How long must brakes remain applied to pass a retest of the Transfer Train Air Brake Test?

To pass a retest of the Transfer Train Air Brake Test, the brakes must remain applied for a duration of three minutes. This time frame is established to ensure that the air brake system has reached a stable state, allowing for an accurate assessment of the brakes' performance and effectiveness. By holding the brakes for this specific duration, it allows any leaks or pressure drop to be noted and ensures that the air pressure is consistent, confirming the reliability and functionality of the braking system under operational conditions. Adhering to this standard is critical for safety and efficiency during train operations, as it ensures that all brakes are properly functioning before the train is put into motion.