NCCCO MOBILE CRANE-2026 ACTUAL
EXAM 120 QUESTIONS AND CORRECT
DETAILED ANSWERS |ALREADY
GRADED A+ LATEST
SECTION 1: SITE & GROUND CONDITIONS (Questions 1–12)
1. A crane is set up on outriggers over ground that appears
stable. During the lift, one outrigger pad sinks 2 inches. The
load is still suspended. What is the FIRST action the operator
must take?
A. Boom up to reduce the load radius
B. Swing the load toward the opposite side of the crane
C. Lower the load to the ground immediately
D. Retract the sinking outrigger to equalize pressure
Answer: C
Rationale: The immediate priority is to remove the suspended
load from the crane. A sinking outrigger indicates a loss of ground
bearing capacity. Every second the load remains suspended
increases the tipping moment on the unstable side. Lowering the
load stabilizes the situation. Never swing or boom up—these
motions change the center of gravity unpredictably and could
accelerate tipping.
,2. What is the MINIMUM distance that outriggers or tracks
must be placed from the edge of an excavation if the
excavation is 12 feet deep?
A. 6 feet
B. 12 feet
C. 15 feet
D. 24 feet
Answer: B
Rationale: OSHA requires that equipment be set back at least the
depth of the excavation from the edge. This is based on the angle
of repose of soil (typically 45 degrees). A 12-foot-deep hole
requires a 12-foot setback. This prevents the trench wall from
sliding out from under the outriggers.
3. A crane is set up on a slope. The bubble level in the cab
shows the crane is level within 0.5%. The slope itself is 8
degrees. According to NCCCO standards, is this setup
acceptable?
A. Yes, as long as the crane is level within 1%
B. No, the slope itself must not exceed 5 degrees
C. Yes, as long as outriggers are fully extended
D. No, the crane must be level within 0.25% on a slope
Answer: A
,Rationale: The load chart validity requires the crane to be level
within 1% regardless of the underlying slope. The crane can be on
a steep slope as long as the outriggers or tracks are cribbed to
bring the chassis to level. The critical factor is the chassis level, not
the ground slope angle.
4. A crawler crane is positioned on tracks. The ground bearing
pressure is calculated to be 12 psig. The soft clay soil has a
rated capacity of 8 psig. What is the minimum required
action?
A. No reduction—crawler tracks distribute load evenly
B. Reduce capacity by 25%
C. Reduce capacity by 33% (12 ÷ 8 = 1.33 factor)
D. Do not operate—ground is inadequate regardless of capacity
reduction
Answer: D
Rationale: If the crane's ground pressure exceeds the soil's
bearing capacity at zero load, the crane cannot be safely operated
at any capacity. The crane's self-weight alone will cause sinking.
The only solution is to add mats or cribbing to increase footprint
area, relocate to stronger ground, or not operate.
5. Which of the following soil conditions would provide the
HIGHEST bearing capacity for crane outriggers?
, A. Thawing ground
B. Soft clay
C. Compacted gravel
D. Wet sand
Answer: C
Rationale: Compacted gravel provides the highest bearing
capacity among common soil types. Thawing ground loses
bearing capacity rapidly. A site that was solid when frozen may
become soft and unstable during a thaw. The operator must
reinspect outrigger pads for sinking, check for water pooling,
recalculate ground pressure requirements, and add cribbing or
mats if necessary.
6. A crane is set up with outrigger pads measuring 24 inches
by 24 inches. The crane exerts a maximum outrigger load of
80,000 lb. What is the ground bearing pressure in pounds per
square foot (psf)?
A. 10,000 psf
B. 15,000 psf
C. 20,000 psf
D. 25,000 psf
Answer: C
Rationale: Area = 24 in × 24 in = 576 sq in = 4 sq ft. Pressure =
80,000 lb ÷ 4 sq ft = 20,000 psf.
EXAM 120 QUESTIONS AND CORRECT
DETAILED ANSWERS |ALREADY
GRADED A+ LATEST
SECTION 1: SITE & GROUND CONDITIONS (Questions 1–12)
1. A crane is set up on outriggers over ground that appears
stable. During the lift, one outrigger pad sinks 2 inches. The
load is still suspended. What is the FIRST action the operator
must take?
A. Boom up to reduce the load radius
B. Swing the load toward the opposite side of the crane
C. Lower the load to the ground immediately
D. Retract the sinking outrigger to equalize pressure
Answer: C
Rationale: The immediate priority is to remove the suspended
load from the crane. A sinking outrigger indicates a loss of ground
bearing capacity. Every second the load remains suspended
increases the tipping moment on the unstable side. Lowering the
load stabilizes the situation. Never swing or boom up—these
motions change the center of gravity unpredictably and could
accelerate tipping.
,2. What is the MINIMUM distance that outriggers or tracks
must be placed from the edge of an excavation if the
excavation is 12 feet deep?
A. 6 feet
B. 12 feet
C. 15 feet
D. 24 feet
Answer: B
Rationale: OSHA requires that equipment be set back at least the
depth of the excavation from the edge. This is based on the angle
of repose of soil (typically 45 degrees). A 12-foot-deep hole
requires a 12-foot setback. This prevents the trench wall from
sliding out from under the outriggers.
3. A crane is set up on a slope. The bubble level in the cab
shows the crane is level within 0.5%. The slope itself is 8
degrees. According to NCCCO standards, is this setup
acceptable?
A. Yes, as long as the crane is level within 1%
B. No, the slope itself must not exceed 5 degrees
C. Yes, as long as outriggers are fully extended
D. No, the crane must be level within 0.25% on a slope
Answer: A
,Rationale: The load chart validity requires the crane to be level
within 1% regardless of the underlying slope. The crane can be on
a steep slope as long as the outriggers or tracks are cribbed to
bring the chassis to level. The critical factor is the chassis level, not
the ground slope angle.
4. A crawler crane is positioned on tracks. The ground bearing
pressure is calculated to be 12 psig. The soft clay soil has a
rated capacity of 8 psig. What is the minimum required
action?
A. No reduction—crawler tracks distribute load evenly
B. Reduce capacity by 25%
C. Reduce capacity by 33% (12 ÷ 8 = 1.33 factor)
D. Do not operate—ground is inadequate regardless of capacity
reduction
Answer: D
Rationale: If the crane's ground pressure exceeds the soil's
bearing capacity at zero load, the crane cannot be safely operated
at any capacity. The crane's self-weight alone will cause sinking.
The only solution is to add mats or cribbing to increase footprint
area, relocate to stronger ground, or not operate.
5. Which of the following soil conditions would provide the
HIGHEST bearing capacity for crane outriggers?
, A. Thawing ground
B. Soft clay
C. Compacted gravel
D. Wet sand
Answer: C
Rationale: Compacted gravel provides the highest bearing
capacity among common soil types. Thawing ground loses
bearing capacity rapidly. A site that was solid when frozen may
become soft and unstable during a thaw. The operator must
reinspect outrigger pads for sinking, check for water pooling,
recalculate ground pressure requirements, and add cribbing or
mats if necessary.
6. A crane is set up with outrigger pads measuring 24 inches
by 24 inches. The crane exerts a maximum outrigger load of
80,000 lb. What is the ground bearing pressure in pounds per
square foot (psf)?
A. 10,000 psf
B. 15,000 psf
C. 20,000 psf
D. 25,000 psf
Answer: C
Rationale: Area = 24 in × 24 in = 576 sq in = 4 sq ft. Pressure =
80,000 lb ÷ 4 sq ft = 20,000 psf.
