Degree of Curve : The angle subtended at the centre by a chord of 100 ft (30.5 m) length.
Super-elevation (cant) : The raising of the outer rail to counteract centrifugal forces on curves.
Gradient : The rate of change of vertical alignment of a railway line.
Permanent Way : The earthen formation and track structure of a railway line.
Gauge : The separation distance between two rails of a track.
Broad Gauge (BG) : A gauge of 1.676 m, commonly used in India.
Formation : The earthwork supporting a railway track.
Ballast : Layer of broken stone between the sleeper and the formation.
Sleeper : Part of the track on which rails rest.
Sleeper Density : The number of sleepers per unit length of the rail.
Rail : Part of the Permanent Way on which the wheels move.
Flat-footed Rail : The rail section with a flat foot commonly used in India.
Fish-plate : The fastening to hold two rails together.
Creep : The forward movement of rails in the direction of dominant movement of traffic over a period of time.
Triangle : A track arrangement for turning the engineers.
Gathering Lines : A track arrangement whereby a number of parallel tracks merge.