NCCCO MOBILE CRANE OPERATOR
PRACTICE EXAM (COMBINED EXAM 3
& 4)
1. When lifting a load, the boom will often deflect. What is the effect of this deflection on the
crane’s operation?
A. It decreases the operating radius.
B. It has no effect on the load chart capacity.
C. It increases the operating radius.
D. It increases the boom angle automatically.
Answer: C
Conceptual Explanation: Boom deflection under load causes the boom to bend slightly
downward and outward, which increases the horizontal distance from the center of
rotation to the load, thereby increasing the operating radius.
2. According to OSHA 1926.1408, what is the minimum clearance distance for power lines up
to 50kV when the voltage is unknown?
A. 10 feet
,B. 20 feet
C. 15 feet
D. 45 feet
Answer: B
Conceptual Explanation: For voltages up to 350kV, if the voltage is unknown, OSHA
requires a minimum clearance of 20 feet unless the utility owner confirms the voltage.
3. When a crane’s boom length is between two values listed on the load chart, which value
should the operator generally use?
A. The value for the next shorter boom length.
B. The value for the next longer boom length.
C. Interpolate between the two values.
D. The average of the two values.
Answer: B
Conceptual Explanation: Standard practice and most manufacturer instructions require
using the capacity for the next longer boom length listed to be conservative.
4. What is the ‘Net Capacity’ of a crane?
A. The total weight the crane can lift including the boom.
B. The capacity listed in the chart without any deductions.
, C. The weight of the load only.
D. The Gross Capacity minus deductions for attachments and rigging.
Answer: D
Conceptual Explanation: Net Capacity is the actual weight of the cargo that can be lifted
after deducting the weight of the block, ball, rigging, and other attachments from the Gross
Capacity.
5. Which of the following is an indication of a stability failure rather than a structural failure?
A. The boom buckles or collapses.
B. The crane tips forward or side to side.
C. The wire rope snaps.
D. The outrigger beam bends.
Answer: B
Conceptual Explanation: Stability failure occurs when the crane’s tipping moment
exceeds its righting moment, whereas structural failure occurs when components bend,
break, or shear.
6. When working on outriggers, the pads should be supported by:
A. Blocking or mats that are at least 3 times the area of the pad.
B. Loose soil or fill.
C. The concrete edge of a sidewalk.
PRACTICE EXAM (COMBINED EXAM 3
& 4)
1. When lifting a load, the boom will often deflect. What is the effect of this deflection on the
crane’s operation?
A. It decreases the operating radius.
B. It has no effect on the load chart capacity.
C. It increases the operating radius.
D. It increases the boom angle automatically.
Answer: C
Conceptual Explanation: Boom deflection under load causes the boom to bend slightly
downward and outward, which increases the horizontal distance from the center of
rotation to the load, thereby increasing the operating radius.
2. According to OSHA 1926.1408, what is the minimum clearance distance for power lines up
to 50kV when the voltage is unknown?
A. 10 feet
,B. 20 feet
C. 15 feet
D. 45 feet
Answer: B
Conceptual Explanation: For voltages up to 350kV, if the voltage is unknown, OSHA
requires a minimum clearance of 20 feet unless the utility owner confirms the voltage.
3. When a crane’s boom length is between two values listed on the load chart, which value
should the operator generally use?
A. The value for the next shorter boom length.
B. The value for the next longer boom length.
C. Interpolate between the two values.
D. The average of the two values.
Answer: B
Conceptual Explanation: Standard practice and most manufacturer instructions require
using the capacity for the next longer boom length listed to be conservative.
4. What is the ‘Net Capacity’ of a crane?
A. The total weight the crane can lift including the boom.
B. The capacity listed in the chart without any deductions.
, C. The weight of the load only.
D. The Gross Capacity minus deductions for attachments and rigging.
Answer: D
Conceptual Explanation: Net Capacity is the actual weight of the cargo that can be lifted
after deducting the weight of the block, ball, rigging, and other attachments from the Gross
Capacity.
5. Which of the following is an indication of a stability failure rather than a structural failure?
A. The boom buckles or collapses.
B. The crane tips forward or side to side.
C. The wire rope snaps.
D. The outrigger beam bends.
Answer: B
Conceptual Explanation: Stability failure occurs when the crane’s tipping moment
exceeds its righting moment, whereas structural failure occurs when components bend,
break, or shear.
6. When working on outriggers, the pads should be supported by:
A. Blocking or mats that are at least 3 times the area of the pad.
B. Loose soil or fill.
C. The concrete edge of a sidewalk.
