Just wondering why railroads spend time and money on cleaning the ballast around their tracks? Is it simply a “looks” thing, a saftey thing, or something else?
From Railway Track & Maintenance by E. E. Russell Tratman
" In time, the bed of ballest becomes choked with dirt and cinders so it does not drain properly, but hard ballast such as stone and hard slag may then be restored to condition by screening out the fine stuff…"
The book recommends intervals of 1-3 years for terminals, 3-5 years for heavy traffic main lines and 5-8 years for light traffic lines. —I’m sure the demise of steam lengthed the life of the ballast bed somewhat. I have never seen this mentioned but it is perhaps another reason for the railroad’s acceptance of diesel locos.—
perhaps diesels create less dirt but I wonder if today’s heavier cars pump up more dirt
Dave Nelson
Cleaning of ballast is done to promote good drainage. Good drainage helps to prevent damage from freeze-thaw cycles in cold-weather territory and helps to preserve wooden ties in all climates.
When a train goes over the tracks it pushes the ties down, if the ballast is wet, when the wheels go off the ties, the ties pop back up, that creates a vacuum under the tie and “pumps” thewater and mud up under the ties. Then the water has a harder time draining out of the ballast, increasing the problem. The UP and BNSF have found a bad problem with this in the coal regions where the coal dust blows off the tops of the cars and gets down into the ballast, fouling it badly.
Dave H.
Amen abt the coal dust. As Andy Rooney would say, “J’ever notice that there are certain pieces of track that pump all the time, no matter how often you work on them?” I can think of several examples here on the old C&O.
work safe
Wow. I never really thought about the problems with drainage over time and how built up dirt would defeat the purpose of ballast. This even though I have to flush out the crud that build up around the lava rocks I use as a filter for my water garden.
The things one learns on here!!
In addition to drainage (the # 1 concern), there is also the attraction uncleaned ballast has for flora – you would be amazed at what the persistent hydraulic pressure from plants can do to any structure over time.
Railroads spend a lot of money for weed control of right of way. I worked for a company which invented a substitute for paraquat, and while no longer there, I understand they still sell a good deal of the stuff.
Weeds, trees and other plants can certainly be a problem. If they are large enough, they can be bent over by the train and crushed by the wheels. The juice from the stems and leaves can reduce traction. Roots are capable of moving the ballast and contributing to destruction of the ties. On a ballasted deck bridge, tree roots can cause structural damage weakening the bridge. When the plant dies, it causes drainage problems as discussed above. In urban areas, weeds can be an eyesore and can draw the ire of local residents and governments. Then there are insects, rodents, etc. drawn to the plants.
I have seen major parts of a little used spur be almost totally undermined by, of all things, woodchuck holes. Of course the nearby mainline was a constant source of fresh grain from leaking covered hoppers …
Dave Nelson