Jeff Aley wrote
Not to belabor this point, but let's suppose the railroad agent/clerk
follows the AAR rules and sends a PRR, WABASH, SP and UP box car to a
single shipper on the SP for loading -- with the intention that the
PRR box car will be sent to the PRR, the WABASH car to that railroad,
and so on.
Now all four cars get shoved up to the shipper's dock. The shipper
asked for four cars, and has his loads all prepared at their doors.
The ORDER of the four cars is random -- the railroad certainly did
not sort them according to each load's destination.
So the shipper loads the 1st car, the 2nd car, etc -- without any
regard to the ownership of the car!! How could it be otherwise? Can
you imagine the shipper worrying about whether AAR rules are being
followed properly? He just wants to get his shipments loaded.
I don't know if the above scenario is true, but I've never heard any
contradictory evidence. Looking at photos of railroad freight houses
in the Chicago area, it sures looks like a dog's breakfast of cars
was shoved onto the loading/unloading tracks, taking care only to
line up the doorways for crossing via ramps between cars.