What statement is true concerning the platform interlock devices associated with a winding drum or traction drive cargo elevator onboard ship?

Correct Answer: Option B — Platform interlocks are used to prevent door operation if the platform is at other than a deck level and only allow door operation when the platform is proved at a deck level.

Safety regulations for shipboard elevators require platform interlocks to ensure the elevator is flush with the deck before the doors can open. This prevents personnel from stepping into an open shaft or tripping over a platform that is not level with the deck surface.