Rigging Techniques Flashcards
6 cards from real Millwright Certification 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 Techniques flashcards as text
What is the purpose of a proof load test on rigging hardware?
Answer: To verify that the hardware can withstand a load above its rated capacity (typically 2x WLL) without permanent deformation
Proof testing applies a controlled overload (typically 2x the Working Load Limit) to verify the hardware's integrity without reaching the breaking strength, confirming it can safely handle its rated capacity in service.
What are the standard hand signals for crane operations, and why are they important?
Answer: Standardized hand signals (per ASME B30.5) ensure clear communication between the signal person and crane operator, especially when radio or voice communication is not possible
Standard crane hand signals (hoist, lower, boom up/down, swing, stop, emergency stop) ensure clear, unambiguous communication between the designated signal person and the crane operator, which is critical for safe crane operations.
What factors must be considered when selecting a shackle for a rigging application?
Answer: Working load limit, type (screw pin vs. bolt type), pin diameter compatibility with sling eyes, and proper load orientation
Shackle selection requires matching the WLL to the load, choosing the correct type (screw pin for non-permanent, bolt-type for multi-sling), ensuring the pin diameter fits the sling eyes, and verifying the load direction matches the shackle's rated orientation.
What is the purpose of a load chart on a mobile crane?
Answer: To show the maximum safe lifting capacity at each boom length and radius, accounting for the crane's configuration
The load chart is the crane's capacity reference, showing the maximum weight that can be safely lifted at each combination of boom length, operating radius, and configuration (outrigger position, counterweight, boom type).
Why must the center of gravity (CG) of a load be determined before rigging?
Answer: The CG determines the rigging attachment points, sling lengths, and balancing needed to lift the load level and stable
The center of gravity determines where the load will balance when lifted. Rigging must be arranged so the hook is directly above the CG, and sling lengths may need adjustment to keep the load level.
What inspection criteria would require a synthetic web sling to be removed from service?
Answer: Cuts, punctures, burn marks, acid or caustic damage, knots, excessive abrasion, missing or illegible labels, or broken stitching
Synthetic web slings must be removed from service when any defect compromises structural integrity: cuts across load-bearing fibers, burn damage, chemical exposure damage, crushed or broken hardware, missing identification tags, or significant abrasion.