Rail grinding quality assurance based on profile correction and RCF control

Rail grinding is used by rail infrastructure owners to remove rail corrugations, rolling contact fatigue (RCF) cracks and for re-profiling the rail. In North America, the standard practice is Preventive and Preventive-Gradual grinding strategy which uses high production rail grinders to complete a single pass on most track locations at high grinding speed. These practices have been proven in field tests to be the most cost effective grinding strategies. To plan rail grinding on Queensland Rail a Rail Inspection Vehicle (RIV) is used to gather data of rail profiles and rail surface photos. This inspection technology generates a Grinding Quality Index. This paper proposes the standards utilised in accepted best practices [13] as a standard for Australian railways and their challenges and drawbacks to implementation as well as a better method of addressing RCF defects. Grinding Quality Index (GQI) is estimated by comparing the measured rail profile with the target rail profile template for the area of material to be removed for a particular grinding pass.Based on the rail surface photos taken by the RIV, the operator decides the additional depth of cut and number of passes based on experience with that track. GQI is currently estimated based on profiles and do not consider RCF. Current GQI does not show any relationship with the RCF cracks and can be very good from a profile perspective, but still can have RCF cracks on the surface. Close monitoring of pre and post grind rail profiles for compliance and inclusion of RCF factor has been proposed as an enhancement to the current GQI for effective assurance on the quality of grinding. This paper is on an appropriate index covering both the rail profiles and RCF control for rail grinding.