Ballast cleaning

Depending on the climate and terrain, ballast may become contaminated with fine dust (especially cola dust from many passing loaded coal trains, as in Wyoming), and with rain and drying cycle, become solid/hard packed. When ballast becomes hard or solid, it no longer offers any cushioning effect to the track & ties, and generally becomes very "ruff riding", which then results in train derailments.

The most recent classic example, happened in the Powder River Coal Basin, about 10 or so years ago. The constant blowing coal dust from freshly loaded unit coal trains, sifted into the ballast and eventually cemented everything solid, causing MAJOR train derailments. The many miles of double and triple track all had to be rebuilt, and then the BNSF & UP railroads required that every coal mine in the area spray a sticky coating substance on the freshly loaded coal hoppers, in order to prevent blowing coal dust.

A Roadmaster I worked with at the Ohio Central once commented that there were three keys to good track, drainage, drainage and drainage.

If ballast becomes contaminated with dirt, dust or organic matter (weeds, grass, etc.) its ability to drain water away from the track is compromised. Once that happens, the track starts "pumping mud" here and there, literally pumping dirt from the bottom of the ballast up to track level whenever the track structure is wet. Mud is not stable and the track starts to move around. Not good...

Saw this video and it made me wonder.  Seems like they are only doing the ballast on the outsides of the rail.  I have to be missing something here.  Would not the ballast compact and contaminate under and between the rails too?

Now, on parts of BNSF's "transcon", they "paved" the subgrade with asphalt.  Does that help long term?

And how does concrete ties affect the situation.

Thanks. Dave G.

A most interesting, and appropriate topic.

Looking forward to more input/comments.

Thanks, Greg