NCCCO Mobile Crane Operator Test 2 — Questions and Answers
Question 1: What action does a signal person intend the operator to perform if he extends his arm at shoulder height, makes a fist with his hand, and sticks his/her thumb up?
- Swing
- Boom up (Correct answer)
- Extend boom
- Boom down
Correct answer: Boom up
The hand signal described – extending the arm at shoulder height, making a fist, and sticking the thumb up – is the universally recognized standard signal for 'Boom up' in crane operations. This clear and consistent signal ensures effective communication between the signal person and the crane operator, enhancing safety on the job site.
Question 2: When hoisting personnel, within what percentage of level must a telescopic boom crane be in order for the gross ratings in the load chart to remain valid?
- 2%
- 5%
- 8%
- 1% (Correct answer)
Correct answer: 1%
When hoisting personnel, maintaining precise levelness is critical for safety and to ensure the validity of the crane's load chart ratings. A telescopic boom crane must be level to within 1% of grade, as even minor deviations can significantly impact stability and the accuracy of the lift, posing a serious risk to personnel.
Question 3: The load line of the crane you're operating contacts an energized power line. There's no sign of any other danger, such as fire. What should you do?
- Stay in the cab until the lines are de-energized (Correct answer)
- Get as far away from the crane as possible
- Climb down carefully from the crane cab
- Jump down, feet together
Correct answer: Stay in the cab until the lines are de-energized
If a crane's load line contacts an energized power line and there is no immediate danger like fire, the safest course of action is for the operator to remain in the cab. The cab provides a degree of insulation, and exiting could expose the operator to dangerous step and touch potentials, which can be lethal.
Question 4: According to OSHA 1926.1413, how many randomly distributed broken wires in rotation- resistant rope are cause for replacement of the rope?
- 2 broken wires in 30 rope diameters
- 1 broken wire in 6 rope diameters
- 2 broken wires in 6 rope diameters (Correct answer)
- 3 broken wires in one strand in one lay
Correct answer: 2 broken wires in 6 rope diameters
According to OSHA 1926.1413, rotation-resistant wire rope must be replaced if there are two randomly distributed broken wires in six rope diameters. This specific criterion indicates significant wear and potential for failure, necessitating replacement to maintain the integrity and safety of the rope.
Question 5: What is the net capacity of a crane on main boom unless the manufacturer states otherwise?
- The capacity listed in the load chart minus the weight of the rigging and all attachments not in use
- The capacity listed in the load chart minus the weight of the rigging and all attachments (Correct answer)
- The capacity listed in the load chart minus the weight of the rigging alone
- The capacity listed in the load chart plus the weight of the rigging and all attachments
Correct answer: The capacity listed in the load chart minus the weight of the rigging and all attachments
The net capacity of a crane is the actual weight it can safely lift, which is determined by subtracting the weight of all rigging and attachments (like hooks, slings, and headache balls) from the gross capacity listed in the load chart. This calculation ensures that the total weight being supported by the crane's boom and hoist system does not exceed its safe working limit.
Question 6: What may happen to a properly rigged load when lifted off the ground unless the operator takes account of boom deflection?
- It could shift in its rigging
- It could swing out away from the crane (Correct answer)
- It could swing out away from the crane
- It could raise absolutely vertically
Correct answer: It could swing out away from the crane
When a load is lifted, the crane's boom will naturally deflect or bend slightly under the weight. If the operator does not account for this boom deflection, the load will swing out away from the crane as it is lifted, increasing the operating radius and potentially exceeding the crane's stability limits or rated capacity.
Question 7: Who should an operator respond to a "stop" signal from?
- Anyone (Correct answer)
- Superintendent only
- Appointed signal person only
- Project manager only
Correct answer: Anyone
A 'stop' signal is an emergency signal that takes precedence over all other signals in crane operations. Any person who observes an unsafe condition or potential hazard can give a stop signal, and the crane operator is required to respond immediately, regardless of who gives the signal, to prevent accidents.
Question 8: What is the definition of "operating radius"?
- The distance from the center of rotation of the crane to the center of the load
- The distance from the base of the boom to the center of the load
- The distance from the center of rotation of the crane to the center of gravity of the load (Correct answer)
- The distance from the front of the crane to the center of gravity of the load
Correct answer: The distance from the center of rotation of the crane to the center of gravity of the load
The operating radius is a critical measurement defined as the horizontal distance from the crane's center of rotation to the center of gravity of the load. This distance is essential for accurately determining the crane's lifting capacity from the load chart, as capacity significantly decreases with an increasing operating radius.
Question 9: According to federal requirements, under what conditions is it okay for a person to ride the headache ball?
- When other means would be more dangerous
- When there is no other way to gain access
- When the lift has been approved by an engineer
- It is never okay (Correct answer)
Correct answer: It is never okay
According to federal regulations, specifically OSHA standards, it is strictly prohibited for any person to ride on the headache ball or any other load-handling device. This practice is considered extremely dangerous due to the high risk of serious injury or fatality from falls or being struck by the load.
Question 10: According to OSHA, which accessible area of an operating crane must always be barricaded?
- The carbody or chassis
- The swing radius of the rear of the rotating superstructure (Correct answer)
- The distance between the car body or chassis and the boom tip
- The swing radius of the crane
Correct answer: The swing radius of the rear of the rotating superstructure
OSHA regulations require that the swing radius of the rear of the rotating superstructure of an operating crane must always be barricaded. This is a critical safety measure to prevent personnel from being struck or crushed by the rotating counterweight, which poses a significant and often unseen hazard on job sites.
Question 11: What is the OSHA regulation governing cranes in construction?
- 1926.1400 (Correct answer)
- 1926.556
- 1910.184
- 1910.180
Correct answer: 1926.1400
OSHA regulation 1926.1400 is the specific federal standard that governs cranes and derricks in construction. This comprehensive regulation outlines the safety requirements for the operation, inspection, maintenance, and training associated with crane use on construction sites to ensure worker safety.
NCCCO Mobile Crane Operator Test 2
What action does a signal person intend the operator to perform if he extends his arm at shoulder height, makes a fist with his hand, and sticks his/her thumb up?