Re-signalling Update: Your Questions Answered Here

Last month, we answered 7 commonly asked questions about SMRT Trains’ new signalling system.
As system-level performance checks on the new signalling system for the North-South Line (NSL) continue, we seek to regularly answer the questions you have on re-signalling.

The signalling systems on the CCL and the DTL were implemented before the lines commenced passenger service. Each line has one type of train, which was easier. On the other hand, the NSL currently has four different fleets of trains. Each fleet has its characteristics, and every train is unique.
Moreover, the newer lines run completely underground so they are not subject to inclement weather conditions. In contrast, our NSL operates on both open viaducts and tracks underground.
All these factors add to the complexities of our re-signalling project.

2. Has there been any progress after a month of system-level performance checks?

Yes, we have rectified several teething issues including the following:
• Improved alignment of train doors and platform screen doors at stations;
• Better regulation of train service intervals and train dwell time at stations;
• Significantly reducing incidents of train overshoot at platforms; and
• Smoother train braking and acceleration along the viaduct during adverse weather conditions.

3. The Tuas West Extension (TWE) was launched on 18 June 2017. Why was there a disruption on 28 June 2017, just ten days later?

Unlike the main stretch of the East-West Line (EWL) which is still running on the legacy Westinghouse system installed since 1987, the newly-completed TWE operates on the new signalling system.
This explains why trains moving to and from the TWE will have to pause at Pioneer MRT Station for a few minutes each time to switch signalling systems. On the evening of 28 June, the radio communication network of the new signalling system failed and affected the NSL and TWE.

In a briefing last month (May 2017), LTA shared that a complex system like the new system would take about four to six months to stabilise from the time it is rolled out on a regular basis (29 May 2017). We are not alone in this. Our fellow operators in London and Hong Kong faced similar issues when they renewed their old signalling systems. They also took a while to rectify the issues.