 In 1966 during the cultural revolution the locomotives were given the class FD (反帝 "Fandi" meaning 'anti-imperialism'), after 1971 the class was renamed again becoming the QJ class ("Qian Jin", meaning 'march forward' or 'progress').The prototypes used 8 wheel tenders, while later production models used 12 wheel tenders.QJs were equipped with mechanical stokers, feedwater heaters, electric lights, and air horns.