There was a good discussion of the
Salida rotary dumper that is worth a read posted about 4 years ago. It includes photos, discussion and a video of a similar rotary dumper in operation.
The Salida dumper was originally constructed to transfer coal from the Crested Butte mines from narrow gauge to standard gauge and if my memory serves there were tracks for the various coal grades i.e. lump, slack etc. I may have a track diagram somewhere in my files (or perhaps it is in one of the published books) but a lot of the original mfg. (McMyler Interstate) drawings of the Salida rolling transfer (as the D&RGW called it) are available from the Denver Public Library.
In the original thread Jerry Day mentioned he was doing a book on the D&RGW Crested Butte branch that would include the operations of the rolling transfer so stay tuned for that plus Greg's video.
Rod Jensen