Launch of new train signalling system delayed for more tests
An SMRT staff testing the upgraded signaling system on the North-South Line. Photo: Ernest Chua/TODAY
SINGAPORE — The new signalling system promising speedier rides on the North-South Line (NSL) and the new four-station Tuas West Extension (TWE) by the end of this year will miss its target launch schedule because more tests are needed to ensure its reliability, said the Land Transport Authority (LTA).
Instead, commuters using the NSL will have to wait until the first quarter of next year for the rollout of the new system, for which installation works began four years ago.
The TWE, which connects the East-West Line (EWL) from Joo Koon to Tuas Link, will start even later, in the second quarter.
This new Communications-Based Train Control System trumps the existing Fixed Block System in that trains can arrive at platforms every 100 seconds, down from the current 120 seconds — effectively bumping up the NSL’s capacity by 20 per cent.
It has been fully installed on the NSL, and 80 per cent completed on the EWL, for which it is expected to be operational in 2018.
In a statement on Wednesday (Oct 26), the LTA said it needed more time to carry out “more extensive tests to ensure the reliability of the system before launching it” because porting to a new signalling system was a complex project and any hiccups could impact the whole line.
The decision to run more tests was also upon the advice of international metro operators that have carried out similar re-signalling projects, such as those in Taipei and London.
The LTA said more than 1,300 tests need to be run on the NSL’s new signalling system, which can be carried out only during non-service hours from 1am to 4am.
For example, it needs to check if train and platform doors are aligned when a train reaches a station.
LTA Re-signalling Project director Tan Yih Long said: “There may be some software bugs in the system. For example, the train may not be able to stop accurately, hence, we need to test the stopping accuracy of trains at every station platform to make sure that the train stops accurately at the platform.”
Tests are also needed to check if bi-directional signalling — allowing trains to move in either direction — works. This way, trains can be re-routed to the opposite track to bypass a track fault, which means passengers will not have to detrain. Since August, 93 per cent of these tests have been completed.
With the shorter headways promised by the new signalling system, the LTA said it will progressively add 57 new trains fitted with the new signalling system to the rail network from now till 2019, bringing the total train fleet on the NSL and EWL from 141 to 198.
The LTA will also call for a tender to replace 66 first-generation Kawasaki Heavy Industries trains which have been in service for 29 years.
For the time being, it will work with SMRT to improve the reliability of those trains until they are replaced.
Separately, the LTA has also started implementing the recommendations of the Independent Advisory Panel for Power Supply. The panel was appointed in December last year and comprised international experts in power supply systems.
More frequent equipment inspections will be carried out to detect and deal with potential issues early. A fault identification system that allows operators to pinpoint and isolate faults to specific stretches of the network will be installed on the Downtown Line.
An alternative power supply, which will automatically kick in in the event of a loss of power, will also be put in place, as proposed by the panel.
For the NSL and EWL, the LTA is considering upgrading to a brand new power supply system with better monitoring tools.
