All,
Thank you for the input about the various pipe sizes, especially the various diameters.
As a point of reference, the 9600's were stenciled as having an interior length of 40'-3, while the D&RGW Folio Sheets state car length as 40'-3 1/2" over the end sills.
In some photos out there, the ends of the pipe being carried are at least 2' to 3' (perhaps more) from the end of the car which suggests some pipe was from 35' to 38'
in length. I have yet to come across anything in the files that specifically states length or diameter.
John T.