Hello, I am James Smith a Safety Inspector with the Department of Labor and Industries, Division of Occupational Safety and Health. In September, 2009, I investigated a workplace incident involving an tree trimming worker who was electrocuted when his pole saw contacted a 7200-volt power line.
The worker, a 48 year old father of two, was trimming branches on this tree, he was secured with an arborist climbing saddle near the top of the tree about 20 feet above the ground, using a seven foot long pole chain saw. The power line can be seen above the tree. The larger lower lines are phone and TV cables.
These photos show the pole saw, essentially a small chain saw mounted on the end of long metal pole. The pole saw had a warning label, shown on the lower left photo about the hazard of using it near electrical power lines.
The power line was about seven feet above the tree where the worker was working, as shown by the power company's one foot increment measuring pole in this photo. It had not been de-energized before starting the tree trimming job. A computer animation of the incident is shown in the following slide.
When the worker raised up the pole saw, he hit the power line and then collapsed on top of the tree. The sound of the pole saw hitting the ground caught the attention of his co-workers. They yelled to him, asking if he was O.K. and he answered, “No, I'm not.” Since he was suspended by his harness in the top of the tree, the co-workers immediately grabbed a ladder to rescue him. One of the co-workers climbed above the injured worker to release his harness from the safety line [or lanyard]. In doing so, the co-worker climbed within ten feet of the same energized 7200-volt power line, exposing himself to the same electrical shock hazard. Paramedics arrived as the victim was lowered to the ground and transported him to the hospital where he later died.
The worker and his employer had discussed the power lines prior to starting the job. Even though the employer was well aware of the hazards of working near energized power lines, the power company had not been contacted to de-energize the lines and the worker had simply been told to be careful and keep his pole saw away from the power lines. Further, the worker was an unqualified arborist and had no training in line-clearance operations. The employer was cited and fined for allowing an employee to work and use an electrically conductive tool within 10 feet of an energized power line. Lets keep Washington safe and working by always having power lines de-energized before trimming trees within 10 feet of these power lines.