Indian locomotive class WDM-3A

WDM-3A
Krishnarajapuram based WDM-3A at Yeshwantpur.
Type and origin Power type Diesel–electric Designer BLW, RDSO Builder BLW, PLW Model Alco DL560C Build date 1994–2015 Total produced WDM-3A: 1402 Rebuilder PLW
Specifications Configuration: ​  • UIC Co′Co′  • Commonwealth Co-Co Gauge 1,676 mm (5 ft 6 in) Bogies AlCo Asymmetric Cast Steel Trimount Bogie (Old), Advance Trimount High Speed (ATHS) fabricated bogie (New) Wheel diameter 1,092 mm (3 ft 7.0 in) Wheelbase: ​  • Axle spacing (Asymmetrical) 1,702 mm (5 ft 7 in) 2,108 mm (6 ft 11 in) Pivot centres 10,516 mm (34 ft 6 in) Length: ​  • Over couplers 17,132 mm (56 ft 2+1⁄2 in)  • Over beams 15,862 mm (52 ft 1⁄2 in) Width 2,900 mm (9 ft 6+1⁄8 in) Height 4,185 mm (13 ft 8+3⁄4 in) Axle load 18.8 t (18.5 long tons; 20.7 short tons) Loco weight 112.8 t (111.0 long tons; 124.3 short tons) Fuel type Diesel Fuel capacity 5,000 L (1,100 imp gal; 1,300 US gal) Lubricant cap. 1,270 L (280 imp gal; 340 US gal) Coolant cap. 1,210 L (270 imp gal; 320 US gal) Sandbox cap. 160 L (35 imp gal; 42 US gal) Prime mover Alco 251-B (BLW Uprated) RPM range 400–1050 rpm Engine type V16 Four-stroke diesel engine Aspiration ABB VTC304-VG15 OR Napier NA-295IR OR GE 7S1716 Turbo-supercharged Displacement 175.14 L (38.53 imp gal; 46.27 US gal) Alternator BHEL TA10102CW Generator BHEL AG2702AZ (Old), BHEL AG3101AY-1 (New) Traction motors BHEL TM4906AZ or BHEL TM4907BZ ​  • Rating 1 hour 1060 amps  • Continuous 1000 amps Cylinders 16 Cylinder size 228.6 mm × 266.7 mm (9.00 in × 10.50 in) bore x stroke Transmission Diesel–electric AC-DC Transmission Gear ratio 18:65 MU working 2 Loco brake Air Brake, Dynamic Brake, Hand Brake Train brakes Air Brake Compressor 2,266 L/min (@ 400 rpm), 5,665 L/min (@ 1000 rpm)
Performance figures Maximum speed 120 km/h (75 mph) Power output Max: 3100 HP/ 3300 HP (Rebuilt) Site rated: 2900 HP/ 3007 HP Tractive effort 30.45 tf (298.6 kN) @ 27% adhesion Factor of adh. 2.6 Brakeforce 22 tf (220 kN)
Career Operators Indian Railways Bangladesh Railway Numbers 13xxx, 14001-14057, 14058-14143, 16000-, few in 18xxx series and 17xxx series Nicknames Cheetah, Prabal, Velociti, Awadh, Firex, Sher Punjab, Veer Preserved 1 Disposition active

The Indian locomotive class WDM-3A is a class of diesel–electric locomotive that was developed in 1993 by Banaras Locomotive Works (BLW), Varanasi for Indian Railways. The model name stands for broad gauge (W), Diesel (D), Mixed traffic (M) engine, with 3300 horsepower (3A). The WDM-3A is a later classification of earlier WDM-2C. They entered service in 1994. A total of 143+ were built at ALCO and Banaras Locomotive Works between 1994 and 2003 with rest of the 1246 units being rebuilt from WDM-2 which made them the most numerous class of mainline diesel locomotive until the WDG-4.

The WDM-3A is one of the most successful locomotives of Indian Railways serving both passenger and freight trains for over 26 years. A few WDM-3A units were exported to neighboring countries like Sri Lanka and Bangladesh. 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 April 2022, 769 locomotives still retain "operational status" on the mainline as WDM-3A, with further examples having been converted back to WDM-2 or WDM-2S. The loco is now^[when?] widely used across India for long-distance passenger trains due to its ruggedness and high tractive loads and acceleration.