SINGAPORE: All circuit breaker trip coils along the Tuas West Extension have been replaced, the Land Transport Authority (LTA) said on Thursday (Dec 17).
As a pre-emptive measure against power cable faults and potential service disruptions, LTA announced last month that all 113 trip coils would be replaced by the end of 2020. Trip coils are components in circuit breakers which function to isolate power faults.
Plans for the replacement were announced after more than 120,000 commuters were affected by a three-line MRT disruption on Oct 14. LTA said in a report following the incident that the disruption was caused by the "occurrence of concurrent faults", starting with a faulty power cable on the Tuas West Extension.
On Thursday, LTA said that the early closures carried out last month along the Tuas West Extension helped to expedite the completion of the trip coil replacement programme.
The changeout of the 22kV circuit breaker trip coils was conducted by LTA, their main contractor Alstom, and SMRT.
As part of the precautionary measures, about 150km of 22kV power cables along the Tuas West Extension will also be replaced.
The new batch of “higher-specification cables” are expected to progressively arrive from the middle of this month, said LTA.
Replacement works will begin in January, starting with the section along Tuas Depot Intake and Tuas Link station.
Works will be carried out during normal engineering hours at the start. To speed up cable replacement works, LTA and SMRT will schedule early closures and late openings on weekends or full Sunday closures along the Tuas West Extension from March to May.
Cable replacements are expected to be completed by the end of next year.
LTA said members of the public will be given advance notice of the scheduled early closure dates and affected stations.