NCCCO Hazard Identification and Power Line Safety 5 — Questions and Answers
Question 1: What is the purpose of an 'encroachment prevention device' when working near power lines?
- It insulates the crane boom to allow contact with lines
- It provides an audible or visual warning before the crane reaches the minimum approach distance (Correct answer)
- It automatically shuts off the crane engine upon contact
- It measures the load weight to prevent overloading near power lines
Correct answer: It provides an audible or visual warning before the crane reaches the minimum approach distance
Encroachment prevention devices warn the operator before the crane's components reach the established minimum approach distance to energized lines.
Question 2: Under NCCCO standards, who is responsible for ensuring that a pre-work hazard assessment addressing power line proximity is completed before crane operations begin?
- The utility company representative only
- The qualified rigger on the crew
- The employer and/or the person in charge of the operation (Correct answer)
- The crane manufacturer's field representative
Correct answer: The employer and/or the person in charge of the operation
The employer and the person in charge of the operation share responsibility for conducting and documenting hazard assessments before lifting operations begin.
Question 3: If a crane's load line swings and contacts an energized power line, which path is electricity most likely to take to reach ground?
- Through the load directly to the rigger's hands
- Through the load line, crane structure, outriggers, and into the ground (Correct answer)
- Through the crane cab's air conditioning system
- Through the crane's hydraulic fluid lines only
Correct answer: Through the load line, crane structure, outriggers, and into the ground
Electricity will travel through the conductive load line and crane structure down through the outriggers or tires into the earth, energizing the entire crane.
Question 4: According to OSHA 1926.1407, before beginning crane operations, the operator must determine the location of all power lines within what distance of the intended swing radius?
- 5 feet
- 10 feet
- 50 feet (Correct answer)
- 100 feet
Correct answer: 50 feet
OSHA requires surveying and identifying all power lines within 50 feet of the equipment's intended swing radius before operations begin.
Question 5: A crane is working in a location where the exact voltage of nearby power lines is unknown and cannot be obtained. What minimum approach distance must be used?
- 5 feet
- 10 feet
- 20 feet (Correct answer)
- 50 feet
Correct answer: 20 feet
When line voltage is unknown and cannot be determined, OSHA requires a minimum approach distance of 20 feet until the voltage is confirmed.
Question 6: What action must a crane operator take if they lose sight of the designated spotter during operations near power lines?
- Continue at reduced speed and watch the lines personally
- Stop operations immediately until communication with the spotter is re-established (Correct answer)
- Switch to radio communication and proceed at half speed
- Have the signal person assume the spotter's role temporarily
Correct answer: Stop operations immediately until communication with the spotter is re-established
Loss of visual or communication contact with the assigned power line spotter requires an immediate halt of all crane movement until proper monitoring is restored.
Question 7: Which of the following is an example of a 'proximity hazard' that a crane operator must identify during a pre-operation site survey?
- The rated capacity of the load hook
- Overhead power lines, energized substations, or electrified rail systems near the work area (Correct answer)
- The weight of the counterweight assembly
- Wind load tables in the crane's load chart
Correct answer: Overhead power lines, energized substations, or electrified rail systems near the work area
Proximity hazards include any energized electrical infrastructure — power lines, substations, or electrified rail — that the crane or its load could contact.
NCCCO Hazard Identification and Power Line Safety 5
What is the purpose of an 'encroachment prevention device' when working near power lines?