New Monitoring System for Wheel/Rail Contact Force without a Special Wheel-Set

Abstract

A new measuring method introduced in this paper can measure contact forces between wheel and rail without special wheel-set with slip rings or telemeters. In this method the lateral contact force is measured from the lateral distortion of wheel measured directly by several non-contact gap sensors. Normal and longitudinal contact forces are also measured from the deflection of spring or the strain of parts of the bogies except special wheel-set. This new method, unlike the conventional method, is able to store the data everyday on every curve of commercial lines, which change according to friction coefficient and train running speed and so on. In this paper the authors describe the new measuring method without strain-gauge-equipped wheel-set, estimations of comparing the new method and the conventional method, and data analysis of measurements by commercial service trains. Practicable use of this new method enables us to easily obtain the statistical data of derailment coefficients with an on-board measuring method. Statistically analyzing the variation of rail-lubrication conditions and characteristics of wheel-rail contact force on every curve with this new system can help to improve track conditions for maintenance.