WDP 4D. The WDP4B with its tweaked GM engine got a facelift with the WDP4D. After numerous complaints from loco pilots, engineers, media and the general public who refused to allow trains with WDP4s to operate in LHF mode, IR finally realized that it would be a good idea to add another cab to the EMD. The WDP4D was the result where D stands for “Dual Cab” and not for horsepower. These are long, very long locos which apart from the extra cab share all features with the WDP4B. The extra cab is a bit wider than the other one and looks slightly ungainly but is more efficient, easier to operate and better looking, besides being more safer, faster and comfortable for the poor loco pilots. It was only the second dual-cab diesel locomotive after the WDP3A. Till 18 August 2017, about 250 units are built. Its production started in the year of 2010 and still goes on. Its has a rated speed of 130 kmph.
