Patent US 3,944,986

Data and voice communication links are provided between a movement direction center, a data processing center, and all mobile work units of a railroad terminal control system. A work assignment input from the movement direction center, e.g., an order to assemble a train, activates the data processing center to prepare and transmit to the selected switching locomotive an itemized work list, which is recorded in printed form at the locomotive to serve as specific instructions for accomplishing the assignment. The work unit crew reports readiness to begin and subsequent completion of each work list item. The data processing center responds to these and other information inputs, e.g., vehicle movement indications, to check the work done and to remotely establish the field conditions, e.g. track routes, necessary to accomplish the successive work items until the entire assignment is completed. The data processing center sets up the next route and authorizes the locomotive crew to perform the next work step only when the checking process indicates that the prior work step was correctly completed.