A yard line may also be used to supply air to a train or block of cars that have already been tested.

A yard line may also be used to supply air to a train or block of cars that have already been tested.

• A. True
• B. False
• C. Only in daylight
• D. Only if additional testing is needed

Answer: (A)

Yard air is an auxiliary source of compressed air used in the yard to charge and maintain a train’s brake system while cars are being moved or reconfigured. It can be connected to a train or a block of cars that have already been tested to re‑pressurize the brake pipes, hold or release brakes, and allow safe movement within the yard without depending on the locomotive’s air system. This is why the statement is true: you use the yard line whenever air pressure is needed in the yard, not just during daylight or only for extra testing.

Yard air is an auxiliary source of compressed air used in the yard to charge and maintain a train’s brake system while cars are being moved or reconfigured. It can be connected to a train or a block of cars that have already been tested to re‑pressurize the brake pipes, hold or release brakes, and allow safe movement within the yard without depending on the locomotive’s air system. This is why the statement is true: you use the yard line whenever air pressure is needed in the yard, not just during daylight or only for extra testing.