Mobile Crane Operator Test 1 Flashcards
6 cards from real NCCCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Mobile Crane Operator Test 1 flashcards as text
When setting up a mobile crane on outriggers, what must the operator verify before beginning any lift?
Answer: The outrigger floats are fully extended and bearing on ground of adequate capacity, with the crane level within manufacturer tolerances
Outrigger floats must be fully extended (unless the load chart specifies a partial-extension configuration) and the ground must be capable of bearing the imposed load. The crane must also be level within the manufacturer's specified tolerance — typically ±1% — because load charts are based on level operation.
A mobile crane's load chart lists capacities based on different boom lengths and radii. What is the 'radius' as used in crane load charts?
Answer: The horizontal distance from the center of rotation to the center of the load
Radius is the horizontal distance from the crane's center of rotation (centerline of the turntable) to the center of the suspended load. As radius increases, rated capacity decreases due to the increased overturning moment.
What action should a mobile crane operator take if a load starts to swing uncontrollably during a pick?
Answer: Lower the load as smoothly and quickly as possible to a safe location
When a load swings uncontrollably, the safest immediate response is to lower it to a stable surface. Attempting to counter-rotate or extending the boom can worsen the dynamic loading and risk tipping the crane.
Under OSHA 1926 Subpart CC, who is responsible for ensuring that the weight of the load to be lifted is known before the lift begins?
Answer: The employer, though the operator may also refuse the lift if the weight is unknown
OSHA 1926.1412 and 1926.1416 place the duty on the employer to provide the operator with the load weight. The operator has the authority and responsibility to refuse a lift if the weight is unknown or if conditions are unsafe.
What does 'structural competency' of a mobile crane refer to?
Answer: The crane's ability to handle a load without any component failing due to stress
Structural competency means the crane's structural members — boom, jib, and frame — can withstand the stresses imposed by the load without failing. Load charts account for both tipping (stability) limits and structural limits; the governing limit is the lower of the two.
When is a crane operator required to halt operations and consult with a competent person before continuing?
Answer: When the operator encounters site conditions not addressed by the manufacturer's specifications or the pre-lift plan
OSHA 1926.1417 requires the operator to stop and seek guidance when site or lift conditions fall outside the planned scope or the manufacturer's specifications — for example, unexpected soft ground, obstructions, or a load heavier than anticipated. Operating outside known parameters without reassessment is prohibited.