I was looking at some photos of 1960's B&O Railroad coal operations. In many photos, I see mixed engine consists of EMD F-units and GP's around the mining areas of Grafton WV. There were also many of these consists parked in the engine facilities and yards in Connellsville PA and Clarksburg WV.
I've seen mixed consists before, but not nearly to this degree.
Do the two different locomotives bring different characteristics to the consist? Or, it was sheer coincidence …B&O quickly cobbling together whichever running engines were available, during trying financial times?
Thanks.