 20000 upwards till 20103 and further numbering of the loco along with its WDP-4B/4D variants is from 40001 up until 40608.The jump in the numbering is due to the 20XXX series almost breaching the start of the numbering of another locomotive class, the WCG-2 which is a DC electric locomotive whose numbering started from 20105.The first set of 10 locos starting from road number 20000 to 20009 were manufactured by the Electro Motive Diesel (EMD) of (General Motors) while road numbers 20011 upwards have been manufactured by Diesel Locomotive Works (DLW) of Varanasi in collaboration with GM (General motors).