Why must a boom lift occupant wear a harness and lanyard even though the basket has guardrails?
- A bump or sudden boom movement can throw the occupant out
- The guardrails are only rated to hold tools and materials
- The lanyard keeps the basket from tipping forward
- The harness is needed to climb between basket and structure
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A. A bump or sudden boom movement can throw the occupant out
A long boom whips when a wheel drops in a hole or the lift is struck, and that catapult effect can launch a person over the rails. The lanyard keeps the occupant in the basket; it is not for climbing out.
Reference: 29 CFR 1926.453(b)(2)(v); ANSI/SAIA A92.22
In earthwork, what does shrinkage describe?
- Loaded soil settling in the truck bed during a long haul
- Stockpiled soil losing volume as it dries in the sun
- Compacted fill taking up less volume than the soil did in the bank
- Excavated soil taking up more volume in the truck than it did in the bank
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C. Compacted fill taking up less volume than the soil did in the bank
Compaction can pack soil tighter than nature left it, so a bank yard often makes less than a yard of compacted fill. The last choice describes swell, the opposite effect.
Reference: NCCER Heavy Equipment Operations Level 1, Introduction to Earthmoving
How does a skid steer loader turn?
- By pivoting the frame at a center hinge joint
- By turning the front axle with a steering gear
- By steering the rear wheels with a hydraulic cylinder and ram
- By driving the wheels on each side at different speeds
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D. By driving the wheels on each side at different speeds
The wheels on each side of a skid steer are driven independently, so slowing or reversing one side makes the machine skid around. Center-hinge (articulated) steering is how a wheel loader turns.
Reference: NCCER Heavy Equipment Operations Level 1, Identification of Heavy Equipment
A stake beside a hub reads C 2.5. What must be done at that point?
- Remove material to 2.5 feet below the hub
- Add fill material up to 2.5 feet above the hub
- Cut a slope of 2.5 to 1 from the hub
- Move 2.5 feet over before cutting
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A. Remove material to 2.5 feet below the hub
C means cut, and the figure is the vertical distance from the reference point (the hub) down to the planned grade. Reading the C as a fill would leave the grade 5 feet too high.
Reference: NCCER Heavy Equipment Operations Level 1, Grades
How should an operator check for a pinhole leak in a pressurized hydraulic hose?
- Run a bare hand slowly along the hose
- Pass a piece of cardboard or wood along the hose
- Wrap a rag around the hose and squeeze
- Hold a gloved hand close to the hose to feel for spray
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B. Pass a piece of cardboard or wood along the hose
A fine jet of hydraulic oil can pierce skin and gloves and cause a serious injection injury, so a piece of cardboard or wood is used to find the leak. A leather or cloth glove does not stop high-pressure oil.
Reference: NCCER Heavy Equipment Operations Level 1, Heavy Equipment Safety