Summary of incident
In January 2018, an unloaded autonomous truck was ascending a ramp when it was struck by lightning. The strike caused the position 2 tyre (front right) to explode, resulting in extensive damage to the upper structure of the truck including the deck, autonomy cabinet, engine and cab. An exclusion zone was maintained until it was ascertained that the area was safe for inspection and recovery planning. No workers were injured.
Note: Preliminary findings from a tyre specialist concluded that the explosion was caused by extensive pyrolysis (chemical decomposition by heat). There was no pre-existing tyre damage that contributed to the event.
Direct causes
Lightning struck the truck, causing pyrolysis of the tyre (resulting in an explosion).
Contributory causes
The hazards associated with lightning were not identified (e.g. working during periods of likely lightning activity, the potential effects of a lightning strike on a vehicle).
Actions required
Review the risk assessments for the use of all vehicles (manned and autonomous) during storms, or where there is a possibility of lightning strikes, and confirm they identify the hazards and risks to workers and equipment from lightning strikes.
- Adequately control the hazards and risks relating to lightning strikes, to reduce the exposure of workers to potential harm.
- Review the work procedures relating to working when there is a potential for exposure to lightning, to confirm the procedures are in line with the outcomes of risk assessments.
Further information
Department of Mines, Industry Regulation and Safety, Mining safety publications,
www.dmp.wa.gov.au/Safety/Mining-Safety-publications-16162.aspx
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