A concrete truck hit a 13.2 KV overhead powerline which broke the latter and fell on the cab of a tractor trailer truck, according to a report by the Mine Safety and Health Administration (MSHA). The driver of the tractor trailer remained inside the cab until the powerline was de-energised. There were no injuries from the close call accident.
MSHA has issued best practice guidelines following the incident.
- Overhead high-potential powerlines shall be installed as specified by the National Electrical Code.
- High-potential powerlines should be visually examined by the mine operator to determine if clearances over roadways, parking lots, walkways or other areas accessible to people may create a hazard.
- Clearances of high-potential powerlines above roadways, parking lots and walkways should generally be greater than 18.5 feet.
- Locate all overhead powerlines during a workplace examination.
- Keep people and equipment 10 feet away from all overhead powerlines.
- Lower equipment apparatus before driving under overhead powerlines.
- Do not touch anything that is in contact with an overhead powerline.
- Stay at least 35 feet away from fallen powerlines.
- If a powerline has fallen within 35 feet of your location, and you are not exposed to direct contact, do not move until power is removed. Step potential can be fatal or cause serious injury.