point and crossing railway

Point and crossing

points and crossing are special arrangement on the track to facilitate smote diversion of train from One track to another.

Important terms in points and crossing

main track: track from which are trains to be diverted is called main track.

Branch track: track to which a train is diverted is called branch track.

Tongue rail: the tappered movable rail which is attached at or near one end to a running rail is called tongue rail.

Stock rail: stock rail is a running rail to which our tongue rail is attached.

Switch: which is a pair of tongue rail with necessary connection.

Points: a pair of tongue rail and stock rail with necessary connection form points.

Heel of switch: heel of switch is untampered end of switch rail which is fixed to the lead rail.

Toe of switch: toe of switch is the thin tapering end of the tongue rail.

Heel of divergence:heel of divergence is a distance between the running face of the stock rail and that of the tongue rail measured at the heel of the switch.

Heel block: heel block is the first CI block from the two side fixing the tongue rail to the stock rail.

Lead rail: lead rail is the rail which lead the track  from the heel of the tongue rail to the toe  of crossing.

Point rail: point rail is the rail of main track forming the nose of crossing.

Splice rail: splice rail is the rail of branch track which meet the point rail at the nose of crossing

Wing rail: wing rail is the bend portion off rail used in front of nose off crossing which guides the train wheel in the proper route.

Check rail: check rail is rail length provided on opposite side of crossing to check the tendency  of wheel to climb over the crossing.

Throat of crossing: throat of crossing is the point at which the converging wing rail of a crossing are nearest.

Stretcher bar: stretcher bar is a bar by means of which toe of tongue rail are connected together.

Flange way clearance: flangeway clearance is a distance between the check rail and the adjacent face of the stock rail.

Theoretical nose of crossing: theoretical nose of crossing is the point of intersection of gauge line of a crossing and is used as a reference point for all calculation for turn outs.

Actual nose of crossing:in practice it is not possible to maintain a line in track and so short length is cutoff to give certain with to the nose this point is called the actual nose of crossing.

Turnout

turnout is an arrangement of points and crossings with lead rail by which train may be diverted from one track to another moving in the facing direction