Ultrasonic guided waves have been shown to propagate large distances in continuously welded rail track.
Reference:
Loveday, P.W. and Long, C.S. 2019. Rail track monitoring using ultrasonic guided waves. Journal of Non Destructive Testing and Evaluation, vol. 17(19): 23-26
Loveday, P. W., & Long, C. S. (2019). Rail track monitoring using ultrasonic guided waves. http://hdl.handle.net/10204/11469
Loveday, Philip W, and Craig S Long "Rail track monitoring using ultrasonic guided waves." (2019) http://hdl.handle.net/10204/11469
Loveday PW, Long CS. Rail track monitoring using ultrasonic guided waves. 2019; http://hdl.handle.net/10204/11469.
