What is the last action to take if all else fails in a braking emergency?

In a braking emergency, the most appropriate last action to take, if all other methods to manage the situation have failed, is to tow the train out of service. This action is crucial because it prioritizes safety and ensures that the train is removed from the operational track in a controlled manner to prevent potential accidents or collisions. Towing the train out of service allows for a proper investigation into the fault and ensures that passengers and crew are no longer at risk.

In contrast, turning off the communication system would hinder coordination and the ability to manage the situation effectively. Contacting train management could provide guidance, but if all else has truly failed, engaging in further communication might not be the immediate solution when the primary concern is safety. Shifting to manual control may not fully address the emergency if the braking system has failed, as manual control does not guarantee that the braking issue will be resolved or managed effectively in a critical situation. Therefore, towing the train out of service stands out as the appropriate decisive action in this context.