Scrapping the problematic Bukit Panjang LRT (Light Rapid Transit) and replacing it with a bus-only transport system is not a feasible option, Transport Minister Khaw Boon Wan said yesterday.
The reason he gave is that the road network in Bukit Panjang will not be able to cope with the increased congestion.
Instead, an ongoing study is looking into how the 17-year-old system can be re-designed and upgraded to improve reliability, Mr Khaw said in his reply to Mr Liang Eng Hwa (Holland-Bukit Timah GRC).
Scrapping the Bukit Panjang LRT was one of several options being considered by its operator SMRT and the Land Transport Authority (LTA), the rail operator said in a blog post last month.
Yesterday, Mr Khaw said many key components of the LRT, including the trains, power rail and the signalling system, have to be replaced in about four to five years' time as they would be out of date.
Minister says Circle Line signal problems to be identified soon
The authorities are "very close" to uncovering the cause of the disruptions on the Circle Line MRT system, said Transport Minister Khaw Boon Wan.
He is confident the investigation findings, along with the solution, will be made known in a few days' time.
"The cause is clear - that there is, or there was signal interference. A particular signal is interfering with our wireless signalling system and causing some of this difficulty," Mr Khaw said in Parliament yesterday when replying to Non-Constituency MP Dennis Tan.
"But tracking down the cause of the signal requires a lot of effort and is intellectually very challenging because there are many possibilities and we've just got to (go), one-by-one, through elimination, and try to establish what exactly is the cause," he added.
In late August, a mysterious signal interference resulted in slower train speeds and reduced service frequency for a week.
Similar problems popped up again last Wednesday during the morning peak hours, causing a three-hour disruption that affected thousands of commuters.
Later in the week, telco operators temporarily suspended mobile services on the Circle Line to help investigators pinpoint the source of the signal interference.
During the suspension, commuters could not call, text or access the Internet.
The authorities are already sourcing for new trains, power rail, signalling system and other critical components to replace the first-generation assets, he added.
They are also "taking this opportunity to re-do the LRT to enable a step jump in reliability", he said.
The revamp could see a re-design of the Bukit Panjang Station, its track layout and the service routing so that the trains do not have to constantly switch tracks.
The switch point is a "critical vulnerability", Mr Khaw said.
The study will also look at smoothening parts of the LRT's alignment.
The minister said LRT systems are typically for straightforward, point-to-point connections on flat terrain, but in Bukit Panjang, it required "shoe-horning" the system into a built-up town.
"This has posed significant engineering challenges, requiring the LRT to make sharp bends and over undulating terrain," he said.
This worsened the problem of misalignment between the power rail and the trains' collector shoes, which draw electricity from the rails.
In the past three years, 60 per cent of the major disruptions were caused by power trips or dislodged collector shoes.
Mr Khaw said the LRT's reliability has been "unsatisfactory", despite efforts by the LTA, SMRT and the train manufacturer, Bombardier, over many years to improve it.
Mr Liang also asked if a separate entity could run the LRT on a non-profit basis, since it looked like SMRT was not placing enough priority on it, or lacked the resources to deal with the problems.
That was a "rather unfair" comment, said Mr Khaw as he defended SMRT, adding that all staff treated the LRT and other train lines it ran very seriously.
The Bukit Panjang LRT has always been a loss-maker, Mr Khaw said, but it is part of SMRT's portfolio of several train lines.
"The team does not look at it from the pure bottom-line angle, (but) that we are a public service provider, we have a duty to perform."
Mr Khaw is confident the LRT problems would be resolved.
"I'm more confident about this than my bet on who is the next American president," he quipped, referring to the US presidential election results that were being released as he spoke.