How will a Class III Brake Test be conducted if the EOT at the rear of the train is not working?

Answer: C — Charge the brake pipe and check if brakes apply with a decrease in brake pipe pressure.

In a Class III Brake Test, the goal is to ensure that the train's air braking system is functioning correctly without the ability to verify status through the EOT (End of Train) device. When the EOT is not operational, the approach taken is critical to confirming that the brakes are functioning as intended. Charging the brake pipe and checking for a decrease in brake pipe pressure is a standard method to verify brake functionality. When air is pumped into the brake system, the pressure will initially rise. If the brakes are functioning properly, a decrease in brake pipe pressure will indicate that the air brakes are indeed applying as they should. This step is essential in ensuring that the entire brake system is operational from the locomotive through to the last car, even without EOT feedback. This method is more reliable than a visual inspection of only the head car or relying solely on the HEU for indications of brake performance. A handheld gauge to measure air pressure provides insufficient confirmation without verifying the application itself through changes in brake pipe pressure. Thus, tracking the pressure change after charging ensures all brakes respond appropriately, which is the key requirement of the Class III Brake Test.