Technology Digests / Track Buckles in a Controlled Environment

TD22-027

October 1, 2022
Authors
  • Stephen Wilk
  • Brandon Zane
Share

Key Findings

  • MxV Rail produced and monitored two track buckle events in a controlled environment. The first buckle resulted in a track misalignment of about 1 1/4 inches and the second buckle resulted in a misalignment of 30 inches. In order to induce a buckle, it was necessary to: 1) lower the RNT, 2) partially skeletonize the track in the buckle region, and 3) heat the rail to cause “rail running” into the buckle location.
  • To induce buckling for the first buckle event, the rail temperature above RNT was approximately 80°F, with an initial 1/4-inch lateral misalignment. For the second buckle event, the rail temperature above RNT was about 74°F, with an initial 1 1/4-inch lateral misalignment.
  • The total buckle “influence zone” was estimated to be between 700 and 1,000 feet, and approximately 2 inches of rail was pulled toward the buckle from both directions.

Track Buckles in a Controlled Environment

In May 2022, MxV Rail (formerly TTCI) intentionally produced and monitored two track buckle events to characterize and report on those events. Initially, MxV Rail was performing buckle testing for a proprietary demonstration when the monitoring was added as part of the Association of American Railroads’ Strategic Research Initiative (SRI) program, and thus, reported here. Predicting when high-impact events such as track buckles may occur can be difficult because of the large number of contributing factors. Buckles are most often the result of a combination of: low rail neutral temperature (RNT), high rail temperatures, reduced lateral track resistance, rail running, and vehicle forces. Track buckle policy usually involves managing the RNT and applying speed restrictions, either when the ambient temperature is too hot or after track maintenance work. These measures have been very effective in reducing the incidence of track buckles, as evidenced by the dramatic decline in the number…