In September 1958 Dalian Locomotive and rolling Stock Work (D Loco) produced a 2 unit, 4000 horsepower diesel electric engine. This engine was performed several enhancements on its major components and parts before it went into production.
According to the Sino-Soviet technology cooperation agreement, in 1959 the Soviets provided a full set of TE3 blueprints to Loco. Based on these blueprints and the trial runs done on Julong. DLoco made improvements and redesigned its blueprints. In September 1964 the production of the diesel engine formally began. This locomotive was classified as ND (Nei Dian which means diesel electric in Chinese). In August 1966, the classification was changed from ND to DF (Dong Feng which means east wind) to represent good fortune. Since 1970 over 100 units of DF were produced annually. By 1973 a total of 706 units were built.
In order to fulfill the urgent need for dieselization of passenger services DLoco modified DF’s traction motor to increase the maximum speed from 100km/h to 120km/h. DLoco accomplished this by changing the gear ratio from 75/17 to 71/21. With this change came a new classification DF3. DF signified a gear ratio of 75/17 and was generally used for freight traffic, while DF3 signified a gear ratio of 71/21 and was used fro passenger travel.
For 10 years between 1964 and 1973 DF’s and DF3’s were massively produced. During this time over 50% of the nation’s diesel fleet was DF or DF3 class. However, in 1974, DF3’s role in passenger services gradually decreased because of the introduction of a more efficient and powerful diesel engine DF4. At this point many DF3’s were geared back to 75/17 and thus became DF class throughout the years. Thus, DF3s honourably retired. Between 1983 and 1992 the role of DFs was for freight traffic. The number of DF’s reached its peak at 886 by 1990. DFs also held a record for length of service. The longest service span for a DF diesel engine was 35 years, and the second longest service span was 25 years. Most DFs slowly faded out of history’s stage. Now only a few remain in good condition and are being used for light switching jobs.
DF diesel engines were the backbone of early stage dieselization and have contributed tremendously to the development of China’s transit system. As the father and soul of China’s diesel engine DFs and DF3s have certainly played a vital role in the development of the China railway industry.
