Coupler Yoke M-205 AAR Qualification Testing


CTLGroup was contracted to conduct qualification tests on cast yokes for freight car applications in the North American market.  Yokes were tested in accordance to the Association of American Railroads specifications (AAR) Manual of Standard and Recommended Standards (MSRP) M-205 “Yoke, Coupler – Test Requirements”.

Yoke testing occurred to assess the ability of the cast yokes to resist the loading conditions described in AAR M-205.  Yoke samples were subjected to static loading to a datum load of 5,000 lbs., an initial load of 20,000 lbs., a permanent set load of 750,000 lbs. and an ultimate load of 900,000 lbs.

Testing included geometric measurements pre- and post- testing to validate the yoke against the applicable requirements for permanent set.  Additionally, a high-speed data acquisition system was used to accurately measure the necessary displacements and loads throughout the testing sequence and served as an alternate method of instrumentation, not specifically prescribed in the AAR test method.  This alternate method producing similar results, thereby validating the methodology.