Technology Digests / Characterization of Rail Anchor Performance Through Laboratory Testing

TD26-010

Date Posted: May 28, 2026
Authors
  • Yin Gao
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Key Findings

  • During their initial application, all tested anchors exceeded AREMA’s recommended minimum of 6,000 pounds in the anchor slip test when applied to rail at the upper end of the base width tolerance.
  • Wrench-on anchors demonstrated higher and more consistent slip strength than drive-on anchors, especially after multiple applications.
  • For drive-on anchors, slip strength decreased by 15-37 percent after the first installation and continued to decline with additional applications, though the rate of reduction slowed significantly after three applications.
  • Both rail base width and loading conditions were influential factors in anchor slip strength.

Characterization of Rail Anchor Performance Through Laboratory Testing

Given the increasing demands of heavier axle loads, higher traffic volumes, and more extreme temperature ranges in modern rail networks, a comprehensive understanding of rail anchor performance is essential for optimizing track design and maintenance strategies. By providing a longitudinal resistance mechanism, anchors transfer longitudinal rail forces into the tie and ballast system, thereby limiting rail creep and distributing thermal and traffic-induced rail loads into the lower track structure (ties, ballast, subgrade). This Technology Digest presents MxV Rail’s experimental evaluation of anchor performance using the anchor slip test setup described in the American Railway Engineering and Maintenance-of-Way Association (AREMA) Manual for Railway Engineering, Chapter 5, Part 7.1.4.1 This evaluation was conducted to understand the basic factors that affect individual anchor resistance. The findings are intended to support improved anchoring practices and contribute to the development of more reliable longitudinal restraint systems for railroad track structures. BACKGROUND Railroad track systems are…