WDM 4

The Indian locomotive class WDM 4 was a class of diesel-electric locomotives that were built in 1962 by General Motors for Indian Railways. A total of 72 WDM-4 locomotives were imported between 1961 and 1962.

With A Speed of 145 km/h, The WDM-4 was one of the fastest locomotives of Indian Railways serving both passenger and freight trains for over 38 years. It still remains the fastest Goods Locomotive to Ever Operate in India. A few decommissioned WDM-4 units were exported to Bangladesh. By 2000s, all 72 locomotives were withdrawn form Mainline service. 2 units Were preserved.

History
WDM 4 was a contender for Indian Railway's Tender during 1960 for Diesel Electric Locomotives that would replace the Steam Locomotives on IR network. Two Companies responded, EMD of GM and ALCo. They Sent WDM 4 and WDM 2 prototypes for trials. During the Trials, The WDM 4 proved to be much more Faster and was technologically advanced. India asked For a Transfer of Technology agreement with EMD for Indigenous mass production of WDM 4 but EMD declined, prompting Indian railways to select the WDM 2 instead as ALCo were ready for the agreement.

Railways, although unable to get a transfer of technology agreement, still bought 72 Units, All completely Assembled in US for Use In IR. The first Units Arrived By 1962 and were quickly put into service. Although Fast, They were somewhat Under Powered to Haul 18 coach Trains, so the locomotive was commonly used as dual MU'ed Units. Their fast speed allowed them to Haul the Howrah Rajdhani and they kept hauling it for almost 20 years until the WAP 1 and proved itself to be more suitable for the job.

Service History
The WDM 4 was the First Locomotive Ever to Haul Howrah Rajdhani in 1969, Hauling it until1983. Only Some WDM 4 were Assigned to Haul the Rajdhani, These Special Locomotives had a higher Speed of 130 km/h (others were restricted at 120 km/h). Mughalsarai, the Home shed of all WDM 4 units had a dedicated Workshop for these faster WDM 4 units. Although the New Delhi-Howrah Route Was fully Electrified By 1976, Double WDM 4 continued to Haul the Howrah Rajdhani due to their superior speed. They continued spontaneously Hauling the Rajdhani for 3 more years, even after the Purpose built WAP 1 was Introduced.

They were also the first non steam locomotives to Haul the Doon Express and hauled many premium trains.

By mid 1980s, WDM 4 were out competed by newer and much powerful Locomotives and as a result were increasingly assigned to Goods and intercity Passenger trains. By 1990s, a sizeable fleet was still operational as goods locomotives and by 2000, all were withdrawn from active mainline duty after 38 years of service. 20 units were retained at the Mughalsarai Loco Shed and the rest were sent to Alambagh Stores Depot to be Scrapped. It remains unknown what happened to those 20 units kept at Mughalsarai.

4 of the decommissioned units were sold off to Bangladesh in 2000, they were withdrawn due to age.

Preserved Units
WDM 4 #18001 At National Rail Museum Delhi.

WDM 4 #18086 Plinthed At Lucknow Diesel Locomotive Shed.