Built in 1962 by General Motors. This broad-gauge locos were fitted with vacuum brakes, 16-cylinder 2-stroke turbo-supercharged engines, having haulage capacity of 2400 tonnes with Co-Co type wheel arrangement. initially considered as alternative to the WDM2 (ALCO make) & were superior in many ways, but as GM did not agree to do transfer of technology, WDM4s considered as ill-fated locos