The specification of the rail electric flat car is determined by the load tonnage (excluding the weight of the car), generally divided into 5T, 10T, 16T, 20T, 30T, 40T, 50T, 60T, 80T, 100T, 120T, 150T, 180T, 200T, whose main purpose is to format the drive system components to choose; the load tonnage can also be customized non-standard, and its tonnage number can be selected in the range of 1 to 200 tons of tonnage can be selected arbitrarily, and its drive components in the absence of special requirements in the case of its still according to the standard product near the upward selection.