Risk-Based Maintenance Planning for Rail Fastening Systems

Failures in rail fasteners can lead to misalignments of the rails and even cause a train derailment. 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 opportunities, a risk-based maintenance philosophy, driven by a risk management framework, is proposed for rail fasteners. The framework was primarily developed from international standards alongside high-level industry guidelines. Reliability tools were then incorporated, 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 embedded 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., embedded anchors, the failure modes of which are dependent on time); thereby, the time frames in which risk for the component transits to different 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 to other failure modes.