Effect of wheel and rail profiles on gage widening behavior

The Association of American Railroads (AAR) and Norfolk Southern (NS) participated in a joint research project which implicated poor wheel set steering as the cause of a gage widening derailment in a 6 degree curve on the NS in June, 1993. Through track tests and analytical modeling, the research project successfully demonstrated that poor wheel set steering can initiate truck warp and lead to the production of large gage widening forces. Furthermore, the project demonstrated that poor wheel set steering results from a combination of the following factors: (1) two-point wheel/rail contact caused by excessive gage corner relief grinding of the high (outer) rail, (2) wheels with treads worn to a hollow shape, and (3) high rail gage face lubrication