The dep can be delayed to 610 and Kovai shifted to 615. As VB has quick acceleration it can clear the track by the time Kovai crosses Basin Bridge. Chennai 610 RU 800 VJA 1230. It is running 20 mins ahead in RU and VJA section in both directions. Return dep time should be same 1520 RU 1950 Chennai 2140. In return they are DD express arriving at 2035 which is already effected by VB overtake from MYS and Brindavan at 2110 Shatabdi 2130 Coimbatore Shatabdi 2150. It can't fit into the gap between DD and Brinda between Arakonam to Chennai as Alleppy Dhanbad is running. If placed before DD at Arakonam at 1900 to reach 2000 it has to trail Patna slot trains and also Ernakulam Tatanagar with perambur arrival 1945 lot of complications so was given 2200.