Failure analysis of stacker-cum-reclaimer in ore handling plant

Abstract

A catastrophic failure of a Stacker-cum-Reclaimer led to loss of several days of service in one ore handling plant in India. The failure was severe enough to initiate an investigation into the possible causes of failure and estimation of the residual life for other units of Stacker-cum-Reclaimer of the same design and age, working in the plant. The failure analysis included a visual inspection of the failed structure, metallographic studies, static stress and stability analysis under normal operating conditions, stress analysis for a possible impact load on the structure, experimental stress analysis, and fatigue life cycle analysis. The results obtained indicate that the failure could be caused by an impact load arising out of some operational conditions resulting from the conditions of the rail track on which the machine travels. The material properties, the physical conditions of the material, and a fatigue analysis indicate that the existing system can work for several more decades, provided some checkpoints are planned and instituted to monitor the health of the structure at regular intervals.