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


​Digger Derrick Operator

Written Exam - Sample Questions

The following are sample test questions typical of the style and content of the questions used in CCO Written Examinations.

  1. The reason for using blocking under the digger derrick’s outrigger pads is to:
    1. Shorten the length of the outrigger extensions
    2. Decrease the applied ground pressure
    3. Raise the digger derrick in order to reach higher
    4. Extend the tipping axis of the digger derrick
  1. Which function could cause the shackle/hook to contact the boom tip?
    1. Raising the boom
    2. Rotating the boom
    3. Extending the boom
    4. Retracting the boom
  1. It is always the operator’s responsibility to:
    1. Know the load weight before lifting
    2. Assure that a suitable digger derrick has been assigned to the job
    3. Designate a qualified signalperson
    4. Supervise the rigging crew
  1. According to ANSI A10.31 who is permitted to operate a digger derrick?
    1. Employees with a valid CDL
    2. Ground worker
    3. Linemen
    4. Trained and authorized personnel
  1. Where shall the digger derrick operator’s manual be located?
    1. On the digger derrick vehicle
    2. On the service truck
    3. In the supervisor’s truck
    4. At the office
  1. Using configuration listed below, what is the farthest radius a 3,125 lb. load can be set over the rear of the digger derrick (see load charts)?

    Make: Terex
    Second Section: ??
    Boom Angle: N/A         
    Third Section: ??
    Radius: ??
    Rigging: 75 lb.
    Others: N/A
    Jib: N/A
    Load Line: 1-part
    Jib Length: N/A

    1. 26.9 ft.
    2. 27.5 ft.
    3. 36.2 ft.
    4. 36.4 ft.

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