SINGAPORE - The renewal of the North-South and East-West Lines' (NSEWL) power supply system will be a complex project which may require MRT service hours to be shortened, so engineers have more time to do the upgrading.
For commuters, this mean stations closing earlier and opening later on certain days - a practice which has been taking place since December last year for maintenance work to be carried out.
Transport Minister Khaw Boon Wan said on Friday (May 11) that the upgrade of the power system, which kicks off later this year, will cost nearly $900 million and take five years to finish.
Speaking at a forum on infrastructure maintenance at the Land Transport Authority (LTA), Mr Khaw gave details of the extensive work needed for this project.
The power supply system is one of six core assets that are being replaced on the ageing NSEWL, which is more than 30 years old, to boost the lines' reliability.
Mr Khaw said that temporary mobile substations must be set up before the existing power supply system can be removed.
The new power system can then be installed and reconfigured to perform the same functions as the old system. A re-commissioning test must also be done, Mr Khaw said.
He said all these tasks must be completed satisfactorily before passenger service can resume the following morning. This is why the early closures and late openings of train stations is important, he said.
"If necessary, we will seek commuters' understanding for more extended engineering hours to help us complete the power system renewal more quickly," Mr Khaw said.
"If the renewal is not well executed, it can have a widespread impact on passenger service. No power, no train service," he added.
Mr Khaw said the early closures and late openings have helped to speed up the upgrading of the East-West Line's signalling system, by giving engineers more time to test it out, without passengers onboard.
In an update, he said full-day tests during passenger service, on the last two Sundays, have been smooth, and will continue for the next three Sundays.
He is "optimistic" that full-day tests can be done daily during the June school holidays.
The EWL's new signalling system, when fully operational, will allow trains to arrive at shorter intervals of 100 seconds than the current 120 seconds. It is not known when the system will be fully operational.
Last year, there were teething issues during the testing of the North-South Line's signalling system, resulting in train service delays.
Mr Khaw said the early closures and late openings have also given rail engineers more time to do maintenance, and the reliability of the NSEWL has improved.
The MRT network is on track to achieve, by 2020, the target of having trains travel for an average of 1 million km before encountering a disruption of more than five minutes, he added.
Mr Khaw said the shorter train operating hours inconvenience commuters and cost the LTA and operators money to run shuttle buses in place of train services.
He said public acceptance of the practice shows commuters' understanding and appreciation of the need for sufficient engineering hours to carry out maintenance.
On Friday, Mr Khaw also launched a Minister for Transport Challenge Shield, which recognises the most reliable MRT line and the most improved line. This will be based on the "mean kilometre between failure" during a calendar year.
Each award will come with a cash prize to be used for staff welfare and the appreciation of engineering and maintenance crew, Mr Khaw added.
"It is to remind ourselves permanently why rail reliability is such a priority for us, how we have neglected it, and please, never to neglect it again going forward," he said.