Sand is another good material for railway ballast. It is one of the cheapest and most readily available materials for ballast. The sand ballast is not used for important lines.
This is not preferred for the main and branch lines. It is only used for packing pot sleepers and is also used in the case of unimportant rail tracks.
Following are the advantages of sand ballast
1. It has good properties to drain off rainwater immediately.
2. This material produces a silent track and has been found very good for packing cast-iron pot sleepers.
3. It is very cheap, so it is very helpful for low-cost rail tracks.
4. It is available everywhere.
The following are the disadvantages of sand ballast:
1. The sand ballast requires frequent renewal as sand can be easily blown off by winds or washed away by rainwater.
2. It has no stability and gets disturbed easily by vibration, hence, the maintenance of the track becomes very difficult.
3. Sand ballast causes wear of rails, seats, and keys.