I know that the Buffer time for the Second and Third train is Just 5 mins. Third train which leaves from Chennai Central never Overtake or din't Run before Second Train (Msb-Gpd EMU). This chain will be Helpful for those who don't want to Travel in a Crowdy Emu's. Second Connecting Train is a Peaceful one coz it's departing time is same as another Emu which is from Chennai Central at 18:30. So, Whatever the Rush they board Mas-Gpd local and the Known People only board this Msb-Gpd Emu from Korukkupet to Gummidipundi. After alighting at Gummidipundi will have to wait for few mins for the 3rd connecting Train. It will arrive on other Platform which is Just beside and there's no need for any foot over bridge for crossing to other Platform's.