Crane Electrocution Accident after Crane Boom Contacted Electrical Power Line Worker Killed when he Grabbed Door Handle of Crane
Crane Accident Electrocution Accident
A 24-year-old foreman for a telecommunications company was electrocuted when he grabbed the door handle on a truck-mounted crane whose boom was in contact with a 7,200-volt overhead power line. The foreman and three other workers (a lineman, a cable splicer, and a laborer) were attempting to remove four poles that had supported a billboard. The poles stood 20 feet high and were buried 5 feet in the ground. They were located 15 feet away from (and parallel to) the power line. To remove the poles, the lineman positioned the crane directly under the power line. He controlled the crane boom while standing on the ground using rubber-coated hand controls mounted on the back of the truck. The poles were removed by hooking the crane boom cable around the middle of each pole and vertically pulling each pole out of the ground. While the workers were pulling out the third pole, the end of the boom contacted the overhead power line.
The laborer (who was working in the back of the truck) noticed that the lineman was being shocked and was unable to let go of the hand control. The laborer kicked the lineman in the chest and the lineman fell unconscious to the ground. He revived without assistance about 3 minutes later with electrical burns to his left hand. However, the crane boom remained in contact with the power line, the truck tires ignited, and the truck began to burn. When the foreman noticed that the boom remained in contact with the power line, he tried to open one of the truck doors (presumably to move the truck). When his hand contacted the door handle, he provided a path to ground and was electrocuted
ANSI Standard – Crane Electrocution Prevention
The American National Standards Institute (ANSI) has published a standard for mobile and locomotive cranes that includes operation near overhead power lines [ANSI 1994]. This consensus standard (B30.5-1994) contains guidelines for preventing contact between cranes and electrical energy. The standard addresses the following issues:
* Considering any overhead wire to be energized unless and until the person owning the line or the utility authorities verify that the line is not energized
* De-energizing power lines before work begins, erecting insulated barriers to prevent physical contact with the energized lines, or maintaining safe clearance between the energized lines and boomed equipment
* Limitations of cage-type boom guards, insulating links, and proximity warning devices
* Notifying line owners before work is performed near power lines
* Posting warnings on cranes cautioning the operators to maintain safe clearance between energized power lines and their equipment
Crane Accident Electrocution after Crane Cable Contacted Electrical Power Line
Crane Accident Electrocution Facts
A 29-year-old worker was electrocuted when he pushed the crane cable on a 1-yard cement bucket into a 7,200-volt power line. The victim was a member of a crew that was constructing the back concrete wall of an underground water-holding tank at a sewage treatment plant. Before work on the tank began, the company safety director made sure that insulated line hoses were placed over sections of the power line near the jobsite and that a safe clearance zone was marked off for arriving cement trucks to use for loading their cement buckets.
After the wall was poured, the driver of the cement truck cleaned the loading chute on his truck with a water hose mounted on the truck. As he began to pull away, the crew supervisor yelled to him, asking if the crew could use his water hose to wash out the cement bucket suspended from the crane. The driver stopped the truck under the power line and the crane operator (not realizing that the truck had been moved) swung the boom to position the bucket behind the truck. The victim grasped the handle of the bucket door and pushed down to open it, bringing the crain cable into contact with the power line. The victim provided a path to ground and was electrocuted.
Crane Boom Contact Accident Two Killed
A 20-year-old male truck driver and his 70-year-old male employer (the company president) were electrocuted when the boom of a truck-mounted crane contacted a 7,200-volt conductor of an overhead power line. The incident occurred while the driver was unloading concrete blocks at a residential construction site. The driver had backed the truck up the steeply sloped driveway under a power line at the site and was using the crane to unload a cube of concrete blocks. The company president and a masonry contractor watched as the driver operated the crane by a handheld remote-control unit. The driver was having difficulty unloading the blocks because the truck was parked at a steep angle.
While all three men watched the blocks, the tip of the crane boom contacted a conductor of the overhead power line and completed a path to ground through the truck, the remote control unit, and the driver. The company president attempted to render assistance and apparently contacted the truck, completing a path to ground through his body. He died on the scene. The truck driver was airlifted to a nearby burn center where he later died as a result of electrical burns.