Before opening a knuckle to make a coupling, what communication must take place?

• A. Red zone monitoring only; no other communication is required.
• B. Red zone and 100 feet; tie handbrakes if needed.
• C. Ignore the red zone; proceed with the coupling.
• D. Notify the crew every five minutes regardless of zone.

Answer: (B)

Before opening a knuckle to couple cars, clear safety communication and securing the cars are essential. You must notify and ensure everyone in the red zone and within 100 feet is aware and out of the danger area, so no one is at the pinch points when the knuckle is opened. If needed, tie the handbrakes to prevent movement during the coupling. This combination reduces the risk of injury from moving cars and ensures the crew can stay clear and prepared for the operation. Ignoring these steps or delaying communication would heighten the chance of an accident.