Technical Reports

Next-Generation Foundations for Special Trackwork – Phase III

  • 27
  • May
  • 2016
AUTHOR: Federal Railroad Administration
KEYWORDS: Dynamic load environment, special trackwork frog foundations, wheel-rail impact
ABSTRACT: Transportation Technology Center, Inc. (TTCI) conducted a series of tests, funded by the Federal Railroad Administration, which evaluated the potential beneficial effects of various configurations of high angle frogs and frog foundations on wheel-rail vertical forces and frog performance. The tests were conducted under 315,000-pound cars with nominal 39-ton axle loads at the High Tonnage Loop of the Facility for Accelerated Service Testing at the Transportation Technology Center in Pueblo, CO. Results from previous phases of this project were used to develop this testing plan, and the project had previously determined that track stiffness, track damping and frog flexibility (i.e., the capability for differential vertical movement between opposite sides of the frog across the flangeway) affects wheel-rail vertical forces. A prototype crossing diamond was built using an existing design that offered the potential for increasing frog flexibility, while the commercially available straight rail reversible design was modified to add rail seat pads of various configurations above the frog platework. Additionally, the team developed options for joining the four castings that make up each frog. These options allowed assessment of frog flexibility on wheel-rail forces and frog performance. A total of 14 frog configurations were evaluated over about 70 MGT.

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