SMRT escapes scot-free on embarrassing Circle Line disruption

LTA's official investigation absolves the transport firm from negligence or fines relating to last year's extensive breakdown.

In its report, the Land Transport Authority instead blamed faulty cables "that affected traction power to the trains" for the service disruption on the Circle Line (CCL) on on 20 September 2011 that affected about 27,000 commuters. 

"As LTA’s findings showed that SMRT is not at fault for the damaged cable, no penalty will be imposed on the operator for this incident," said LTA, blaming instead "certain manufacturing defects in some batches of these cables as well as damage in some cables sustained during the installation process."

"Immediate investigations conducted after the incident found that the disruption was caused by a damaged direct current (DC) cable at Dakota station. In addition, it was found that the deterioration of the defective cable was exacerbated by the presence of water in some cable pits. LTA had then instructed its contractor to replace the damaged cable at Dakota station and to conduct checks on all DC cables that were installed for the CCL. The checks uncovered three other cables at risk which had since been replaced by the contractor," it said.

"While these defects do not immediately impede the functioning of the cables or affect MRT operations, LTA will nonetheless embark on a planned cable replacement programme to replace the defective cables for greater MRT reliability. In the meantime, checks will be done every three months to identify if any cables have deteriorated and, if so, they will be changed immediately. The full completion of the replacement programme is targeted for end December 2015, and the costs will be borne by the contractor," it added.

LTA assured that the CCL passenger service will not be affected during the cable replacement programme, and that the trains resumed service without any risk to passenger safety.

"As a precautionary measure, while the cable replacement programme is ongoing, SMRT will conduct insulation tests on the cables more frequently so that any signs of cable failure can be detected early and rectified. SMRT will also continue to regularly inspect cable pits and ensure that they are dry at all times," it said.

"Learning from the incident, LTA has worked with SMRT to improve the work processes to identify and isolate cable faults, so that the traction power and train service can resume within a shorter time. LTA has also put in place more rigorous factory acceptance tests to check such cables and tighter procedures to supervise the cable installation process to reduce the risk of cable damage," it added.

"LTA would like to assure the public that during the disruption and recovery process of this incident, commuter safety was at no time compromised. For commuter safety, the rail system is equipped with a safety feature that will temporarily shut down train service in the event of a power trip. This allows for sufficient time to isolate the problem. Train service is only resumed when the system is confirmed to be safe," it said further.