On cranes, lowering the boom with the hook blocks raised will most likely result in?

Lowering the boom with the hook blocks raised can lead to a situation called two-blocking. This occurs when the hook block, which is at the end of the hoisting line, makes contact with the boom or the boom tip. The consequence of two-blocking can be severe, as it can cause damage to the crane and its components, potentially leading to a loss of control over the load being lifted.

In cranes, the hook block is designed to operate within specific limits, and if those limits are exceeded due to improper lowering techniques, it compromises the crane's safety mechanisms. When two-blocking happens, it can also create a risk of the load falling, endangering personnel and property underneath the crane. Therefore, understanding the operation of the crane and the importance of maintaining a safe distance between the hook block and the boom is critical for safe crane operation.