South-Bound train services were delayed during the morning peak period yesterday by a rail crack - the third such damage in five weeks.
SMRT said the crack was discovered between the Yio Chu Kang and Ang Mo Kio stations at 6:25am. A speed limit of 40km/h along the stretch was imposed and journey times were up to 40 minutes longer.
However, trains could move faster and journey times improved after G-clamps were put in place to stabilise the affected area. By the evening peak period, train services were largely back to normal.
An SMRT spokesman said the latest crack was in a section that appeared worn but was still within operating tolerance.
It will be inspected more closely upon replacement after service hours last night. SMRT will also hold a technical meeting this morning to get to the bottom of the matter.
Rail cracks have been rare in the Singapore network until recently. Before the recent three incidents, there was an average of only one crack per year.
While the last two cracks occurred at welded joints, yesterday's fracture did not. All, however, appeared on the North-South Line.
