What does it mean if a fault log shows an interlock failure?

What does it mean if a fault log shows an interlock failure?

• A. The interlocking logic prevented a safe movement, indicating a fault in the interlocking or aligned signals/routes.
• B. Interlock failures indicate a successful movement.
• C. They show normal operation of track circuits.
• D. They only relate to power supply.

Answer: (B)

Interlock systems ensure safety by tying together signals, switch positions, and route alignment so a train can move only when every part of the safety chain is correctly set. When a fault log shows an interlock failure, it means the interlocking logic has detected an unsatisfied condition or a fault within the interlocking chain. The result is a blocked or prevented movement to avoid unsafe conditions. This points to an issue in the interlocking or in how the signals/routes are aligned, not to a normal or successful movement. So, this isn’t a sign of normal operation, a confirmed track-circuit operation, or a power-related condition alone. It’s a safety fault indicating the interlock would not permit movement until the fault is fixed. Investigate the interlocking hardware, verify switch positions and route alignment, check associated sensors and signal indications, and review any recent changes to the interlocking or wiring.

Interlock systems ensure safety by tying together signals, switch positions, and route alignment so a train can move only when every part of the safety chain is correctly set. When a fault log shows an interlock failure, it means the interlocking logic has detected an unsatisfied condition or a fault within the interlocking chain. The result is a blocked or prevented movement to avoid unsafe conditions. This points to an issue in the interlocking or in how the signals/routes are aligned, not to a normal or successful movement.

So, this isn’t a sign of normal operation, a confirmed track-circuit operation, or a power-related condition alone. It’s a safety fault indicating the interlock would not permit movement until the fault is fixed. Investigate the interlocking hardware, verify switch positions and route alignment, check associated sensors and signal indications, and review any recent changes to the interlocking or wiring.