The Educational Railroading Conference Leader Since 1994


2021 Heavy Haul Session


The Benefits of Applying the AAR 2A Wheel Profile to Locomotive Wheels

Walter Rosenberger

Walter Rosenberger
Transportation Technology Center Inc.

The Association of American Railroads (AAR) recently adopted the AAR 2A profile for application to freight cars in interchange service. The 2A profile is a refinement of the AAR 1B profile adopted in the 1990s, designed to approximate the shape of a stable, slightly worn 1B profile. Given that the 2A profile was developed for interchange service, why would a railroad want to apply a 2A profile to locomotive wheels? In recent research, Transportation Technology Center Inc. (TTCI) found that the 2A profile on locomotive wheels developed significantly lower L/Vs (lower derailment risk), and had lower wheel-rail wear rates than typical locomotive wheel profiles. This presentation explains how this assessment was made, using extensive NUCARS® simulations. It will also address optimization of typical curve-worn rail profiles.