The Reading and Chessie System had run-through services to Allentown, Pennsylvania in pre-Conrail days. Here a Chesapeake & Ohio SD40 waits for its return assignment at Bethlehem Engine Terminal.

Two 1966-built SD40s are pushing an eastbound freight up the old B&O mainline, with a Vesuvian plume of smoke emanating from the ex-WM unit, No. 7572.