Electrical supply to North South, East-West Lines to be delinked: Khaw
SINGAPORE - Electrical breaks will soon be installed at Jurong East and Raffles PLace interchange stations, to delink the North-South and East-West lines when necessary. This is to prevent the situation on July 7 when a train fault could not be identified and both lines had to be shut down, causing a major disruption and leaving thousands of commuters stranded.
Transport Minister Khaw Boon Wan wrote this in a blogpost on Thursday, entitled.
The two lines are linked to allow trains to move from the NSL to the EWL, and vice versa.
Wrote Mr Khaw: "Friends who are engineers were puzzled why we built such a closely-linked system where a breakdown caused by a power fault on one line could trigger a failure on the other line. Surely, we must be able to contain any failures so as to reduce their impact?"
"I put this question to LTA, who explained that the two lines were electrically linked to allow trains to move from the NSL to the EWL, and vice versa. The link was, and still is, essential as Bishan Depot on the NSL is the only depot across the two lines with heavy maintenance and overhaul capability.
"A decision was made in the early 80s to build only one such depot to minimise costs and land-take. (This limitation would disappear when the Tuas West Extension is completed next year, when we will have a depot on the EWL with similar facilities, at the Tuas West Depot.)
"Other than for maintenance, allowing cross-overs gives operational flexibility. Unfortunately, this also means that a power fault on one line could affect the other."
The solution, according to experts from the Land Transport Authority (LTA) and SMRT, is to delink electrical supply to the lines.
According to Mr Khaw's post, the electrical breaks will be installed by the end of next month.