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