NCCCO Mobile Crane Certification
Exam | Verified Questions and 100%
Correct Answers | Grade A Study
Material | Latest 2026/2027 Update
This set includes 100 questions with verified correct answers and clear, understandable
rationales. Questions cover:
Site setup & ground conditions
Crane operations & safety
Load charts & capacity calculations
Rigging & load handling
Technical knowledge (crane components, wire rope, signals)
OSHA/ASME B30 standards & NCCCO rules
All answers are accurate per current NCCCO reference materials (ASME B30.5, Mobile Crane
Manual, etc.).
Q1 When lifting loads on tires, mobile cranes are generally rated at what percentage of tipping?
A) 50% B) 75% C) 85% D) 100%
B) 75%
Rationale: Per ASME B30.5 and NCCCO load chart notes, on-rubber ratings are limited to 75%
of tipping for stability (except when manufacturer specifies otherwise).
Q2 On what principle is crane stability primarily based?
A) Leverage B) Counterweight mass C) Boom length D) Outrigger extension
A) Leverage
Rationale: Crane stability relies on the leverage created by the distance from the center of
rotation to the tipping line versus the load moment.
Q3 A crane must be level within what percentage for the load chart ratings to remain valid?
A) ½% B) 1% C) 2% D) 5%
, B) 1%
Rationale: NCCCO and ASME B30.5 require the crane to be level within 1% (approximately 1
degree) for published capacities to be valid.
Q4 Which area do truck cranes without a 5th outrigger generally have no lifting capacity unless
the manufacturer states otherwise?
A) The rear B) The side C) The front D) Over the outriggers
C) The front
Rationale: Without a 5th outrigger or front stabilizer, truck cranes have zero or severely limited
capacity over the front (carrier cab area) due to lack of stability.
Q5 What is the definition of "operating radius"?
A) Distance from boom tip to load center B) Distance from center of rotation to center of gravity
of the load C) Horizontal distance from boom foot to load D) Vertical distance from ground to
hook
B) Distance from center of rotation to center of gravity of the load
Rationale: Operating radius (or load radius) is measured from the center of rotation (turntable
bearing) to the vertical centerline of the load.
Q6 According to ASME B30.5, if a load test is performed on a repaired crane, what percentage
of the manufacturer's rating must not be exceeded?
A) 100% B) 110% C) 125% D) 150%
B) 110%
Rationale: ASME B30.5 requires proof load testing of repaired cranes not to exceed 110% of
rated capacity.
Q7 When working around power lines of more than 750 kV, what is the minimum clearance
required from any part of the crane or load (per OSHA & ASME)?
A) 10 ft B) 20 ft C) 35 ft D) 45 ft
D) 45 ft
Rationale: OSHA 1926.1408 Table A requires 45 ft clearance for lines over 350 kV up to 1,000
kV (and more for higher voltages).
Exam | Verified Questions and 100%
Correct Answers | Grade A Study
Material | Latest 2026/2027 Update
This set includes 100 questions with verified correct answers and clear, understandable
rationales. Questions cover:
Site setup & ground conditions
Crane operations & safety
Load charts & capacity calculations
Rigging & load handling
Technical knowledge (crane components, wire rope, signals)
OSHA/ASME B30 standards & NCCCO rules
All answers are accurate per current NCCCO reference materials (ASME B30.5, Mobile Crane
Manual, etc.).
Q1 When lifting loads on tires, mobile cranes are generally rated at what percentage of tipping?
A) 50% B) 75% C) 85% D) 100%
B) 75%
Rationale: Per ASME B30.5 and NCCCO load chart notes, on-rubber ratings are limited to 75%
of tipping for stability (except when manufacturer specifies otherwise).
Q2 On what principle is crane stability primarily based?
A) Leverage B) Counterweight mass C) Boom length D) Outrigger extension
A) Leverage
Rationale: Crane stability relies on the leverage created by the distance from the center of
rotation to the tipping line versus the load moment.
Q3 A crane must be level within what percentage for the load chart ratings to remain valid?
A) ½% B) 1% C) 2% D) 5%
, B) 1%
Rationale: NCCCO and ASME B30.5 require the crane to be level within 1% (approximately 1
degree) for published capacities to be valid.
Q4 Which area do truck cranes without a 5th outrigger generally have no lifting capacity unless
the manufacturer states otherwise?
A) The rear B) The side C) The front D) Over the outriggers
C) The front
Rationale: Without a 5th outrigger or front stabilizer, truck cranes have zero or severely limited
capacity over the front (carrier cab area) due to lack of stability.
Q5 What is the definition of "operating radius"?
A) Distance from boom tip to load center B) Distance from center of rotation to center of gravity
of the load C) Horizontal distance from boom foot to load D) Vertical distance from ground to
hook
B) Distance from center of rotation to center of gravity of the load
Rationale: Operating radius (or load radius) is measured from the center of rotation (turntable
bearing) to the vertical centerline of the load.
Q6 According to ASME B30.5, if a load test is performed on a repaired crane, what percentage
of the manufacturer's rating must not be exceeded?
A) 100% B) 110% C) 125% D) 150%
B) 110%
Rationale: ASME B30.5 requires proof load testing of repaired cranes not to exceed 110% of
rated capacity.
Q7 When working around power lines of more than 750 kV, what is the minimum clearance
required from any part of the crane or load (per OSHA & ASME)?
A) 10 ft B) 20 ft C) 35 ft D) 45 ft
D) 45 ft
Rationale: OSHA 1926.1408 Table A requires 45 ft clearance for lines over 350 kV up to 1,000
kV (and more for higher voltages).
