The lights should not only indicate in a suitable position on the bridge, but the entire circuit should be designed on a fail-safe basis so that if there should be an electrical failure in any switch circuit the system would indicate danger. Indicator lights should be fitted to all superstructure doors, such as passenger access, bunkering and storing doors. It is desirable that a dedicated door alarm panel be fitted, similar to that commonly used for watertight doors. Finally, the condition of superstructure door indicator lights should be logged before departure just as is the condition of the watertight doors below the bulkhead deck.