The Tamil Nadu Express or T.N. Express is a passenger train route of the Indian Railways. The train was first started on 7 August 1976 by then Prime Minister, Mrs. Indira Gandhi as a bi-weekly was the first State named train of the south. It runs between Chennai (Chennai Central) and New Delhi (New Delhi railway station) In 1976 it was a tri weekly train, then made four times a week just before the 1982 Asias and then converted to a daily train by Madhav Rao Scindia in June 1988 and who added Gwalior to the stoppages. Numbered 12621/12622 this train belongs to the superfast category of Indian Railways.
The train numbered 121/122 when it was introduced. It started off with RED-CREAM...
more... livery (a la old style Rajdhanis), briefly switched to GREEN-YELLOW (like present day Garib Raths) before falling in line with the REGULATION BLUE.
When it was a non-daily train it shared time slots with AP Express and KK Express. Yes the KK express, when introduced a couple of months later, was the KERALA-KARNATAKA EXPRESS. The train from Delhi used to split at Katpadi or Jolarpettai and one portion used to go to Bangalore and the other to Trivandrum (now called Thiruvanthapuram). Similarly the 2 portions used to combine at one of these stations and run to New Delhi. Later on all of them were made dailies with separate time slots.