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.

WDM-3A
Freshly repainted Ratlam-based WDM-3A resting at Ghaziabad Jn.
Type and origin Power type Diesel Builder Banaras Locomotive Works, Diesel-Loco Modernisation Works Model ALCO DL560C variant Build date 1994–2015 Total produced WDM-3A: 1402 Rebuilder Diesel-Loco Modernisation Works, Patiala
Specifications Configuration: ​  • UIC Co-Co Gauge 1,676 mm (5 ft 6 in) Bogies ALCO Asymmetric cast frame trimount Wheel diameter 1,092 mm (3 ft 7 in) Wheelbase 12.834 m (42 ft 1+1⁄4 in) Length 17.12 m (56 ft 2 in) Width 2.864 m (9 ft 4+3⁄4 in) Height 4.185 m (13 ft 8+3⁄4 in) Axle load 18,800 kg (41,400 lb) 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) Prime mover ALCO 251-C RPM range 400 - 1050 rpm Engine type V16 Diesel engine Aspiration ABB VTC304-15 or Napier NA 295 IR turbocharger Traction motors Bharat Heavy Electricals TA 10102 CW (new), BHEL TG 10931 AZ(old) Cylinders 16 Cylinder size 228 mm × 266 mm (8.98 in × 10.47 in) bore x stroke Transmission Diesel–electric MU working 2 Train brakes Air, Vacuum and Dual
Performance figures Maximum speed 120 km/h (75 mph) Power output WDM-3A: 3100 HP, WDM-3D: 3300 HP, WDM-3E: 3500 HP, WDM-3F: 3600 HP. Tractive effort 30.45 t (30 long tons; 34 short tons) Factor of adh. 0.27
Career Operators Indian Railways Numbers 13xxx, 14001-14057, 14058-14143, 16000-, few in 18xxx series and 17xxx series Nicknames Cheetah, Prabal, Velociti, Awadh, Firex, Sher Punjab, Veer Locale All over Indian Railways Preserved 1 Disposition active

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 widely used across India for long-distance passenger trains due to its ruggedness and high tractive loads and acceleration.

History

The first one was delivered on August 22, 1994, it was then WDM-2C.[1][2] First 57 units produced till March 1996 (Indian Railway road number 14001–14057) had rounded front hood profile similar to contemporary newer classes of locos built by DLW (WDG3A and WDP1).

After that there was a gap of long four years in the WDM-3A production line in BLW. These units have been retro-fitted with dual brakes, in addition to the air and vacuum brakes. The WDM-3A locos have a maximum speed of 120 km/h (75 mph). The gear ratio is 65:18.[3] These new locomotives had their control stand shifted to the left side of the cabin. Meanwhile, Diesel Loco Modernization Works (erstwhile Diesel Modification Works which again was known as Diesel Component Works) in Patiala started rebuilding the existing WDM-2 locomotives, which had reached midlife, with upgraded power-packs. DLMW Patiala re-calibrates the power-pack and upgrades the output power rating to 3100HP.[4] DLW again started building WDM-3A from the year 2000 and continued till the end of 2002 with locomotive road numbers in the range 14058–14143. All the locomotives rebuilt by DLMW and later batch from DLW had regular WDM-2 type square short hood profile and control stand position. DLW again built WDM-3A variant locomotives, during 2005–2006, in the road number range 14144-14167 which were classified as WDM-3B due to their difference in bogie design from classic ALCo asymmetrical trimount to HAHS design which was employed in WDG2 and later WDM-3D classes too. Most of the WDM-B were later converted to WDM-3D.

In 2011, DLMW rebuilt locomotive number 16502 as WDM-3A and equipped it with an Electronic Fuel Injection (EFI) system jointly developed by Engine Research Laboratory of IIT Kanpur, Engine Development Directorate of RDSO, and DLMW Patiala.[5] DLMW continues to rebuild WDM-2 as WDM-3A and recently they have started rebuilding the DLW built WDM-3A too when they reach their midlife. Recent rebuilt locomotives are rated at 3300 HP, and from 2009 onward they are equipped with Daulat Ram DBR, and since 2014 they are also equipped with an Auxiliary Power Unit (APU) in the short hood.[6] Some rebuilt locomotives have Co-Co-fabricated ATHS (Advanced Trimount High Speed) bogies instead of ALCo cast-iron type.[7] All the rebuilt WDM-3A bear the "-R" suffix to their road numbers.

In 2012 Bangladesh Railway ordered 26 WDM-3A from DLW. They are classified as Class 6500 there. These units, however, lack the dynamic braking which happens to be an essential component in their Indian counterparts.

Sub-classes

WDM-3C

The WDM-3C were just upgraded and more powerful WDM-3As with the ALCO engine gain rebuilt to output 3300 hp. It was the first follow-up experiment after the WDM-3A to squeeze more power out of the ALCO engine, an intermediary that would later lead to the development of the WDM-3D. Not many were produced, all of which were rebuilds of the WDM-2 or WDM-3A and were identical to the previous variants in every aspect. They can no longer be found over the railway network as all of them have been rebuilt into the WDM-3A or WDM-2 type.[8]

Locomotive sheds

Technical specifications

Technical details are as follows:[11][12]

See also

• Indian locomotive class WDM-2
• Indian Railways
• List of diesel locomotives of India
• Rail transport in India

References