What is the expected outcome of opening the trip cock on a subway car?

Opening the trip cock on a subway car leads to an emergency brake application. The trip cock is a safety device designed to ensure that if a train passes a stop signal or experiences a significant emergency, it can quickly halt operations. When the trip cock is opened, it triggers a series of mechanisms that activate the emergency brakes, bringing the train to a stop.

This feature is crucial for maintaining safety on the tracks, especially in situations where a sudden stop is necessary to prevent accidents. The trip cock’s role is to provide an immediate response to hazards, ensuring that the train's operators can manage unforeseen circumstances effectively. The timely engagement of the emergency brakes protects both passengers and railway infrastructure, thereby preventing possible collisions or derailments.