What is the function of the trip cocks on a subway car?

The trip cocks on a subway car play a crucial role in enhancing safety by activating emergency brakes. When the trip cock is triggered, usually by the loss of air pressure in the braking system or a train on a collision path, it signals the braking system to engage immediately. This mechanism ensures that any issues that could endanger the train's operation are addressed swiftly, allowing for rapid deceleration and stopping of the train in critical situations.

While regulating air pressure, controlling signaling systems, and managing passenger load are important functions within the overall operation of a subway system, they are not the primary functions of the trip cocks. The primary focus of trip cocks is to ensure the safety and security of the train by providing an automated emergency response.