The development of a condition-based maintenance (CBM) framework for freight locomotives – AC traction motors case study

Purpose The present work is a case study representing a condition-based maintenance (CBM) approach that can be implemented to either complement or completely replace any Time-based maintenance approach in the field of freight locomotives maintenance to allow triggering maintenance events when potential failures are detected and unlocking even greater benefits to enable the prediction of possible future issues on the locomotive before failures occur. Design/methodology/approach In this paper, the maintenance model of a diesel-electric freight locomotive that is primarily operated in harsh desert environments is analyzed with a particular focus on the alternating current (AC) traction motor, which is the most dominant component failure from the reliability point of view of this locomotive at the time of this study. A critical review of the current maintenance strategy is conducted including Weibull analysis, Failure mode and effects analysis and fault tree analysis using historical AC traction motors failure data over a 15-month period. Following this critical review is an improved maintenance approach with a summary of its implementation and benefits that relies on the deployment of sensors to detect anomalies in locomotive systems and subsystems by fusion or separate monitoring of parameters such as vibrations. Findings This study is expected to provide a greater understanding of the value gained from the application of CBM to diesel-electric locomotives in operation within harsh and hot desert environments, as well as other environments in general. Research limitations/implications Research at this stage is theoretical, nothing practical has been implemented. All conclusions drawn are limited until implementation is completed. Originality/value No such study has been undertaken previously in the field of freight locomotive maintenance in the manner that is followed in this paper, which will provide a framework for maintenance organisations to follow in the application of CBM to diesel-electric freight locomotive maintenance and demonstrate the potential value that can be gained from it.