Surface Construction Sand & Gravel - A miner was moving an excavator from the pit to an area where the mechanic could work on a loose bucket attachment pin. As the excavator was traveling parallel to overhead 4160 volt powerlines the pin came loose. The operator swung the boom to the right to avoid dropping the bucket in the path of travel. In doing so, the boom came close enough to overhead powerlines that an arc occurred.
- Ensure safe access is available when moving equipment.
- Keep booms/beds/buckets on mobile equipment stowed in safe travel mode to avoid coming into contact with energized power lines and overhead obstructions
- Correct deficiencies on mobile equipment before movement or placing it into service.
- Ensure that potentially hazardous conditions such as overhead powerlines are conspicuously marked.
- Deenergize overhead powerlines if there is a possibility of an arc when mobile equipment is operating or traveling nearby.