Out-of-round tram wheels – current state and measurements

Abstract

This article is an attempt at summarising the current scientific achievements concerning out-of-round (OOR) tram wheels. The gathered research may provide an introduction to the broader analysis of this issue in tram technology. The measuring methodology of out-of-round tram wheels is also described in this article. Appropriate measurements were made on the wheels of selected vehicles operated by municipal tram company in Poznań. The obtained results allowed us to learn the characteristic forms of out-of-round tram wheels, among them, several forms of polygonization (ovalization, triangularization, etc.). Therefore we confirmed the thesis, that the method of fixing tram wheel rims in the lathe has a significant effect on the unevenness of its rolling surface, both when new (just after rolling) and, after some time of use, when even small irregularities become amplified.