WAP 7 is a high speed locomotive indigenously developed by Chittaranjan Locomotive Works. It is capable of hauling trains at speeds ranging between 140 and 160 km per hour and is now largely used by Northern Railways (NR), South Central Railways (SCR),Southern Railways (SR), Eastern Railways (ER), South East Central Railway (SECR),Central Railways (CR), Western Central Railways (WCR).
With a maximum speed rating of 205 km/h (IR restricts it to 160 km/hr), the WAP-7 has the highest acceleration figures while hauling mail/express trains. The WAP-7 can also haul loads of 24-26 passenger coaches (1430-1550t) at 140+ km/h per hour. It is also known to haul 18 heavyweight Air Conditioned coaches (1120t) in 1:40 inclines single-handedly. At a trial conducted by Indian Railways, it clocked a speed of 177 km/h. It is the most successful passenger locomotive in the Indian Railways portfolio after the WAP-4. It is used to haul premium trains like the Rajdhani Express and the Shatabdi Express apart from other regular mail/express trains. It also regularly hauls other trains like the Hyderabad – New Delhi, H.Nizamuddin-Thiruvananthapuram, H.Nizamuddin-Chennai, H.Nizamuddin-Bangalore, New Delhi-Sealdah and the New Delhi – Mumbai Rajdhani Express and Nizamuddin-Ernakulam Duronto Express.
WAP-7 locomotive can deliver 6000 HP with regenerative braking being one of its salient features. The regenerative braking is deployed on down gradients conserving energy to the tune of 30-35 percent. It has an inbuilt microprocessor based fault diagnostic system to make trouble shooting easier. Another feature of this locomotive is that it eliminates the need to have separate DG sets for air-conditioning in long distance trains hence providing significant amount of savings on maintenance and running costs. This technology, called HOG or “Head On Generation”, transfers electric power from the loco’s pantograph to the coaches instead of “End on Generation” in which a Power Car equipped with diesel generator capable of generating adequate power of 3-phase 50-cycle 415V/750V AC (called as hotel load) is provided at either end of the train rake to supply power.A 24-coach (1500t) passenger rake can be accelerated to 110 km/h in 240 seconds (over 4.7 km) by a WAP-7; to 120 km/h in 304 sec. (6.7 km); and to 130 km/h in 394 sec. (9.9 km).
The locomotive has started running to/from the Mumbai area of Western Railway from February 2012 and is expected to be used in the Mumbai area of Central Railway by January 2013. 160 WAP-7 locomotives have been put to service as of June 2013. Currently a 7000 hp version codenamed WAP 7-D with IGBT traction is under development by Chittaranjan Locomotive Works.
Manufacturers : Chittaranjan Locomotive Works, West Bengal, IndiaABB, Switzerland
Axle load : 20.5 tonnes
Locomotive weight : 123 tonnes
Electric system(s) : 25 kV 50 Hz AC
Top speed : 160 km/h (99 mph)
Test Runs : 205 km/h
Power output : 6,350 hp (4,735 kW)
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