The National Academies

Safety IDEA Project 28 [Completed (IDEA)]

Field Validation of Inspection Gauges for Wheels Climb Safety at Switch Points

  Project Data
Funds: $82,179
Staff Responsibility: Jo Allen Gause
Research Agency: University of Delaware
Principal Investigator: Allan M. Zarembski
Effective Date: 8/14/2015
Fiscal Year: 2015

The University of Delaware, working with Norfolk Southern and Amtrak, conducted a field assessment of improved inspection tools, developed under Rail Safety IDEA Project S-28 to be used to reduce wheel climb derailments at switch points. Four potential switch point gauges were evaluated and assessed, each of which addresses a different wheel climb mechanism that is of particular concern to U.S. railways:
• Chipped or damaged switch points
• Poor wheel/rail contact through the point for new or moderately worn wheel profile
• Excessive gauge face wear of the switch point
• Severely worn wheel-related climb.

The goal of this project was to provide railroads and transit systems with a set of practical and directly useable gauges for track inspectors to evaluate the condition of switch points. During the two sets of field assessments, approximately 350 switches on seven railroads/consultant organizations were inspected and evaluated. The evaluations included direct correlation between inspector and gauges, statistical analyses, and decision tree analyses all looking at the effectiveness of the gauges in identifying switch points that are in a condition that can contribute to or result in a derailment.

The results of the two field inspections showed extremely good agreement, with overall ratings in the range of 80%, in line with the statistical analysis. In several cases, agreement was more than 90% (and in one case it was 100%). Feedback from the railroads and inspectors was very favorable, noting that the gauges addressed several conditions that are often overlooked and, in general, made for a more detailed inspection of the switch point. In addition, the gauges will help train inexperienced inspectors and refine their judgment in this area.
Based on the results of this program, the committee has recommended that these gauges be made available to the railroad industry, as well as to such railroad standards organizations as AREMA for industry implementation.

The final report is available.

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