Abstract

The rail operator in South Africa is currently facing a challenge related to motor alternator failures in electric locomotives that operate between Durban and Johannesburg. A study was conducted to identify the causes of motor alternator failures in a locomotive between Johannesburg and Durban using Failure Mode and Effects Analysis (FMEA). A focus group of 13 participants was used to gather the necessary data. The study found 35 root causes, with the top 20% responsible for 80% of failures. The major causes identified included overhead sparks, inconsistency in overhead voltage, insulation failure, slow speed, bearing quality, humidity, defective rivets, and deterioration of windings. Sparks in overhead railway catenaries are mainly caused by impulsive noise, whereas voltage inconsistency can be caused by dynamic stiffness, wind-induced vibrations, high winds, geometric parameters, faults, and environmental influences. Insulation failure in electrical systems can be caused by factors such as space-charge accumulation, partial discharge, thermal loading conditions, high-temperature exposure, moisture, material degradation, and electrical treeing. Based on this study, it is recommended to develop a maintenance strategy to detect challenges in advance and to implement an overhaul program to address system deterioration.