What is anti two block in crane system?

Anti-two block is a safety feature in crane systems designed to prevent the crane's hook from being raised too close to the upper block or the boom, which can lead to dangerous situations. It typically involves a mechanism that detects when the hook is nearing the limit and automatically stops the hoisting action to avoid potential damage or accidents. This feature helps protect both the crane and the operator by preventing the risk of two-blocking, where the hook and block collide.