The Indian Railway is one of the world’s largest railway networks comprising 117,996 km of track over a route of 66,030 km and 7,137 stations.
Anyone in India can be expected to have seen a railway line. Have you observed crushed stones placed along the railway tracks. Ever wondered why?
Well! There is scientific reason behind it.
FYI, these stones are collectively known as track ballast.
Railway tracks are made up of steel and were previously supported by wooden ties which are now being replaced by concrete rectangular slabs known as sleepers.
To put it in easy language, their purpose is to hold the wooden cross ties in place, which in turn hold the rails in place.
Railway tracks are subject to heat expansion and contraction, ground movement and vibration, precipitation buildup from rough weather, and weed and plant growth from underneath.
In order to keep the sleepers intact in one place and hold the tracks firmly, crushed stones are placed between the sleepers (or wooden ties) and also around the tracks.
The stones are well crushed in order to make sure that their surface is not smooth and that they do not slide over each other when the train is passing over them.