WAP-5 and WAP-7 are more powerful than WAP-4 like WCAM-2 and WCAM-3 are more powerful than WCAM-1 but thier outputs appears to be the same.
Like for 12951Mumbai Rajdhani, WCAM 2 did avg speed of 90 Kmph from BCT to BRC while WAP-5/7 did 89 Kmph from BRC to NDLS.
But atlast the work was fully handed over to WAP-5/7 after WR ac conversion
3...
more... phase mostly given to important those connect capital cities like
CR- Sevagram exp connecting second capital (of Maha) nagpur to capital mumbai, Pune GR i.e connecting nagpur and third capital pune, etc.
NR- Rajdhanis, Shatabdis connecting the capitals of diff states.
and also the long rake trains and high speed trains too like.
SCR- AP exp, Dakshin exp, etc