Automated Broken Spike Detection – Phase I
Rail spikes connect railroad rails to the supporting crossties and secure tie plates and crossties together. Recent field inspections and observations have revealed broken spike failures (cut spikes and drive/screw spikes) when used with elastic fastener tie plates in mountainous, high-degree curvature territory on North American Class I railroads. Spikes typically break within the crossties, approximately 1 to 1.5 inches below the tie surface, making detection difficult. This study discusses some preliminary efforts to detect the broken spikes using ultrasonic testing (UT) nondestructive evaluation (NDE) approaches. Transportation Technology Center, Inc. performed ultrasonic modeling and simulation to determine and optimize ultrasonic parameters for broken spike detection. Laboratory and in-track testing were also conducted to verify the modeling results and to evaluate the detection accuracy of the UT NDE method. The preliminary results obtained support the continued development of ultrasonic methods for nondestructively, and automatically, detecting broken spikes in track.