What should a train operator NOT do when descending to the track after experiencing brake failure?

When determining what a train operator should not do after experiencing brake failure, it's essential to consider the safety protocols in place. Pulling the emergency alarm in this context is not advisable because the emergency alarm is typically used for signaling to others in a situation where immediate help is needed or to alert others about a concern regarding the train's condition, rather than directly addressing the brake failure issue.

Once brake failure is detected, the train operator must focus on assessing the situation and ensuring the safety of passengers and the train. Checking the train’s wheels, inspecting the brake systems, and assessing the train’s position can provide critical information about the status of the train and the immediate environment. These actions can help the operator make informed decisions about the next steps, including communicating the issue effectively and ensuring that the train is secured before any further actions are taken.

Therefore, pulling the emergency alarm is not the most responsible choice in this specific situation, as it does not directly contribute to resolving the brake failure or securing the train. It is crucial for the operator to prioritize concrete actions that assess and stabilize the situation first.