After the good results of the several acquired series and subseries of Japanese locomotives, the network decided to expand its order of 269 locomotives, leading to subseries 200. This subseries, divided into two parts, represented an advancement based on both experience and available technological improvements. The last part of the subseries, named "High Series," included all these functional enhancements, the most characteristic of which were the installation of Young-type side windows for the cabins as well as new cooling devices with resistance on the roof and underbody.