all construction of a single coach is with fixed parameters that can carry maximum weight at maxi speed...
now one can reduce the weight and increase speed
or inversely
increase the weight and reduce the weight
So...
more... if Berths are to be introduced as per "Indian conditions' what will be done ?
it is not 'temperature' of boggey or texture of the berth...
It is just to accommodate the 'no. of heads' or no of passengers
and then the economics of Fare is there... one boggey must bring so much rupees ...
Now if one boggey has only 36 berths as per Spanish standard.... India will loose 36 berths if it is SL, and proportionately for 2 tier 3 tier...