Overhead Power Lines Kill When Equipment Gets Too Close
Confirm clearance before the boom ever swings
Contact with energized overhead power lines is a leading cause of electrocution on construction and utility sites. Cranes, aerial lifts, dump beds, and even hand-carried materials can bridge the gap to a line and send lethal current through anyone in the path. OSHA Scan analyzes job-site photos to flag equipment operating within dangerous clearance distances of overhead lines before the boom, mast, or load moves.
- Overhead line contact is any situation where equipment, a load, or a worker comes within the required clearance distance of an energized overhead power line. It shows up as a crane boom rotating beneath a distribution line, an aerial lift raised near service drops, a dump truck bed elevated under wires, or scaffolding and ladders erected too close to a line running along the property.
- In practice, these hazards appear when crews misjudge distance from the ground, when lines are assumed to be deenergized or insulated when they are not, or when an operator focuses on the load and forgets the line overhead. Wind-blown lines, sagging spans on hot days, and moving equipment across a site all change the clearance moment to moment, and a spotter is often missing when it matters most.
- The danger is that power lines give no warning before contact and the current does not require a direct touch — electricity can arc across an air gap to a boom or load. A worker touching the equipment or standing near the point of contact can be electrocuted through step and touch potential, which is why confirming clearance from a photo before work matters.
How far must a crane stay from overhead power lines?
Under 29 CFR 1926.1408, the default minimum clearance is 20 feet for lines up to 350 kV, with larger distances for higher voltages. The distance can be reduced only if the line is deenergized and grounded or specific protective measures and clearances are established.
Do power lines have to be touched to cause electrocution?
No. High-voltage electricity can arc across an air gap to a boom or load without direct contact. Anyone touching the equipment or standing near the point of contact can be injured through the equipment and the ground.
Are overhead lines insulated for safety?
Most overhead distribution and transmission lines are bare or only weather-coated, not insulated for contact. Never assume a line is insulated or deenergized; treat every overhead line as energized until the utility confirms otherwise.
Who determines the voltage and clearance distance?
The employer must determine the line voltage before work, usually by contacting the utility owner or operator, and then apply the correct minimum clearance distance. A dedicated spotter is required when equipment could breach the clearance zone.