Rigging Fundamentals and Hardware 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 Rigging Fundamentals and Hardware flashcards as text
What is the purpose of a 'tag line' in crane rigging, and who typically controls it?
Answer: A tag line is a rope attached to the load to control its swing and rotation during the lift; it is controlled by ground personnel
Tag lines are hand-held ropes attached to the load by ground personnel to control load swing, spinning, and precise positioning during the lift, especially during placement.
A four-leg bridle sling is used to lift a uniformly loaded pallet. Under ASME B30.9, how many legs are assumed to carry the load for rated capacity calculations?
Answer: Only two legs are assumed to carry the load, due to the possibility of unequal load distribution among legs
ASME B30.9 requires that for four-leg slings, only three legs be considered load-bearing for rated capacity purposes, because load distribution among four legs cannot be guaranteed to be equal.
What does the term 'fleet angle' mean in wire rope reeving, and what is the maximum acceptable fleet angle for most crane drums?
Answer: Fleet angle is the angle between the rope's approach and the drum centerline plane; maximum is typically 1.5 degrees for parallel-grooved and 2 degrees for helically-grooved drums
Fleet angle is the off-center angle between the wire rope and the drum's horizontal centerline plane. Excessive fleet angle causes uneven spooling, rope crossover, and accelerated wear. Maximum is typically 1.5° for parallel-grooved and 2° for helically-grooved drums.
When inspecting a synthetic web sling for removal from service, which condition requires the sling to be taken out of use?
Answer: Any cut, tear, or hole in the sling body or end fittings
Any cut, tear, or hole in a synthetic sling's body or end fitting area is an immediate removal-from-service deficiency, as it directly reduces the sling's load-bearing cross-section.
What is the purpose of a 'spreader bar' (lifting beam) in crane rigging, and when is it typically used?
Answer: A spreader bar is used to maintain horizontal spacing between sling attachment points, reducing sling angle effects and controlling sling forces on the load
A spreader bar maintains the horizontal distance between sling attachment points, allowing vertical sling geometry that minimizes sling leg forces and prevents inward compression on the load.
Under ASME B30.9, a wire rope sling with a mechanical splice (Flemish eye splice) has what efficiency relative to the rope's breaking strength?
Answer: Not less than 90% efficiency of the rope's rated breaking strength
ASME B30.9 establishes that mechanical splices (Flemish eye splices) must have an efficiency of not less than 90% of the rated breaking strength of the rope used in the sling.