CO Cranes & Hoisting Contractor Exam
Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary purpose of a crane's load chart?
A. To identify the crane manufacturer
B. To determine the crane's fuel capacity
C. To establish allowable loads under specified operating conditions
D. To determine the operator's maximum working hours
Answer: C. To establish allowable loads under specified operating
conditions
Rationale: A crane load chart specifies the maximum permissible loads
for different boom lengths, operating radii, configurations, and other
conditions. Exceeding the chart's limits can cause structural failure,
tipping, or loss of control.
, 2. What does the term "working radius" generally refer to in crane
operations?
A. The length of the crane's boom
B. The horizontal distance from the crane's center of rotation to the
load's center of gravity
C. The height of the crane's counterweight
D. The distance between two outriggers
Answer: B. The horizontal distance from the crane's center of rotation
to the load's center of gravity
Rationale: Working radius is a critical factor in determining crane
capacity. As radius increases, the crane's lifting capacity generally
decreases because the load creates greater overturning forces.
3. Before beginning a lifting operation, what should the operator
verify first?
A. That the crane's paint is intact
B. That the crane has sufficient lifting capacity for the planned load and
configuration
C. That the fuel tank is completely full
D. That the cab windows are open
,Answer: B. That the crane has sufficient lifting capacity for the
planned load and configuration
Rationale: Confirming crane capacity is fundamental to safe lifting. The
operator must consider load weight, radius, boom length, configuration,
ground conditions, and applicable load-chart limitations before making
the lift.
4. What is the purpose of outriggers on a mobile crane?
A. To increase engine speed
B. To reduce fuel consumption
C. To improve stability and distribute loads to the supporting surface
D. To increase the boom's length
Answer: C. To improve stability and distribute loads to the supporting
surface
Rationale: Outriggers extend the crane's support base and transfer
loads to the ground through pads or floats. Proper deployment helps
stabilize the crane and reduce the likelihood of overturning.
5. What should be done if the actual weight of a load is unknown?
A. Lift it slowly to determine its weight
B. Assume the load weighs half its estimated weight
, C. Determine or reliably establish the load weight before lifting
D. Increase the crane's counterweight without checking the load chart
Answer: C. Determine or reliably establish the load weight before
lifting
Rationale: An unknown load weight presents a significant hazard
because the crane may be overloaded. The weight should be established
from reliable documentation, calculations, manufacturer information,
or an appropriate weighing method before the lift.
6. What is the main function of a crane's counterweight?
A. To increase the engine's horsepower
B. To help balance the crane against overturning moments created by
the load
C. To reduce the boom's length
D. To prevent sling abrasion
Answer: B. To help balance the crane against overturning moments
created by the load
Rationale: Counterweights provide a balancing moment that helps
maintain crane stability. They must be installed and configured
according to the manufacturer's requirements because incorrect
counterweight configuration can create serious hazards.
Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary purpose of a crane's load chart?
A. To identify the crane manufacturer
B. To determine the crane's fuel capacity
C. To establish allowable loads under specified operating conditions
D. To determine the operator's maximum working hours
Answer: C. To establish allowable loads under specified operating
conditions
Rationale: A crane load chart specifies the maximum permissible loads
for different boom lengths, operating radii, configurations, and other
conditions. Exceeding the chart's limits can cause structural failure,
tipping, or loss of control.
, 2. What does the term "working radius" generally refer to in crane
operations?
A. The length of the crane's boom
B. The horizontal distance from the crane's center of rotation to the
load's center of gravity
C. The height of the crane's counterweight
D. The distance between two outriggers
Answer: B. The horizontal distance from the crane's center of rotation
to the load's center of gravity
Rationale: Working radius is a critical factor in determining crane
capacity. As radius increases, the crane's lifting capacity generally
decreases because the load creates greater overturning forces.
3. Before beginning a lifting operation, what should the operator
verify first?
A. That the crane's paint is intact
B. That the crane has sufficient lifting capacity for the planned load and
configuration
C. That the fuel tank is completely full
D. That the cab windows are open
,Answer: B. That the crane has sufficient lifting capacity for the
planned load and configuration
Rationale: Confirming crane capacity is fundamental to safe lifting. The
operator must consider load weight, radius, boom length, configuration,
ground conditions, and applicable load-chart limitations before making
the lift.
4. What is the purpose of outriggers on a mobile crane?
A. To increase engine speed
B. To reduce fuel consumption
C. To improve stability and distribute loads to the supporting surface
D. To increase the boom's length
Answer: C. To improve stability and distribute loads to the supporting
surface
Rationale: Outriggers extend the crane's support base and transfer
loads to the ground through pads or floats. Proper deployment helps
stabilize the crane and reduce the likelihood of overturning.
5. What should be done if the actual weight of a load is unknown?
A. Lift it slowly to determine its weight
B. Assume the load weighs half its estimated weight
, C. Determine or reliably establish the load weight before lifting
D. Increase the crane's counterweight without checking the load chart
Answer: C. Determine or reliably establish the load weight before
lifting
Rationale: An unknown load weight presents a significant hazard
because the crane may be overloaded. The weight should be established
from reliable documentation, calculations, manufacturer information,
or an appropriate weighing method before the lift.
6. What is the main function of a crane's counterweight?
A. To increase the engine's horsepower
B. To help balance the crane against overturning moments created by
the load
C. To reduce the boom's length
D. To prevent sling abrasion
Answer: B. To help balance the crane against overturning moments
created by the load
Rationale: Counterweights provide a balancing moment that helps
maintain crane stability. They must be installed and configured
according to the manufacturer's requirements because incorrect
counterweight configuration can create serious hazards.
