Rigging Techniques & Equipment Inspection 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 Rigging Techniques & Equipment Inspection flashcards as text
When inspecting a wire rope sling, which condition requires immediate removal from service?
Answer: Six randomly distributed broken wires in one rope lay
ASME B30.9 requires removing a wire rope sling from service if six or more randomly distributed broken wires are found in one rope lay.
What is the primary purpose of a shackle's safety pin or bolt?
Answer: To prevent the pin from unscrewing under load
The safety pin or cotter pin on a shackle prevents the screw pin from backing out due to vibration or load cycling during a lift.
A choker hitch reduces the rated capacity of a synthetic web sling to approximately what percentage of its straight-basket capacity?
Answer: 75%
A choker hitch applied to a synthetic web sling reduces its rated capacity to approximately 75% of the straight-basket (vertical) capacity.
During pre-use inspection of a chain sling, a rigger finds a link that is stretched and narrowed. What action should be taken?
Answer: Remove the sling from service immediately
A stretched or elongated link indicates overloading or shock loading; the sling must be removed from service and destroyed or repaired by a qualified person.
What does the term 'D/d ratio' refer to in rigging?
Answer: The ratio of the diameter of curvature to the wire rope diameter
The D/d ratio compares the diameter of the curve a wire rope bends around (such as a hook or sheave) to the rope's own diameter, directly affecting rope service life.
Which type of rigging hardware is specifically designed to allow a load to rotate freely without untwisting the hoist line?
Answer: Swivel hook
A swivel hook contains a bearing that allows the load attachment point to rotate freely, preventing torque from being transferred to the hoist rope.
When using a bridle sling with four legs, the load is typically distributed among how many legs for rating purposes?
Answer: Three legs
For load distribution calculations, a four-leg bridle sling is rated assuming only three legs share the load because perfect load equalization across four legs cannot be guaranteed.