Key Findings

• Multiple surfacing events into a turnout resulted in a localized, long-term RNT drop of approximately 21 degrees (°F) occurring 62 feet from the point of switch. The long-term RNT drop at 216 feet from the point of switch was less at 12 degrees (°F), suggesting the RNT change is localized near the turnout. Due to the de-stressing procedure prior to maintenance, the final RNT was well within ±20 degrees (°F) of the desired RNT.
• The amount of RNT change likely varies depending on 1) track type and condition, 2) type of fixed object, 3) maintenance type and execution, 4) pre-set RNT, 5) vehicle traffic details, 6) geography, and 7) temperature.
• The maximum measured longitudinal rail movement was 1 inch, and the tapering of the longitudinal movement roughly aligned with the tapering of the vertical movement.
• Longitudinal rail movements can be measured in track, but accurate measurements require extensive baselining and setup.