Redesign of frog geometry at new york city transit to reduce vibration, noise and accelerated wear

摘要

This paper summarizes a study conducted at New York City Transit to analyze the accelerated ware and associated noise and vibration experienced in newly installed RBM frogs. The study's objective was to understand the phenomenon of wheel-rail interaction at a critical are aof the frog point and to propose solutions to the problems experienced. Several RBM frogs in service were selected for the study and periodic field measurements and inspections were performed. Wheel profiles were also evaluated to determine their level of hollowness. New RBM frogs were inspected to determine if they were manufactured according to our standards and specifications. The material hardness was also examined and the material specifications were reviewed and updated accordingly. The historical evolution of frog geometry in New York City Transit was also researched to determine what changes were made in the past that could explain the recent problems experienced with new RBM frogs.