Wheel climb derailments in switches remain a major derailment category for both freight and passenger rail operations in the US. Wheel climb derailments occur at both high and low speeds in both facing and trailing moves through the switches. While some causes are relatively straightforward, such as over speed entering or leaving the switch, or a broken point, most wheel climb derailments are a combination of a worn switch point (to include profile and angle of the switch point) and a worn wheel. A number of European railroads have adopted switch maintenance practices that focus on wheel climb in the switch point area, several of which have the potential to improve current US rail maintenance practices. This report includes the results of a survey and detailed engineering analysis of international maintenance practices aimed at reducing the risk of wheel climb at switch points and describes the potential application of these practices for US freight and passenger railways. As part of this activity, the study team examined international standards and practices from several major international rail systems and compared them to AREMA, FRA and individual US railroad switch point inspection practices. They then analyzed several of these practices from the perspective of the dynamic load environment of US railroads to include expected lateral (L), vertical (V) and L/V force levels and the associated potential for wheel climb in the switch point areas. (Author/publisher)
Abstract