The Yew Tee to Kranji stretch on the North South Line was described in The Straits Times, as the “most problematic section” of the North South Line (“Wanted: Experts to give rail network thorough health check”). In this blog post, Mr Lee Ling Wee, Managing Director of SMRT Trains, explains how SMRT is working to improve reliability not just along the 4.1 km of tracks between Yew Tee and Kranji, but throughout the North South-East West Line.
Renewing the ageing infrastructure
We recognise that the stretch of track from Yew Tee to Kranji seems to have more issues than other parts of the North South East West Line. From January this year, the stretch of track recorded six track-related faults. All faults were fixed by our engineers and technicians with a view to keeping trains moving with minimal disruptions and maximum safety for passengers. The shortest delay was 5 minutes long while the longest took 4 hours and 42 minutes to fix, largely due to a thunderstorm which delayed access by our maintenance team to the open viaduct.
Track faults detected from February to March 2015 were due mainly to defective 3rd rail components. These have since been inspected and rectified.
What are we doing about it?
We are doing a thorough review of the issues related to track infrastructure such as permanent way and signalling equipment along this stretch. Meanwhile, we will ensure our maintenance teams are on standby to respond to issues in this area – especially during peak hours – to ensure that recovery can be faster in the event of an incident.
The Yew Tee to Kranji stretch has been prone to lightning strikes. We have installed lightning arrestors along this stretch to protect trackside infrastructure from lightning strikes, which could affect the reliability of track infrastructure, especially electrical equipment.
As we work to renew ageing infrastructure and trains under a multi-year programme, our engineers and technicians will be monitoring our rail network closely to ensure faults are kept to a minimum. The benefits from changing deteriorated timber sleepers to concrete sleepers for a smoother ride, modernising the signalling system for trains to travel faster and arrive more frequently, changing the third rail, upgrading older trains and introducing new trains are expected to improve the ride experience for commuters.
Investing in Technology
In the meantime, we will leverage on technology to monitor the condition of the entire track network under various conditions. We have implemented a reliability-centered maintenance process anchored on preventive maintenance and the use of track monitoring sensors.
One example is the use of a sensor called the Linear Variable Displacement Transducer, which is capable of making precise third rail measurements and can detect even the slightest anomaly. Close monitoring of the line has also been aided by the addition of Rail Vision video cameras below selected trains, which allow the engineering team to review the track condition recorded during service. Another example is seen in the use of the Wheel Impact Load Device, which is a highly sensitive fibre-optic strain gauge. This is mounted on selected stretches of the track to detect abnormal impact loading arising from wheel-track interactions, which could be a precursor to a track or train fault.
There are also plans to implement other methods to gather precise information on track conditions during service, including the use of high-definition cameras and laser technology for more detailed in situ track geometry measurements.
The SMRT team’s attention to track safety extends throughout our rail network, not just the Kranji-Yew Tee stretch. Even as SMRT works to renew our ageing rail network, we remain committed to a rigorous maintenance process to keep ageing parts of the line safe and operationally-ready in order to provide passengers with a reliable and smooth journey.
Lee Ling Wee (Mr)
Managing Director, SMRT Trains