Run Through/Pool Units on Chessie Between '80 and '85?

Would anyone be kind enough to tell me what foreign power (if any) appeared on Chessie System prior to implementation of CSX operations? I do recall Seaboard units becoming quite common as CSX began to consolidate the Chessie and SBD motive power rosters so the thrust of my inquiry would precede the appearance of the SBD units.

As for Chessie power venturing out of the system, I remember seeing them in the consists of N&W trains on the former NKP Buffalo Line during the late 70's and early 80's. Chessie also operated trains over Conrail's ex-CNJ trackage to Elizabethport, NJ so they were a frequent sight there as well. Did Chessie units operate off line elsewhere?

Thanks in advance for any information.

Regards,

Earle

I don't remember seeing any foriegn units those years. Between 1980-82 I hostled engines on the C&O at Fulton Yard in Richmond, Va and Gladstone, Va in the roundhouses then worked the road as a firemen. The fleet was mainly Chessie from the C&O, B&O, and WM this was in Virginia, but I don't even recall foriegn units in the '70s when I worked in Walbridge, Ohio.