What rule pertains to propelling trains?

The rule that pertains to propelling trains is specifically NTR424. This rule outlines the procedures and safety measures that must be followed when a train is propelled, ensuring that all safety protocols are adhered to in order to prevent accidents or incidents while trains are in motion. Propelling refers to the practice of pushing a train rather than pulling it, which can involve unique risks and requires specific actions from the crew to maintain control and communication.

The context of this rule emphasizes the importance of proper communication between crew members, as well as ensuring that all relevant signals and controls are monitored closely during the action of propelling. Understanding NTR424 is crucial for safe train operations, as it aims to mitigate risks associated with the movements of trains in this manner.

Other options might cover different aspects of train operation or safety that don’t specifically address the act of propelling, which is why they are not the correct choice for this particular question.