The effect of locomotive radial steering bogies on wheel and rail wear

Since Electro-Motive Division's (EMD) 3-axle radial steering bogie for heavy haul freight locomotives was introduced in production in 1993, over 70 million miles of service have already been accumulated on this new design. By the end of 1996, over 800 AC and DC traction locomotives with this new bogie technology will have been put into service. Wheel wear data, which is relatively straightforward to obtain, is showing that wheel flange wear has been virtually eliminated and that wheel tread wear has not increased in spite of dramatic increases in adhesion to 45% for starting heavy trains and to 35% and higher for train operation. Wheel wear data indicates that wheel life will likely double, even in operations where wheels are re-profiled for tread wear. This is due to the profound effect of low flange wear on minimizing metal removed in wheel truing. The wheel wear results also suggest changes to traditional railroad wheel truing policies. The effect of the radial bogie design on rail wear savings is more difficult to assess, and this paper discusses several rail wear considerations. Laboratory tests have provided considerable insight into the influence of wheel-rail angle of attack on wheel and rail wear. An approach is suggested for combining the available field and lab data with a cost model to project the life cycle cost savings for rail wear as well as wheel wear improvements.