Sorry to contradict you. 3:50 AM is when the congestion begins. Out of the 12 platforms at MAS, 4 cant be used by trains as 1,2,2A are not long enough for 24 coaches. At 3:50 HWH Mail arrives on PF.No.8 after which it remains there without going to yard till it departs as Coromandel. Now considering the earlier timings, all these forementioned trains used to depart from MAS at around 4:05. Now from 4:05 AM, daily trains start arriving. Already they wait at BBQ/PER home for clearance. And mostly some arrive early. They need to wait for these trains which undergo reversal to clear the lines. Even if somehow a platform is got for weeklies, the problem is they get delayed terribly. They often arrive late by atleast an hour or more during peak hours at MAS. This eventually affects train movement( and also EMU movement towards GPD when they arrive...
more...

late). Perambur is no longer a corner of the city. It serves for North Chennai. Also there are EMUs for those who wish to go other parts of Chennai.
-@Praveen:
Sir, MS is already choked or even more than choked with its daily arrivals starting from 3:45 AM. Again SR will not shift daily trains to TBM. Weeklies to MS can be extended to TBM as they will halt at MS anyway. Terminating dailies at TBM will cause inconvenience to passengers as most of them arrive before EMU services begin. Shifting dailies from MAS to MS is not feasible.