UDAY ka Concept to bekar tha...But Tejas ka Concept Fruitful tha... Kyunki pahli baar es train me Automatic Doors ki suvidha ka Implementation hua ...Jiske Proggressive Phase me Baad me T-18 ka Concept aaya...ye ek Progressive Move tha Resultant T-18 & T-19 Concept aaya....👍👍👍