Which mechanism engages to stop the lift during overspeed?

• A. Electrical Relay
• B. Brake Pad
• C. Safety Wire
• D. Mechanical Pawl

Answer: (D)

The mechanism uses a mechanical pawl to stop the lift during overspeed. When the escalator’s governor detects speed above the safe limit, it moves a pawl into a toothed part of the drive (a ratchet) to lock the drive train and bring the steps to a halt. This creates a positive, rapid stop that doesn’t rely on slowing the motor with friction alone, which is essential for rider safety. The other options aren’t the primary overspeed stop: a brake pad provides friction braking, but the standard overspeed protection relies on the pawl locking the drive; an electrical relay is part of control logic, and a safety wire serves a different safety function rather than stopping due to overspeed.