train dispatching

At first I laughed when I saw this picture on shorpy but then I got curious.



Fortunately there is a commenter who shed soms light on it.

This dispatcher is practicing the art of directing rail traffic by the use of train orders, communicating with his order operators by telephone.

The microphone on his chest is activated by a foot pedal while the speaker is an open "party line" to all his operators as well as the offices of yardmasters, wayside telephone boxes, etc. The box in front of him is used to patch in the person he wishes to address. He dictates the orders to one or more operators simultaneously while at the same time writes the orders in his train order book.

To ensure accuracy, each operator reads back the order one by one while the dispatcher underlines each word or number in his book. When the orders are ready to be delivered, the operator (on the Santa Fe) rolls them up and ties them with a string which he attaches to a train order delivery fork.

When the train is approaching his office he will stand a prescribed distance from the track and hold one fork up at the correct height so that the engineman can place his arm through a loop in the string. The operator then takes the second fork and holds it up for the trainman in the caboose or in one of the passenger coaches.

And then with some wiki help we understand what it is about:

Train orders supplemented the timetable and the rule book. They were addressed to a particular train or trains and directed that train or trains to do whatever the train dispatcher had decided needed to be done: meet another train, wait at specified locations, run late on its published schedule, be cautious under the circumstances described or numerous other actions.