Which Category 2 operator aid is used with telescopic booms?

• A. Boom angle or radius indicator
• B. Jib angle indicator
• C. Boom length indicator
• D. Load weighing device

Answer: (C)

When using a telescopic boom, how far the boom is extended directly changes the crane’s lifting capacity. The boom length indicator gives the operator a real-time readout of that extension, so the operator can correctly reference the load chart and stay within safe limits. Other indicators serve different purposes or configurations: a jib angle indicator is relevant when a jib is attached, a boom angle indicator is more about the crane’s angle in other setups, and a load weighing device tells you the load amount but not how reach affects capacity. Therefore, the boom length indicator is the best Category 2 operator aid for telescopic booms.