Mid-life structural assessment of transit rail cars at WMATA

The Washington Metropolitan Area Transit Authority (WMATA) contracted with Booz Allen Hamilton to conduct a nondestructive structural assessment of the 2000 and 3000 series rapid transit rail cars. The main goals of the assessment were to identify any significant changes that have occurred to key elements of the car body structure since their date of manufacture and to confirm that no significant and obvious structural deterioration or damage exists. The methodology behind selecting a small representative sample of cars is discussed as an introduction to this work. The paper then discusses the process by which several critical areas were selected for nondestructive inspection. One of the biggest challenges in successfully completing this project was not interfering with WMATA´s fleet operating requirements. The use of WMATA facilities had to be coordinated to create minimum interference with WMATA´s daily maintenance activities. Also, the inspection work had to be planned in such a way as to minimize the amount of vehicle component disassembly in order to return the vehicle to revenue service as soon as possible. The inspections produced valuable results regarding the construction and condition of these cars. The structural welds of the car appear to have performed satisfactorily through the operational life of the cars to date without any significant deterioration. Some corrosion was noted in the door opening areas of the cars, particularly at the door thresholds. The findings of this report are used to target specific areas of the car during the upcoming mid-life rehabilitation project.