The Indian locomotive class WDP-4 is a passenger-hauling diesel-electric locomotive with AC electric transmission designed by General Motors Electro-Motive Division and built by both GM-EMD and under license by Banaras Locomotive Works (BLW) of Varanasi, India for Indian Railways as the classes WDP4, WDP4B and WDP4D. The GT46PAC is a passenger version of the previous Indian Railways EMD GT46MAC freight locomotive. The locomotive has a 16-cylinder 710G3B diesel engine and is one of the fastest diesel-electric locomotives in service in Indian Railways.

The EMD 710 is a line of diesel engines built by Electro-Motive Diesel. The 710 series replaced the earlier EMD 645 series when the 645F series proved to be unreliable in the early 1980s 50-series locomotives which featured a maximum engine speed of 950 rpm. The EMD 710 is a relatively large medium-speed two-stroke diesel engine that has 710 cubic inches displacement per cylinder, and a maximum engine speed of 900 rpm.