| WDM-3A | |
| Powertype: | Diesel–electric |
| Designer: | BLW, RDSO |
| Builder: | BLW, PLW |
| Buildmodel: | Alco DL560C |
| Builddate: | 1994–2015 |
| Totalproduction: | WDM-3A: 1402 |
| Rebuilder: | PLW |
| Britishclass: | Co-Co |
| Uicclass: | Co′Co′ |
| Bogies: | AlCo Asymmetric Cast Steel Trimount Bogie (Old), Advance Trimount High Speed (ATHS) fabricated bogie (New) |
| Wheeldiameter: | 1092mm |
| Pivotcentres: | 10516abbr=onNaNabbr=on |
| Wheelspacing: | 1702abbr=onNaNabbr=on 2108abbr=onNaNabbr=on |
| Over Couplers: | 17132abbr=onNaNabbr=on |
| Over Bufferbeams: | 15862abbr=onNaNabbr=on |
| Width: | 2900abbr=onNaNabbr=on |
| Height: | 4185abbr=onNaNabbr=on |
| Axleload: | 18.8t |
| Locoweight: | 112.8t |
| Fueltype: | Diesel |
| Fuelcap: | 5000L |
| Lubecap: | 1270L |
| Coolantcap: | 1210L |
| Sandcap: | 160L |
| Primemover: | Alco 251-B (BLW Uprated) |
| Rpmrange: | 400–1050 rpm |
| Enginetype: | V16 Four-stroke diesel engine |
| Aspiration: | ABB VTC304-VG15 OR Napier NA-295IR OR GE 7S1716 Turbo-supercharged |
| Displacement: | 175.14L |
| Alternator: | BHEL TA10102CW |
| Generator: | BHEL AG2702AZ (Old), BHEL AG3101AY-1 (New) |
| Tractionmotors: | BHEL TM4906AZ or BHEL TM4907BZ |
| T/M Amps 1 Hr: | 1060 amps |
| T/M Amps Cont: | 1000 amps |
| Cylindercount: | 16 |
| Cylindersize: | 228.6x bore x stroke |
| Transmission: | Diesel–electric AC-DC Transmission |
| Gear Ratio: | 18:65 |
| Multipleworking: | 2 |
| Maxspeed: | 120km/h |
| Poweroutput: | Max: 3100 HP/ 3300 HP (Rebuilt) Site rated: 2900 HP/ 3007 HP |
| Tractiveeffort: | 30.45tf @ 27% adhesion |
| Factorofadhesion: | 2.6 |
| Locobrakes: | Air Brake, Dynamic Brake, Hand Brake |
| Locobrakeforce: | 22tf |
| Trainbrakes: | Air Brake |
| Compressorcap: | 2,266 L/min (@ 400 rpm), 5,665 L/min (@ 1000 rpm) |
| Operator: | Indian Railways Bangladesh Railway |
| Fleetnumbers: | 13xxx, 14001-14057, 14058-14143, 16000-, few in 18xxx series and 17xxx series |
| Nicknames: | Cheetah, Prabal, Velociti, Awadh, Firex, Sher Punjab, Veer |
| Preservedunits: | 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 widely used across India for long-distance passenger trains due to its ruggedness and high tractive loads and acceleration.
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 (WDG-3A and WDP-1).
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 120km/h. 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 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.
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]
| Zone | Name | Shed code | Quantity | |
|---|---|---|---|---|
| PA | 2 | |||
| CLA | 1 | |||
| HWH (D) | 9 | |||
| JMP | 11 | |||
| TKD (D) | 24 | |||
| LDH (D) | 66 | |||
| LKO | 16 | |||
| North Eastern Railway | IZN | 7 | ||
| NGC | 3 | |||
| ERS | 5 | |||
| GOC | 1 | |||
| TNP | 17 | |||
| GTL (D) | 4 | |||
| MLY | 10 | |||
| South Western Railway | KJM | 15 | ||
| ET (D) | 11 | |||
| NKJ (D) | 1 | |||
| Total locomotives active as of December 2024[9] [10] | 203 | |||
Technical details are as follows:[11] [12]
| Manufacturers | DLW, DLMW (DMW/DCW) | |
| Engine | Alco 251-C, 16 cylinder, 3300abbr=onNaNabbr=on, earlier 3100hp (3007abbr=onNaNabbr=on site rating, earlier 2900hp) with Napier NA2951R/ ABB VTC-304-VG15/ GE 7s 1716 turbo supercharged engine. 1,050 rpm max, 400 rpm idle; 228.6x bore x stroke; compression ratio 12.5:1. Direct fuel injection, centrifugal pump cooling system (2457L/min at 1,050 rpm), fan driven by eddy current clutch (90abbr=onNaNabbr=on at 1,050 rpm) | |
| Governor | EDC / Woodward 8574-650 | |
| Transmission | Electric, with BHEL TA 10102 CW alternator (1,050 rpm, 1100 V, 4,400 amperes) (Earlier used BHEL TG 10931 AZ alternator) | |
| Traction motors | BHEL TM 4906 AZ/ 4907 BZ (435hp) (with roller bearings) | |
| Axle load | , total weight 112.8t | |
| Bogies | Alco design cast frame asymmetric trimount (Co-Co) bogies | |
| Starting TE | 30.45t at adhesion 27%, continuous 28.05t | |
| Length over buffer beams | 15862abbr=onNaNabbr=on | |
| Distance between bogies | 10516abbr=onNaNabbr=on |