About suspension of operation of municipal Subway Blue Line (return driving) (final report)

At 7:15 pm on December 19, an abnormal current between Isezaki-Chojamachi Station and Yoshinocho Station was detected at a substation, and a return operation was carried out, but at 11:40 pm, the safety was confirmed at 11:40 pm As it was finished, the operation will resume.
We apologize for any inconvenience this may have caused to you.

1 Overview of driving obstacles
（1） Date and time of occurrence
　　 7:15 pm Tuesday, December 19, 2023

（2） Location of occurrence
　　 Municipal Subway Blue Line Between Isezaki-Chojamachi Station and Yoshinocho Station

（3） Progress, etc.
　　 7:15 pm Detected an abnormal current between Isezaki-Chojamachi Station and Yoshinocho Station at a substation.
　　 7:16 p.m. Deadline operation
　　 8:4 pm Return operation starts back between Kami-Ooka Station and Shonandai Station
　　 8:11 p.m. Returns from Azamino Station and Yokohama Station
　　 11:40 p.m. Safety confirmation completed
　　 Scheduled to resume operation at 0:10 a.m.

2. Number of affected personnel
　　 About 50,000 people

3 Causes
　　 The curing net installed on the ceiling of the tunnel between Isezaki-Chojamachi Station and Bandobashi Station and the wire that was holding it came off and fell.
　 As a result, a short circuit between the third rail and the running rail, causing excessive current flowing, and a power outage.

　　 ※Third rail
　　 　A power supply rail called a third rail (the third rail) is installed beside the running rail, and the power collection shoes equivalent to pantographs.
　　 　A method in which powers a train using a power collector called (collector Shoo).