Avoiding flange climb derailment is one main issue with ensuring the running safety of railway vehicles. This paper discusses the different causes that can lead to the derailment of a railway wheel, particularly in the light of different derailment criteria used by the standards or proposed by various researchers. Furthermore the paper presents two case studies, one for a vehicle with solid axles and one for a bogie with independently rotating wheels, reporting a description of the derailment case and discussing the causes that led to derailment, by making combined use of measurements and numerical simulation. Based on these exemplary cases, some conclusions are drawn concerning the validity of the derailment criteria presently used by the standards in force
