10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
These 10 free MR questions are organized by exam domain, so you can see how each part of the Master Rigger blueprint is tested. Reveal the answer and explanation under each question.
During inspection of a Harrington LB015 Model L5 lever hoist, the measured five-link chain pitch is 103.4 mm and the minimum link-wire diameter is 6.8 mm. The manufacturer's limits are 102.9 mm maximum pitch and 6.4 mm minimum diameter. No cracks are found, and the brake passes its functional check. What disposition follows from these findings?
Correct answer: D - Withdraw the hoist; excessive pitch requires replacing the load chain.
An unloaded two-fall chain hoist runs partway upward, then binds. Inspection shows the two chain falls wrapped around each other between the body and bottom block. The chain specification and wear measurements are correct. Which fault is most likely?
Correct answer: A - The bottom hook block has capsized through the chain loop.
A fixed snatch block redirects a rope carrying 6,000 lbf of tension in each leg. The angle between the two rope legs, measured outward from the block, is 60°. The block's working load limit is 11,000 lbf of resultant force; its anchorage permits 9,500 lbf in the resulting pull direction. Neglect the block's weight. Which assessment is correct?
Correct answer: C - The resultant is about 10,390 lbf; only the anchorage is overloaded.
A skid is slid at steady speed first uphill and then downhill on the same ramp. The reeving is unchanged, the pulling line remains parallel to the ramp, and the sliding-friction coefficient is unchanged. The downhill move requires less uphill restraining force than the uphill move requires pulling force. What accounts for the difference?
Correct answer: C - Sliding friction aids restraint downhill but increases pulling resistance uphill.
A verified manufacturer weight places a construction lift at 82% of the crane's rated capacity at its longest planned radius. The weight matches the actual assembly and contents, required chart deductions are included, and the lift plan permits this utilization. Someone cites OSHA's 75% weight-check provision as a reason to weigh the load again. Which response correctly applies that provision?
Correct answer: D - The verified manufacturer weight already satisfies the recognized-source verification method.
The lifting lugs on a thin-walled vessel are rated for vertical loading only. A two-leg bridle runs directly from those lugs to one centered hook; the slings and shackles are within their working load limits. Adequate headroom is available. Which change removes the inward force on the lugs?
Correct answer: A - Use a rated spreader with vertical lower slings.
A 9,600-lbf load hangs at rest from a symmetric two-leg bridle with equal load sharing. Each straight sling leg is 10 ft long, and the upper connection is 6 ft above the two lower lifting points. Each leg has a 7,500-lbf working load limit for axial tension. Neglect sling and fitting weight. What does the sling-loading check show?
Correct answer: B - Each leg carries 8,000 lbf, so its working load limit is exceeded.
A 4,200-lbf component is to be lifted in a single choker hitch with its supporting sling part vertical. The sling's manufacturer lists 6,400 lbf for a vertical hitch, 5,000 lbf for a choke angle of at least 120°, and 3,600 lbf at a 90° choke angle. The current fit gives 90°; an alternative arrangement provides 135° with adequate grip, clearance, and edge protection. Which configuration-and-rating pairing is correct for this lift?
Correct answer: C - Use the 135° choke arrangement and apply the 5,000-lbf choker rating.
During a frame turnover about a retained floor pivot, the center of gravity passes directly above the pivot and continues to the opposite side. The plan calls for a restraining system through this part of the turn. What change makes that restraint necessary?
Correct answer: C - Gravity begins assisting the rotation instead of opposing it.
A qualified person has developed a two-crane construction lift plan and determined that additional engineering expertise is not needed. A competent lift director will lead with that person's assistance. The operators have reviewed the plan, but the riggers and receiving crew have not. What remains required under OSHA's multiple-crane lift rule?
Correct answer: A - The lift director must review the plan with all workers involved.
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