On Wed, Nov 2, 2022 at 10:13 AM, nyc3001 . wrote:

Note that there are 3 SLRX insulated boxcars in the foreground. In the consists at canadasouthern.com, there isn't a single instance of a SLRX car recorded, which makes me wonder if the SLRX cars were confused with Swift (SRLX) cars.

Others have noted that confusion between SLRX and SRLX did occur in the real world. Also among model railroaders and perhaps manufacturers.
However, I don't think that has anything to do with the absence of SLRX in the large collection of consists at canadasouthern.com. All the SRLX loads reported have contents shown as some type of meat or related food product;  no beer or beverages.  Empties fall in the same number ranges as the loads, valid Swift number series. I think this eliminates significant reporting or transcription errors as the reason we don't find SLRX.

So why do we see many SRLX cars and no SLRX?  I think the explanation is routing.  The consists on the CASO site are NYC traffic, principally Toledo-area.  We get traffic moving in the Chicago-New York corridor, plus some more local Michigan/Ohio/Indiana stuff.  There's a lot of meat and  livestock going east from the Chicago area, Swift and other packers in the data.  SLRX loads, by contrast, would be originated in St Louis, and eastbounds would be likely to be routed through Cincinnati rather than via Toledo.  In short, the data is just collected from the wrong line segments to have a good chance to see SLRX traffic in this dataset. 

 Jack Mullen