SINGAPORE: It was "bad luck" that train service was temporarily disrupted during Sunday's preview of new stations along the Downtown Line (DTL), said Transport Minister Khaw Boon Wan on Monday (Oct 16).

A train fault near Hillview station suspended train service between Bukit Panjang and Beauty World stations on DTL2 for about 40 minutes, while services along DTL3 were also affected.



Still, the DTL remains one of the most reliable lines in terms of mean kilometre between failure (MKBF), Mr Khaw noted during a question and answer session after a news conference on the North-South Line tunnel flooding incident on Oct 7.

The DTL, which is operated by SBS Transit, clocked an MKBF of more than 1 million kilometres in a mid-year report by the Land Transport Authority (LTA).

“I hope commuters realise that high MKBF doesn’t mean no delay," said Mr Khaw. "Sometimes things will happen … For it to happen when we are doing an open house, that is bad luck.

“But I was happy to read that the recovery effort was quite speedy. And I hope we do appreciate some of these improvements that have been made in the system - that people are able to go in, identify the fault, correct it and and fix it."





He added: “So what are the odds for bad things to happen, when you are celebrating good things?”

Citing an article in The Economist, Mr Khaw said there was “a rational basis for it”.



“Supposing the line is very reliable and you hit 1 million km MKBF,” he explained. “You praise them, but what does it mean? When you reach a million, the risk of you getting a failure is anytime now, unless you achieve 2 million km MKBF.



“When you’ve just achieved 1 million, then the likelihood of a delay happening the next day or next week is very high. That is how things work. It is statistical.”

Mr Khaw added: “But of course, we should all try to strive towards perfection, meaning infinite MKBF. We know it’s very difficult, but we should look at the outcome versus the current status quo. Are we improving?



“If we do, let us pay compliments to our hardworking staff. If occasionally an issues crops up, then let’s get to the root of it, understand it, and fix it as much as we can.”

