The Indian locomotive class WDG-3A is a class of diesel-electric locomotive that was developed in 1994 by Banaras Locomotive Works (BLW),Varanasi for Indian Railways. The model name stands for broad-gauge (W), Diesel (D), Goods traffic (G) engine, 3,100 hp (3A) locomotive. They entered service on 18 July 1995. A total of 1,164 WDG-3A units were built between 1994 and 2015 at BLW, Varanasi with a few units being produced by Diesel Loco Modernisation Works (DLMW) and Parel Workshop.
It is the dedicated freight version of the very successful WDM-2 and shares the same engine and horsepower rating with WDM-3A. It is considered to be a successful locomotive class with high reliability and few maintenance problems. Despite the introduction of more modern types of locomotives like WDG-4 and electrification, a significant number are still in use, both in mainline and departmental duties.
As of September 2023, 787 locomotives still retain "operational status" on the mainline as WDG-3A, with a few examples having been converted to WAGC-3 or WAG-10.
