Work to upgrade and renew the power supply and track circuit systems on the ageing North-South and East-West lines (NSEWL) will begin later this year, said the Land Transport Authority (LTA).
The upgrading work, which is expected to be completed by "the early 2020s", will reduce the number of power-related faults, as well as allow for faster recovery after signalling system failures, it added.
Three contracts were awarded for a combined $573 million, the LTA announced yesterday.
Japanese technology firm Meiden Singapore won two deals to upgrade and renew the power supply system on the two lines, worth a combined $500 million.
The new power supply system will be able to automatically switch the power supply source during an outage. It will also have real-time monitoring features and better fault prediction, detection and identification.
The capacity of traction substations and the intake of power substations at three locations - Yasin, Bishan and Stamford - will also be increased.
"This will increase the NSEWL's power capacity and allow us to safely support more trains running on the lines," said an LTA spokesman, adding that the overall resilience of the power supply network will also improve.
The contract to replace the track circuit systems on the two lines was awarded to a consortium of German industrial giant Siemens and French firm Engie Services Singapore for $73 million.
The new track circuit system, working together with the new signalling system, will be able to detect the location of trains on the lines. It will also be able to detect broken rails and will have a condition monitoring system that can identify and fix potential track circuit failures, added LTA.
LTA deputy chief executive for infrastructure and development Chua Chong Kheng said: "We expect the new power supply and track circuit systems to significantly reduce the number of power and track circuit related faults."
The authority is working closely with SMRT to ensure the projects are "implemented smoothly", he added.
The power supply and track circuit systems are among the six core systems being upgraded to improve the reliability of the two lines.
The improvement includes a $195 million upgrade of the signalling systems of the two lines, which began in 2012 and is expected to be completed this year.
The LTA will also award a tender for the replacement of 66 ageing trains on the North-South and East-West lines in the coming months.