National Commission for the Certification of Crane Operators (NCCCO) Core Practice Test

The anti-two block device is a critical safety feature on telescopic boom cranes designed to prevent the hook from colliding with the boom. If this device is not functioning properly, it poses a significant safety risk. Therefore, the correct action in this situation is to stop all operations immediately. This ensures the safety of those around the crane and prevents potential accidents or damage.

Using a spotter may seem like a temporary solution to monitor the situation, but it does not mitigate the underlying hazard posed by the malfunctioning device. Relying on a spotter introduces risk, as they cannot fully replace the safety function intended by the anti-two block device. Ignoring the issue is unacceptable, as it contradicts safety protocols and can lead to dangerous situations. Additionally, limiting operations to daylight hours does not address the malfunction and could still result in an incident at any time.

Thus, stopping all operations is the necessary and appropriate response to ensure safety in the absence of a functioning anti-two block device.