LTA explains hairline cracks on trains; North-South & East-West Lines (NSEWL) safe
The Land Transport Authority would like to address some of the issues related to the 26 North-South and East-West Lines (NSEWL) trains that have been the subject of recent media and online discussion.
The Land Transport Authority awarded Contract 151A in 2009 to Kawasaki Heavy Industries and CSR Sifang to design, manufacture, and deliver 35 new trains for the NSEWL. The trains were progressively put into service from February 2011, following rigorous testing of their safety and reliability.
Battery and Draughtscreen Issues
Prior to the commencement of passenger service, all new trains arriving in Singapore would be put through testing and commissioning. The same was done for the KHI-CSR Sifang trains. During such testing, there was an incident on one train where the cover of the train battery housing flew open due to a build-up of gases. The manufacturer took immediate action to replace its supplier and improved the design of the battery housing for all affected trains.
Incidents of cracks of the draughtscreen on five trains were also discovered. These were found to be caused by errors during the installation process and unrelated to the hairline cracks found on the 26 trains’ car-bodies.
It is not unusual to detect some defects on new trains. We then take appropriate action to have them rectified by the manufacturer.
In July 2013, during a routine inspection of the trains, hairline cracks on the surface of the car-body bolster were found. 22 of the 26 trains were in passenger service then. LTA immediately carried out further inspections. No cracks were found on other components of the trains.
A typical hairline crack on bolster, measuring 142mm in length.
Laboratory tests showed that these hairline cracks were due to localised impurity in the aluminium car-body material that occurred during the manufacturing process. LTA engineers and its contractor assessed that the hairline cracks would not affect the operational safety of the trains. To confirm this, LTA further sought the opinion of an independent third-party assessor, TUV Rheinland, which concurred that the trains were safe to operate.
Due to the nature of the defect, the most effective way of addressing it is to replace the entire car-body shell. As the trains were under warranty, we required the contractor to replace the entire car body shell. Hence, since July 2014, the affected trains have been progressively sent back to the factory for rectification works. The costs of the shipping are borne by the contractor.
To ensure that this unexpected occurrence did not affect our train deployment, LTA has been working closely with SMRT. The replacement of a train car body is time consuming and labour-intensive, with each car body replacement taking up to four months. Hence, to minimise the impact on our train operations in Singapore as well as the lack of facilities and space for repair works of this nature at our depots, only one train is sent back to the factory in China at any one time.
We did not send all of the trains back at once as they were still fit and safe for service and we wanted to ensure sufficient train-availability for commuters.
Starting next year, with the arrival of more new trains for NSEWL and when trains currently undergoing resignalling are ready, LTA will be able to send two trains concurrently for replacement works. This will speed up the rectification programme and its completion can be brought forward to 2019.
As of today, the car-body replacement for five of the 26 trains has been completed. The car-body of the sixth train is being replaced. As per safety protocols, LTA, together with the contractor, will continue to carry out rigorous inspections to ensure that all trains are safe for service.
 A draughtscreen is the glass panel at the side of a row of seats on a train.
 A car-body bolster is a rectangular aluminum alloy structure measuring 2800mm (length) and 750mm (breadth) and 170mm (thick). It is the support for the car-body to rest on the bogie of the train.
 One train consists of six train cars. During the transportation process, it is logistically more convenient to transport the cars either individually or in pairs so that they do not cause any inconvenience on the roads.