When the angle cock and/or cutout cock handles are in-line with the pipe, which of the following valves is open?

When the angle cock and/or cutout cock handles are in-line with the pipe, this indicates that the valve is in the open position. The brake pipe is specifically responsible for transmitting brake pressure throughout the train. Therefore, when the angle cock and cutout cock are aligned with the pipe, the brake pipe is open, allowing air to flow freely for brake operation.

It's important to note that the main reservoir equalizing and actuating valves have specific functions and may not be directly affected by the positioning of the angle or cutout cocks in the same way. The open configuration of the brake pipe ensures that the necessary air pressure can be applied to activate the braking system effectively. This is a critical aspect of air brake operation, enabling efficient communication and functionality of the braking mechanisms on the train.