Wyman Jones
LA Metro
Teever Handal
ARM Corp.
Abstract:
Using Wheel Rail Interface Analysis to Evaluate Rail Transit Maintenance Priorities: A Case Study on the LA Metro Blue Line.
In 2014, a project was undertaken on the LA Metro’s Blue Line by Advanced Rail Management to prioritize maintenance on special trackwork as a means of continuous quality improvement over on a system already having achieved excellent wheel life and acknowledged ride comfort. It was felt by being able to rank maintenance for critical areas of special trackwork, efforts at proactive maintenance could be optimized. A methodology was established to evaluate car performance over selected sites, rank each site using these car measurements, and then determine maintenance critical sites. A primary goal was to gather the data with minimal instrumentation that would provide an accurate representation of operating conditions. This was achieved by the use of truck frame and carbody mounted accelerometers, a string potentiometer to measure truck rotation, under car video and audio to establish events, and speed and GPS data to correlate location. Using both designs of Blue Line cars (Nippon Sharyo P865 and Siemens P2000), system runs were made and the data analyzed. The truck mounted tri-axial accelerometer data was the foundation of a customized Severity Index by which acceptable performance levels were determined and the trackwork maintenance needs were ranked. The success of this method was validated by correlating the maintenance rankings with reported track conditions and/or design issues. In addition, the test provided information about two potential wheel/rail interface issues previously unknown on the Blue Line.