SD80MAC 5115, an ex-Conrail unit, leads the way. When Conrail was split up in 1996, the AP&W got the units, since neither NS or CSX was very much interested in such 'oddball' units. The AP&W was the only other railroad to purchase the SD80MAC, so they were a better fit for them.
The Conrail-spec red class lights are prominent on the front end of the unit; a feature which distinguishes the former Conrail SD80MACs from the AP&W's units.
Trailing 5115 is Missouri Pacific-painted UP 1982 -and a lot of empty cars. Both are unusual; while UP engines are actually quite common on the AP&W, the 'Heritage' units are not. And most intermodal trains are pretty full with containers and/or trailers.
The accountant's nightmare; the entire train is empty! While empty cars -even intermodal cars -are not uncommon in this slowed-down economy, for an entire train to be without loads is very unusual. In all probability, these cars are either being moved for better utilization due to traffic variations, or perhaps some of them are in need of repairs. Still, at least some of them could be carrying a container or two.
Later, a loaded intermodal train passed through, full of trailers. Now THAT will make the bean-counters happy!