Health and Safety Resource

​August-September 2017

 

Accident Report

Event: Electric shock, electrocution
Industry: Residential construction
Worker: Siding installers

 

What happened?

Two workers were attempting to erect a 36-foot, seven-inch aluminum scaffold pole when the pole fell onto energized power lines.

photograph of accident scene

How did it happen?

Two workers started to set up a pump jack scaffold that they were going to use to install siding on a new two-story garage. They had been working at the site for a few weeks, installing siding on the other sides of the garage and expected this day to be just like the others.

The two workers stood on the concrete driveway and began to raise the first of two aluminum 36-foot, seven-inch aluminum scaffold poles while a third worker stood about 25 feet above them on the garage roof and guided the pole with a rope. One of the workers on the ground secured the pole’s rubber base plate while the other worker walked the pole up to a vertical position about three feet from the front of the garage.

After they successfully set up the first pole, they started to erect the second pole the same way.

However, as the two workers walked the pole up to a 45-degree angle, it slipped and tipped away from the garage toward a set of 20,800-volt power lines about 23 feet away. The worker on the roof was unable to stop the pole and let go of the rope just before the pole tipped into the power lines.

The two workers on the ground were still holding onto the pole as it slid along the energized lines and dropped into nearby trees. One of the workers was severely burned on his hands and feet. The other worker was electrocuted.

Findings

The foreman on site that day explained that he knew about the Oregon OSHA rule that required the workers to keep the scaffolding 10 feet away from power lines – but he thought that that the lines were at least 20 feet away. (The power lines were, in fact, 23 feet from the front of the garage, but each scaffold pole was 36 feet, seven inches long.)

The scaffold manufacturer’s instructions warned: “Watch For Wires,” “ALUMINUM CONDUCTS ELECTRICITY,” and “This product will conduct electricity, stay clear of all power lines or other sources of electricity.”

The business owner said he did not train his crew how to erect scaffolds. He explained that he relied on the past experience of his employees and that he had watched them erecting and using the scaffold and felt confident that they could work safely.

The workers did not use fall protection when they were on the scaffold and on the roof. The business owner explained that when his employees were installing the siding from the scaffold, they used a workbench that came with the scaffold as a guardrail. He said he didn’t know that a mid-rail and toe board were also required; however, the scaffold the manufacturer’s instructions said: “Do not use without guardrails, mid-rails, toe-boards and or fall-arrest system” and “Do not use a workbench as a substitute for … a guardrail system.”

Violations

  • 1926.451(f)(6) – Scaffolding, use: Scaffolds were erected, used, dismantled, altered, or moved such that they or any conductive material handled on them could come closer to exposed and energized power lines.
  • 1926.454(a)(2) – Scaffolding, Training requirements: Training did not include the correct procedures for dealing with electrical hazards and for erecting, maintaining, and disassembling fall protection systems.
  • 437-003-1501 – Fall protection: The employer did not ensure that fall protection systems were provided, installed, and implemented according to the criteria in 1926.502 – Fall protection systems criteria and practices.
​​  
​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​