Track Technical Presentation: An Assessment of the Applicability of Heavy Point Frogs to Joint High Speed Passenger and Freight Operations
(Room Sagamore Ballroom)
18 Sep 17
11:15 AM
-
11:45 AM
Tracks:
AREMA Full Program, AREMA Technical Sessions- Track
An assessment of the applicability of heavy point frogs for joint high speed passenger and freight operations was conducted by Transportation Technology Center, Inc. under sponsorship of the FRA Office of Research and Development. Additional work sponsored by AAR developed a modified heavy point frog design which will make compliance with track safety standard for higher speed track easier to consistently achieve. Heavy point frogs have been used with great success by freight railroads for more than thirty years. A heavy point frog differs from a standard frog in the width of the frog point over its first few feet. In this zone, from point of frog to generally four feet towards the heel end, the frog point is wider than a corresponding standard frog. This extra width allows the heavy point frog to resist deformation and wear better than a standard frog; resulting in substantially longer service lives. However, the heavy point frog produces a deviation in alignment of the point rail for both routes of the turnout. For higher speed track classes, this deviation makes it difficult or impossible to comply with all track safety standards related to frog dimensions. Thus, a study of the dynamic performance of passenger equipment at speeds up to 120 mph was conducted using vehicle-track dynamic simulations and limited available test data. The results of the study suggest that the current fixed point (RBM) and moveable wing (spring) heavy point frog designs are capable of meeting all performance requirements of frogs up to and including 110 mph track. Additional work to develop a design that meets all dimensions in the track safety standards for 110 mph track was conducted. The resulting frog design also meets all performance requirements for 110 mph track. The modifications needed to accomplish this are relatively simple. Some material was removed from the wings of the frog adjacent to the heavy point. This change will likely require some adjustment of the point slope of the frog. Prototype testing is expected to begin in early 2017.