Service Truck Crane Operator Test 1 Flashcards

When operating a service truck crane, what is the PRIMARY reason an operator must re-check the load chart after extending the boom to a longer radius?

Answer: Load capacity decreases significantly as the load radius increases

Crane capacity is inversely related to load radius — as the boom extends outward, the moment arm increases, dramatically reducing the rated lifting capacity. Operators must consult the load chart for the specific radius in use to avoid an overload condition.

Which condition would MOST likely cause a service truck crane to overturn during a lift?

Answer: Lifting a load within rated capacity but with outriggers not fully extended

Outriggers must be fully extended and properly set before any lift. Partially extended outriggers narrow the crane's stability footprint, reducing the tipping fulcrum and allowing a load — even one within rated capacity — to overturn the vehicle.

Before beginning a lift with a service truck crane, what must the operator do if a load chart specific to the current boom configuration is NOT posted in the cab?

Answer: Refuse the lift until the correct load chart is obtained and posted

OSHA and ASME B30.22 require that the applicable load chart be available to the operator at all times. Without the correct chart, rated capacity cannot be determined and the lift must not proceed.

On a knuckleboom service truck crane, what is the function of the 'inner boom' and 'outer boom' sections?

Answer: Together they form an articulating arm that can fold and position loads in tight spaces without the crane rotating

A knuckleboom crane has two boom sections connected by a knuckle joint, allowing the arm to articulate — fold at the joint — to reach over obstacles or place loads in confined areas without requiring full slewing of the crane turret.

What does the term 'working radius' refer to when using a service truck crane load chart?

Answer: The horizontal distance from the center of rotation to the center of the suspended load

Working radius is the horizontal distance measured from the crane's center of rotation (swing center) to the plumb line of the load. This measurement is critical because all rated capacities on the load chart are based on working radius.

A service truck crane operator notices that the crane's hydraulic system is producing unusual noise during boom extension. What is the MOST appropriate immediate action?

Answer: Lower the load to the ground, secure the crane, and shut down for inspection

Unusual hydraulic noise — such as cavitation, knocking, or whining — can indicate air in the system, low fluid, pump failure, or internal leakage. Continuing the lift risks sudden loss of boom support. The operator must lower the load safely and remove the crane from service for inspection.