NCCCO Digger Derrick Operator
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a digger derrick on a utility
construction site?
A. To transport personnel between work locations
B. To perform only horizontal excavation
C. To drill holes and handle suspended loads
D. To replace all excavators and cranes
Answer: C. To drill holes and handle suspended loads
Rationale: A digger derrick combines drilling, lifting, and material-
handling capabilities. Its typical applications include drilling utility-
pole holes, setting poles, and handling suspended loads.
2. Before operating a digger derrick, the operator should first ensure
that the machine is:
A. Painted and clean
B. Properly inspected and configured for the planned work
C. Running at maximum engine speed
D. Loaded with maximum counterweight
Answer: B. Properly inspected and configured for the planned work
Rationale: A pre-operation inspection and proper machine
configuration are fundamental safety requirements. The operator must
,identify defects and verify that the machine is suitable for the intended
operation.
3. What does the rated capacity of a digger derrick represent?
A. The maximum engine horsepower
B. The maximum allowable travel speed
C. The maximum load the machine is designed to handle under
specified conditions
D. The maximum drilling depth
Answer: C. The maximum load the machine is designed to handle
under specified conditions
Rationale: Rated capacity depends on the machine configuration and
operating conditions. It is not simply the machine's weight or engine
power.
4. Which document is most important when determining the
machine's allowable lifting capacity?
A. Operator's personal notes
B. Manufacturer's load chart or rated capacity information
C. Fuel receipt
D. Daily weather report
Answer: B. Manufacturer's load chart or rated capacity information
Rationale: The manufacturer's capacity information identifies
allowable loads for specific configurations, boom positions, and
operating conditions.
5. What is the safest response if the operator cannot determine the
weight of a load?
A. Assume the load weighs less than the capacity
B. Lift it slowly to determine its weight
, C. Determine the load weight before proceeding
D. Have a signalperson estimate it after lifting
Answer: C. Determine the load weight before proceeding
Rationale: A load should not be lifted when its weight is unknown if
that uncertainty could result in exceeding capacity. The operator must
obtain reliable load information before lifting.
6. What is the main function of outriggers on a digger derrick?
A. Increase engine speed
B. Improve machine stability by widening the support base
C. Increase drilling rotation speed
D. Reduce hydraulic pressure
Answer: B. Improve machine stability by widening the support base
Rationale: Outriggers transfer forces into the supporting surface and
increase the machine's effective footprint. They must be properly
deployed and supported.
7. When setting outriggers, the operator should consider:
A. Only the paint color of the machine
B. Ground conditions and manufacturer requirements
C. The operator's preferred boom angle
D. The age of the truck tires only
Answer: B. Ground conditions and manufacturer requirements
Rationale: Outrigger performance depends heavily on ground support.
Soft, sloped, wet, or unstable surfaces may require additional
preparation or support.
8. What can happen when an outrigger is placed on inadequate
ground?
A. Increased lifting capacity
B. Improved drilling accuracy
, C. Outrigger settlement and possible machine instability
D. Reduced load weight
Answer: C. Outrigger settlement and possible machine instability
Rationale: Weak ground can allow an outrigger to sink or shift. This
can alter machine geometry and potentially cause loss of stability.
9. Why are outrigger pads or mats sometimes required?
A. To improve the machine's appearance
B. To distribute support forces over a larger area
C. To increase fuel capacity
D. To reduce boom length
Answer: B. To distribute support forces over a larger area
Rationale: Pads and mats increase the area over which outrigger
reactions are transmitted, reducing ground pressure and helping
prevent settlement.
10. Before extending an outrigger, the operator should verify
that:
A. No person or obstruction is in the hazard area
B. The engine is off permanently
C. The boom is removed
D. The drill bit is underground
Answer: A. No person or obstruction is in the hazard area
Rationale: Moving outriggers can crush or strike people and objects.
The operator must ensure the area is clear before deploying or
retracting them.
11. What is the purpose of a boom on a digger derrick?
A. To provide a movable structure for positioning lifting or drilling
equipment
B. To store hydraulic oil
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a digger derrick on a utility
construction site?
A. To transport personnel between work locations
B. To perform only horizontal excavation
C. To drill holes and handle suspended loads
D. To replace all excavators and cranes
Answer: C. To drill holes and handle suspended loads
Rationale: A digger derrick combines drilling, lifting, and material-
handling capabilities. Its typical applications include drilling utility-
pole holes, setting poles, and handling suspended loads.
2. Before operating a digger derrick, the operator should first ensure
that the machine is:
A. Painted and clean
B. Properly inspected and configured for the planned work
C. Running at maximum engine speed
D. Loaded with maximum counterweight
Answer: B. Properly inspected and configured for the planned work
Rationale: A pre-operation inspection and proper machine
configuration are fundamental safety requirements. The operator must
,identify defects and verify that the machine is suitable for the intended
operation.
3. What does the rated capacity of a digger derrick represent?
A. The maximum engine horsepower
B. The maximum allowable travel speed
C. The maximum load the machine is designed to handle under
specified conditions
D. The maximum drilling depth
Answer: C. The maximum load the machine is designed to handle
under specified conditions
Rationale: Rated capacity depends on the machine configuration and
operating conditions. It is not simply the machine's weight or engine
power.
4. Which document is most important when determining the
machine's allowable lifting capacity?
A. Operator's personal notes
B. Manufacturer's load chart or rated capacity information
C. Fuel receipt
D. Daily weather report
Answer: B. Manufacturer's load chart or rated capacity information
Rationale: The manufacturer's capacity information identifies
allowable loads for specific configurations, boom positions, and
operating conditions.
5. What is the safest response if the operator cannot determine the
weight of a load?
A. Assume the load weighs less than the capacity
B. Lift it slowly to determine its weight
, C. Determine the load weight before proceeding
D. Have a signalperson estimate it after lifting
Answer: C. Determine the load weight before proceeding
Rationale: A load should not be lifted when its weight is unknown if
that uncertainty could result in exceeding capacity. The operator must
obtain reliable load information before lifting.
6. What is the main function of outriggers on a digger derrick?
A. Increase engine speed
B. Improve machine stability by widening the support base
C. Increase drilling rotation speed
D. Reduce hydraulic pressure
Answer: B. Improve machine stability by widening the support base
Rationale: Outriggers transfer forces into the supporting surface and
increase the machine's effective footprint. They must be properly
deployed and supported.
7. When setting outriggers, the operator should consider:
A. Only the paint color of the machine
B. Ground conditions and manufacturer requirements
C. The operator's preferred boom angle
D. The age of the truck tires only
Answer: B. Ground conditions and manufacturer requirements
Rationale: Outrigger performance depends heavily on ground support.
Soft, sloped, wet, or unstable surfaces may require additional
preparation or support.
8. What can happen when an outrigger is placed on inadequate
ground?
A. Increased lifting capacity
B. Improved drilling accuracy
, C. Outrigger settlement and possible machine instability
D. Reduced load weight
Answer: C. Outrigger settlement and possible machine instability
Rationale: Weak ground can allow an outrigger to sink or shift. This
can alter machine geometry and potentially cause loss of stability.
9. Why are outrigger pads or mats sometimes required?
A. To improve the machine's appearance
B. To distribute support forces over a larger area
C. To increase fuel capacity
D. To reduce boom length
Answer: B. To distribute support forces over a larger area
Rationale: Pads and mats increase the area over which outrigger
reactions are transmitted, reducing ground pressure and helping
prevent settlement.
10. Before extending an outrigger, the operator should verify
that:
A. No person or obstruction is in the hazard area
B. The engine is off permanently
C. The boom is removed
D. The drill bit is underground
Answer: A. No person or obstruction is in the hazard area
Rationale: Moving outriggers can crush or strike people and objects.
The operator must ensure the area is clear before deploying or
retracting them.
11. What is the purpose of a boom on a digger derrick?
A. To provide a movable structure for positioning lifting or drilling
equipment
B. To store hydraulic oil
