What is the proper action regarding a derail in the vicinity to ensure safety before movement?

• A. Leave it as is
• B. Lock the derail in the derailing position
• C. Lock the derail in the non-derailing position
• D. Remove the derail from service

Answer: (C)

When a derail is nearby and movement is about to occur, the device should be secured so it cannot cause an unintended derail. A derail has two positions: non-derailing, where the wheel runs on the rail as normal, and derailing, where the wheel would be guided off the rail. Locking the derail in the non-derailing position ensures trains or equipment can move safely without being diverted off the track. This keeps the movement on the intended route and protects workers and equipment. Leaving it in the derailing position could trigger a derailment unexpectedly, while removing the device from service is unnecessary unless the entire device is being removed for maintenance.