A study on the wheel-rail interaction at switch points to reduce derailments in turnouts
Date
2014
Authors
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Publisher
University of Delaware
Abstract
Railroad transportation has been very important for human being for last two centuries. Although it is known as one of the safest forms of land transportation systems; mechanical, operational, and human behavioral problems result in a significant number of derailments on US railroads every year. While a collision represents the impact between two trains in any direction, a derailment occurs when a wheel of a car runs off the track. One of the most common derailment cause category is wheel climb derailments. Wheel climb derailments can be results of wheel problems, rail problems and operational problems or combination of these. A significant percentage of the wheel climb derailments occurs at turnouts. Thus, it is vitally important to determine the conditions of switch points before a derailment occurs. In this study, a mechanism for wheel climb derailments has been applied to turnouts by using data taken from an Automated Switch Inspection Vehicle (ASIV). This data was used to conduct a set of wheel climb analysis to determine the critical points through the specific turnouts and the risk of wheel climb derailment. This thesis introduces the background of this methodology, conducts an analysis of collected data, and discusses the results and conclusions of this analysis. This methodology will help to evaluate condition of any switch point. Furthermore, hand held switch point inspection tools were evaluated and modified as a part of an IDEA Transportation Research Board project to reduce derailments in turnouts, and they are also presented in this thesis as a remedy of reducing wheel climb derailment risk. The author participated in this IDEA project, and conducted research on producing hand held tools for the US railroads. This thesis includes discussion of these newly generated tools. This study has an importance since it will change the inspection technique from visual type to a more reliable one. As a result of this study, critical locations that have a risk of wheel climb on turnouts are identified by the proposed methodology. The IDEA project outcomes also provided newly generated inspection tools to be used to inspect these critical points.