you are right and i am not opposing your and official comment but this is generally seen in every section passenger trains have big number of stoppages and if i am not wrong then 22 intermediate Stations between Katpadi Junction and Villupuram Junction and the passanger stops all of the station which have listed on railways official website and if we calculate one on one station then roughly 10-20 minutes gap on TT then the passenger have not much of speed 90 if it go then it is around 40 to 50 if over speed like 90 or 100 then the pilot or train controller will not able to stop train within 10 to 20 minutes or 30 minutes stoppage, main thing is that the member @Nellai king has maded question which loco is sufficient for passenger then i guessed WAM because all the passenger which i have seen on...
more... working in electrified section runs on WAM and WAG because train not want sections high speed but Express/Mail and Super Fast will go around 90 because of less stoppages.