The Freight Train Emergency Brake System and a Method to Calculate Stop Distance and Time

Determining the arrival time for a freight train at a railroad crossing and how the train engineer could affect the arrival is a common question. This paper discusses the freight train brake system, the freight train makeup variables and considerations, and a method to calculate the freight train brake to stop time and distance. The pneumatic brake system, AB brake valve, air propagation rate, braking ratios, braking efficiencies, wheel/shoe adhesions, and the brake system development times are addressed. With the ability to calculate the change in speed, the freight train change in arrival time at a crossing can be determined.