AUTOMATION OF FLAT CLASSIFICATION YARDS

Systems in use in Europe and Japan are described wherein the cars are propelled along classification tracks by means of propulsion and braking units which are so controlled that impact between cars is minimized. In one instance the propulsion is by means of continuous wire rope and in the other by linear induction motor. In both cases the cars themselves are propelled by rollers which engage on the flanges of car wheels. While the main objective is the reduction of damage to freight in transit, the system of car propulsion by linear motor offers promise of application to yards which have hitherto been considered insufficiently large or important to warrant automation on the hump system. A study was made of the Belleville Yard of the Canadian National Railways and a computer program devised to simulate the operation of this yard using a system of linear induction motors. The result of the study showed that the proposed system was capable of dealing in an expeditious manner with traffic likely to be offered. Detailed design would be necessary in order to provide an accurate estimate of cost but preliminary figures relating to a yard capable of classifying cuts of 60 cars into 16 classification tracks, each capable of holding 60 cars, indicate that cost would be about $400,000. An alternative switching system has been considered wherein cars are attached to the end of the train being made up at a given point, the train being moved forward by an amount corresponding to the length of each car as it is attached. Because of the great mass of the train as it nears completion, together with the slow speed of progression throughout the classification process, the linear motor is considered to be unsuitable and rope haulage is recommended for this system. It is concluded that it is feasible to provide an automated classification yard without the expense associated with the provision of a conventional hump yard by using a linear motor for the propulsion of cars within the yard. The investment required would be comparatively modest and should result in less damage to freight and better manning arrangements within the yard. It is recommended that a prototype system be commissioned for application to a yard for which economic justification for re-equipment exists.