Bro I know that south of AJJ is not electrified. I'm here trying to say that no need to change the loco at YPR since it already runs with D-loco from PDY. It can run with same loco upto CSTM. A D-loco can run upto 2300 kms on full tank like LTT-GHY express does. But its okay since there's already a need of rake reversal at YPR.