The members which are placed in the cross section of the rail, to support the rail and to transfer the load from the rail to the ballast, are called sleepers,
functions of sleepers
The main functions of sleepers in railway tracks are as follows:
- These hold the rail to the proper gauge in all situations i.e. accurate gauge along straight and flat curves, slightly looser on sharp curves and slightly tighter in diamond curves.
- These support the tight rails in the diamond curves.
- These distribute the transmitted load through the rails over a large area of ballast for the bottom or bridge girders.
- These turnouts hold the rail to the proper level in crossovers and 1 in 20 inclinations on straight tracks.
- These provide an elastic medium between the rail and the ballast and absorb vibrations caused by moving trains.
- These maintain the proper alignment of the track. Proper grades are provided by raising the outer rails on the curves and tamping the required amount of ballast under the rails.
- These provide general stability of the standing track on the whole.