Singapore’s Land Transport Authority (LTA) has completed the North-South and East-West lines (NSEWL) upgrade and renewal multi-year programme.
Started in 2012, the comprehensive renewal and upgrading of the NSEWL’s six core systems was conducted in phases, in close collaboration with SMRT. The replacement of wooden sleepers with concrete sleepers was completed in December 2016 and the replacement of the third rail was completed in September 2017. The new Communications-Based Train Control (CBTC) signalling system was completed in 2018. Since then, works have been focused on the renewal of the remaining three core systems including track circuits, power supply, and NSEWL train fleet. A common feature of these three systems is a condition monitoring feature to allow faults to be pre-emptively addressed, thus preventing service disruptions and before it causes a wider system failure or disruption.
The works for the track circuit system of the NSEWL included the replacement of 1,100 track circuits. Working in tandem with the CBTC signalling system, these new track circuits help to indicate the position of all trains on the track. In the event of a fault, this helps the operator focus its response efforts and speed up the train recovery process, minimising the impact on commuters. The new track circuit system will enhance rail reliability. In addition, the new track circuit system can help to detect broken rails that are in need of repair, reducing the risk of disruption and enabling more efficient preventive maintenance.
Under the upgrade programme, LTA installed a new power supply system has enhanced features for real-time monitoring, to improve fault detection and prediction. For example, it constantly monitors the insulation of traction cables, enabling the operator to assess the condition of the traction cables. With this condition-based alarm, the operator can take appropriate pre-emptive interventions when necessary. The power supply renewal works covered the replacement of 1,300 km of power cables, 250 km of fibre-optic cables, 206 power transformers, 172 switchboards, and various equipment in 171 substations. In addition, all NSEWL stations have replaced the 64P touch voltage protection systems with new Voltage Limiting Devices to isolate power faults and prevent line-wide disruptions.
Related to the deployment of new trains, LTA awarded in 2018 a contract to Bombardier for the delivery of 66 trains to progressively replace the first-generation NSEWL trains, which have served commuters since 1987. Another 40 new trains were purchased in 2020 to replace the second and third generation NSEWL trains. These new trains are equipped with sensors to monitor the performance of various train subsystems and track conditions, to enable early fault detection. 26 new trains have arrived in Singapore, of which seven are in passenger service, while the remaining 19 are undergoing testing and commissioning. The rest of the trains will arrive in Singapore and be put progressively into service from now until 2026.