The No. 52 Fire Car works on the same principle as the No. 50 gang car and reverses electrical polarity to the field armature when it strikes a bumper, causing the car to go in the opposite direction.

According to Lionel, the design is based on an amalgamation of several types of equipment used by the railroads.

Lionel had originally planned to use a flashing lamp No. L-257 when this unit premiered in 1958, but they were not available until the next year when they were included in the Lionel Service Manual. Further problems were caused by the fact that the foam lamp pad usually deteriorates over time and causes the lamp to tilt to one side and melt the red dome housing. Collectors should be aware of this problem and check these units for heat damage. The fireman should also change direction when the unit reverses direction.