The East-West Line is being equipped with the same signalling system as the North-South Line but it has yet to be fully installed for trials to be conducted.
SMRT will begin replacing the East-West's Line power-supplying third rail next month which will cost the company an estimated $13 million.
Train services on a portion of the North-South Line were delayed by up to 20 minutes yesterday, after SMRT engineers detected a sagging third rail.
Train services from Pasir Ris towards Tanah Merah were delayed by roughly 30 minutes yesterday afternoon due to a defective third rail.
In a joint briefing with LTA, SMRT has revealed plans to overhaul the older train fleet to enhance commuters' experience.