5. Train performance

5.1 Towing loads

Drawing up a traction program [25] , for a given type of traction unit, involves determining the highest load to be towed, on the most difficult route on the network, in the shortest possible timetable. The three factors that determine these specifications are :

• the strength of couplings between vehicles ;

• overheating of the windings of electrotechnical machines (motors and transformers) and of the power electronics of static converters in the drive unit;

• wheel-rail grip for starting.

This last factor is therefore available to the operator. Based on the...