Friday, September 20, 2019

Safety Message: Track Condition and Derailment Risk

ONRSR is emphasising to all Rail Infrastructure Managers (RIMs) the increased risks posed by poorly maintained track following a series of recent derailments, particularly on freight networks. In some cases multiple derailments have taken place within the same track section in a three-month period.

Investigations by ONRSR Rail Safety Officers have identified that degraded track conditions, particularly on downhill grades, are a key contributory causal factor in these incidents.

Furthermore the continued presence of deficient track conditions raises the potential for further incidents to occur.

Track infrastructure considerations that a RIM should address during assessments to eliminate or minimise the risk of derailment will include:

• Presence of an appropriate ballast specification
• Efficiency of drainage within deficient ballast
• Remedial correction to “boghole” or “wet bed” conditions
• Broken or defective timber sleepers, especially at rail joints
• Loose rail-sleeper fastenings assemblies
• Corroded and/or pitted rail
• Removal of rail defects within specified remedial limits
• Management of rail head profile

Many of these causal factors will be exacerbated during periods of significant rainfall or temperature changes that occur seasonally throughout Australia.

Good practice would see a RIM establish and implement Technical Maintenance Plans (TMP) for the management of infrastructure under their responsibility. In addition to regular maintenance activities, these should include specific instruction for the effective management of infrastructure or situations that are not a standard installation or environmental situation.

Significant sections of rail network across Australia contain items of infrastructure that have been in service for over 100 years and that may no longer be compliant with current requirements. These in particular require an assessment of their performance integrity and an appropriate TMP to be in effect where required.

RIMs are encouraged to consider this advice during the performance of their maintenance activities. Due diligence of RIM responsibilities will be to periodically review assessment criteria and management of risk associated with ageing track infrastructure that may already be subject to axle load limits and/or speed restrictions.

This advice is effective immediately.