Before opening a knuckle to couple, what distance and action are required in regard to the red zone?

• A. Red zone and 50 feet; secure the air brakes.
• B. Red zone and 100 feet; tie handbrakes if needed.
• C. 300 feet of clear space; release all brakes.
• D. No specific distance requirement.

Answer: (B)

The important idea is maintaining a safe clearance around the coupling area and securing the cars before you manipulate the knuckle. The red zone marks the dangerous area where a moving knuckle or cars could cause injury, so you don’t approach it until you’re prepared and protected.

Before opening the knuckle to couple, you must stay 100 feet away from the red zone. If there’s a risk of movement, tie (set) the handbrakes on the cars to prevent any rolling during the coupling operation. This combination—distance plus handbrake security—reduces the chance of injury from unexpected car movement or awkward coupler operation.

Other options don’t fit because they suggest incorrect distances or incorrect actions (like working with air brakes or releasing brakes during this step). Staying 100 feet back and applying handbrakes when needed aligns with safe coupling practices.