(Old class name was WDG-2, new class name is WDG-3A.) This 3100hp model was developed in response to problem areas noted with the WDM-2, such as ride quality, lateral oscillations, and poor traction with heavy loads. Power-pack is the same as that of the WDP-2.
First loco delivered on July 18, 1995. A WDG-3A / WDG-2 can haul about 3000 tonnes on ordinary gradients. Shares bogie design with WCAG-1, WCAM-3, WAG-7 (high-adhesion trucks). They are the most common goods locos seen on KR. The gear ratio is 74:18. Most of these are air-braked, but some (e.g., at Pune) are being retrofitted with vacuum brakes to make them dual-braked to handle the vacuum-braked freight stock (TP, TK petroleum tankers between Loni petrol depot and Miraj; some BCX rakes, etc.).
WDG-3Balancing speed of 69km/h with a 58 BOXN wagon load. Max. speed 100km/h. The WDG-2A variants are dual-braked. Some older WDG-3A units were made with left-hand-side driving position in the cab. [7/02] Newer units of the class are being fitted with microprocessor governors. The first of these variants, Garuda (#14951) is at Gooty. One WDG-3A, #14944 at Erode, has an air-conditioned cabin.
Engine: Alco 251C-16 upgraded by DLW, 3100hp. 1050rpm max / 400rpm idle. Fuel injection, cooling, fan, bore/stroke as with WDM-2C. Compression ratio 12.5:1. NAP NA2951R or ABB VTC304-15 turbo-supercharger.
Transmission: Electric, with BHEL TA 10102 CW alternator (1050rpm, 1130V, 4400A).
Axle Load: 20.5t; total weight 123t.
Bogies: Alco High-Adhesion Co-Co fabricated bogies
Starting TE:37.9t at 30.8% adhesion.
Length over buffer beams: 17850mm
Distance between bogies: 11500mm