As far as we know, they started operation in 1900 with this GE built critter. 

Then as business improved, #50 joined the roster in 1913. Although these are builder's photos, it doesn't appear that any of the electrical apparatus has been installed yet. There doesn't seem to be a motor on the axle that's visible at the end of the car.

#50 photos courtesy Ed Lybarger, PTM archivist.