| (EMD) 1997–1998
(EMD) 12 complete, 8 kit form
(DLW) 8 kit assembled, 564 + under license (still in production)
The EMD GT46MAC is a freight-hauling diesel-electric locomotive with AC electric transmission built by General Motors Electro-Motive Division in 1997–1998 for Indian Railways, where they are classed as WDG4. Thirteen were built by EMD as order #958647, and a further eight were exported in kit form and were assembled in India. The class entered service in 1999.
Further construction has been under license in India by the Diesel Locomotive Works (DLW); more than 60 additional locomotives have been built as of 2006. They are numbered from #12001 upward. A similar type, the EMD GT46PAC, has also been produced for passenger service in India.
As of 2007, EMD and DLW have begun building GT46Ace's using IGBT technology to replace the older gate turn-off thyristor technology. Newer editions with 4,500 hp (3,360 kW) have been produced. Over 1000 WDG4 locomotives are currently in operation.
EMD GT46MAC Wikipedia
WDG4s first started operations in 1999 with the numbering starting from 12001 (this loco can still be seen in a splendid condition and is homed at the parent shed of Hubli) Hubli Diesel Locomotive Shed has been operational since 1999, and it houses the maximum number of WDG4s from 12001-12064, 12067-12153, 12156, 12169, 12189, 12227, 12276, 12311–12313, 12325, 12326. The original WDG4s from 12001–12021 were imported and later on DLW started manufacturing it indigenously. With six traction motors, this locomotive has the capability of touching 105 km/h (65 mph) with a fully loaded freight train of 58 wagons. The locomotive has been praised for its ability to work smoothly in regions with massive gradients, especially in the (Braganza Ghats) and the Subrahmanya ghats having a gradient of 1:37 and 1:50 respectively.
A new model of the WDG4 has been manufactured which develops 4,500 hp (3,360 kW) and has a broader fibreglass cabin, wider wind screens, among other features. These locomotives have been specified as GT46ACe models. WDG4s are being looked into as future locomotives for freight operations in non-electrified sections of India. A new EMD locomotive classified as WDG5 # 50001 with 5,500 hp (4,100 kW) of power output has been manufactured, and is currently under testing at DLW (diesel locomotive works).
Sheds holding WDG4s as of August 2015: