RO-1999-117

On Tuesday, 6 July 1999, a loaded petrol wagon on Train 230, a northbound Wellington to Auckland express freight, derailed approximately 4 km south of Paraparaumu when a wheel on the leading bogie moved in on its axle. The brakes on the wagon had failed to release which caused the wheels to overheat. This overheating had been reported by a passing motorist and the train duly stopped just short of Paraparaumu, but not before the wagon had derailed. An incorrect tolerance fit of the wheel on the axle allowed the wheel to move inwards on the axle and derail the wagon. Safety issues identified were the absence of accepted engineering practices in fitting the wheel and inadequate checkout procedures. One safety recommendation was made to the operator.