How many types of safety prevention devices are mentioned for escalators?

The correct answer indicates that there are three types of safety prevention devices mentioned for escalators. This number reflects the standard safety measures designed to protect users and ensure the secure operation of escalators. Each type of device plays a specific role in preventing accidents and enhancing safety during escalator operation.

Common safety prevention devices for escalators include:

1. Emergency stop buttons: These are typically located at the top and bottom landings, allowing users to halt the escalator immediately if they sense danger or an emergency situation.

2. Safety sensors: These devices monitor the escalator's operation to detect any irregularities or malfunctions. For instance, they can detect when an object is caught in the escalator steps or if the escalator is not aligned correctly with the landing.

3. Skirt brushes or deflector strips: These are positioned along the sides of the escalator steps to prevent users' clothing or belongings from getting caught in the gap between the steps and the escalator's side panels.

Recognizing these types indicates a comprehensive understanding of escalator safety features, which are vital for ensuring user safety and mitigating risks associated with escalator operation. Other options suggest a different count of devices, which may overlook the importance of one or more critical