| Here is page 21 of a 22-page booklet published by the Pennsylvania Railroad entitled "Modern Power For Today's Trains: 1949." It was issued originally during July of 1949. Partial Caption: "The Pennsylvania Railroad's inductive trainphone system provides two-way communication between moving trains and wayside control towers, among moving trains in the same vicinity, and between the ends of the same train. This illustration depicts a trainphone circuit between a tower operator (above), a freight conductor in his cabin car (above, right), and the train's engineman (right), over which the train crew informs the operator of the progress of their train over the road." |