What is Ballast
Railway Ballast is the foundation of railway track and provide just below the sleepers. The loads from the wheels of trains ultimately come on the ballast through rails and sleepers.
Functions of Ballast
Some of the important functions of railway ballast are:
- To provide firm and level bed for the sleepers to rest on
- To allow for maintaining correct track level without disturbing the rail road bed
- To drain off the water quickly and to keep the sleepers in dry conditions
- To discourage the growth of vegetation
- To protect the surface of formation and to form an elastic bed
- To hold the sleepers in position during the passage of trains
- To transmit and distribute the loads from the sleepers to the formation
- To provide lateral stability to the track as a whole
Requirements for Ideal Ballast
The ideal material for ballast should fulfill the following requirements
- It should be possible to maintain the required depth of the material in order to distribute the load of passing train on the formation ground
- The material to be used for ballast should not be too rigid but it should be elastic in nature
- The material for ballast should be of such nature that it grips the sleepers in position and prevent their horizontal movement during passage of train
- It should not allow the rain water to accumulate but should be able to drain off the water immediately without percolating
- It should be strong enough a resistance to abrasion
Materials for Ballast
The following materials are used for ballast on the railway track.
- Broken Stone
- Gravel
- Cinders / Ashes
- Sand
- Kankar
- Moorum
- Brick Ballast
- Selected Earth
