Pic 1
125/126 is Kerala Express of today at that time it was Karnataka-Kerala Express(Biweekly)
At that time Karnataka Express was attached to Kerala Express at JTJ and used to run as one combined train.
Tamil Nadu, Telangana and Karnataka-Kerala were not daily at that time and all 3 of them used to run in same slot between NDLS and BPQ.
185/186 is Karnataka Slip which was attached to Kerala at JTJ.
No idea about 187/188 Slip Used to run till JTJ attached with Kerala.
Synopsis:
This 1979 Kerala was faster than today's 130 MPS wali Kerala. Even after carrying 1 set of slip coaches of 187/188 from TVC to JTJ and another slip of Karnataka from JTJ to NDLS, plus obviously a very long halt at JTJ it was still faster.
For Karnataka its not about fast or slow its about after separation from Kerala why did SWR choose SUR DD route when shorter route via SC and Kurnool was there.
Pic 2
Please note that this route was Metre Gauge back then.
177/178 is Rockfort
135/136 is Vaigai
117/118 is Pandiyan
101/102 is Boat Mail
No idea about current versions of
153/154 looks like Cholan but it isn't as Cholan was introduced in 2010.
137/138 between Madras Egmore and Quilon
119/120 between Madras Egmore and Tirunelveli
105/106 Mail between Madras Egmore and Quilon
103/104 Madras Egmore and Tuticorin Janta Express
Synopsis
All the trains are massively speeded up but Vaigai could have been speeded up more.