Technology Digests / Updates on Western Megasite Rail and Weld Testing

TD25-016

September 17, 2025
Authors
  • Ananyo Banerjee
  • Kerry Jones
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Key Findings

  • Since 2014, the HS rail test has accumulated over 1,350 MGT with no rail breaks. In the two test curves, however, eight total weld breaks have occurred.
  • Vertical metal loss, gage corner loss, and area loss were compared for the four rail types. Where statistical differences existed, the control rail type performed as well as or better than the other rail types.
  • Nine full section high hardness (FSHH) welds, eight treated with ultrasonic impact treatment (UIT), and three standard hardness UIT treated welds installed on the revenue service tracks in 2021 have accumulated more than 230 MGT with no defects developing in any of the welds. Compared to the standard hardness welds, the FSHH welds show less longitudinal wear on the running surface.

Updates on Western Megasite Rail and Weld Testing

Over the last two decades, MxV Rail has been conducting different track related tests at a revenue service site on the Union Pacific Railroad (UP)-owned and operated South Morrill subdivision (sub). In 2014, researchers initiated a rail performance test using premium or high strength (HS) rails from four different manufacturers. As part of this test, in 2021, researchers began monitoring the effects of ultrasonic impact treatment (UIT) on thermite welds. The preliminary and interim results from the rail test have been published in previous publications.1,2,3 This Technology Digest summarizes the latest results from the rail and weld performance tests. The western megasite, or revenue service site, is located in the plains of western Nebraska on a major heavy haul coal route owned and operated by UP. When the test began (2014), the route saw around 180–190 million gross tons (MGT) of traffic per year, but in 2020, traffic reached a…