National Commission for the Certification of Crane Operators (NCCCO) Mobile Crane Practice Exam

An anti-two-block device can be utilized for what purpose?

1. To increase lifting capacity

2. To test the LMI

3. To extend the boom

4. To reduce operational noise

The correct answer is: To test the LMI

An anti-two-block device is primarily utilized to prevent the crane hook from coming into contact with the boom or other structural components, which is referred to as "two-blocking." This scenario can cause severe damage to the crane and pose safety hazards. The presence of an anti-two-block device serves to ensure that the crane's lifting mechanism remains safe by providing a physical barrier that interrupts the lifting process before contact occurs. The function of an anti-two-block device is crucial for maintaining safe operations when testing various crane systems, including the Load Moment Indicator (LMI). The LMI is a highly integral part of crane operation that assesses the load on the crane and helps to prevent overloading, so testing it with the anti-two-block device ensures that all components work harmoniously to protect against accidents. Using an anti-two-block device contributes to the overall safety protocol in crane operations, ensuring that the crane can be used effectively and efficiently without risk of damaging equipment or harming personnel.