The Chennai Suburban Electric Trains are the life line for many in the suburbs of Chennai to reach their schools / colleges / work. They ply between Chennai Beach to Tambaram (30 Kms & 18 stations) & further to Chengalpet in the South, Chennai Central to Pattabiram (25 Kms & 15 stations) and further to Arakonam in the west(addnl 34 Kms and 14 more stations) and Chennai Central to Gummidipoondi in the North (48 Kms & 16 stations)

Also the MRTS which runs between Beach till Tiruvanmiyur & further to Velachery is another spin-off of these Electric Trains in the North – South Corridoralong the Buckingham Canal and also to be extended till St. Thomas Mount.

Now with the Chennai Metro being planned as 7 corridors, with the 1st two getting implemented in the first between (corridor 1) Airport to Washermanpet and (corridor 2) Fort – Annanagar – Ring Road – St Thomas Mount.

This brilliant map by PlaneMad is very descriptive of the Train service.

Found a brilliant reminiscence of a EMU user here.