Crane hand signals shall be those prescribed by ______.

Crane hand signals are essential for ensuring safe communication between the operator and ground personnel during lifting operations. The correct reference for these signals is established by ANSI, which stands for the American National Standards Institute. ANSI has set forth standard practices that cover a wide range of safety and operational guidelines, including the hand signals used by crane operators. These standards are widely accepted in the industry and are designed to promote safety and clarity in communication, thus minimizing the risk of accidents.

In contrast, the other options pertain to different aspects of occupational safety or equipment standards. OSHA focuses on workplace safety regulations, while UL 455 relates to product safety standards, specifically for electric equipment. The SPCA (Specialized Carriers & Rigging Association) is more focused on industry practices but does not specifically set the standards for crane signals as ANSI does. Therefore, acknowledging the role of ANSI in defining crane hand signals directly aligns with established safety practices within the industry.