When a Comeng is involved in a train rescue, what action is always taken?

In the context of a Comeng train involved in a rescue scenario, tripping the EP (Emergency Plug) Circuit Breaker is a critical safety procedure. This action is taken to disable the electrical systems of the train, ensuring that it cannot inadvertently move while personnel are conducting the rescue or performing necessary maintenance or assessment of the situation.

This procedure helps prevent any accidental activation of traction motors or other electrified components, which could pose risks to individuals working in proximity to the train. By stopping the flow of electricity, safety is maintained, allowing rescue efforts to proceed without additional hazards from the train itself.

The other options, while they may have their own significance in operational procedures, do not address the immediate concern of ensuring a safe environment during the rescue operation in the same direct manner as tripping the EP Circuit Breaker does. For instance, applying the emergency brakes or checking speed sensors pertains to the immediate operational state of the train, but does not directly impact the safety of people working on or near the train in a rescue scenario. Turning the towing cock may relate to operational procedures for towing the train but does not prioritize the safety associated with electrical systems in an emergency context.