SINGAPORE'S Land Transport Authority (LTA) and transport operator SMRT have decided to delink the electrical connections between the city-state's two major rail lines, the North-South (NSL) and East-West Lines (EWL), to avoid simultaneous breakdowns.
Transport Minister Khaw Boon Wan said in a blog entry that electrical breaks will be installed at Jurong East and Raffles Place interchange stations.
The decision was made following the July 7 train disruption when a breakdown caused by a power fault on one line triggered a failure on the other line.
"Under normal operations, these breaks will not be activated as we want to continue to have the flexibility between the NSL and EWL. But when the need arises, the two lines can be electrically disconnected,'' Mr Khaw said.
"The electrical breaks will be fully installed by the end of next month. After that, a simultaneous breakdown of NSL and EWL, as happened on 7 July, can then be avoided.''
The LTA had 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. 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,'' Mr Khaw wrote.
He added that when the Tuas West Extension is completed next year, Singapore will have a depot on the EWL with similar facilities, at the Tuas West Depot.