SINGAPORE - Rail operator SMRT is upgrading a fleet of 20-year-old trains used for the North-South and East-West Lines.

The overhaul of the 19 six-car trains will include replacing their traction motors, air conditioning systems, and train doors.

When the upgraded trains hit the tracks progressively from the second quarter of 2017, commuters will also enjoy a graphical route map information system onboard.

The company revealed details of the train upgrading project, during a site visit to the Bishan depot on Wednesday (Nov 19).

The German-made C651 trains are manufactured by Siemens, and have been in service since 1996. With the upgrades, their lifespan will be extended by another 15 to 20 years.

"The improvements will reduce the incidence of train faults common to the Siemens C651 fleet, such as its propulsion system and door system faults," SMRT said on Wednesday.

The train upgrading project, which is led by Singapore Rail Engineering, a subsidiary of SMRT Corp, is expected to be completed in 2018.