A bus operator reported earlier this year that a fire had occurred in the roof cavity of a coach causing significant damage to it.
The operator’s investigation into the cause of the fire identified the main wire to the air-conditioning unit had frayed due to rubbing against a metal frame.
The wire’s protective casing eventually wore away causing the internal wire to arc on the metal frame, resulting in sparks igniting combustible material inside the roof cavity.
The Safety Director has on several occasions issued Safety Alerts stressing the importance of inspecting wiring looms.
This incident highlights that no matter where a wiring loom is located, it must be inspected to ensure it is securely fastened.