What is “two-blocking” in rigging?

Two-blocking refers to a hazardous situation in rigging where the hook block of a crane comes into contact with the boom. This condition can occur when the load is raised too high, causing the block to collide with the boom. This contact can lead to catastrophic failure, including the potential for the load to drop or the crane to become damaged.

Understanding two-blocking is critical for ensuring safety in rigging operations. It highlights the importance of being aware of the crane's limits and the need for proper communication and monitoring during lifting operations to prevent this dangerous occurrence. Additional measures, such as using limit switches or proper rigging techniques, are typically employed to avoid two-blocking scenarios and ensure safe lifting practices.