What must all hoistway doors be provided with?

Hoistway doors must be provided with interlocks to ensure safety during the operation of elevators. Interlocks serve as a critical safety feature by preventing the hoistway doors from being opened when the elevator is not properly positioned at a landing. This mechanism ensures that passengers cannot prematurely enter or exit the elevator, thereby reducing the risk of accidents such as falls or entrapments.

Interlocks work in conjunction with the elevator’s control system, allowing the doors to remain securely closed while the elevator is in motion. It reflects an essential safety requirement outlined in elevator codes and standards, which are designed to protect both passengers and service personnel. The implementation of interlocks minimizes the potential for unsafe behavior and enhances the overall safety of elevator operations.

While other options like locks, push buttons, and alarms may be part of an elevator system, they do not provide the same protective function as interlocks do in relation to hoistway doors. Locks might secure the doors but do not automatically prevent access or enhance safety when the elevator is in operation, push buttons are intended for operation rather than safety, and alarms serve more for alerting rather than physically securing door access. Thus, interlocks are the necessary components for ensuring safety when dealing with hoistway doors.