NCCCO Digger Derrick Operator Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
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1. Before operating a digger derrick, you should always:
A. Start digging immediately
B. Perform a pre-operational inspection
C. Only check the fuel level
D. Ask a coworker to operate it first
pre-operational inspections ensure that all components are
functional and safe, reducing the risk of accidents.
2. Which type of soil is the most likely to cause auger slipping during
digging?
A. Clay
B. Loose sand
C. Hard clay
D. Rocky soil
Loose sand offers less resistance and can cause the auger to slip or
spin without proper torque control.
3. What is the maximum load you should lift without knowing the
load chart?
A. Half of rated capacity
B. Never lift without checking the load chart
C. Full capacity if it looks safe
, D. Only light loads
The load chart provides the safe operating limits for different
boom angles and extensions; ignoring it can lead to tip-over or
structural failure.
4. When extending the boom, you should always:
A. Extend as fast as possible
B. Monitor stability and use outriggers properly
C. Rely on counterweights only
D. Ignore ground conditions
Proper boom extension requires attention to machine stability,
especially on uneven ground.
5. What should you do if you encounter underground utilities while
digging?
A. Continue digging slowly
B. Stop immediately and notify the utility company
C. Move to a different site
D. Dig manually without machinery
Striking underground utilities can cause electrocution, gas leaks,
or service interruptions; calling the utility company is required.
6. When positioning outriggers, you should ensure:
A. They are partially extended
B. Full contact with firm, level ground
C. Only the front outriggers are extended
D. They touch soft ground for flexibility
Outriggers must be fully supported on stable ground to prevent
tipping.
7. How often should a digger derrick operator check the fluid levels
(hydraulic, engine oil, etc.)?
A. Once a month
, B. Before each shift
C. After completing a job
D. Only when the machine shows a warning light
Routine checks before each shift catch leaks or low fluids before
they cause equipment failure.
8. When operating near power lines, what is the minimum OSHA-
required clearance for voltages up to 50 kV?
A. 5 feet
B. 10 feet
C. 15 feet
D. 20 feet
OSHA sets minimum approach distances to prevent electrical
contact; for up to 50 kV, 10 feet is required.
9. The purpose of a boom angle indicator is to:
A. Measure wind speed
B. Show the angle of the boom for safe lifting
C. Record fuel consumption
D. Control the digger speed
Knowing the boom angle ensures that lifts stay within safe
operating limits according to the load chart.
10. What should you do if a hydraulic hose begins to leak during
operation?
A. Ignore it
B. Stop the machine and repair it before continuing
C. Wrap it with tape and continue
D. Continue if pressure is low
A leaking hydraulic hose can fail catastrophically; immediate
shutdown and repair are required.
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Before operating a digger derrick, you should always:
A. Start digging immediately
B. Perform a pre-operational inspection
C. Only check the fuel level
D. Ask a coworker to operate it first
pre-operational inspections ensure that all components are
functional and safe, reducing the risk of accidents.
2. Which type of soil is the most likely to cause auger slipping during
digging?
A. Clay
B. Loose sand
C. Hard clay
D. Rocky soil
Loose sand offers less resistance and can cause the auger to slip or
spin without proper torque control.
3. What is the maximum load you should lift without knowing the
load chart?
A. Half of rated capacity
B. Never lift without checking the load chart
C. Full capacity if it looks safe
, D. Only light loads
The load chart provides the safe operating limits for different
boom angles and extensions; ignoring it can lead to tip-over or
structural failure.
4. When extending the boom, you should always:
A. Extend as fast as possible
B. Monitor stability and use outriggers properly
C. Rely on counterweights only
D. Ignore ground conditions
Proper boom extension requires attention to machine stability,
especially on uneven ground.
5. What should you do if you encounter underground utilities while
digging?
A. Continue digging slowly
B. Stop immediately and notify the utility company
C. Move to a different site
D. Dig manually without machinery
Striking underground utilities can cause electrocution, gas leaks,
or service interruptions; calling the utility company is required.
6. When positioning outriggers, you should ensure:
A. They are partially extended
B. Full contact with firm, level ground
C. Only the front outriggers are extended
D. They touch soft ground for flexibility
Outriggers must be fully supported on stable ground to prevent
tipping.
7. How often should a digger derrick operator check the fluid levels
(hydraulic, engine oil, etc.)?
A. Once a month
, B. Before each shift
C. After completing a job
D. Only when the machine shows a warning light
Routine checks before each shift catch leaks or low fluids before
they cause equipment failure.
8. When operating near power lines, what is the minimum OSHA-
required clearance for voltages up to 50 kV?
A. 5 feet
B. 10 feet
C. 15 feet
D. 20 feet
OSHA sets minimum approach distances to prevent electrical
contact; for up to 50 kV, 10 feet is required.
9. The purpose of a boom angle indicator is to:
A. Measure wind speed
B. Show the angle of the boom for safe lifting
C. Record fuel consumption
D. Control the digger speed
Knowing the boom angle ensures that lifts stay within safe
operating limits according to the load chart.
10. What should you do if a hydraulic hose begins to leak during
operation?
A. Ignore it
B. Stop the machine and repair it before continuing
C. Wrap it with tape and continue
D. Continue if pressure is low
A leaking hydraulic hose can fail catastrophically; immediate
shutdown and repair are required.
