Track Irregularities
Track Irregularities are precursor safety occurrences – events which could, under specific circumstances, lead to an accident. For example, an undetected broken rail leading to a train derailment.
Three subcategories of track irregularity are reported nationally under OC-G1 - broken rail, misaligned track and spread track.
Broken rails are cracks in, or complete breaks of, the track. They occur more frequently in the cooler months in response to expansion and contraction of the steel track. Misaligned track covers a broad range of irregularities including vertical and horizontal defects. Spread track comprises rails spreading beyond a tolerable limit and are generally associated with deteriorating timber sleepers. This type of defect may only become apparent when a train passing over the affected track forces the rails apart.
An important note about the definition of track irregularities. The definition and classification of track irregularities under OC-G1 is different to that of ON-S1. The graphs below now exclude track irregularities in yards and irregularities detected during maintenance.
The graph below displays the latest published data on track irregularities in NSW.
