If a train unexpectedly goes into emergency with no slack action and air appears to be restored at the rear, what action should be taken?

If a train unexpectedly goes into emergency with no slack action and air appears to be restored at the rear, what action should be taken?

• A. Increase Locomotive Throttle
• B. Release the Automatic Brake
• C. Apply Full Service Brake
• D. Use the Set-Out Function

Answer: (D)

When a train’s braking is controlled by a brake pipe that runs through every car, an emergency brake application happens because the brake pipe pressure drops along the train. If there’s no slack action and air seems to come back at the rear, it suggests a fault localized to the rear portion rather than the whole train. The Set-Out Function is used to isolate a specific car or section from the train’s brake system by venting its brake pipe to atmosphere, which causes that car’s brakes to release and prevents its fault from dragging the rest of the train into brake or release cycles. Using set-out lets the front portion stay under control with restored air while the back portion is removed from service for inspection or repair. The other actions would either fail to contain the fault or could destabilize control during an emergency.

When a train’s braking is controlled by a brake pipe that runs through every car, an emergency brake application happens because the brake pipe pressure drops along the train. If there’s no slack action and air seems to come back at the rear, it suggests a fault localized to the rear portion rather than the whole train. The Set-Out Function is used to isolate a specific car or section from the train’s brake system by venting its brake pipe to atmosphere, which causes that car’s brakes to release and prevents its fault from dragging the rest of the train into brake or release cycles. Using set-out lets the front portion stay under control with restored air while the back portion is removed from service for inspection or repair. The other actions would either fail to contain the fault or could destabilize control during an emergency.