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


Mobile Crane Operator

Written Exam - Core Exam Outline

The Core Examination portion of the CCO certification program tests the following knowledge areas relating to the operation of mobile cranes:

Domain 1: Site
(Approximately 20% of the test)

Domain 2: Operations
(Approximately 26% of the test)

Domain 3: Technical Knowledge
(Approximately 28% of the test)

Domain 4: Load Charts
(Approximately 26% of the test)


(Approximately 20% of the test)

  1. Understand elements that affect ground stability:
    1. Below surface (e.g., voids, tanks, loose fill)
    2. On surface (e.g., retaining walls, slopes, excavations, depressions)
    3. Boom position
  2. Know the proper use of supporting materials (e.g., mats, blocking/cribbing).
  3. Know electric power line hazards during assembly/disassembly.
  4. Know the requirements to travel without load.
  5. Know how to identify and evaluate hazards concerning:
    1. Access to job site
    2. In-transit clearances
    3. Pinch/crush points
    4. Personnel
  6. Know the responsibilities of the controlling entity concerning site conditions.
  7. Know how to review lift requirements with site supervision.


(Approximately 26% of the test)

  1. Know how to inspect the crane for unsafe conditions.
  2. Know personnel safety requirements during crane inspections.
  3. Know how to level the crane.
  4. Know how to obtain dimensions, weight, and center of gravity of the load.
  5. Know how to verify the radius.
  6. Know electric power line hazards during operations.
  7. Know wire rope:
    1. Reeving
    2. Parts of line
  8. Know types of signals:
    1. Hand signals
    2. Voice/radio signals
    3. Audible signals
    4. New or non-standard signals
  9. Know the requirements for:
    1. Multi-crane lifts
    2. Suspended personnel platforms
    3. Duty cycle operations
    4. Barge operations
    5. Multi-drum operations
  10. Know the effects of lifting loads from beneath the surface of the water.
  11. Know the requirements and procedures for when load is not in full view of the operator.
  12. Know the requirements of tag lines.
  13. Know how to react to:
    1. Block and line twisting
    2. Personnel in fall zone
  14. Know the use/function of the following operator aids:
    1. Load moment indicator, load moment limiter, load weighing devices
    2. Anti–two block devices
    3. Boom angle indicator
    4. Wind indicator
    5. Drum rotation indicators
    6. Radius indicators
  15. Know alternative operating procedures when operator aids malfunction.
  16. Know the use/function of the following safety devices:
    1. Horn
    2. Level indicator
  17. Know emergency procedures for:
    1. Electric power line contact
    2. Loss of stability
    3. Control malfunction
    4. Carrier or travel malfunction
    5. Two-blocking
    6. Overloading
    7. Fires
  18. Know the effects of dynamic loading from:
    1. Shock loading
    2. Moving loads
  19. Know the effect of side loading.
  20. Know the effects of operating in various weather conditions (e.g., wind, temperature, wave action)
  21. Understand the condition where backward stability presents limitations.
  22. Know how to use the manufacturer-approved attachments and their effect on the crane’s operation.
  23. Know operator’s authority to stop operations.
  24. Know how to shut down and secure the crane when leaving it unattended.


(Approximately 28% of the test)

  1. Know current federal regulations and industry standards, including but not limited to ASME B30.5, B30.10, OSHA 1910.180, 1926 Subpart CC.
  2. Know basic crane terminology and definitions.
  3. Know functions and limitations of cranes and attachments.
  4. Know the inspection requirements for:
    1. Shift inspections
    2. Monthly inspections
    3. Annual inspections
    4. Notifying supervision of inspection deficiencies
  5. Know basic procedures for rigging devices and their use, such as slings, softeners, lifting beams, and shackles.
  6. Know basic procedures for termination of wire rope.
  7. Know the proper use of hook blocks and overhaul balls.
  8. Know wire rope:
    1. Types and designations of wire rope and their application
    2. Replacement criteria and inspection procedures of running ropes
    3. Maintenance and lubrication
  9. Know relationship between line pull and safe working load of running ropes.
  10. Know protective measures against electrical hazards and their limitations.
  11. Know the significance of the instruments and gauge readings.
  12. Know requirements for fall protection.
  13. Know requirements for access and egress of the crane.


(Approximately 26% of the test)

  1. Know the terminology necessary to use load charts.
  2. Demonstrate basic math skills without the use of a calculator.
  3. Know how to ensure that the load chart is the appropriate chart for the machine in its particular application.
  4. Know how to use load charts, including:
    1. The difference between capacity limited by stability and factors other than stability
    2. The range diagram
    3. The work area chart
    4. “Parts-of-line” information