MTR Corporation's chief engineer said rogue computers operating without orders caused the worst system breakdown to ever hit Hong Kong's railway on Tuesday, but he did not know why the failure had happened.
Hong Kong experienced a six-hour long traffic disruption on Tuesday after a signalling failure occurred on four major MTR lines – Island, Tsuen Wan, Kwun Tong and Tseung Kwan O during rush hour.
MTR Corporation's chief engineer Tony Lee Kar-yun said on Wednesday that the preliminary investigation conducted by MTR railway technicians and the signalling system supplier showed the signalling fault was caused by computer programmes and did not involve human error.
Lee said on a radio programme that during the signal failures, a large amount of data was transferred between computers controlling different sections of the rail lines, causing instability in the system because a large amount of power was being used on data processing.
“They were doing something we called ‘synchronisation’. It occupied large amounts of computing resources and made the computers unstable. We believe this was related to [problems in] programmes and setting.”
He added that the failure had nothing to do with the testing of the new signalling system which was conducted the night before.
Relevant data will be sent to the signalling system supplier’s headquarters in France for further analysis.