Why are there crushed stones alongside railway tracks?

[John Ashworth]

Why are there crushed stones alongside railway tracks?

Nothing new here for railway enthusiasts, but interesting to see it in a mainstream British newspaper.

[Philip Martin]

That's a good article. Here's another. It mentions cinder ballast. I was in school in Illinois, in 1954, and the Illinois Central used cinder ballast; it was supposed to be very good.
Funny, stone ballast was first used in sailing ships in place of cargo.

http://www.american-rails.com/ballast.htm

[Philip Martin]

In the above post, I have cinder ballast confused with slag ballast. Slag is what the IC used on their main line sixty years ago. It is a product of iron and steel making. Since the steel industry pretty much no longer exists in the US, slag may not be as easy to come by as it was then.