IPR is the station code for Islampur, not IPP (Just to correct you).
Shramjeevi extension was planned by MR, Magadh's extension was requested by us (Our MP at that time was George Fernandes, Defence Minister).
As Primary maintenance could not be done at IPR, its' base was shifted to NR whereas RGD was having Washing Pit, therefore, its' base shifted to ECR.
Another purpose...
more... of these extension was to shift load of RJPB / PNBE.