WAG-9 is the name of a type of electric locomotive used in India. It is currently the most powerful locomotive in Indian Railways’ fleet. It is very similar to WAP-7; the only difference being the gear ratio which makes it suitable for heavy freight operations. In November 1998, CLW started producing these with indigenous components. The first one, ‘NAVYUG’ (translated, ‘New Era’), was flagged off on Nov. 14. They have ,like the WAP-5 units, GTO thyristorconverters and 3-phase asynchronous motors.
Newer versions starting from WAG-9 31248 feature full IGBT traction control. The class is named as WAG-9i. There is a technical variant of this class named WAG-9H.
This locomotive is referred to as the Heavy Haul freight locomotive of the Indian Railways, capable of hauling 6000 tonne freight trains at 120 kmph. This locomotive was conceived owing to the extreme growth in the rail freight transportation sector. The growth in this sector is considered to be of great importance in the growth of the economy of India. This need had arisen the need for more electrification and electric locomotives in India. Around 60-65% of the freight haulage of the Indian Railways takes place on the electrified section of the Golden Quadrilateral (Indian Railways) & diagonals (which account for 25% of the route). These routes are highly busy routes, so clearance is a necessity. This power give it a great sectional clearance ability. Thus these locomotives are important for the Indian Railways.
Around 400 of these locomotives have been put to service as of early 2013. These locos will enter Mumbai Area in Western Railway some time during the end of December 2011 or Start of January 2012 and Mumbai area of Central Railways at the start of January 2013.
Manufacturers : Chittaranjan Locomotive Works, West Bengal, IndiaABB, Switzerland
Axle load : 20.5 tonnes (20.2 long tons22.6 short tons)
Locomotive weight : 135 t.
Electric system(s) : 25 kV 50 Hz AC
Test Runs : 100 Km/ph (Hauling Capacity 60 Loaded BOXN or Container Load)
Power output : 6,350 hp (4,735 kW)
Tractive effort : 460kN  (WAG-9), 520kN (WAG-9H)