Anti-Two-Blocking Devices are a device required to lift personnel.

• A. True
• B. False
• C. Only for large cranes
• D. Optional

Answer: (A)

Anti-Two-Blocking Devices are safety features that prevent the crane’s hook block from being pulled up into the boom tip, which can cause the hoist to jam, the load to drop, or the crane to be damaged. When you’re lifting personnel, this risk becomes even more dangerous because a fall or a sudden halt could directly harm a worker. The device detects when the hook is approaching a two-block condition and automatically stops or limits hoist movement, reducing the chance of a dangerous jam or uncontrolled movement. For lifts involving people, this safety measure is required, which is why the statement is true.