East Japan Railway Company says broken overhead wires were the likely cause for the trouble that led to a full suspension of the Yamanote Line loop railway service in central Tokyo on Friday morning.
The railway company said that at about 10 p.m. on Thursday, it received a report from the conductor of a train on the line’s outer loop that an electrical discharge was observed from the train’s pantograph. The company confirmed through checks that some trains on the line had partially bent pantographs.
The company suspended the outer loop service later on Thursday and investigated the matter. It said overhead wires for the outer loop service were found to have been broken near Shimbashi Station. The broken wires appear to have touched pantographs. The company said 20 of the 50 trains on the line had damaged pantographs.
The railway operator suspended both the outer and inner loops of the Yamanote Line service since the first departures on Friday, before resuming service at about 8:30 a.m. The Keihin-Tohoku Line, which runs parallel to the Yamanote Line in some sections, was also partially suspended.
A total of 176 trains were canceled during the suspensions, affecting about 249,000 people.
AloJapan.com