When I was a college kid working for the AT&SF for a summer in the late '70s, a Supervisor gave me this photo mounted on a Masonite board for wall hanging and it's graced various dorms, apartments and houses for 40 years now. At the time, the 6358 was fresh from GE's Erie Shops in April 1978.
Not all that long ago. St. Maries, Idaho. What was once a very busy place, thriving. Now slowly fading away and poorly maintained.
Saw this on a flatcar... Then, spotted this on a siding further down the line days later. note, not the same flat
Looks like someone is remotoring their loco... Cool to model that with a dead motor from a loco and stick that on a flat car.
Considering the size of a can motor in an HO locomotive, the loco that motor is going into must be humongous, at least twice the size of a standard 1:1 loco.
A friend told me that the colorful tank cars you photographed are used for emergency response training as a rolling classroom for training local fire departments on tank car basics, such as car classifications, valve configurations, construction, etc. All of the class I RR's and chemical shippers like Dow have these in service in one form or another.
I think I posted those photos here before and someone was able to identify the load, but I can't recall. It demonstrates that your "junk" box for modelers always holds promise.