USE OF ADDITIONAL ASSESSMENT CRITERION FOR TRAFFIC SAFETY AGAINST RAILWAY WHEEL DERAILMENT FOR FORENSIC RAILWAY TRANSPORT EXAMINATION

Abstract

A number of methods have been developed to determine the possibility of a wheelset derailment from track, which to some extent take into account specifics of their interaction. However, methods used in the calculation are different between themselves. The problem is complicated by the lack of sufficient experimental data which would allow to verify the adequacy of models used for calculations. Authors conducted research of an influence of an additional assessment criterion for traffic safety. According to this criterion the railway wheel derailment of a rolling stock was analyzed by actually raising the wheel flange to the railhead. It is noted that increase of the radius of wheels taken into account while calculating indicated criterion depends on transverse displacement of the wheelset, horizontal unevenness, numerical value of the wheel taper profile at the contact point with a rail, and the nominal gaps between the wheel flange and the inner edge of the railhead. On the basis of performed researches, it was concluded that use of an additional criterion, according to which the stability of the wheel from the derailment of a rolling stock is analyzed by actually raising the wheel flange on a railhead, allows to track the time when it is necessary to check the possibility of rolling the wheel on railhead. However, obtaining a negative clearance between the wheel flange and the railhead does not indicate that the wheel is rolling on the railhead. The indicated feature will allow to explore the development of a railway accident mechanism, to define more precisely its proximate technical cause and the sequence of intermediate technical reasons which have led to it.