The MTR Corporation has promised to replace a suspect batch of electrical insulators on the East Rail Line after a second fault in 10 days caused delays for three hours during the evening rush.
Yesterday's chaos prompted operations director Dr Jacob Kam Chak-pui to admit that the MTR had failed to screen a batch of insulators from a "famous European brand" that were installed in 2011 and are being blamed for the problems.
Services were hit from about 4pm after a faulty insulator in an overhead cable near Fanling station triggered a short circuit. Trains travelling in both directions between Tai Po Market and the Lo Wu and Lok Ma Chau stations were forced to share a track until the problem was fixed some three hours later.
Trains ran at 15-minute intervals between Hung Hom and Tai Po Market, every 20 minutes between Tai Po Market and Lo Wu and every 30 minutes from Tai Po Market to Lok Ma Chau.
"It's even worse than the diesel-fuel trains in the old days," said passenger Cheung Kun-sing, who was forced to wait for more than half an hour at Fanling for a train to Hung Hom.
"Of course I'm extremely dissatisfied with the MTR. Breakdowns a few times in just a few months," said Cheung.
He complained that he had not even been told there was a problem until he reached the platform at Fanling.
MTR chief executive Jay Walder apologised to passengers for the delay and admitted the cause of the delays was "very similar" to the one at University station on February 9.
He promised an independent external review. Meanwhile, the MTR will deploy 60 to 70 staff to replace all the insulators from the batch that are installed at 65 critical locations along the East Rail Line. This would take 10 days.
Insulators, usually made of porcelain, are needed to separate the cables above the train tracks from the steel columns supporting them, explained engineer Edmund Leung Kwong-ho .
Professor Lo Kok-keung, of Polytechnic University's department of mechanical engineering, said damaged insulators were a serious problem because they could cut power to the cables and halt the system.
He said insulators normally lasted longer than 10 years and it would be very rare for them to break within three years. He said the Fanling insulator may have been faulty when it was produced, but said such a scenario was unusual. He thought it unlikely that the whole system was installed with faulty insulators.
The two latest incidents on the East Rail Line were unrelated to interruptions on the Tseung Kwan O Line and the Light Rail in December and last month, said Walder. However, he agreed the frequency of incidents over the past 10 days was concerning and admitted the MTR could have provided better service.
Additional reporting by Shirley Zhao
Watch: Hong Kong's MTR during peak hours