Construction Lockout Tagout

Case Study: The National Institute for Occupational Safety and Health (NIOSH) Fatality Assessment and Control Evaluation program investigated an incident in which a millwright was fatally injured because of an uncontrolled release of energy while he was repairing a debarker. The teeth on the debarker feed rolls had become worn, and the worker had been assigned to weld additional metal to build up the feed roll teeth. He had not made this type of repair before.

To safely de-energize this machine, six electrical sources and one pneumatic energy source needed to be disconnected and locked out. Also, the pressure in the air line that automatically controls the up and down motion of the feed rolls needed to be bled off. The victim disconnected and locked out two of the electrical sources, but he did not disconnect and lock out the other four electrical sources or the pneumatic energy source. He also did not bleed off the pressure in the air lines. In this condition, the machine's automatic control system remained energized. As the victim welded metal to the feed roll teeth, he leaned forward and placed his head between the feed rolls to reach areas that required more metal. The feed rolls automatically cycled and closed over his head.