What does 'two-blocking' refer to in lifting operations?

In lifting operations, 'two-blocking' refers to a situation where the hook of a crane or hoist makes contact with the upper block, which can lead to potentially dangerous situations. This occurs when the load is raised too high, causing the lines or cables to become dangerously taut. The consequence of this contact can result in equipment damage or failure, and it can even create a safety hazard for personnel in the vicinity.

Understanding the implications of two-blocking is crucial for safe lifting. Operators are trained to be mindful of load heights and to stop lifting before this contact occurs, ensuring the safety of both the load and those involved in the lift. Consequently, knowing the definition and effects of two-blocking is essential for anyone working in environments that involve lifting operations, as it emphasizes the importance of maintaining control over load heights to prevent accidents.