The structural collapse of an iron ore Bucketwheel Stacker Reclaimer at the beginning of its operations was investigated through mechanical tests, microstructural characterization, computational structural analysis and evaluation of the operational status at the time of the accident. The failure occurred by brittle fracture at the welded connection between a rectangular hollow section member and a flange. The main factors for failure were the highly restricted welded joint combined with cleavage crack propagation in direction of lower fracture toughness. This particular connection was responsible for the load transference between the frontal tie member and the boom extremity. The structural analysis showed that the joint fractured was one of the most likely points of primary collapse, corroborated by the important value of the service loading versus structural resistance ratio. The combination of these factor lead to the premature collapse of the structure.
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