The trailing bogie of wagon RCPF31882C was found to have loose and broken wedge wear plates. It could not be verified whether the wedge wear plates had broken free before or during the derailment sequence. However, if the condition had existed prior to the derailment, it is likely that body roll induced while traversing a series of track irregularities could result in undamped harmonic oscillations.
The trailing bogie of wagon RCPF-31882C was found to have loose and broken wedge wear plates. While it could not be verified whether the wedge wear plates had broken free before the derailment or during the derailment sequence, if the condition had existed prior to the derailment, it is likely that body roll induced while traversing a series of track irregularities could result in un-damped harmonic oscillations. The ATSB recommends that the Pacific National Pty Ltd should address this safety issue.
PNL has train examination procedures in place for these items. It is also included in the new version of the Pacific National Wagon Pocket Field Manual.
The ATSB is satisfied that the intended action by PNL would adequately address the safety issue.
