Something drastic and very innovative design solutions are required for the AC DD coaches/trains being operated by IR to become successful.
Instead of current design, IR should look forward to the Double decker 300kmph trains being successfully operated by TGV Rly system. The bogie fitted at end of coaches in these trains-sets are highly suitable for DD coach construction. IR should try to go for DD coaches in a big way after it successfully start operating such kind of SHS train sets within a few years as per current plan. Till then it is better to keep introduction of new DD trains in the back burner, as they are most likely to be a failure today.