Re: Ballast questions

I'll try as best I can to answer...I'm not an expert on D&RGW practice and if anyone out there knows a better answer, feel free to jump in.

1) These are the same cinders as those from cleaning the fireboxes. Cinders aren't exactly the best material (they break down over a relatively short time) but do have the advantage of being cheap (actually free if you don't count the cost of transporting them from the ashpit to the trackwork area.) But they are acidic, and can act to shorten the life of the track structure. Also as they break down, they compact and retard drainage.

2) As far as I know, only the rebuilt Navajo relocation (done at government expense to compensate for right-of-way lost to the backwaters of the Navajo dam) had this sort of ballast. And of course, it's now abandoned. I don't believe that crushed rock was used anywhere else on the system... the narrow gauge wasn't all that profitable, and cinders were cheap...

3) Properly maintained and cleaned, crushed rock ballast should last a long time. A VERY long time.

4) Crushed rock ballast works much like any other material. It supports the track structure, carrying and spreading the load. It also provides for good drainage, if the ballast is maintained by regular cleaning. It is the best material because it doesn't break down, compact or otherwise fail. The only thing that happens to it is that cinders from locomotives will fill the pores and prevent drainage. Railroads spent a lot of money keeping ballast in top shape back in the days of steam, especially coal-fired steam. Oh, yes, drippings from ice-activated refrigerator cars also were highly damaging to the track structure as well as ironwork.

5) As I mentioned above, it holds up better because it doesn't break down and compact with time. Since one of the main purposes of ballast is to hold the track structure you can probably understand why the track stays in alignment better over time with rock ballast. And why cinder ballast allows track to move. If the ballast prism doesn't drain properly, the residual moisture combines with dirt and the like to form mud which supports the track like... well mud. Nuff said...

6) Again, better support for the track translates to better riding for the locomotive. Better riding means less wear and tear on the running gear (especially with older locomotives with fabricated bar frames).

Anybody else have more to add?

Bill Daniels, P.E. (Civil)
Tucson, AZ