Interface - The Journal of Wheel/Rail Interaction

OPTIMIZATION

Optimizing Wheel and Rail Profiles on Amtrak's Northeast Corridor
by Eric E. Magel • September 20, 2004

Wheel wear is an inevitable byproduct of wheel/rail interaction. Excessive wear, however, indicates an imbalance in some aspect of the wheel/rail interface. Amtrak’s high-speed Acela trains, running on track with much greater curvature than other high-speed systems, were quickly found to exhibit very high rates of wear. Recognizing that this and other wheel/rail performance issues were best addressed through a proper, systemic approach, the Federal Railroad Administration (FRA) sponsored a program directed at developing methods for improving wheel/rail performance on Amtrak's Northeast Corridor (NEC). The study focused on wheel and rail profiles, friction management and rail profile grinding, and led to the development of a new Amtrak wheel profile.

High rates of wheel flange wear on the high-speed Acela trains may have been the catalyst for the investigation, but the study also considered the conventional Amfleet cars and the 16 other commuter and freight railroads that operate over the same track on the corridor. Among the considerations are the unfavorable wheel wear patterns on the conventional fleet, which include a geometrical stress raiser that develops between adjacent running bands on the wheel and leads to high stresses on the wheels and the rail (see Figure 1). Also of concern are hollow-wheels with a false flange condition that impairs wheelset steering and damages the low rail in curves.

While wheel/rail performance can be characterized by randomly sampling wheels and rails on a system, each wheel and each section of rail tells only one story. To obtain a system-wide story, engineers from the National Research Council of Canada's Centre for Surface Transportation Technology (CSTT) performed a Pummeling Analysis — a look at the distribution of wheel-to-rail contacts across the system — to characterize how a wheel or section of rail is shaped by wheel/rail interaction, and to validate the performance of custom-designed profiles. This examination enabled researchers to assess the damage contributed by all of the wheels—new wheels, worn wheels, leading axles, trailing axles, heavy axle loads, light axle loads — passing a specific section of track.

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