The new signaling system promising speedier rides on Singapore's 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, said the Land Transport Authority (LTA) in a press statement on 26 October 2016.
This is due to more tests are needed to ensure its reliability, local media Today said in a report.
With this new Communications-Based Train Control System, trains can arrive at platforms every 100 seconds. This is down from the current 120 seconds on the existing Fixed Block System, efficiently bumping up the NSL's capacity by 20 percent.
LTA said that porting to a new signaling system was a complex project and any hiccups could impact the whole line. The decision to run more tests was upon the advice of international metro operators that have carried out similar re-signally projects, such as those in Taipei and London.
More than 1,300 tests need to be run on the NSL's new signaling system, which can only be carried out only during non-service hours from 1am to 4am.
"There may be some software bugs in the system," said Tan Yih Long, Re-signaling Project Director, LTA. "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 signaling works. This will allow trains to be re-routed to the opposite track to bypass a track fault, which means passengers will not have to detrain.
The new system has been fully installed on the NSL, and is 80 percent completed on the EWL. It is expected to be operational in 2018.
More frequent equipment inspections will be carried out to detect and deal with potential issues early, according to the press statement.
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 put in place.
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