Rail spacing data from track inspections conducted by Hokkaido Railway Co. and reported to its headquarters doesn't match all of the data in the divisions that originally conducted the checks, according to transport ministry sources.
Speaking to reporters after a Cabinet meeting Tuesday, transport minister Akihiro Ota said it would be "very regrettable" if the discrepancies are part of an attempt to intentionally cover up track irregularities.
According to the sources, the discrepancies were reported by senior officials of JR Hokkaido during on-site inspections by the ministry's Hokkaido District Transport Bureau, which Ota said had started Monday night in accordance with the Railway Business Act.
JR Hokkaido plans to conduct an internal investigation to determine what led to the discrepancies, including the possibility it was intentional.
Attempting to conceal irregularities from the ministry and obstruct its special inspection would violate the Railway Business Act, the sources said.
The data are fed into a computer system at individual divisions responsible for maintaining specific railway sections.
The carrier is trying to determine whether there were intentional attempts at fabrication during the input process, the sources said.
According to JR Hokkaido, maintenance workers directly take rail spacing and other measurements of sidings using measuring instruments, and railroad switches, using rulers. After this information is put into the system, it becomes available to the headquarters.
JR Hokkaido's in-house rules call for preserving inspection data stored in its computer systems for specified periods, but it has no such rules for paper documentation, leaving it up to each division.