Indian locomotive class WDM-2

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A WDM-2 locomotive
A WDM-2 locomotive

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.

Contents

[edit] History

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 engines to be built 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).

The WDM-2 is the diesel workhorse of the Indian Railways, being very reliable and rugged.

[edit] Technical specifications[1]

Builders Alco, DLW
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.
Transmission Electric, with BHEL TG 10931 AZ generator (1,000 rpm, 770 V, 4,520 amps).
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.

[edit] Notes and references

  1. ^ Indian diesel loco information

[edit] See also

[edit] External links

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