Indian locomotive class WDM-2
|Build date||1962 onwards|
|Gauge||1,676 mm (5 ft 6 in)|
|Bogies||ALCO Asymmetric cast frame trimount|
|Wheel diameter||1,092 mm (3 ft 7.0 in)|
|Wheelbase||12.834 m (42 ft 1.3 in)|
|Length||17.12 m (56 ft 2 in)|
|Width||2.864 m (9 ft 4.8 in)|
|Height||4.185 m (13 ft 8.8 in)|
|Axle load||18,800 kg (41,400 lb)|
|Locomotive weight||112,800 kg (248,700 lb)|
|Fuel capacity||5,000 l (1,100 imp gal; 1,300 US gal)|
|Prime mover||ALCO 251-B|
|Engine RPM range||400 - 1000 rpm|
|Traction motors||GE752, BHEL 4906 BZ and 4907 AZ|
|Top speed||120 km/h (75 mph)|
Max:2,600 hp (1,900 kW)Site rated:2,430 hp (1,810 kW)
|Tractive effort||30.4 t (30 long tons; 34 short tons)|
|Train brakes||Air, Vacuum and Dual|
|Number||16000-16887, 17100-17999, 18040-18079, 18112-18514, 18523-18900, 18903-18999|
|Locale||All over Indian Railways|
The class WDM-2 is Indian Railways' workhorse diesel locomotive. The first units were imported fully built from the American Locomotive Company (Alco) in 1962. Since 1964, it has been manufactured in India by the Diesel Locomotive Works (DLW), Varanasi. The model name stands for broad gauge (W), diesel (D), mixed traffic (M) engine. The WDM-2 is the most common diesel locomotive of Indian Railways.
The WDM-2A is a variant of the original WDM-2. These units have been retro-fitted with air brakes, in addition to the original vacuum brakes. The WDM-2B is a more recent locomotive, built with air brakes as original equipment. The WDM-2 locos have a maximum speed of 120 km/h (75 mph), restricted to 100 km/h (62 mph) when run long hood forward - the gear ratio is 65:18.
In the early 1960s Indian Railways began conversion of its mainline from steam to diesel locomotives. For this conversion General Motors Electro-Motive Division (EMD) and the American Locomotive Company (ALCO) were asked to submit designs for new diesel locomotives. Each company submitted prototypes. Indian Railways designated these prototypes the WDM-4 class and the WDM-2 class respectively. Technologically the General Motors WDM-4 was superior to ALCO's WDM-2, but Indian Railways required a transfer of technology agreement that would allow these locomotives to be manufactured in India. General Motors did not agree to the transfer of technology agreement so the ALCO prototype was selected for production. The first few prototype WDM-2s were imported. After Diesel Locomotive Works (DLW) completed construction of its factory in Varanasi, production of the locomotives began in India. The first 12 locos were built using kits imported from ALCO in the United States. After that DLW started manufacturing the WDM-2 locomotives from their own components. Since then over 2,800 locomotives have been manufactured and the WDM-2 has become the most popular locomotive in India.
However, even before the arrival of WDM-2 another type of diesel locomotive was imported from ALCO beginning in 1957. This locomotive was classified as WDM-1.
Later a number of modifications were made and a few subclasses were created. This includes WDM-2A, WDM-2B and WDM-3A (formerly WDM-2C). Now a few WDM-2 locos are being rebuilt by Diesel Loco Modernization Works (DLMW) Patiala, Punjab - These are fitted with Daulat Ram DBR's
The WDM-2 is the diesel workhorse of the Indian Railways, being very reliable and rugged.
|Engine||Alco 251-B, 16 cylinder, 2,600 hp (2,430 hp site rating) with Alco 710/720/?? turbo supercharged engine. 1,000 rpm max, 400 rpm idle; 228 mm x 266 mm bore/stroke; compression ratio 12.5:1. Direct fuel injection, centrifugal pump cooling system (2,457 l/min at 1,000 rpm), fan driven by eddy current clutch (86 hp at 1,000 rpm)|
|Governor||GE 17MG8 / Woodwards 8574-650 / Medha MEG 601|
|Transmission||Electric, with BHEL TG 10931 AZ generator (1,000 rpm, 770 V, 4,520 amperes)|
|Traction motors||GE752 (original Alco models) (405 hp), BHEL 4906 BZ (AZ?) (435 hp) and (newer) 4907 AZ (with roller bearings)|
|Axle load||18.8 tonnes, total weight 112.8 t|
|Bogies||Alco design cast frame trimount (Co-Co) bogies|
|Starting TE||30.4 t, at adhesion 27%|
|Length over buffer beams||15,862 mm|
|Distance between bogies||10,516 mm|
In Sri Lanka
Eight WDM-2 locomotives were purchased by Sri Lanka Railways, the state run railroad operator in Sri Lanka in 1996. This is was the longest and most powerful locomotive owned by Sri Lanka Railways at that time. These were allocated M8 Class. However some modifications to the appearance were done by SLR.
|Sri Lanka||Sri Lanka Railways||M8||8||841 - 848||All locomotives are operational.|
- Indian Railways
- History of rail transport in India
- Locomotives of India
- Rail transport in India
- Sri Lanka Railways M8
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