In this research, investigations are focused on the study of railway vehicle wheel flange climb derailment. A three dimensional nonlinear dynamic model of the wheel-set and suspension system is developed. Having validated the model through field tests, the effect of friction coefficient, wheel-set AOA, vehicle suspension system and running speed on the wheel flange climb derailment are investigated. In addition, different rail lubrication methods are studied and their effects on the wheel flange climb derailment are compared in the case of two point contact for nonlinear wheel-rail profiles. The results are debated and recommendations proposed to improve running safety against derailment.