Sling Types and Load Distribution 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 Sling Types and Load Distribution flashcards as text
What is the purpose of a spreader bar (lifting beam) in rigging, and when is it preferred over a direct multi-leg sling arrangement?
Answer: A spreader bar keeps sling legs vertical by spacing out the attachment points, preventing compressive forces on the load, and maintaining controlled load geometry for long, flexible, or sensitive loads
Spreader bars maintain a controlled attachment point spacing, keep sling legs at known angles (often near vertical), and prevent horizontal compressive forces from sling angles from crushing or distorting the load.
How does load balance affect the choice and length of sling legs in a multi-point lift?
Answer: If a load's center of gravity is not at the geometric center, sling lengths must be adjusted so that all legs are under equal tension, ensuring the load hangs at the correct angle during the lift
When the load's center of gravity is offset from the geometric center of the lift points, slings of equal length will cause the load to tilt. Adjusting sling lengths to equalize tension keeps the load level and ensures no single sling is overloaded.
What is the removal-from-service criterion for a synthetic web sling that shows heat or chemical damage?
Answer: Any synthetic web sling showing heat damage (melted or charred fibers), chemical degradation (weakened, brittle, or discolored material), or acid or caustic attack must be immediately removed from service
ASME B30.9 requires immediate removal from service of any synthetic web sling showing heat damage, chemical attack, or degradation. These conditions compromise the fiber structure and cannot be reliably assessed for residual strength.
What is the purpose of a rigging pre-use inspection and who is responsible for conducting it?
Answer: A qualified rigger must inspect all rigging hardware (slings, shackles, hooks, beams) before each use to verify condition, identity, and WLL marking, and remove any deficient component from service
ASME B30.9 and B30.26 require a qualified rigger to perform a pre-use inspection of all rigging components before each lift. This is the last verification that rigging is in serviceable condition before life-safety loading.
What does equalizing mean in the context of a four-point rigging arrangement, and why is it important?
Answer: Equalization refers to using a hardware device (equalizer hook, equalizing beam, or ring) that automatically distributes load among sling legs even if attachment heights vary, ensuring each leg shares the load proportionally
An equalizing device in four-point rigging allows the sling attachment point to self-adjust so that load is distributed among all legs even if they are at slightly different heights, preventing all load from concentrating on the highest attachment point.
What is a basket hitch load shift and what operational precaution addresses it?
Answer: A basket hitch load shift occurs when a load in a basket hitch tilts or rotates, causing one leg to bear more load than the other — addressed by ensuring the load CG is centered directly beneath the hook and using tag lines to prevent rotation
When a load in a basket hitch is not balanced or when the load tilts, one side of the basket bears a disproportionately greater load. Centering the CG under the hook and using tag lines addresses this.