Faulty power cables caused 20 Sep 2011 Circle Line disruption

Faulty power cables caused the disruption on the Circle Line (CCL) on 20 September last year. The disruption affected nearly 27,000 commuters. 

In a statement, the Land Transport Authority (LTA) said it has completed its investigations into the train service disruption. 

LTA said the faulty power cables had affected traction power to the trains. 

LTA said checks were conducted on all direct current (DC) cable at Dakota station. It was found that the deterioration of the defective cable was made worse by the presence of water in some cable pits. 

LTA 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 The checks uncovered three other cables at risk which have since been replaced by the contractor. 

LTA said subsequent laboratory tests conducted revealed certain manufacturing defects in some batches of these cables as well as damage in some cables sustained during the installation process. 

While these defects do not immediately impede the functioning of the cables or affect MRT operations, LTA will embark on a planned cable replacement programme to replace the defective cables for greater MRT reliability. 

LTA says 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. 

As LTA's findings show that SMRT is not at fault for the damaged cable, no penalty will be imposed on the operator for this incident.