Indian locomotive class WDAP-5

The Indian locomotive class WDAP-5 is a class of diesel-electric dual mode locomotive that was developed by the Banaras Locomotive Works (BLW), Varanasi for Indian Railways. The model name stands for broad gauge (W), Diesel (D), AC Current (A), Passenger (P) and 5000 Horsepower (5). The locomotive can deliver 5500 hp (4.1 MW) in electric mode and 4500 hp (3.4 MW) in diesel mode.

Since 2016, Indian Railways has pushed for greater electrification of the railway network.^[1] At the time, Indian Railways had electrified 52,247 route kilometers (RKM), about 80% of the total broad gauge network.^[2] In this interest, the government, in 2019, approved plans for 100% electrification.^[3] Using electric locomotives allows the railways to save time as they accelerate faster and also save fuel costs. However, these advantages were offset under certain circumstances where the route of the train was partly electrified. In such cases, trains used to run with a diesel locomotive in non-electrified sections and would be switched with an electric locomotive as soon as they enter an electrified section. Instead of the benefits of electrification, a loss of punctuality in such trains was observed due to the time being lost to switch between diesel and electric locomotives. To counter this, in August 2019, Railways issued a circular, asking all zones to haul trains with a diesel locomotive if their route was not completely electrified.^[4] This meant that electrification of railway lines, unless completed end-to-end, did not provide any advantage. This problem had been identified by the Railways, way back in 2016, which is when RDSO was requested to study the feasibility of dual-mode locomotives as a stop-gap until 100% electrification was achieved.^[5]

The first and only unit of the class WDAP-5 locomotive, numbered as 71000, was turned out of the BLW workshop in March, 2020. However, in the same month, the railways had to shut down all regular train services due to the COVID-19 pandemic. ^[6] This oportunity was used to rapidly electrify the railways. Still, in 2021, trial runs were conducted in the stretch between Kota and Nagda, with the locomotive reaching speeds of upto 150 km/h (93 mph) in electric mode.^[7] The locomotive was transferred to Kazipet loco shed and tested. ^[8] As of June 2025, 68,952 route kilometres (RKM) had been electrified, which is 99% of the broad gauge network. ^[9]Hence, no practical use case for the dual-mode locomotive could be perceived as its purpose is served mainly by electric locomotives. So, no other units of WDAP-5 locomotives were produced other that 71000. The one unit produced never entered commercial service. As of 2025, this locomotive is stored in the diesel loco shed of Tughlakabad.