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).