A series of unresolved cable faults which had beset the Tuas West Extension since it opened in 2017 led to the massive three-line MRT breakdown on Oct 14.
All the power cables on the extension will now be replaced. In all, French engineering group Alstom - which installed the power lines - will replace 150km of cables with new ones of a higher quality.
The decision came after a section of cables burnt through on Oct 14. The failure would have been isolated by circuit breakers in the area - as was the case in four previous incidents. But on Oct 14, one failed to work. In fact, it melted from the heat.
Alstom will also replace 113 trip coils - the main component of circuit breakers - in this three-year-old extension of the East-West MRT line.
The move - which will involve early closures and late openings of stations over weekends up till the end of next year - is reminiscent of the re-cabling exercise for the equally new Circle Line.
In 2012, after repeated power-related train disruptions on the orbital line, the fault was traced to power cables - also installed by Alstom - which were exposed to water in the train tunnels.
The decision was made then to replace the cables, which usually last 20 to 30 years, with a more water-resistant type. The exercise, involving 120km of cables, was completed in 2014 for $15 million. Alstom was said to have borne the bulk of the cost.
