The WAP-7 has been serving passengers for Indian Railways since their introduction in 1999. It is a passenger variant of the WAG-9 freight locomotive with a modified gear ratio to pull lighter loads at higher speeds. With an output of 6,125 hp, it is the most powerful passenger locomotive in the Indian Railways fleet, and the most numerous passenger locomotive in India. The WAP-7 is capable of hauling 24 coach trains at speeds of 130 km/h.
The WAP-7 is largely used by most regional zones of Indian Railways. As of October 2021, all of these are fitted with H-type transition couplers which are compatible with both screw coupling and centre-buffer coupling.[original research?] In February 2017, Banaras Locomotive Works built their first WAP 7 class locomotive.[2]
In 2019, a variant of the WAP-7, designated the WAP-7HS, was introduced for higher speeds. The WAP-7HS has a max speed of 180 km/h (110 mph), and is capable of hauling a 24-car train at 160 km/h (99 mph) as opposed to the 140 km/h (87 mph) of the original. Indian Railways plans to use the WAP-7HS for Shatabdi, Rajdhani, and Duronto express trains. However, as of September 2022, it has not been confirmed[according to whom?] if any others have been built, and the single completed WAP-7HS has remained[as of?] restricted to 130 km/h (81 mph) operation.[This paragraph needs citation(s)]
In 2025, a variant of the WAP-7, designated the WAP-7AD, was introduced with an aerodynamic design. The WAP-7AD has a maximum speed of 180 km/h (110 mph), and is capable of hauling a 24-car train at 160 km/h (99 mph), as opposed to the 140 km/h (87 mph) of the original. Indian Railways plans to use the WAP-7AD for Amrit Bharat Express & other Express trains. The first WAP-7AD 37873 entered service on September, 2025 hauling 12284 Ernakulam Duronto express. A pair of WAP 7AD, painted with Amrit Bharat livery are currently parked at ICF, Chennai waiting for rake & route allotment.
The HOG ports are equipped on right side upper and left side down on Erode based WAP-7 at White Field railway station
Many locomotives of this class are fitted with head-on generation (HOG), eliminating the need to have separate End on Generation (EOG) sets or DG (Diesel Generator) sets for supplying power to the train and thus resulting in significant savings on maintenance and running costs. The HOG transfers electric power from the loco's pantograph to the coaches instead of EOG where a power car equipped with diesel generator capable of generating adequate power of 3-phase 50 Hz 415 V / 750 V AC (called 'head-end power') is provided at either end of the train rake to supply power.[3][4][5]
