At About 6:30 pm on the 3rd of November 2018,
two tyre fitters at the Bengalla Coal Mine
were tasked with replacing a water cart’s damaged rear earthmoving tyre.
One of the fitters removed the tyre,
rotating the tyre in the grabs
from a vertical to a horizontal position,
using an Omega tyre handler.
He drove the tyre handler, with the tyre in its grabs,
to the heavy vehicle wash bay to clean the rim.
He positioned the tyre handler on a wash pad,
with the grabs and tyre facing a high-pressure water cannon,
fixed to an elevated work platform.
The tyre was then positioned vertically and suspended.
The fitter used the fixed high-pressure water cannon to clean the rim.
During this process, the fitter left the elevated work platform
and entered the restricted work zone, to likely retrieve a handheld hose.
After hearing a thud and not being able to see his co-worker,
the second fitter walked over to the heavy vehicle wash bay.
He found the fitter trapped under the tyre, in a restricted work zone.
He called for help and an emergency response was activated.
The investigation identified that the tyre fitting contractor had cleaning procedures
that required the tyre to be placed on a flat surface
in the tyre bay service area, with the tyre handler isolated.
The approved cleaning methods included the use of a grinder, a scraper and a wire brush.
The Regulator’s investigation into the incident
found that fitters only rely on visual cues,
observing bulges in tyre walls
to ensure that the tyres are sufficiently secured in the grabs of the tyre handler during operation.
The investigation determined that the actual force required
to sufficiently hold the tyre involved in the incident
was 70 kilonewtons.
However,
an examination of the tyre handler indicated
the likely force applied to the tyre at the time of the incident
was only 40 kilonewtons
- or almost half the pressure required.
The investigation also found that the grabs were in a horizontal orientation.
This resulted in a smaller surface area between the grip face and the tyre surface.
However, the investigation was unable to determine
whether this materially contributed to the tyre becoming dislodged.
For more information and to see the full report, visit our website.