A multi-national survey of the contact geometry between wheels and rails

The project DynoTRAIN, which was funded under the European Seventh Framework Programme, was set-up in order to close the open points in the Technical Specification of Interoperability (TSI) of the trans-European rail system. The project was divided in seven work packages. The focus in work package 3 (WP 3) was the contact geometry between wheels and rails. More general information about the DynoTRAIN project is given in the foreword of this special edition. WP 3 was split into several tasks. In the first and second tasks worn wheel and rail profiles were collected. Since the wear behaviour of wheels and rails depends (among other factors) on bogie design, operating conditions, rail inclination and curve radius, a large number of wheel and rail profiles were investigated in order to obtain a representative picture of the contact conditions on the trans-European network. The wheel and rail profiles were analysed in terms of equivalent conicity, which is an important indicator for the running stability of railway vehicles. Based on the collected data, reference profiles for wheels and rails were defined for the calculation of conicity maps. The reference wheel and rail profiles act as a sort of coordinate (scaling) system for the conicity maps. The conicity maps were calculated from selected wheel and rail profiles that had the same frequency distribution as the whole sample. The conicity maps were calculated for different speed categories and for wheels operating on networks with rail inclinations of 1/20 and 1/40. Finally, limit values of the equivalent concity for the authorization of vehicles and in-service limits for tracks were derived from these conicity maps. This approach enabled the open point ‘equivalent conicity’ in the TSI: Locomotives and Passenger Rolling Stock and TSI: Infrastructure to be closed.