Wassup with the rocks that they lay underneath the railway lines?What does that do?

Question

Wassup with the rocks that they lay underneath the railway lines?What does that do?

Answer 1

Those rocks are called ballast.

The ballast serves a few purposes. Drainage would be one of the most important. It prevents water and other fluids from puddling up around the ties, expanding the life of the ties and the rail line.

It also provides a stable structure as to which the rail line can be built on. If ties and rails were laid directly onto dirt, they would gradually sink down into the ground, especially after a rainstorm. The ballast, although not entirely preventing this, definitely increases the stability of the line.

Answer 2

I think you're referring to Track Ballast - these are used to

(A) provide drainage, (B) create an even surface for the tracks to be laid, and (C) stabilise the track as trains speed by.

Answer 3

The answer above is right. Technically, they stabilize the structure.

Answer 4

They absorb the shock of the vibration and weight.