Sunday 24 June 2012

Circle Line's faulty cables to be replaced; LTA completes investigation of CCL train service disruption on 20 Sept 2011

Contractor to bear cost; no fine for SMRT as it was not at fault
By Royston Sim, The Straits Times, 23 Jun 2012

THE Land Transport Authority (LTA) will be replacing defective and damaged cables along the new Circle Line, in a move to improve reliability of the train service.

These cables were uncovered in the course of tests done after a breakdown last September that affected 27,000 commuters.

The faults in the cables were traced to manufacturing defects and poor workmanship.

As a result, new checking processes have also been introduced on top of replacing the cables under a programme that is likely to start next year and end by December 2015.

But the replacement of the cables will not affect the train service, said the LTA yesterday.

It also said rail operator SMRT will not face any penalty for the four-hour breakdown as investigations showed it was not at fault.

Instead, Alstom, the contractor in charge of laying the cables, will bear the replacement cost. When contacted, it declined to give the cost.

The Circle Line, which opened in stages from May 2009, was fully up and running last October.

As a result, the breakdown took many by surprise.

Immediate investigations uncovered a damaged direct current cable at Dakota station had caused a power trip that shut down the entire line.

But subsequent tests found there were also manufacturing defects in some batches of the Circle Line cables, like gaps in the cable insulation.

In addition, some cables were damaged while being installed, with scratches on the external sheath.

These defects 'do not immediately impede the functioning of the cables or affect MRT operations', said the LTA. Still, the cables will be replaced for 'greater MRT reliability'.

The LTA is working with Alstom to do a site survey and assess the extent of replacement.

Meanwhile, SMRT will do checks more often, at three-month, not six-month, intervals to ensure faulty cables are promptly replaced.

Procedures to identify such faults have also been improved so that SMRT can resume service more quickly, said the LTA.

Other changes include 'more rigorous' tests of the cables at the factory before they are accepted and more stringent supervision of cable installation.

Asked why the defects were not spotted earlier, an LTA spokesman said tests done during the testing and commissioning stage and routine tests by SMRT did not pick up any deterioration of cable insulation.

As for the Dakota station cable that was responsible for the September breakdown, the spokesman said its defect coupled with exposure to water in the cable pit caused it to deteriorate at a faster rate than expected.

The SMRT will ensure the cable pits are dry 'at all times' by checking it regularly, said the LTA.

LTA to look at improving acceptance process of MRT infrastructure
By Olivia Siong, Channel NewsAsia, 23 Jun 2012

The Land Transport Authority (LTA) is looking at how it can improve its "acceptance process" of rail systems before putting them into service.

Transport Minister Lui Tuck Yew said this is one of the lessons drawn from last year's Circle Line train service disruption.

The acceptance process looks at whether the equipment and installations on new rail structures match LTA's specifications.

Some 27,000 commuters were affected in last September's Circle Line train disruption, which lasted four hours during the morning peak period.

The LTA said on 22 June that the cause was traced to faulty power cables.

Investigations also revealed manufacturing defects on some cables.

LTA will embark on a planned cable replacement programme to change the defective cables for greater MRT service reliability.

Speaking on the sidelines of a community event on Saturday, Transport Minister Lui Tuck Yew said LTA will look at improving its acceptance test of new rail lines.

He added that authorities took some time to investigate last September's Circle Line breakdown, as some defects are not easy to detect.

"Hopefully we will learn from it to improve on it, to improve on the acceptance process of the system. Before the system is put into operation you do extensive testing, but you also do an acceptance process. So we will need to look at it and see how we can improve on the acceptance.

"But some of these defects, let me tell you, are also not easy to pick up. It is not easy to pick up, which is why, we had to have such a long interval between the September Dakota incident and now the release of the investigation because we had to actually send quite a number of batches of the cables for further testing, in order to be able to identify and determine how extensive some of the defects in the cable are."

Mr Lui also gave an update on the Committee of Inquiry (COI) tasked to look into last December's train disruptions on the North-South line.

More than 200,000 commuters were affected in the two major disruptions, which took place on the December 15 and 17 in 2011.

He said the committee, which completed its hearing on 25 May, is finalising its report.

He added the inquiry has been thorough and comprehensive.

"We have already seen some of the possible recommendations that were talked about even as they went through the process of the COI. I believe they are at the end stage of putting together the report and I will await their submission.

"When the recommendations come out, we will of course study them very carefully, look at what else we need to do to make sure we improve on the maintenance and the reliability of the system.

"It will take time and I think it will be a process where we really need to pay stringent attention to what is being done both within SMRT and in time to come what is also done in SBS Transit."

Mr Lui reiterated that improvements have been made already. This includes establishing the joint LTA and SMRT team to investigate faults and problems.

He said the maintenance philosophy has also been re-looked.

Mr Lui said he expects to receive the committee's report soon.

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