What is one function of the emergency alarm system in the subway?

The emergency alarm system in a subway serves several critical functions to ensure the safety and security of passengers and crew. One key function of the system is to signal for help. When the emergency alarm is activated, it notifies train operators and control personnel of an urgent situation, prompting immediate response. This could be necessary in various scenarios, such as accidents or medical emergencies, where timely assistance is crucial.

While the removal of power from the third rail and activation of emergency brakes are vital safety mechanisms, these actions are typically triggered by different systems rather than the emergency alarm itself. The emergency alarm primarily serves as a communication tool indicating that assistance is needed, thereby allowing for a rapid response to any dangerous situation or emergency on the train. Notifying the control center can also be a part of the broader emergency response, but the core function of the emergency alarm system revolves around signaling for help.