A dedicated spotter or signalperson is required when which of the following conditions exist?

A dedicated spotter or signalperson is essential to ensure safety when the boom can come within the limit of approach. This situation poses a significant risk, as it may lead to potential hazards such as contact with nearby structures, power lines, or personnel. The presence of a spotter helps maintain situational awareness, allowing for clear communication between the operator and the signalperson. This can prevent accidents by ensuring that the operator receives accurate signals about the proximity of the boom to obstacles, thus ensuring safe and controlled operations.

Other considerations, such as the crane's weight exceeding 10 tons or poor ground conditions, are important for crane operation but alone do not necessitate the need for a dedicated spotter. While having an inexperienced operator may increase risk, it doesn't inherently require a spotter unless combined with other situational factors that could compromise safety, such as limited visibility or working in close quarters. Therefore, the need for a dedicated spotter is most critical in scenarios where the risk of collision or hazard is heightened, such as when the boom approaches the limits of safe operation near obstacles.