The hairline cracks found on the 26 China-made trains did not pose a safety concern, hence the issue was not made public when the defects were first discovered in 2013, said Transport Minister Khaw Boon Wan yesterday.
The defects, which required the trains to be sent back progressively to the manufacturer in Qingdao to have their car-bodies replaced, also did not impact reliability or capacity, he added during a press briefing.
This issue, first brought to light by Hong Kong media FactWire last week, is a “seemingly routine matter” that had been “misspun” by “mischievous hands”, said Mr Khaw.
The trains are manufactured by Chinese-Japanese consortium Kawasaki-Sifang and used on the North South-East West Line (NSEWL).
While the trains – which each required around four months to be rectified – were sent back to China one at a time, this did not affect service operations.
This is because there is a “buffer” of trains, said Mr Khaw, meaning that currently only 124 of the 140 trains available on the NSEWL are needed to meet commuter demand.
To date, five of the 26 trains manufactured by Kawasaki-Sifang have been rectified.
The Land Transport Authority expects all 26 trains to be rectified by 2019.
The hairline cracks, which were discovered in July 2013, were found on the surface of the car-body bolster – the aluminium alloy structure under the train carriage.
About 85 per cent of the hairline cracks are shorter than 20cm and did not pose a safety risk. This was ascertained through tests conducted by LTA, Kawasaki-Sifang and an independent consultant from Germany, TUV.
Tests found that the bolsters could still withstand loads of three times greater than normal usage, and this is an acceptable safety margin, said the LTA.
Under the rectification works, the bolsters used will be cast in Japan rather than China.
adrianl@sph.com.sg
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See also:
– Our trains in Singapore are safe, says firm behind China-made MRT trains
– 5 out of 26 China-made MRT car-body replacements completed, rest to be finished by 2019
– HK operator to query company behind faulty SMRT trains
– Letter: Train cracks a telltale sign of inferior materials used
