issue which has been given utmost priority(One of the Five Goals set for this budget). So when speed comes into Picture you can rely on 3 names in Passenger Locomotive world
WAP 4, WAP 7 and WAP 5.
Now out of these 3 friends "WAP 5" has to be kept seperate why????
a It is a lightweight locomotive as compared to both P4 and P7
weight of P5 78 tons
Source:
click hereSee Specifications for weight of P5
weight of P7 123 tons
click hereSee Technical Specifications for weight of P7
weight of P4 112,800 kg (248,700 lb)=124 ton(1 ton=907.185 kg)
Source:
click hereSee Specifications for weight of P4
b It is capable of hauling 18 coacher light trains only. Heavier trains can't be hauled by WAP 5.
2 RM proposed to make all Most Popular Trains of IR to 26 Coacher so the charge of these will be shared between P4 and P7 brothers.
3 Electrification of Tracks are giving most priority so demand of Electric locomotives will be increased now if you have to run trains in 140 + speed(What RM wants for future) then P7 will be demanded more than p4
4 Lastly RM told to convert RDSO a "Center Of Excellence" in future and if you look at Past RDSO reports and specifications they have laid due emphasis on WAP 7. WAP 5 is hardly mentioned in past RDSO reports. Regarding WAP 4 RDSO wants "Hotel Load" to be commissioned in all WAP 4s like WAP 7s. So from the viewpoint of RDSO WAP 7 is also favorite.
So, considering the aforesaid circumstances and seeing the Reports of CLW regarding their 3 Phase Loco Project(Ref Entry #1353010) it can be concluded that demand of P7 will be increased in future.
However I came to know a news that presently a training programme is going in SRC regarding handling and maintenance of 3 Phase Locos though no official proof has yet not been seen either in Web or here in support of this training.
But SER should use WAP 7 for increasing the speed of their trains as because it is already in "Hotlist" regarding maximum number of passenger reduction in last 2 years and in SER average speed of trains is not more than 50 to 53 which is very shameful.
***** Lastly AC Locomotives have some crucial advantages over DC Locos( Ref Entry # 1355084) . These advantages are very important regarding "Cost of Running and Maintenance of Locomotives".********
Please see the "Electrical" Section of the last Annual Report of RDSO(Annual Report 2011-12) by clicking on the following Link
click hereYou can see what RDSO wants from P7 and P4
Index Page Link of Annual Reports Of RDSO (Annual Report 2011-12 is the last Annual Report of RDSO)
click here 
