to be executing a ''facing-point movement''. For many types of switch, a train coming from either of the converging directions will pass through the switch regardless of the position of the points, as the vehicle's wheels will force the points to move. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lever
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or ''fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is divided into three types. Also, leverage is mechanical advantage gained in a system. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever. As such, the lever is a mechanical advantage device, trading off force against movement. Etymology The word "lever" entered English around 1300 from Old French, in which the word was ''levier''. This sprang from the stem of the verb ''lever'', meaning "to raise". The verb, in turn, goes back to the Latin ''levare'', itself from the adjective ''levis'', meaning "light" (as in "not heavy"). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Box
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' includes audio, video, speech, image, sonar, and radar as examples of signal. A signal may also be defined as observable change in a quantity over space or time (a time series), even if it does not carry information. In nature, signals can be actions done by an organism to alert other organisms, ranging from the release of plant chemicals to warn nearby plants of a predator, to sounds or motions made by animals to alert other animals of food. Signaling occurs in all organisms even at cellular levels, with cell signaling. Signaling theory, in evolutionary biology, proposes that a substantial driver for evolution is the ability of animals to communicate with each other by developing ways of signaling. In human engineering, signals are typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Track Layout
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 * ''Trac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railroad Tie
A railroad tie, crosstie (American English), railway tie (Canadian English) or railway sleeper (Australian and British English) is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright and keep them spaced to the correct gauge. Railroad ties are traditionally made of wood, but prestressed concrete is now also widely used, especially in Europe and Asia. Steel ties are common on secondary lines in the UK; plastic composite ties are also employed, although far less than wood or concrete. As of January 2008, the approximate market share in North America for traditional and wood ties was 91.5%, the remainder being concrete, steel, azobé (red ironwood) and plastic composite. Tie spacing may depend on the type of tie, traffic loads and other requirements, for example 2640 concrete ties per mile on North American mainline railroads to 2112 timber ties per mile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Track Maintenance Machines
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 * ''Trac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Junction
A double junction is a railway junction where a double-track railway splits into two double track lines. Usually, one line is the main line and carries traffic through the junction at normal speed, while the other track is a branch line that carries traffic through the junction at reduced speed. A number of configurations are possible. At grade Diamond The simplest and oldest arrangement consists of two turnouts (points) and a fixed Diamond crossing. Because the diamond needs to be relatively coarse, say 1 in 8, the curve radius is necessarily small, leading to a speed of perhaps . This type of junction is common on street-running tramways, where speeds are quite low and junction must fit into the available road space. Because the points are close together, the entire junction can be controlled by the mechanical point rodding of a single signal box. Signal passed at danger (SPAD) protection — A train from R to P with 12 points reverse is protected from a train from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
