Got a reply to one of my grievance on pgportal.
[{Grievance Description : Sir, Through this i kindly request you add two more sleeper class coaches and a second class unreserved coach to 18047/18048 Amaravathi Express. It is very difficult to get a confirmed ticket in this train especially for intermediate halts and also the unreserved coaches are jam packed. Train has very few coches presently for Howrah so two more coaches can be easily added to the convinience of passengers. So kindly please look into this matter and act promptly by necessary coach augmentation.
Current...
more... Status : CASE CLOSED
Date of Action : 15 Jan 2014
Details : e-mail representation is acknowledged with thanks. The matter has been examined carefully and remarks are appended below: Due to operational and other technical constraints between Guntakhal Madgaon extra coaches can not be attached by this train. Necessary efforts is being taken to augment the train in future. }]
I think the main constraints they mentioned here are the slip coaches. whats your view