Questions and Answers
Which area do truck cranes without a 5th outrigger generally have no lifting capacity unless the manufacturer states otherwise?
What is the definition of 'operating radius'?
The distance from the center of rotation of the crane to the center of gravity of the load
What applies to the capacities below the bold line shown on a load chart?
In which quadrant are rough terrain crane capacities generally greater?
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What percentage do most manufacturers require a crane's load chart capacity to be reduced by for duty cycle operations?
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From which two points should the boom be measured?
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What is the preferred method of installing wire rope from a reel onto a hoist drum?
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Over which quadrant are truck crane capacities usually greater?
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According to OSHA, which accessible area of an operating crane must always be barricaded?
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What is the OSHA regulation governing cranes in construction?
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According to ASME, what percentage of the manufacturer's crane rating must not be exceeded if a load test is done on a repaired crane?
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Where is the tipping axis of a crawler crane located?
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What should be done with materials placed under overhead energized power lines?
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What determines the amount of deduction required for an erected jib that is not being used?
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What happens to ground bearing pressure if you move a crawler crane from soft ground to harder ground?
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How should the wheels of a crane be positioned when it is set up for working on outriggers?
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Where are the Standard Method hand signals found?
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A truck crane is set up on outriggers. The part of the load chart governed by stability is based on what percentage of the crane's capacity?
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Truck crane capacities are usually greater over the _________
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If the operator makes two audible signals when moving a crane, he/she intends to ______________
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Blocking (cribbing) may be placed under outrigger beams.
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Timber blocking placed under the tips of the tracks on a crawler crane will:
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What is the primary purpose of placing blocking under the ends of the tracks on a crawler crane?
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Suppose you are traveling a crawler crane with the drive trains to the rear, and you need to turn right on hard, level ground. What should you do?
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When using outrigger jacks to level a crane, what is the best procedure to follow?
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How does the use of outriggers increase the tipping capacity of a crane?
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Many load charts for cranes state that the area of least stability is over the side. What statement explains this the best?
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Study Notes
Truck Crane Operations
- Truck cranes without a 5th outrigger typically have no lifting capacity in the front area unless specified by the manufacturer.
- Operating radius is defined as the distance from the crane's center of rotation to the load's center of gravity.
Load Chart Capacities
- Capacities below the bold line on a load chart reflect the stability of the crane.
- Rough terrain cranes generally have greater lifting capacities over the front quadrant.
Duty Cycle Operations
- Manufacturers typically require a 20% reduction in crane load chart capacity for duty cycle operations, such as high-volume concrete placements.
Boom Measurements
- Boom measurements are made from the boom hinge pins to the center of the boom tip sheave.
- Preferred installation method for wire rope involves running the rope from the top of the reel to the top of the hoist drum.
Safety Regulations
- According to OSHA, the swing radius at the rear of a rotating superstructure must always be barricaded.
- OSHA regulation 1926.1400 governs crane operations in construction sites.
Crane Testing and Ratings
- ASME specifies that a repaired crane should not exceed 100% of the manufacturer's rated load during tests.
- The tipping axis of a crawler crane depends on whether the idler or sprocket is in line or offset from the track rollers.
Safety Precautions
- Materials near energized power lines should not be lifted with cranes.
- The deduction for an unused jib is based on its effective weight.
Ground Conditions
- Ground bearing pressure increases when a crawler crane is moved from soft to harder ground.
- When setting up a crane on outriggers, its wheels should be elevated just enough to relieve weight from the tires.
Load Chart and Stability
- Stability governs 85% of the load chart capacity for a truck crane set on outriggers.
- Truck crane capacities are typically greater over the rear quadrant.
Communication Signals
- Two audible signals from the operator indicate the intention to proceed with the operation.
Outrigger and Stability
- Blocking or cribbing under outrigger beams is not permitted.
- Timber blocks under crawler crane track tips enhance stability and ensure the tipping axis is aligned with the sprocket or idler.
Crawler Crane Maneuvering
- When maneuvering a crawler crane with rear drive trains, traveling the left track forward minimizes wear.
- The best leveling procedure with outrigger jacks involves making firm contact with all jacks and adjusting two at a time on either side of the lowest corner.
Tipping Capacity
- Outriggers enhance tipping capacity by moving the tipping axis away from the crane's center of gravity.
- The area of least stability for many cranes is over the side, as the distance between the center of gravity and the tipping axis is smallest there.
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Description
Prepare for the NCCCO certification with these flashcards covering essential crane operation concepts. Test your knowledge on lifting capacities, operating radius, and load charts to ensure you are well-prepared for your final exam.