CSX R171 (OBSS, Orange Blossom Special-South), with RF&P GP40 123 plus three, is westbound approaching Poplar (mp 82.5) on CSX's (former B&O) Philadelphia Subdivision, shortly after nine o’clock on 07/19/1987.
The trailing units are (2) B&O GP40 6577(CSX#), ex-B&O 4002 (3) CS/B&O GP40-2 4249 (4) RF&P GP35 135