SMRT moves to lower risk of repeat breakdown; root cause of disruptions still unknown

EVEN as the root cause of Tuesday night's train service disruption has not yet been determined, SMRT is putting in place immediate measures that it says will "mitigate the risk of a recurrence of the disruption" that brought services on the North-South East-West lines to a halt this week.

In a statement on Friday evening, the train operator said that these measures include rescheduling longer-term track upgrade and renewal programmes as necessary. This is so that priority for track access during the "limited maintenance hours at night" can be given to immediate remedial actions that can "safeguard the system against a recurrence".

SMRT is working with external experts to "review the design robustness of the power network" and to find ways to "further segment it in order to avoid a similar network-wide power failure", it added.

A number of retired SMRT staff with experience in network power issues have also been brought onboard to assist in the investigations.

While SMRT established on Friday that it is "highly unlikely" that the disruption could have been caused by a defective train, it is "actively" investigating the possible degradation in the insulation of power substation, power cable or third rail, it said.

"The rectifications made on the night of July 7 have stabilised the system sufficiently for normal service to have resumed these past three days," SMRT added. "However, until the root cause can be conclusively determined, SMRT is taking all possible precautionary and preventive measures to safeguard the system in terms of safety and service reliability."