NCCCO Digger Derrick Operator Practice
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary function of the outrigger system on a digger
derrick?
A. Increase engine power
B. Stabilize the vehicle during operation
C. Reduce hydraulic fluid consumption
D. Assist in steering
Rationale: The outrigger system stabilizes the vehicle to prevent tipping
while lifting loads.
2. When performing a pre-operation inspection, which item should be
checked first?
A. Hydraulic fluid levels
B. Control functions
, C. Tire pressure
D. Worksite conditions
Rationale: Control functions must be checked first to ensure the operator
can safely control the equipment.
3. Which OSHA regulation applies to digger derrick operations?
A. 1926 Subpart M
B. 1910.147
C. 1910.269
D. 1926 Subpart P
Rationale: OSHA 1910.269 covers electric power generation, transmission,
and distribution, including digger derrick operation safety.
4. What is the maximum allowable load on a digger derrick boom
determined by?
A. Operator experience
B. Load chart
C. Boom angle only
D. Engine horsepower
Rationale: The load chart provides the safe lifting capacity based on boom
length and angle.
5. Which of the following can cause a digger derrick to tip over?
A. Using outriggers properly
B. Exceeding the rated load
, C. Operating on level ground
D. Following manufacturer guidelines
Rationale: Exceeding the rated load exceeds the stability margin and can
cause tipping.
6. What is the purpose of a boom angle indicator?
A. Measure hydraulic pressure
B. Show the boom’s angle relative to horizontal
C. Indicate vehicle speed
D. Measure load weight
Rationale: The boom angle indicator helps the operator determine the
boom position to avoid unsafe lifting angles.
7. How often should the digger derrick be inspected according to NCCCO
standards?
A. Annually
B. Weekly
C. Before each shift
D. After every lift
Rationale: NCCCO requires daily or pre-shift inspections to ensure safe
operation.
8. Which type of soil requires extra caution when setting outriggers?
A. Concrete
B. Soft or uneven soil
, C. Asphalt
D. Gravel
Rationale: Soft or uneven soil can cause the outriggers to sink or shift,
compromising stability.
9. What is the primary hazard when working near overhead power lines?
A. Noise exposure
B. Electrocution
C. Falling objects
D. Mechanical failure
Rationale: Contact with energized lines can result in fatal electrocution,
making clearance critical.
10. Which safety device prevents the boom from overextending?
A. Hydraulic pump
B. Boom angle limiter
C. Outrigger pads
D. Load block
Rationale: The boom angle limiter prevents operators from raising the
boom beyond safe angles.
11. Before lifting a load, what must the operator ensure about the
rigging?
A. It is lubricated
B. It is properly secured and rated for the load
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary function of the outrigger system on a digger
derrick?
A. Increase engine power
B. Stabilize the vehicle during operation
C. Reduce hydraulic fluid consumption
D. Assist in steering
Rationale: The outrigger system stabilizes the vehicle to prevent tipping
while lifting loads.
2. When performing a pre-operation inspection, which item should be
checked first?
A. Hydraulic fluid levels
B. Control functions
, C. Tire pressure
D. Worksite conditions
Rationale: Control functions must be checked first to ensure the operator
can safely control the equipment.
3. Which OSHA regulation applies to digger derrick operations?
A. 1926 Subpart M
B. 1910.147
C. 1910.269
D. 1926 Subpart P
Rationale: OSHA 1910.269 covers electric power generation, transmission,
and distribution, including digger derrick operation safety.
4. What is the maximum allowable load on a digger derrick boom
determined by?
A. Operator experience
B. Load chart
C. Boom angle only
D. Engine horsepower
Rationale: The load chart provides the safe lifting capacity based on boom
length and angle.
5. Which of the following can cause a digger derrick to tip over?
A. Using outriggers properly
B. Exceeding the rated load
, C. Operating on level ground
D. Following manufacturer guidelines
Rationale: Exceeding the rated load exceeds the stability margin and can
cause tipping.
6. What is the purpose of a boom angle indicator?
A. Measure hydraulic pressure
B. Show the boom’s angle relative to horizontal
C. Indicate vehicle speed
D. Measure load weight
Rationale: The boom angle indicator helps the operator determine the
boom position to avoid unsafe lifting angles.
7. How often should the digger derrick be inspected according to NCCCO
standards?
A. Annually
B. Weekly
C. Before each shift
D. After every lift
Rationale: NCCCO requires daily or pre-shift inspections to ensure safe
operation.
8. Which type of soil requires extra caution when setting outriggers?
A. Concrete
B. Soft or uneven soil
, C. Asphalt
D. Gravel
Rationale: Soft or uneven soil can cause the outriggers to sink or shift,
compromising stability.
9. What is the primary hazard when working near overhead power lines?
A. Noise exposure
B. Electrocution
C. Falling objects
D. Mechanical failure
Rationale: Contact with energized lines can result in fatal electrocution,
making clearance critical.
10. Which safety device prevents the boom from overextending?
A. Hydraulic pump
B. Boom angle limiter
C. Outrigger pads
D. Load block
Rationale: The boom angle limiter prevents operators from raising the
boom beyond safe angles.
11. Before lifting a load, what must the operator ensure about the
rigging?
A. It is lubricated
B. It is properly secured and rated for the load
