That's a cool old & unusual pic Iain-surprising too.
I remember reading years ago in Trains mag that there was a 8 mile
or so short line in Illinois that as of the late 70's was still running
steam, & the majority of the traffic handled on the line was intermodal
trailers. Was it the Crab Orchard & Egyptian? I could be VERY wrong on
that. But I don't -think- they had their own trailers like the NS one above-
They just handled the traffic.
All in all-a neat pic-thanks!