An ATSB investigation has found that fatigue cracking in an XPT axle led to a minor derailment of an XPT passenger service from Melbourne to Sydney on 9 February 2006 at Harden.
The Australian Transport Safety Bureau investigation into the derailment concluded that train ST22 derailed as a result of the axle completely fracturing and eventually derailing one wheel.
Subsequent examinations by RailCorp, the train operator, led to the discovery of thirteen other XPT power car axles with surface defects, or cracks initiated by surface defects, in highly stressed areas.
The ATSBs examination of…