Indian locomotive class WDG-4

The Indian locomotive class WDG-4 (EMD GT46MAC) is a type of six-axle (Co-Co) freight-hauling diesel–electric locomotive with AC electric transmission designed by General Motors Electro-Motive Diesel in 1997–1998 for Indian Railways, where they are classed as WDG-4. Derived from the EMD SD70MAC, it is powered by a 4,000 hp (3,000 kW) 16-cylinder EMD 710G3B prime mover. Thirteen were built by EMD as order #958647, and a further eight were exported in kit form and assembled in India. The class entered service in 1999. A Dedicated Passenger version of this locomotive, the WDP-4 (EMD GT46PAC), has also been produced, with a Bo1-1Bo Wheel Configuration, which entered service in 2001. These locomotives are also famous for, and can be identified by, the distinct jet-airplane–like sound of the EMD 710 prime mover.

WDG-4
A three WDG-4s standing at Castle Rock.
Type and origin Power type Diesel–electric Builder EMD BLW Model GT46MAC (1997-2007) GT46ACe (2007-2016) JT46ACe (2013-2018) Build date (EMD) 1997–1998 (BLW) 2002–2018 Total produced WDG-4: 1188 WDG-4D: 583 (Mainline Production has stopped, but happens occasionally for Non-Railway Customers)
Specifications Configuration: ​  • UIC Co′Co′  • Commonwealth Co-Co Gauge 5 ft 6 in (1,676 mm) Trucks HTSC Length 21.26 m (69 ft 9 in) Height 4.11 m (13 ft 6 in) Axle load 21,000 kg (46,000 lb) Loco weight 126,000 kg (278,000 lb) or 126 t (124 long tons; 139 short tons) Fuel type Diesel fuel Fuel capacity 6,100 Litres Prime mover EMD 16-710G3B Engine type two-stroke V16 diesel Aspiration turbocharged Displacement 186.2 liters (11,360 cubic inches) Alternator TA-17-CA6A AC Traction motors 1 inverter per truck, AC traction motors Cylinders 16 Transmission diesel–electric Loco brake Air Train brakes Graduated Release Twin Pipe Air Brake, Dynamic Brakes, Blended
Performance figures Maximum speed 105 km/h (65 mph) Power output 4,000 hp (2,980 kW) / 4,500 hp (3,360 kW) Tractive effort 540 kN (120,000 lbf)
Career Operators Indian Railways, Sri Lanka Railways [as locomotive class M-11, Down-tweaked to 3,250 HP (2.4 MW) using a v12-710 prime mover] Numbers WDG-4: 12001–12999 & 70001–70190 WDG-4D: 12681 & 70301–70882

Further construction has been under license in India by the Banaras Locomotive Works (BLW), with the first purely indigenously built WDG-4 locomotive, numbered 12022, that rolled out in 2002. More than 60 additional locomotives have been built as of 2006. They are numbered from #12001 upward.

As of August 2007, EMD and DLW have begun building GT46ACe's using IGBT technology to replace the older gate turn-off thyristor technology and along with increase of 500 hp, ie, 4,500 hp (3.4 MW), using the Newly tweaked EMD 16N-710G3B-EC, like the passenger WDP-4B have been produced. Newer versions with widened Piggy-face cab profile for enhanced visibility, just like the later variants of WDP-4's and WDP-4B's were also produced.

As of February 2013, DLW began building the Dual Cab version, EMD JT46ACe, called WDG-4D, based on the passenger variant WDP-4D locos, same for both-side visibility. Here again, many features, including IGBT and 4,500 hp have been carried on from the single cab GT46ACe's. The first WDG-4D, numbered 12681, is named "Vijay". Later WDG-4D's were numbered from 70301, as the 12*** series came to an end in 2014 and got switched to 70*** series. Over 1,500 such locomotives, including both WDG-4's and WDG-4D's are currently in operation.

Indian Railways has also developed the WDG-4 series into EMD GT50AC (aka WDG-5), using a v20-710G prime mover, based on the SD80MAC, rated at 5,500 HP (4,130 kW). However, this locomotive has turned out to be a Failure, due to various reasons.

Since the year 2017, BLW (DLW then) began manufacturing such locomotives for Non-Railway Customers. The first such locomotive, which would be a Dual-Cab WDG-4D, rolled out to serve Odisha Power Generation Corporation (OPGC), in March 2017. Three WDG-4D locomotives currently serve OPGC. As of 2024, two new Single-Cab Piggy-face WDG-4 locomotives have been manufactured and rolled out for Obra Thermal Power Station, based at Sonbhadra, Uttar Pradesh.

Locomotive sheds

Zone	Name	Shed Code	Quantity
			WDG-4/4D
Central Railway	Pune	PA	90
	Kalyan	KYN(D)	64
Eastern Railway	Andal	UDL	133
East Central Railway	Patratu	PTRU	79
East Coast Railway	Visakhapatnam	VSKP(D)	121
Northern Railway	Ludhiana	LDH(D)	26
	Lucknow	LKO	58
	Tughlakabad	TKD (D)	49
North Eastern Railway	Izzatnagar	IZN	6
North Central Railway	Jhansi	JHS (D)	50
Northeast Frontier Railway	New Guwahati	NGC	39
	Siliguri	SGUJ	154
North Western Railway	Bhagat Ki Kothi	BGKT	48
	Abu Road	ABR	107
Southern Railway	Ponmalai Goldenrock	GOC	80
	Ernakulam	ERS	22
	Tondiarpet	TNP	9
South Central Railway	Kazipet	KZJ(D)	62
	Gooty	GY	9
	Vijayawada	BZA(D)	44
	Moula Ali	MLY	18
South Eastern Railway	Bondamunda	BNDM(D)	119
South East Central Railway	Raipur	R	98
South Western Railway	Krishnarajapuram	KJM	26
	Hubli	UBL	156
Western Railway	Sabarmati	SBT	28
West Central Railway	Itarsi	ET(D)	53
Total Locomotives Active as of October 2024			1748

Non-Railway Operators

Name of the Operator	Quantity
	WDG-4/4D
Odisha Power Generation Corporation	3
Obra Thermal Power Station	2

See also

• Indian locomotive class WDP-4
• List of diesel locomotives of India
• Indian Railways
• Rail transport in India

External links

• Detailed Specifications for the WDG4