What is necessary to reopen the doors after they are closed and locked?

To reopen the doors after they have been closed and locked, it is necessary to select the Cut-Out position of the ATC Door Mode switch. This action is specifically designed to override the automatic train control (ATC) system, allowing the train engineer to manually control the door operation. The Cut-Out position ensures that safety systems do not interfere during the process of reopening the doors, facilitating a safe and efficient way to handle door operations when needed.

The other options, while they may seem relevant to safety or operations, do not directly address the mechanism required to reopen locked doors. For instance, notifying passengers or engaging emergency override could be part of safety protocols in different contexts but do not provide the specific means to unlock and open the doors once locked. Switching to Service mode also does not directly correlate with the immediate action needed for door reopening, as this mode pertains more to the overall operational settings of the train rather than a specific door release function.