Hokkaido Railway Co. has admitted to another safety oversight regarding the automatic train stop system on one of its express trains.
According to JR Hokkaido, a Hokuto express train running between Sapporo and Hakodate was in operation for more than a month since late November with its ATS deactivated.
Although the ATS is activated by air pressure, a valve in the air pipe was closed for an unknown reason and the entire system was deactivated as a result, JR Hokkaido officials said, adding that they are investigating to determine why this happened.
The problem surfaced Sunday when workers conducted a regular safety check on the train. JR Hokkaido said the train had traveled 13,800 km in 43 runs and carried about 10,000 passengers since Nov. 28.
In recent years, JR Hokkaido has been plagued with safety oversights. It is struggling to regain public trust after scandals over shoddy track maintenance records and data manipulation.