Which condition requires the engineer to cut out ACSES?

Cutting out ACSES (Advanced Civil Speed Enforcement System) is a critical procedure that must be followed in specific situations to ensure the safety of rail operations. When damage is found on the ACSES apparatus, it can compromise the system's ability to function properly. The integrity of the ACSES is vital for enforcing speed restrictions and other safety measures. If there is any evidence of damage, the system may not operate as intended, which could lead to safety hazards, including the risk of overspeeding.

Cutting out ACSES in this circumstance protects both the train crew and passengers, ensuring that they do not rely on a potentially faulty system while operating the train. Ensuring that safety equipment is fully operational before proceeding with train operations aligns with standard safety protocols.

For the other circumstances: the audible indicator during normal operations may signify a warning, but it does not necessarily indicate immediate system failure; unrestricted movement allowed by the PTC system may still require monitoring or adjustment, and an accurate track speed indicator does not necessitate cutting out the system. In contrast, damage to ACSES clearly signals that immediate action is warranted to prevent potential accidents.