LTA gives fuller details on sending back of MRT trains with defects

There were actually two incidences of cracks found on the batch of 26 trains.

Jonathan Lim | July 07, 2016, 10:51 AM

The Land Transport Authority (LTA) shared an update on Facebook on Wednesday (July 6) that provided greater detail into their shipping back of train carriages to China.

 

Things to note from the update:

- It is the LTA, not SMRT, that purchased the trains. Their contract was awarded to Kawasaki Heavy Industries and CSR Sifang in 2009 for 35 trains. They were progressively put into service from Feb 2013 after "rigorous testing".

- Cracks found on 26 trains' car-bodies were a result of the presence of localised impurities in the aluminium car-body material that were introduced during the manufacturing process. LTA's engineers, contractors and a third-party assessor TUV Rheinland concurred that the trains were safe to operate. 22 of the 26 trains were in operation at that time.

- An additional appearance of cracks on the draughtscreen on five of these trains were determined to be caused by errors in installation.

- The most effective way to rectify the defect was to replace the car-body. The trains were still under warranty, and thus were shipped back at the cost of the contractor.

- LTA worked with SMRT to ship back trains one at a time to avoid disrupting train operations. Each car-body replacement takes up to four months. Five out of 26 trains have been completed so far, while the rectification of all 26 trains will be completed by 2019.

LTA also included two photographs explaining in greater detail the cracks on the car-body bolsters:

carbody bolster crack Screenshot from LTA's Facebook page

carbody bolster Screenshot from LTA's Facebook page

Here is LTA's full statement:

The Land Transport Authority would like to address some of the issues related to 26 North-South and East-West Lines (NSEWL) trains that have been the subject of recent media and online discussion.

LTA awarded Contract 151A in 2009 to Kawasaki Heavy Industries and CSR Sifang to design, manufacture, and deliver 35 new trains for the North-South and East-West Lines (NSEWL). The trains were progressively put in service from February 2011, following rigorous testing on their safety and reliability.

Prior to the commencement of passenger service, all new trains arriving in Singapore are put through testing and commissioning. The same was done for the KHI-CSR Sifang trains, during which there was an incident where the train battery housing cover lid flew open due to a build-up of gases on one train. The manufacturer took immediate action to replace its supplier and improved the design of the battery box for all affected trains.

Incidents on 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.

A routine inspection of the trains in July 2013 found hairline cracks on the surface of the car-body bolster. 22 of the 26 trains were in passenger service then. LTA immediately carried out further inspections and found no cracks on other components of the trains.

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. 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.

LTA has been working closely with SMRT to ensure that this unexpected occurrence did not affect our train deployment. 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 completion brought forward to 2019.

As of today, the car-body replacements for five of the 26 trains have been completed and 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.

 

Related articles:

Ministry of Transport explains why 24 MRT trains were shipped back to the manufacturer

We summarise WTH is going on with MRT train cars being shipped back to China

 

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