According to OSHA 1926 Subpart CC, warnings for power lines must be:

The requirement for warnings regarding power lines, according to OSHA 1926 Subpart CC, emphasizes safety and awareness in crane operations. The correct choice indicates that warnings must be clearly visible in the operator's cab and on the outside of the crane. This is crucial as it ensures that the crane operator is constantly reminded of the presence of power lines, promoting vigilance when maneuvering the crane in proximity to those hazards.

Having the warnings both inside the cab and outside the crane caters to the need for safety from different perspectives. While the operator is seated and actively functioning the crane, they need to be reminded of these hazards without having to divert attention away from the crane’s operation. Similarly, having external visibility allows other personnel on site to be aware of the risks associated with power lines, facilitating a safer work environment for everyone involved.

The emphasis on signage being visible from both the operator's cab and externally reinforces a comprehensive approach to communication about potential electrical hazards, which serves to protect life and prevent property damage.