RSP Rigging Procedures & Equipment 3 — Questions and Answers
Question 1: A synthetic web sling is color-coded yellow. What material is it made from?
- Nylon (polyamide)
- Polyester
- Polypropylene (Correct answer)
- Dyneema (UHMWPE)
Correct answer: Polypropylene
Per ASME B30.9, polypropylene synthetic web slings are color-coded yellow, while nylon is white and polyester is blue.
Question 2: When rigging an asymmetrical load, the lift point should be located:
- At the geometric center of the load
- Directly above the center of gravity (Correct answer)
- At the heaviest corner of the load
- Equidistant from all four corners
Correct answer: Directly above the center of gravity
The hook must be positioned directly above the load's center of gravity to prevent the load from tipping or shifting during the lift.
Question 3: What is the purpose of a spreader bar (spreader beam) in a rigging assembly?
- To increase the working load limit of the crane
- To reduce sling tension by eliminating horizontal compression on the load (Correct answer)
- To raise the hook block above the load
- To allow the load to rotate freely during the lift
Correct answer: To reduce sling tension by eliminating horizontal compression on the load
A spreader bar keeps sling legs vertical or at a wider angle, reducing inward horizontal forces on the load and decreasing sling leg tension.
Question 4: According to OSHA 1926.251, a hook with a crack in its saddle must be:
- Welded and re-proof tested before further use
- Removed from service and destroyed (Correct answer)
- Downgraded to 50% of its rated capacity
- Tagged and tracked for 30 days before replacement
Correct answer: Removed from service and destroyed
Hooks with cracks, deformations, or twist exceeding 10 degrees must be removed from service and not returned to use.
Question 5: The 'D/d ratio' in rigging refers to:
- The ratio of dead weight to dynamic load
- The ratio of the sheave diameter to the rope diameter (Correct answer)
- The ratio of design factor to derating factor
- The diameter difference between two rope sections
Correct answer: The ratio of the sheave diameter to the rope diameter
The D/d ratio compares the diameter of the sheave (D) to the diameter of the rope (d); a larger ratio reduces bending stress and extends rope life.
Question 6: Which condition would require a chain sling to be immediately removed from service?
- Surface rust with no pitting
- Any chain link elongated more than 3% of its original length (Correct answer)
- Links that are cool to the touch after a lift
- A master link with a stamp indicating Grade 80
Correct answer: Any chain link elongated more than 3% of its original length
ASME B30.9 specifies that a chain link elongated more than 3% of its original gauge length is a disqualifying condition requiring immediate removal from service.
Question 7: When using a turnbuckle in a rigging assembly, the minimum thread engagement required is:
- One full thread
- Three full threads (Correct answer)
- The same number of threads as the turnbuckle diameter in inches
- Enough to prevent the body from rotating
Correct answer: Three full threads
A minimum of three full threads of engagement is required to ensure the turnbuckle can carry its rated load without the threads stripping.
RSP Rigging Procedures & Equipment 3
A synthetic web sling is color-coded yellow.
What material is it made from?