You are planning to use a mobile crane with a 150-foot boom to lift materials to the 12th floor of a building under construction. What is the minimum distance the crane must maintain from overhead power lines carrying 50kV?
Correct Answer
A) 20 feet
For power lines carrying 50kV, OSHA requires a minimum clearance of 20 feet for crane operations to prevent electrical contact and electrocution hazards.
Why This Is the Correct Answer
OSHA 1926.1408 establishes specific minimum clearance distances for crane operations near overhead power lines based on voltage levels. For power lines carrying 50kV, the regulation mandates a minimum clearance of 20 feet to prevent electrical arcing and electrocution hazards. This clearance distance accounts for the electrical field around high-voltage lines and provides a safety buffer for crane boom movement and potential electrical discharge.
Why the Other Options Are Wrong
Option B: 10 feet
35 feet exceeds the minimum OSHA requirement for 50kV lines, though it would be safer, it's not the minimum distance required by regulation.
Option C: 15 feet
10 feet is insufficient clearance for 50kV power lines and would create a serious electrocution hazard, as this distance is only appropriate for much lower voltage lines.
Memory Technique
Use '50kV = 20 feet' as a key reference point, with lower voltages requiring less clearance and higher voltages requiring more clearance in the OSHA table.
Reference Hint
OSHA 1926 Subpart CC - Cranes and Derricks in Construction, specifically 1926.1408 Power line safety
More Project Mgmt Questions
What is the minimum R-value required for wall insulation in Florida Climate Zone 2?
A subcontractor brings a new chemical product to your jobsite. Under the Globally Harmonized System (GHS), what information must be immediately available to workers?
A construction site has a trench that is 8 feet deep in Type B soil. What is the maximum allowable slope ratio for the trench walls without protective systems?
What is the maximum recommended spacing between drywall screws when attaching to wood studs?
Your crew discovers suspected asbestos-containing materials during a renovation project. What is the first action you should take?
A scaffold platform is 12 feet long and 5 feet wide. If the maximum load capacity is 25 pounds per square foot, what is the total weight capacity of this platform?
Which CSI MasterFormat Division would contain specifications for fire-stopping and firesafing materials?
In tilt-up concrete construction, what is the primary advantage of this method over conventional cast-in-place construction?
Which OSHA standard specifically addresses construction industry safety and health regulations?
A structural drawing shows a beam labeled 'W12x26'. What does the '26' represent?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass