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
What is the minimum clearance a machine must keep while working near an energized overhead power line rated up to 50 kV?
- 4 feet
- 6 feet
- 15 feet
- 10 feet
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D. 10 feet
For lines up to 50 kV, no part of the machine or its load may come closer than 10 feet, and the distance increases for higher voltages. Electricity can arc across a gap, so merely not touching the line is not enough.
Reference: 29 CFR 1926.600(a)(6); 29 CFR 1926.1408 Table A
Apart from an emergency stop, how many people should be signalling an operator at one time?
- Any two workers who agree
- Every worker near the machine
- One designated signal person
- One person on each side
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C. One designated signal person
Signals from more than one person conflict and confuse, so a single designated signal person directs the machine. The only exception is a stop signal, which anyone can give.
Reference: NCCER Heavy Equipment Operations Level 1, Heavy Equipment Safety