What does the buzzer sequence "O O O O" indicate when a train is standing?

The buzzer sequence "O O O O" is a specific signal used to communicate important operational information regarding a train's status. When a train is standing, this sequence is understood to indicate the command to apply or release the brakes.

In this context, the buzzer's repetitive tone provides a clear and concise auditory signal to the crew. It ensures they are aware of the need to manage the train's braking system effectively. This is crucial because maintaining the correct brake application is fundamental to ensuring the safety and stability of the train while it is not in motion.

Understanding this particular buzzer sequence is vital for crew members, as it emphasizes the importance of quickly and accurately responding to such signals to prevent potential safety breaches or delays in operations.