When operating conditions allow a running release of the train brakes, what must be done prior to releasing the train brakes?

When operating conditions allow a running release of the train brakes, what must be done prior to releasing the train brakes?

• A. Release the train brakes immediately.
• B. Allow the exhaust at the automatic brake valve to stop before releasing the train brakes.
• C. Increase throttle before releasing brakes.
• D. Apply the emergency brake.

Answer: (B)

In an air brake system, a running release must be done only after the exhaust at the automatic brake valve has stopped. The exhaust vent is what releases air from the brake cylinders when brakes are applied. If you release while air is still venting, the brakes may not release cleanly or evenly across the train, leading to an abrupt or uneven transition and loss of smooth control. Waiting for the exhaust to stop ensures the brake pipe pressure has stabilized and that the brake cylinders can release fully and predictably as you continue to move. So, before releasing the train brakes, you wait for the exhaust at the automatic brake valve to stop, then perform the release to achieve a controlled, smooth reduction in braking force. Releasing immediately, increasing throttle first, or applying the emergency brake would not accomplish a proper running release.

In an air brake system, a running release must be done only after the exhaust at the automatic brake valve has stopped. The exhaust vent is what releases air from the brake cylinders when brakes are applied. If you release while air is still venting, the brakes may not release cleanly or evenly across the train, leading to an abrupt or uneven transition and loss of smooth control. Waiting for the exhaust to stop ensures the brake pipe pressure has stabilized and that the brake cylinders can release fully and predictably as you continue to move.

So, before releasing the train brakes, you wait for the exhaust at the automatic brake valve to stop, then perform the release to achieve a controlled, smooth reduction in braking force. Releasing immediately, increasing throttle first, or applying the emergency brake would not accomplish a proper running release.