If Brake Pipe pressure falls below 90 pounds and braking power cannot be maintained, how should it be treated?

When Brake Pipe pressure falls below 90 pounds and braking power cannot be maintained, it should indeed be treated as a brake pipe rupture. This is because a significant drop in Brake Pipe pressure indicates that there is likely a failure in the system that prevents the train from maintaining its braking capacity.

In a properly functioning brake system, the pressure is critical for the effective operation of the brakes. A pressure below the threshold signifies that the integrity of the braking system is compromised. This situation could lead to serious safety issues, as reliable braking is essential for the safe operation of the train.

Recognizing it as a brake pipe rupture allows for immediate response actions to be taken to ensure the safety of the train and its passengers. It prompts engineers to follow emergency protocols to mitigate risk, which might include stopping the train or implementing manual braking measures. Understanding this context is crucial for ensuring that train operations remain safe and effective.