The Load Moment Indicator (LMI) primarily provides protection by doing what?

• A. Monitors wind speed
• B. Controls hoist speed
• C. Records maintenance history
• D. Senses overload and alerts the operator

Answer: (D)

Overload protection is what the Load Moment Indicator provides. It continuously calculates the load moment—weight times boom radius—and compares it to the crane’s safe capacity for the current configuration. If the moment is too high, the LMI triggers alarms and shows readouts to the operator, and in many systems will limit or stop hoist movement to prevent tipping or structural overload. This protective role is why it’s the best choice. Wind monitoring, hoist speed control, or maintenance history aren’t the primary safeguards offered by the LMI.