New signalling system extensively tested before implementation

We thank Mr Wong Shao Voon for his suggestions (“Replicate signal interference during tests of new system on N-S Line”; Nov 17).

The Land Transport Authority assures him that the safety and reliability of the train system is our absolute top priority. As the signalling upgrade for the North-South and East-West lines is a complex project, more than 1,300 tests will be done before the upgraded system is certified safe for operations — significantly more stringent than industry standards. These include simulations to ensure that the system responds quickly and effectively to unexpected conditions such as the loss of communications signals.

Learning from the experience of international operators, we are catering for more time to test the system and iron out any issues before its full operationalisation.

Since August, we have also commenced trial runs of trains on the new North-South Line signalling system with SMRT, after service hours.

This will help familiarise SMRT staff with the operations of the system and to validate operating procedures before the switchover next year in the first quarter.