See there is one rake and it is having schedule for 6 days and monday is reserved for maintaiance . Before this they cant run double dekkers at the decisions of drm first they need to test the train in that route to check eheyher the rake is encountering any problems with pf height of bridges in that route along witjh commissioner of safety get a safety ceryificate approval from both the zones then only they can run for your information dd is tested in sc wl bza route and the same has been sent to railway board througb safety commissioner for review and there is no concrete informatipn about approval of the same. In ltt route uoto madgoan it is tested anx cleared so they are running as special. Moreover sc to vizag requires two full days which is nit possible as of now