Conversion of DF4 rolling stock

Many DF4 and DF4A locomotives built in 1982 or before were gradually rebuilt into the more reliable DF4B when they were returned to the factory for repairs, including the replacement of diesel engines, interlocking cut-off valves, superchargers, and couplings, with no change in the speed of construction. In addition, the Dongfeng 4B type will also be in accordance with the needs of the railroad bureau, machine section to change the gear ratio, passenger type to freight type, or freight type to passenger type of transformation.

There are also some railroad bureaus, in order to save costs, will be part of the Dongfeng 4B freight type from 2001 to transform into the Dongfeng 4D freight type, which will be replaced by the diesel engine of the Dongfeng 4D 16V240ZJD type, and modify the transmission part, so that the Dongfeng 4B to D-type of equipment and performance is completely the same as the Dongfeng 4D freight type. The appearance of the body of the Dongfeng 4B to D is the same as before the modification, and the locomotive number has not been changed, but the paintwork has been changed to the blue and yellow color of the DF4D freight type.

The Dongfeng 4B locomotives, numbered Dongfeng 4 7701-7732, have two locomotives for each number because of duplicate numbers. Thirty-two of them were built by Dalian Locomotive Works. The other 32 were dismantled and rebuilt from 16 sets of 32 Dongfeng 4E heavy-duty internal combustion locomotives originally produced by Sifang Locomotive and Rolling Stock Works, all of which were assigned to the Shanghai Railway Bureau. These two groups of locomotives are identical in appearance and can only be distinguished by the production label. Dongfeng 4 common name

Watermelon: body color is green with light color band. Armed Police: the body color is green with yellow bands of the Dongfeng 4B cargo-type locomotives due to the similar color scheme with the uniforms of the Armed Police Force.

Orange: body color is orange with light band.