Sorry if this is a thread diversion, but while I don't know of anything else being shipped in ore hoppers
other than ore, I HAVE seen the reverse: coal hoppers carrying iron ore.
When I did my research on the Renovo, PA PRR facility, I came upon photos of strings of hoppers running
through there in opposite directions.
Ore used to come down from the Great Lakes and through PA, and coal would go back.
They used to fill the coal hoppers only halfway with the iron because it is so heavy. So in the photo,
you see full coal-loaded hoppers headed one way, and almost identical hoppers headed the other way,
only half-full, with iron ore.
I asked the old-timers up there about this, and nobody knew why they didn't have dedicated ore cars.
