Rodger Ballast Cars and Western Air Dumps

In a comment to this post, Ron Simpson identifies some cars that I think are Rodger ballast cars as 12-yard Western Air Dumps. I took screen shots from a couple of pages off Google Books covering maintenance cars of the period. Here is the page on Western air dumps:

This photo shows what I think is a 12-yard Western air dump at left on a CR&NW construction train:

Here is a screen shot of a page describing Rodger ballast cars:

Here are what I believe are Rodger ballast cars on a CR&NW work train at mile 113:

Ron in his comment says the CR&NW had 100 of the 12-yard Western air dumps. A Moody's manual from about 1916 says the CR&NW had 126 "service" cars, so the 100 12-yard dumps would fit there. I think the CR&NW had both Western dumps and Rodger ballast cars, but I don't know how many of the Rodger cars.

I really appreciate this level of interest and comment from visitors!