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Switches and crossings - Components of turnout or switch 9 Answers Switches and crossings - Components of turnout or switch Turnout or switch is a mechanical device that are used to guide the trains from one rail track to another. Following blogs explain components of turnout Text source: click here Picture source: click here Points (switch rails or point blades) are the movable rails which guide the wheels towards either the straight or the diverging track. They are tapered on most switches, but on stub switches they have square ends. In ordinary conversation, it is common to use the word “switch” when referring to a “turnout,” which is technically incorrect. Source: click here Stock rails are the running rails immediately alongside of the switch rails against which the switch rails lay when in the closed position. The stock rails are otherwise ordinary rails that are machined, drilled, and bent as required to suit the design of the turnout switch and the individual switch point rails. Source: click here Frog is a component placed where one rail crosses another, refers to the crossing point of two rails. The rest of the English-speaking world calls such units by the more obvious term “crossings.” Source: click here Closure rails are the straight or curved rails that are positioned in between the heel of switch and the toe of frog. Source: click here Guard rail (check rail) is a short piece of rail placed alongside the main (stock) rail opposite the frog. These exist to ensure that the wheels follow the appropriate flangeway through the frog and that the train does not derail. Source: click here Heel block assemblies are units placed at the heel of the switch that provide a splice with the contiguous closure rail and a location for the switch point rail to pivot at a fixed spread distance from the stock rail. Source: click here Switch point rail stops act as spacers between the switch point rail and the stock rail. Stops laterally support the switch point from flexing laterally under a lateral wheel load and thereby possibly exposing the open end of switch point rail to head-on contact from the next wheel. Source: click here A switch operating device moves switch rails. Switch rails can be thrown (moved) from one orientation to another by either a hand-operated (manual) switch stand or a mechanically or electro-mechanically (power-operated) switch machine. In both cases, the operating devices are positioned at the beginning of the turnout opposite the switch-connecting rods near the point of the switch rails. Source: click here |