Monitoring rail profile wear with meaningful performance indicators

Introduction

Despite the general recognition of the benefits of adopting performance-based rail monitoring and management programmes, knowledge gaps still remain in terms of: (1) the selection of relevant indicators of rail condition and performance; (2) deterioration rates and the thresholds that trigger maintenance interventions; and (3) the effectiveness of rail grinding in prolonging the life of rail assets. The availability of quality, representative, and timely data underpins efforts in research and practice to close these knowledge gaps, especially as rail asset managers strive toward preventive, rather than corrective, grinding strategies. While grinding serves a variety of objectives, the performance indicators (PIs) described in this article relate specifically to the maintenance of a desired rail profile (i.e., the cross-sectional shape of the rail head) (see Figure 1).

Inventory of rail profile performance indicators

A comprehensive review of performance indicators (PIs) related to rail profile maintenance practices revealed eight of particular relevance¹. Of these, three – head loss, vertical wear, and gauge wear – relate specifically to the shape of the railhead and are well-established in the industry. The grind quality index (GQI) and profile quality index (PQI) focus on measuring grinding effectiveness. The final three indicators – average rail profile, lateral contact position, and contact radius – have emerged from recent research and, consequently, have seen more limited application to date. Figure 1 provides illustrations for six of the performance indicators described hereafter.