Technology Digests / Impact Tests of Boxcars Loaded with Paper Rolls

TD24-024

June 25, 2025
Authors
  • Adam Klopp
  • Alyson Sasaoka
  • Kelsey Even
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Key Findings

  • Maximum coupler forces, carbody accelerations, and paper roll accelerations were lowest for the boxcar equipped with 15-inch EOCC units and highest for the boxcar equipped with standard draft gears.
  • The dual draft gear hybrid system provided better impact protection than the standard draft gear with a shorter displacement stroke than the EOCC unit.
  • Due to the increased relative motion as the paper rolls transitioned from a compressed state to an uncompressed state, the maximum paper roll accelerations for all boxcar configurations were highest during the 6-mph reverse direction impacts.

Impact Tests of Boxcars Loaded with Paper Rolls

As part of the Association of American Railroads (AAR) Strategic Research Initiatives (SRI) program, MxV Rail worked with the End-of-Car Energy Management Task Force of the AAR’s Equipment Engineering Committee (EEC) to update existing draft system standards. Using impact tests1 and in-train simulations,2 MxV Rail evaluated different aspects of draft system performance. Data from this effort was used to develop new standards that provide a more comprehensive assessment of freight car draft system energy management. The new Specification M-902 in the AAR Manual of Standards and Recommended Practices (MSRP) describes the requirements for freight car interchange service of draft systems, such as impact testing, not classified as either standard draft gears (DG) or a hydraulic end-of-car cushioning (EOCC) units.3 The new Recommended Practice (RP)-906 describes a method to perform longitudinal train dynamics simulations to evaluate the in-train performance of freight car draft systems—an aspect of draft system performance that was…