The C151B Proof-of-Concept (POC) train (Train set 649/650) is a modified version of the fifth-generation Kawasaki-Sifang C151B train operated by SMRT Trains on Singapore’s North South Line (NSL) and East West Line (EWL).
The project, a collaboration between SMRT, CRRC Sifang, and STRIDES Technologies, was initiated in 2024 to test new reliability-centred technologies and environmentally sustainable systems on existing trains.
Background
In November 2024, SMRT and CRRC Sifang signed a Memorandum of Understanding (MoU) and a Proof-of-Concept (POC) contract at the 5th LTA-UITP Singapore International Transport Congress and Exhibition (SITCE). The agreements aimed to deepen cooperation in digitalisation, automation, and predictive maintenance for the North–South and East–West Line train fleet.
Technical Upgrades
Under the POC, one of the 45 fifth-generation C151B trains was retrofitted with a suite of smart systems to support predictive and condition-based maintenance. The enhancements include:
- Condition Monitoring (CM) System: Enables data collection to support predictive maintenance activities.
- Structural Health Monitoring (SHM): Tracks micro changes in the train’s structural stresses and strains, helping engineers identify train parts requiring more focused maintenance.
- Upgraded Train Information and Management System (TIMS): Provides detailed and accurate information on the health status of critical train systems.
- Improved Air-Conditioning System: Enhanced cooling capacity and eco-friendly refrigerant technologies for greater passenger comfort and energy efficiency.
- Propulsion and Power Supply Renewal: Replacing obsolete components and increasing power capacity as part of future-proofing efforts.
The POC is scheduled to run from November 2024 to mid-2026, after which findings will be evaluated for possible fleet-wide adoption.
Development and Testing
The Proof-of-Concept (POC) train, designated as trainset 649/650, was shipped by sea to CRRC Sifang’s facilities in Qingdao, China, for modification works. The six-car trainset underwent retrofitting to incorporate the abovementioned component upgrades and modifications.
On 30 December 2024, the three cars from trainset 650 (car numbers 3650, 1650, and 2650) were transported by road from Tuas Depot for shipment, followed by the remaining three cars from trainset 649 (car numbers 3649, 1649, and 2649) on 2 January 2025.
After completion of the retrofit, the train was returned to Singapore, in a white base livery replacing the train’s former SMRT pixel livery. The three cars from trainset 649 arrived at Bishan Depot on 18 October 2025, with the remaining cars from trainset 650 delivered the following day, on 19 October 2025.
Following delivery, the train is expected to undergo local testing and validation at SMRT’s central maintenance facility at Bishan Depot. In early November 2025, the train was observed at the depot with a new “Progress Together” livery, featuring red stripes applied to its original white base.