This is all that remains of the old Rowenna substation in Marietta PA. It was built in 1938 by the Pennsylvania Railroad to power the catenary on their electrified freight line. It stepped down 138kv 25hz transmission lines to 12kv. Conrail ceased all electrified freight operations in 1981 and their portion of the catenary system was abandoned and the wires were removed. The substation was torn down in the early 90s and not much besides the foundations remain. A small portion of the 12kv bus was used up until recently as a switching station which provided power for signals.