Risk-based maintenance planning for rail fastening systems

Failures in rail fasteners can lead to misalignments of the rails and even cause a train derail-ment. Current inspection and maintenance regimes for rail fasteners, however, do not adequately address the credible failure modes found in the field. In response to these improvement opportu-nities, a risk-based maintenance philosophy, driven by a risk management framework, is proposed for rail fasteners. The framework is primarily developed from ISO 31000 with underlying principles inferred from other applicable international standards. Reliability tools were then in-corporated, allowing practitioners to arrive at an appropriate combination of reliability tools based on the circumstances under which the assessment is to be conducted. Monte Carlo simulations were undertaken on the imbedded anchors of rail fasteners to demonstrate how the resultant framework can be innovatively adopted in practice. The general findings highlight that accurate risk depiction is vital for track components (e.g. imbedded anchors, the failure modes of which are dependent on time), thereby, the timeframes at which risk for the component transits to dif-ferent risk categories should be obtained. Note that the finding is unique to the example; thus, the proposed risk framework should be treated carefully before it is applied for other failure modes.