Automatic Railroad Dispatcher

a comprehensive system that provides automated control over the movement of trains. Automatic railroad dispatchers are classified as division, station, and combined (or complex) types.

A division automatic railroad dispatcher is used on divisions between two main stations. A large part of the task is performed by a control computer: collecting and processing information on train movements, compiling and operationally correcting plan-schedules for the movements, transmitting orders for their execution, monitoring, reporting, and so on. However, the dispatchers (a staff which has been reduced to one or two people a shift) retain the overall supervision and specific functions for which it is difficult to write an algorithm. There are two operating modes for a division automatic railroad dispatcher: (1) advisory, where the computer, after obtaining information about the trains through the dispatcher centralization (DC), simulates their movement and compiles an optimal schedule plan, which a dispatcher executes by sending control signals with a key; (2) the automatic mode, where the computer not only compiles the schedule but executes it while a dispatcher retains the right to make any changes within this schedule. In the latter mode, which develops more than ten programs, a schedule plan is issued for two to four hours. For the execution and correction of the schedule plan, information concerning train movements in the division is passed to the computer from the dispatcher centralization every 20 seconds. With the departure of each train from a regular station i a route is automatically established for it as it passes to the next station i + 1 (or sometimes i + 2), with due regard for the movements of other trains. The timetable is not “rigidly” established, and for freight trains the computer compiles daily the most efficient schedule according to the number of trains, their locations, masses (widely termed “train weight”), and other criteria by choosing the best sequence of crossings and passings and thus increasing division speed. Passenger trains proceed according to the timetable and, when it is upset, according to the optimal correction. The planning done by the computer makes it possible to operate with any dislocations of the timetable (schedule). In order to improve the operational reliability of a division automatic railroad dispatcher, two computers can be set up to operate in parallel, comparing all original and final results and mutually correcting each other. A division automatic railroad dispatcher provides centralized control of single-track divisions (and divisions with two-track links) up to 600 km with up to 100 or 150 trains per day at speeds up to 160 km/hr. The principal economic effect is to increase the division speed by 5 to 10 percent. The division automatic railroad dispatcher system was first worked out in the USSR (1959–63).

A station (junction) automatic railroad dispatcher is a system that provides optimization of the operational planning for a main station (particularly for a classification station) or junction and also simulates the movement of every car. Besides the control computer the automatic dispatcher’s apparatus includes a system of information transmitters (for instance, axle counters) sending data on the location of the cars and locomotives. The apparatus has two operating modes: (1) advisory, where all executive functions remain with the operators, and (2) automatic, where a substantial part of the execution of the plans (such as establishing the basic routes and notifying the participating staff members) rests on the computer, which for this purpose is connected with the electric interlock apparatus by telegraph channels and various keys and indicator lights. The principal economic purpose of a station automatic railroad dispatcher is to improve the turnaround time of cars and locomotives and to reduce the switching facilities required.