Which device disables chairlift operation when the seat is unlocked?

• A. Footrest Switches
• B. Traveling Cable Tracking
• C. Swivel Seat Cut-off Switch
• D. Call/Send Devices

Answer: (D)

The safety system is designed so a chair isn’t moved unless every part is in a secured, safe state. The call/send devices are part of the control loop that dispatches a chair from a station, and they include interlocks that verify the chair is ready to move. If the seat is unlocked, the call/send interlock circuit detects that unsecured condition and prevents the chair from being dispatched, effectively disabling chairlift operation. This ensures you don’t have a chair traveling with an unlocked or unsecured seat.

Footrest switches, traveling cable tracking, and the swivel seat cut-off switch each serve important roles, but their functions don’t specifically address the condition of the seat being unlocked in the same direct way as the call/send interlock does.