It's nots a wise move to add 1AC as it gives lesser overall revenue to IR, vacany of berths in many intermediate sections, then an 2AC or 3Ac. Instead they should add 2AC as most trains have only one 2AC. Most 3AC passengers wanted upgrade to 2AC but with lesser coaches they are opting to fly wherever there is opportunity or travel time is more then 24hours. Now a days SL are like genral and 3AC like SL overcrowded.