When should the vapor key be removed from the coupler key switch?

The correct situation for removing the vapor key from the coupler key switch is after turning the coupler key switch to 'OFF.' This is important because the coupler key switch is integral in controlling the vapor or pneumatic systems associated with coupler operations on trains. By ensuring that the switch is turned off, operators can safely remove the key without the risk of unintended activation of coupler functions, which could pose a safety hazard.

Removing the key only after the switch is turned off ensures that all systems are in a neutral state, minimizing the chance of accidental release or operational issues. This practice aligns with safety protocols that prioritize the well-being of personnel and the integrity of the train operations. It highlights the significance of following proper procedures for equipment handling in train operations, ensuring a systematic approach to safety.