sir u have gotted the exact point.this are the pilot coaches which was manufectured as self generation.but they do not meets the railway expectations.but i thing i want to say that railway had not stopped the manufecturing the self generating coach.they had now come with better design.recently i have deleted a annual report of RCF Kapurthala in which they had designed a GS self generating in red livery(which is normal nowdays)coaches.