National Commission for the
Certification of Crane Operators
Committed to Quality, Integrity, and Fairness in Testing since 1995


Mobile Crane Operator

Core Written Exam - Sample Test Questions

These sample questions are intended to convey something of the style and content of the National Operator Certification Program examination developed and administered by the National Commission for the Certification of Crane Operators(CCO). They are not actual test questions, nor do they attempt to address all of the areas of knowledge tested on the CCO certification examination. Response to these questions is not necessarily an indication of performance on the CCO examinations.

Answers to Sample Questions

1. What action does a signal person intend the operator to perform if he extends his arm at shoulder height, makes a fist with his hand, and sticks his/her thumb up?

a. Boom down
b. Swing
c. Boom up
d. Extend boom

2. When hoisting personnel, within what percentage of level must a telescopic boom crane be in order for the gross ratings in the load chart to remain valid?

a. 1%
b. 2%
c. 5%
d. 8%

3. The load line of the crane you’re operating contacts an energized power line. There’s no sign of any other danger, such as fire. What should you do?

a. Climb down carefully from the crane cab
b. Jump down, feet together
c. Stay in the cab until the lines are de-energized
d. Get as far away from the crane as possible

4. According to OSHA 1926.1413, how many randomly distributed broken wires in rotation-resistant rope are cause for replacement of the rope?

a. 1 broken wire in 6 rope diameters
b. 2 broken wires in 30 rope diameters
c. 3 broken wires in one strand in one lay
d. 2 broken wires in 6 rope diameters

5. What is the net capacity of a crane on main boom unless the manufacturer states otherwise?

a. The capacity listed in the load chart minus the weight of the rigging and all attachments
b. The capacity listed in the load chart plus the weight of the rigging and all attachments
c. The capacity listed in the load chart minus the weight of the rigging and all attachments not in use
d. The capacity listed in the load chart minus the weight of the rigging alone

6. What may happen to a properly rigged load when lifted off the ground unless the operator takes account of boom deflection?

a. It could swing out away from the crane
b. It could swing in towards the crane
c. It could raise absolutely vertically
d. It could shift in its rigging

7. What Standard Method hand signal is being illustrated?

a. Swing
b. Stop
c. Emergency Stop
d. Travel

8. Who should an operator respond to a "stop" signal from?

a. Appointed signal person only
b. Project manager only
c. Superintendent only
d. Anyone

9. Which area do truck cranes without a 5th outrigger generally have no lifting capacity unless the manufacturer states otherwise?

a. The side
b. The rear
c. The front
d. The outriggers

10. What is the definition of "operating radius?"

a. The distance from the base of the boom to the center of the load
b. The distance from the front of the crane to the center of gravity of the load
c. The distance from the center of rotation of the crane to the center of the load
d. The distance from the center of rotation of the crane to the center of gravity of the load

11. What applies to the capacities below the bold line shown on a load chart?

a. They are based on the structural strength of the crane
b. They must not be used
c. They are based on the stability of the crane
d. They should only be used if the crane is set up on outriggers

12. In which quadrant are rough terrain crane capacities generally greater?

a. Over the front
b. Over the rear
c. Over the right side
d. Over the left side

13. According to federal requirements, under what conditions is it okay for a person to ride the headache ball?

a. When there is no other way to gain access
b. When the lift has been approved by an engineer
c. When other means would be more dangerous
d. It is never okay

14. By what percentage do most manufacturers require a crane’s load chart capacity to be reduced by for duty cycle operations such as high-volume concrete placement?

a. 10%.
b. 15%.
c. 20%.
d. 30%.

15. From which two points should the boom be measured?

a. From the base of the boom to the center of the boom tip sheave
b. From the boom hinge pins to the boom tip
c. From the boom hinge pins to the center of the boom tip sheave
d. From the base of the boom to the boom tip

16. What is the preferred method of installing wire rope from a reel onto a hoist drum?

a. The rope runs from the top of the reel to the bottom of the drum
b. The rope runs from the bottom of the reel to the top of the drum
c. The rope runs from the top of the reel to the top of the drum
d. There is no preferred method

17. Over which quadrant are truck crane capacities usually greater?

a. Over the front.

b. Over the rear.

c. Over the front right outrigger.

d. Over the side.

18. According to OSHA, which accessible area of an operating crane must always be barricaded?

a. The swing radius of the crane
b. The carbody or chassis
c. The swing radius of the rear of the rotating superstructure
d. The distance between the car body or chassis and the boom tip

19. What is the OSHA regulation governing cranes in construction?

a. 1910.180
b. 1926.1400
c. 1926.556
d. 1910.184

20. Under which circumstance is a crack in the windshield of a crane cab okay?

a. As long as it causes no visible distortion that would interfere with safe operations
b. As long as it is less than 6 inches long
c. As long as the windshield is replaced on the next annual inspection
d. It is never okay

21. Under which circumstance does OSHA permits hoisting of personnel by crane?

a. As long as the prevailing wind speed is less than 35 mph
b. As long as there is no less hazardous or practicable way
c. As long as all personnel have CPR training
d. As long as no aerial work platform is available

22. Unless the manufacturer states otherwise, what crane capacity chart is appropriate when a crane is set up with 3 of its 4 outriggers extended and the fourth is retracted?

a. On-outrigger chart
b. On-rubber chart
c. On-outrigger chart minus 20%
d. On-rubber chart plus 20%

23. According to OSHA, while hoisting personnel, the total load must not exceed what percentage of the crane’s rated capacity?”

a. 45%
b. 50%
c. 75%
d. 85%

24. When is side loading of crane booms permitted?

a. When the operator says it's OK
b. So long as no jib is installed
c. Only when the outriggers are fully extended
d. Only with freely suspended loads

25. What is indicated if an operator makes two audible signals when moving a crane?

a. He/she intends to stop
b. He/she intends to back up
c. He/she intends to go ahead
d. He/she intends to stop (emergency)

26. When may blocking (cribbing) be placed under outrigger beams?

a. When beams cannot be extended all the way out
b. To increase capacity
c. To improve stability
d. Never

27. What is the result of placing timber blocking under the tips of the tracks on a crawler crane?

a. Decreases the permitted capacity of the crane
b. Makes the crane more stable
c. Reduces the capacity of the crane
d. Makes the crane less stable

28. According to ASME, what percentage of the manufacturer’s crane rating must not be exceeded if a load test is done on a repaired crane?

a. 110%
b. 100%
c. 85%
d. 75%

29. Where is the tipping axis of a crawler crane located?

a. It is always at the centerline of the idler or sprocket
b. It depends if the idler or sprocket are in line or offset from the track rollers
c. It is through the centerline of the crane cab
d. It is through the boom butt section

30. What should be done with materials placed under overhead energized power lines?

a. Be dragged out
b. Be lifted as normal
c. Not be lifted by crane
d. Handled with extra care

31. What standard method hand signal is being illustrated?

a. Boom up
b. Boom down
c. Retract boom
d. Hoist

32. Where should the crane’s outrigger pads or tracks be placed when working at ground floor level near a cellar wall?

a. As close as possible to the wall
b. At least as far back as the depth of the wall below ground
c. At a distance at least half the depth of the cellar wall below ground
d. Anywhere, since the wall is unaffected by the weight of the crane

33. How should the wheels of a crane be positioned when it is set up for working on outriggers?

a. Just touching the ground
b. As high as possible off the ground
c. Just high enough off the ground to relieve the tires of crane weight
d. Firmly on the ground to support the crane

34. What happens to ground bearing pressure if you move a crawler crane from soft ground to harder ground?

a. It increases
b. It decreases by a third
c. It remains the same
d. It decreases by half

35. When may a swivel be used with rotation resistant wire rope?

a. Always
b. Never
c. If the rope manufacturer approves
d. If the operator decides it’s OK

36. What should you do on pick and carry operations?

a. Keep the boom as short as possible
b. Keep the load as high above the ground as possible
c. Ensure the load is as far from the carrier/carbody as possible
d. Use maximum boom length

37. What boom position would cause the greatest ground pressure when lifting with crawler cranes?

a. Over the right side
b. Over the end
c. Over the corner
d. over the left side

38. Where should the hook be positioned when preparing to hoist a light load?

a. Slightly to the side you're planning to swing to
b. Slightly to the side opposite you plan to swing to
c. Directly above the load's center of gravity
d. Above the edge of the load closest to the crane

39. According to OSHA 1926.1408, what minimum clearance must be maintained between any part of the crane/load and 850kV energized overhead power lines.

a. 25 ft.
b. 30 ft.
c. 35 ft.
d. 45 ft.

40. How many parts of line are required to hoist a 36,500 lb. load if the maximum allowable line pull is 9,000 lb.?

a. 3
b. 4
c. 5
d. 6

41. What determines the amount of deduction required for an erected jib that is not being used?

a. The actual weight of the jib
b. The effective weight of the jib
c. Nothing, since the jib is not in use
d. The difference between the crane's actual weight and its effective weight

42. What capacity should you use when the boom length of the crane falls between the lengths listed in the load chart?

a. The next longest boom length
b. The next shortest boom length
c. A length estimated between the lengths in the chart
d. The next longest or the next shortest boom length, whichever is the lower capacity

43. When is it okay to temporarily bypass a crane's overload warning system?

a. When a supervisor tells you to
b. When the load to be lifted exceeds the capacity in the chart
c. Never
d. During assembly/disassembly operations

44. What happens to the leverage of the load on a crane as the boom is being lowered?

a. It increases
b. It decreases
c. It stays the same
d. It depends on the weight of the load being lifted

45. Where are the Standard Method hand signals found?

a. OSHA Subpart CC
b. OSHA 1926.550
c. ASME B30.R
d. They are determined by each manufacturer

46. What should an operator do if a crane's load moment indicator (LMI) malfunctions?

a. Cease crane operations and report the condition to the supervisor
b. Turn it off and continue as if the LMI were not installed
c. Make mathematical allowances for any error
d. Attempt to repair the fault