Signage at JR Shimbashi Station in Tokyo notifies passengers of the suspension of services on the Yamanote Line early in the morning on May 23, 2025. (Kyodo)
TOKYO (Kyodo) — Train services on the busy Yamanote Line in central Tokyo were heavily disrupted during the Friday morning rush hour after pantograph problems detected the previous night led to a suspension of operations, according to JR East.
Both the inner and outer loops of the JR Yamanote Line, which circles central Tokyo with stops including Shinjuku, Shibuya and Tokyo stations, were suspended from the first scheduled services of the day. Operations resumed hours later, but the disruption continued until around noon.
A total of 176 trains on the Yamanote Line and the parallel Keihin-Tohoku Line were canceled on Thursday and Friday, affecting around 249,000 people, the operator said.
Irregularities with multiple pantographs — the apparatus that connects train carriages to overhead power lines — were detected Thursday, prompting the cancellation of outer loop service on the line that night.
The resumption of services was delayed by safety checks and restoration efforts, causing a major headache for commuters. Even after operations resumed, the Yamanote Line ran on a significantly reduced schedule, JR East said.
The railway company said a severed overhead wire was found near Shimbashi Station, suggesting faulty installation work. The wire was intended to support the power line and prevent it from sagging.
Trains passing through the section apparently hit the dangling wire, damaging pantographs, JR East said.
The company said it will conduct emergency inspections at 50 locations on four train lines in Tokyo, including the Yamanote and Keihin-Tohoku lines, by the start of the first train on Saturday.
AloJapan.com