Train service on the North East Line (NEL) between HarbourFront NE1 and Dhoby Ghaut NE6 stations was disrupted for about six-and-a-half hours today due to a power fault.
At 9.51am this morning, a power fault caused an initial delay of about 15 minutes. The fault was narrowed down to a stretch between HarbourFront and Outram Park stations and a decision was taken to shut down the line between HarbourFront and Dhoby Ghaut stations to enable engineers to enter the tunnel to conduct repair works. Train services were disrupted from 10.14 am and resumed at 4.32 pm this afternoon.
The cause of the disruption has been traced to a fault in the traction power system where three stainless steel U-shaped bolts holding two cantilever arms of the overhead power cables broke in the northbound tunnel between HarbourFront and Outram Park stations. Each arm is held by two stainless steel U-bolts. As a result of the breakage in the U-bolts, power wires were misaligned. To avoid the risk of damage to the trains and overhead power wires, a section of the tunnel was closed.
The fault is similar to one that had occurred in August 2012 in the same tunnel section. The stainless steel U-bolts in question were checked following the August incident and found to be in good working condition.
Given the August and most recent incident however, all U-bolts in the tunnel, starting with the section between HarbourFront and Outram Park stations, will be replaced. This initial section contains about 1,900 U-bolts and is expected to take about three months for the replacement to be completed. Concurrently, we are working with the Land Transport Authority to review and examine all possible causes and contributory factors to the recent incidents.
During the 6.5-hour disruption today, more than 130 Goodwill Ambassadors were deployed to the five affected stations and 63 free shuttle buses were activated to minimise the inconvenience for passengers. Affected commuters were also able to continue their journeys by taking free bus services at designated bus stops near the affected stations.
We deeply apologise to the estimated 58,000 passengers who were inconvenienced today.