NCCCO Sling Types and Load Distribution 4 — Questions and Answers
Question 1: A nylon web sling should NOT be used when in contact with:
- Smooth steel surfaces
- Painted surfaces
- Acids or bleaching agents (Correct answer)
- Lumber or wood loads
Correct answer: Acids or bleaching agents
Nylon is degraded by acids and bleaching agents; exposure can drastically reduce its strength and lead to sling failure.
Question 2: When lifting a load with a four-leg bridle sling, how many legs are assumed to share the load equally per ASME B30.9 guidance?
- All four legs equally
- Three legs, with the fourth as backup (Correct answer)
- Two legs, with the other two slack
- Only the two shortest legs
Correct answer: Three legs, with the fourth as backup
ASME B30.9 states that for a four-leg bridle, only three legs are assumed to carry the load because one leg may go slack due to load geometry variations.
Question 3: Which condition requires immediate removal of a chain sling from service?
- Surface rust visible on chain links
- Chain elongation exceeding 3% of the original length (Correct answer)
- Minor surface scratches on master links
- Slight discoloration from heat
Correct answer: Chain elongation exceeding 3% of the original length
Chain elongation of 3% or more indicates overload or fatigue and is a rejection criterion under ASME B30.9.
Question 4: What does 'rated capacity' of a sling mean?
- The maximum load a sling has ever lifted
- The maximum working load limit for a specific hitch and angle (Correct answer)
- The breaking strength divided by five
- The weight of the sling itself plus ten percent
Correct answer: The maximum working load limit for a specific hitch and angle
Rated capacity (Working Load Limit) is the maximum load a sling may carry for a specific hitch configuration and sling angle, as specified by the manufacturer.
Question 5: When selecting a sling for a load with sharp edges, which protective measure is required?
- Using a shorter sling to reduce contact area
- Using padding or corner protectors between the sling and load edge (Correct answer)
- Applying lubricant to the sling surface
- Doubling the sling over the edge
Correct answer: Using padding or corner protectors between the sling and load edge
Sharp edges can cut or abrade slings, so padding or corner protectors must be used to protect the sling and maintain its rated capacity.
Question 6: A roundsling (endless loop) is being used in a basket hitch with the legs equally loaded. Compared to a choker hitch, the basket hitch provides:
- Lower capacity due to extra bends
- Double the vertical hitch capacity (Correct answer)
- Same capacity as a vertical hitch
- Capacity reduced by 25%
Correct answer: Double the vertical hitch capacity
A basket hitch with vertical legs can support up to twice the vertical hitch rated capacity because both legs share the load.
Question 7: Which marking is required on all synthetic web slings per ASME B30.9?
- The date of manufacture and sling serial number only
- Manufacturer name, rated load for applicable hitches, material type, and color code (Correct answer)
- Only the color code and breaking strength
- The operator's inspection stamp
Correct answer: Manufacturer name, rated load for applicable hitches, material type, and color code
ASME B30.9 requires synthetic slings to be permanently marked with the manufacturer's name, rated capacity for each hitch type, material, and applicable color code.
NCCCO Sling Types and Load Distribution 4
A nylon web sling should NOT be used when in contact with: