Nationwide, electrocutions caused by a crane, rigging, load, or load line contacting an overhead power line have resulted in numerous injuries and fatalities. In most incidences of power line contact, the workers are aware that power lines were present. Following the safety rules for operating cranes near power lines would likely have prevented contact. Remember – electricity will always seek a path to ground! The dynamics of electrical energy determine the path electricity will take and any conductive material is a likely path. Many factors such as voltage, amperage, resistance, and duration will affect the path, but the bottom line is the human body is conductive enough for electricity to go through while seeking ground.
How can I prevent power-line contact on my work sites?
Keeping a safe distance from a power line is the key to preventing power line accidents. Always assume power lines are energized! When planning to operate a crane on a site where power lines are present you must identify the crane’s work zone and use that work zone to determine how close it could get to that power line.
Could the crane get closer than 20 feet to a power line?
Keeping a safe distance from a power line is the key to preventing power line accidents. The first step you must take when planning to operate a crane on a site where power lines are present is to identify the crane’s work zone and use that work zone to determine how close it could get to that power line. It’s important to establish the boundaries of your work zone using flags or a range control warning device or range limit device and prohibit the operator from working outside those boundaries. If you do NOT establish boundaries, then the work zone is not limited to where you intend to work but where the crane, load, or load line can reach! Note: If the voltage is over 350,000 volt, then a 50-foot minimum clearance must be maintained. If you determine the equipment will operate within reach of the minimum clearance distance, then you must take steps to prevent contact with power lines by using encroachment/ electrocution prevention methods outlined in WAC 296-155-53408(2)(b). If your work zone is inside the minimum approach distance, there are additional precautions that must be taken. You must have the power-line owner/ operator determine the absolute minimum clearance.
Know the safety rules to prevent overhead contact with power lines.
Many construction activities use cranes to move materials to various locations, and in most cases, there are electrical power lines in the vicinity. To prevent power-line accidents, Washington State’s new construction crane rules contain detailed systematic procedures that employers must follow when operating cranes near power lines. These procedures are designed to prevent equipment from making electrical contact with power lines and protect workers in the event that such contact occurs. For more information, please see the Construction Crane link on the L&I website: www.Lni.wa.gov/ Safety/Topics/AtoZ/Cranes.