NCCCO MOBILE CRANE OPERATOR
CERTIFICATION - FINAL EXAM
QUESTIONS AND ANSWERS
1. According to OSHA 1926.1408, what is the minimum clearance distance for power lines
rated at 350 kV while the crane is in operation?
A. 10 feet
B. 25 feet
C. 20 feet
D. 15 feet
Answer: B
Conceptual Explanation: For power lines between 350 kV and 500 kV, the minimum
clearance distance required by Table A is 25 feet.
2. When a crane is not level by 3 degrees on a long boom, the capacity can be reduced by as
much as:
A. 50%
B. 25%
,C. 10%
D. 75%
Answer: A
Conceptual Explanation: On a long boom at a short radius, being out of level by even 3
degrees can reduce the structural capacity by up to 50%.
3. What is the result of using a snatch block in a multi-part reeving system?
A. Increases the line speed
B. Decreases the load on the lead line
C. Increases the total weight of the hoist
D. Increases the leverage and capacity
Answer: D
Conceptual Explanation: Adding parts of line using blocks increases the mechanical
advantage, allowing the crane to lift heavier loads at the cost of speed.
4. Which of the following is considered a ‘deduction’ from the crane’s gross capacity?
A. The weight of the load
B. The weight of the boom
C. The weight of the main hook block
D. The weight of the counterweights
, Answer: C
Conceptual Explanation: Deductions include the hook block, overhaul ball, slings, and any
other load-handling equipment not counted as part of the load.
5. The ‘D/d ratio’ for a wire rope sling relates to:
A. Drum diameter vs. rope diameter
B. Distance between legs vs. rope diameter
C. Density of the load vs. diameter
D. Diameter of the object the rope is wrapped around vs. rope diameter
Answer: D
Conceptual Explanation: The D/d ratio is the ratio of the diameter of the surface the rope
is bent over (D) to the diameter of the rope (d).
6. If the crane is working over the side on outriggers, where is the tipping axis located?
A. The center of the rotation
B. The center of the boom foot pin
C. The edge of the tires
D. The centerline of the outrigger pads
Answer: D
CERTIFICATION - FINAL EXAM
QUESTIONS AND ANSWERS
1. According to OSHA 1926.1408, what is the minimum clearance distance for power lines
rated at 350 kV while the crane is in operation?
A. 10 feet
B. 25 feet
C. 20 feet
D. 15 feet
Answer: B
Conceptual Explanation: For power lines between 350 kV and 500 kV, the minimum
clearance distance required by Table A is 25 feet.
2. When a crane is not level by 3 degrees on a long boom, the capacity can be reduced by as
much as:
A. 50%
B. 25%
,C. 10%
D. 75%
Answer: A
Conceptual Explanation: On a long boom at a short radius, being out of level by even 3
degrees can reduce the structural capacity by up to 50%.
3. What is the result of using a snatch block in a multi-part reeving system?
A. Increases the line speed
B. Decreases the load on the lead line
C. Increases the total weight of the hoist
D. Increases the leverage and capacity
Answer: D
Conceptual Explanation: Adding parts of line using blocks increases the mechanical
advantage, allowing the crane to lift heavier loads at the cost of speed.
4. Which of the following is considered a ‘deduction’ from the crane’s gross capacity?
A. The weight of the load
B. The weight of the boom
C. The weight of the main hook block
D. The weight of the counterweights
, Answer: C
Conceptual Explanation: Deductions include the hook block, overhaul ball, slings, and any
other load-handling equipment not counted as part of the load.
5. The ‘D/d ratio’ for a wire rope sling relates to:
A. Drum diameter vs. rope diameter
B. Distance between legs vs. rope diameter
C. Density of the load vs. diameter
D. Diameter of the object the rope is wrapped around vs. rope diameter
Answer: D
Conceptual Explanation: The D/d ratio is the ratio of the diameter of the surface the rope
is bent over (D) to the diameter of the rope (d).
6. If the crane is working over the side on outriggers, where is the tipping axis located?
A. The center of the rotation
B. The center of the boom foot pin
C. The edge of the tires
D. The centerline of the outrigger pads
Answer: D
