What safety system senses and alerts the operator to imminent danger from overload, angles, radius, and two-block conditions?

• A. Load Moment Indicator (LMI)
• B. Overload Alarm
• C. Boom Angle Sensor
• D. Crane Control Module

Answer: (A)

The Load Moment Indicator is the safety system that continuously monitors the crane’s current load moment by using measurements of the load, the radius, and the boom angle, then compares it to the crane’s rated capacity for that exact configuration. It also watches for two-block conditions by assessing the load path and proximity to potential contact points. When the moment approaches or exceeds safe limits, it warns the operator with alarms and can limit motion or stop the lift to prevent tipping or structural damage. This integrated sensing and alerting function is why it’s the best choice. An overload alarm alone only sounds when a limit is exceeded without accounting for geometry; a boom angle sensor provides angle data but not the overall safety assessment; and the crane control module is the broader controller, while the load moment indicator specifically handles the overload/angle/radius/two-block safety checks.