To pass a red absolute signal at an Automatic Interlocking when stopped with an Approach distant signal, what equipment must be used?

• A. Throttles and dynamic brakes only.
• B. Conductor’s notes and a flashlight.
• C. Main track switches unlocked and manual signals.
• D. Control panel only.

Answer: (D)

Authority to pass a red absolute signal at an Automatic Interlocking comes from the interlocking system itself, and the tool that provides that authorization is the interlocking control panel. When you’re stopped at a red signal with an Approach distant signal in view, you must use the control panel to obtain the required clearance or route set by the interlocking logic. Throttles and dynamic brakes control speed, but they don’t grant permission to move through a red signal. Relying on conductor’s notes and a flashlight isn’t a recognized method to obtain or verify authority or protection. Having switches unlocked and relying on manual signals isn’t the procedure for obtaining interlocking clearance either; without the control panel authorization, you don’t have the necessary protection to proceed. So, using the control panel provides the proper authorization and interface with the interlocking to pass the red signal.