How does an engineer change the operating mode from MATC to MCS?

To change the operating mode from MATC (Manual Automatic Train Control) to MCS (Manual Control System), the engineer must interact directly with the train's control systems. Grabbing the master controller and adjusting the ATC Mode switch is the specific procedure that allows the engineer to initiate this transition. This action ensures that the train's control system can be properly set to the desired operating mode, enabling the engineer to take manual control over the train's operation.

The process involves physical engagement with the train's controls, which is necessary to effectively switch from one operational mode to another. This manipulation of the controls ensures that the systems are accurately coordinated with the engineer's intentions on how to operate the train. It emphasizes the level of direct interaction required by the engineer in managing the train’s control system.

This correct approach contrasts with other options that do not pertain to the proper procedure for changing operational modes. For instance, merely setting the ATC Mode switch to MATC lacks the necessary context of using the master controller, while pressing the emergency brake button addresses safety measures rather than mode changes. Signaling to the conductor does not influence the control systems directly and also does not involve the necessary interaction with the physical controls.