Bolt Loosening Led to Deviated Guard Rail on JR New Tokaido Line

On March 31, a guard rail for preventing derailment was found deviating on the "Sizuoka-Kawagawa" segment of JR New Tokaido Line in Japan. There were signs indicating that the guard rail had collided with the bogie of a passing train, but luckily did not collide with other trains and no injury was reported. According to JR, 4 bolts and pieces of hardware are are fastened onto a side of the guard rail. The bolts loosened to the vibration when the train was passing. The collision mark was found below the bogie which was 9 centimeters away from the guard rail. The guard rail bounced up and collided with the passing train. JR has done a check on a total of 700 thousand bolts along the 430 kilometers line. Nothing unusual was found but JR still reinstalled the bolts and performs a round check every week.