How should the train be operated if the carborne ATC equipment fails?

When the carborne Automatic Train Control (ATC) equipment fails, operating the train in ATC Bypass mode is the most appropriate response. This mode allows the train to continue operating safely despite the failure of the automatic control systems.

ATC Bypass mode maintains a certain level of operational safety by enabling the engineer to manually control train speed and stop commands while bypassing the failed automatic functionalities. This ensures that the train can still be operated under a controlled environment, allowing for necessary adjustments to be made based on track conditions and spacing from other trains.

Using manual override mode would put more reliance on the engineer's subjective judgment in the absence of the systems that assist in maintaining optimal and safe train operation. Operating in normal mode would assume full functionality of the ATC system, which is not the case when there is a failure. Meanwhile, an emergency stop mode would be an extreme response that could lead to unnecessary disruptions and hazards if the situation does not warrant such a drastic measure.

Therefore, utilizing ATC Bypass mode provides a balanced approach to safety and operational continuity in the event of carborne ATC equipment failure.