A load of gravel was being delivered to a farm. After dumping the load as directed by the farmer, the driver moved the
truck forward with its box still raised. As the truck was moving forward, the box contacted an overhead high-voltage
power line. The driver saw sparks, stopped the truck, and jumped from the truck. Fortunately, the truck had broken
contact by then and he was not injured.
All 10 of the tires on the truck had burn marks on them where the power went to ground. One front tire, a balloon-type
tire, exploded, resulting in the aluminium wheel, bearings, and brake shoes being blown up to 12 metres (40 feet) away,
along with parts of the grill.
Safe work practices:
- Check for overhead hazards before raising the box.
- Keep your vehicle a safe distance from overhead power
lines. The distance varies with the voltage:
| Voltage |
Minimum distance |
Over
750 V to 75 kV |
3 metres
(10 feet) |
| 75 kV to 250 kV |
4.5 metres
(15 feet) |
|
Over
250 kV to
550 kV
|
6 metres (20 feet) |
- Contact the owner of the power utility if you cannot
maintain the required minimum distance from the power
line. The power lines may need to be rerouted, de-energized,
or identified and guarded.
