Ballast on bedrock

[TigerGuy]

Since rail is constructed with limited grades, I know I'm not the first to deal with this. When the rail goes from compacted fill to cut into bedrock (layered limestone and shale), I feel it will behave similar to a loading/unloading facility where the rail comes onto a fixed rigid structure. Should I maintain the ballast thickness constant along the length? Or would it be acceptable to use a thinner amount of ballast along the cuts in the bedrock?

 

[dhengr]

TigerGuy:
Check the AREMA Stds. (American Railway Engineering and Maintenance-of-Way Association) Stds., and see what they have to say. Check with your local RR, their maintenance-of-way dept., and ask them what they would do. They’ll have some std. details. I’ll bet that when you put ballast on a hard surface, you have to confine it on the sides, maybe cut a trench in the bedrock for the ballast. Otherwise, usage will just rattle the ballast out from under the track and ties, in fairly short order. They do put track and ties, or just track directly on concrete grade beams.

 

[TigerGuy]

I didn't see anything in AREMA (not that I read the thousands of pages completely ). I'll try and contact the local RR officials.

Thanks