If speedup happen then train will reach very odd time at howrah around 1 AM , to compensate this time whole time table needed to be changed . Revise TT will be like
Jbp 9 pm /train/56758
It will act like saviour intercity train from Dhn to hwh after Black diamond in peak evening time and follow Rnc-hwh shatabdi from dhn till Hwh .
1144...
more... km in 25 hours . Avg speed 46kmph , decent speed for M/E train with 42 halts .