SINGAPORE: Hong Kong’s MTR Corporation has been penalised HK$8 million (US$1 million) after signalling system failure on four major lines caused widespread travel disruption on Oct 16 this year, affecting thousands of commuters.
MTR Corporation on Wednesday (Dec 19) submitted to the government a report of the results of an investigation by a panel set up by the company to look into October’s service disruption.
During its investigation, the panel found that the disruption was caused by differences between two groups of computers in use for the signalling systems of the four lines.
These signalling systems use equipment designed and supplied by two different companies, all designed to the same signalling system functional standards.
Equipment on three of the lines – the Tsuen Wan Line, Island Line and most of the Kwun Tong Line – was designed by Alstom, while that for the Tseung Kwan O Line and the rest of the Kwun Tong Line was from Siemens.
The Alstom system has 25 sector computers and has been in use since 1996, while the Siemens system has eight sector computers and has been in use since 2001.
On Oct 16, problems arose because of a previously unknown discrepancy between these two types of computers.
The Alstom computers could reboot themselves automatically, while the Siemens computers needed to be manually rebooted.
“This internal software function was not made known to the operators and maintainers,” said the MTR Corporation report.
It concluded that the root cause of the signalling system failure was this different software counter “re-initialisation arrangement” of the two connected systems when the re-initialisation was activated on Oct 16.
“Since the four lines are connected, the inconsistent reinitialisation situation led to repeated re-synchronisation, causing instability in sector computers,” said the report.
It added: “The software counter re-initialisation algorithm, the differences in the counter reinitialisation arrangements between the Alstom and Siemens systems and the possible impact on the train service were not known to the operators and maintainers, nor were they explicitly described in the operation and maintenance manuals.
“The panel also concluded there was no correlation between the incident and the signalling replacement project and its testing.”
It also concluded that the disruption was not the result of a computer virus or sabotage.
As part of its penalty, MTR Corporation has “set aside HK$8 million to give concessions to passengers next year”, the Hong Kong government said in a response to the report on Wednesday.