A mobile crane is operating near a building under construction. The swing radius of the crane's counterweight could potentially enter an area where other workers are present. What is the most effective control measure to prevent striking personnel?

Question: A mobile crane is operating near a building under construction. The swing radius of the crane's counterweight could potentially enter an area where other workers are present. What is the most effective control measure to prevent striking personnel?

Answer options:

• Ensure the operator frequently sounds the horn to alert workers.
• Position a signal person to monitor the swing radius and warn workers.
• Rely on safety cones to mark the perimeter of the swing path. ✅ Implement an exclusion zone that prevents all personnel from entering the swing radius.

Correct answer: Implement an exclusion zone that prevents all personnel from entering the swing radius.

Explanation: The most effective control measure is to eliminate the hazard by creating an exclusion zone, physically preventing workers from entering the swing radius of the crane. While a signal person is helpful, an exclusion zone provides a higher level of safety by removing the possibility of interaction. Cones are warning devices, not barriers.