Risk based inspection for rail vehicle gearboxes

Challenge
ESR Technology’s client identified an opportunity to reduce the cost of maintenance for its vehicles by eliminating a mid-life overhaul of the gearbox. ESR Technology was commissioned to demonstrate that the change could be implemented without increased risk to gearbox life or reliability. The gearbox overhaul periodicity was based on the design duty cycle and life expectancy of the bearings. The objective was to use actual operational duty cycle data to show that the mid-life bearing replacement was not necessary.

Solution
ESR Technology developed a strategy for the existing design that demonstrated the comparable risks between the design duty cycle and the maintenance against the actual duty cycle and revised maintenance. We analysed the operation duty cycle for the gearbox and reassessed the design life of the bearings based on the latest bearing life methodology together with in service measurement of the debris level in the oil. This identified opportunities for extending the period of gearbox maintenance. The actual operational duty cycle was then applied to the design and revised maintenance periodicities calculated.