Mobile Crane Operator 4 Flashcards
7 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 7 Mobile Crane Operator 4 flashcards as text
What is 'side loading' of a crane boom, and why is it dangerous?
Answer: Applying a lateral force on the boom it is not designed to handle, risking structural collapse
Boom structures are designed primarily for vertical compression loads; lateral (side) forces can buckle or collapse the boom because it lacks adequate lateral strength.
During a tandem (two-crane) lift, who is responsible for directing the overall operation?
Answer: A designated lift director who oversees both cranes and all personnel
OSHA 1926.1436 and best practices require a qualified lift director to coordinate all aspects of tandem crane lifts to ensure synchronized movement and load sharing.
What does 'working radius' mean in crane terminology?
Answer: The horizontal distance from the crane's rotation axis to the center of the suspended load
Working radius is the horizontal distance from the centerline of rotation to the plumb line of the hook, which determines which column of the load chart applies.
A wire rope sling shows broken wires exceeding the discard criteria. The operator is instructed by the site foreman to use it anyway for a light pick. What should the operator do?
Answer: Refuse to use the defective sling and remove it from service
A sling meeting discard criteria must be immediately removed from service; no one, including supervisors, can authorize use of condemned rigging equipment.
What is the purpose of cribbing and outrigger pads when setting up a mobile crane?
Answer: To distribute the outrigger load over a larger area and prevent ground sinkage
Cribbing and pads spread the concentrated point load of each outrigger over a larger bearing area, reducing ground pressure and preventing settlement or tipping.
Under OSHA 1926.1417, what is the operator required to do if they observe a defect that creates a safety hazard during a pre-shift inspection?
Answer: Remove the crane from service until the defect is corrected
OSHA 1926.1417 requires the crane to be taken out of service whenever a defect creating a safety hazard is found, until the defect is corrected.
What is the significance of the 'structural competence' rating on a mobile crane load chart versus the 'tipping' rating?
Answer: The rated capacity is the lesser of the two — charts typically list the value that controls
The published rated capacity reflects the lesser of structural competence and tipping stability limits at each radius, ensuring both failure modes are accounted for.