First generation of diesel locomotives
In 1953, the 11403-1 and 1403-2 diesel locomotives were imported from Japan. Because no other railway organizations used diesel locomotives at that time and no experience can be gained, the imported locomotives were not suitable for the mountainous terrain of the forest railway. They were only used for pulling train or shunting on the level ground section between Chiayi Station and Zhuqi Station.
Second generation of diesel locomotives
In 1954 and 1955, two 25-metric ton diesel locomotives (11403-3 and 11403-5) were purchased again from Japan. However, due to the limited horsepower of this type of locomotives, the two locomotives had not been used until 1962 when they began to pull express train between Chiayi Station and Fenqihu Station. However, they were mainly used for transportation and shunting on level ground sections. The "Zhongxing Diesel Passenger Car" was a kind of diesel powered car that can be driven on the track with a single unit or multiple units. The car can reach a speed of 35 km/h while running up Alisan and can travel at speeds of 55 km/h on level ground section. Originally, it took more than 7 hours to travel from Chiayi Station to Alishan Station before the inauguration of Zhongxing Diesel Passenger Car, which only took 3 hours and forty minutes to travel from Chiayi Station to Alishan Station, setting a record at that time and warmly received by many passengers.
Third generation of diesel locomotives
In 1969, six 25-ton diesel locomotives, the DL25-30, were purchased. The diesel locomotives' engines have improved horsepower and adopted the car frame center transmission, so they have functioned well and now pull trains on the Zhushan line and the Shenmu line.
Fourth generation of diesel locomotives
Owing to the dieselization of locomotive the speed of the locomotives have increased drastically, the import of Zhongxing Diesel Passenger Car has been stopped, and diesel locomotives have been purchased from Mitsubishi. In 1972, four DL31-34 locomotives were purchased to pull the new passenger cars and the train was named "Guanfu" train.
Fifth generation of diesel locomotives
After breaking diplomatic relations with Japan in 1972, in Japanese goods were boycotted under the pressure of public sentiment. In 1975, three locomotives were purchased from West Germany Q&K Company. However, due to the precision of the machine members and the scarcity of parts, the locomotives were difficult to maintain. In addition, they were different from Japanese locomotives in terms of maintenance and operation. So, they have been discontinued.
Sixth generation of diesel locomotives
Due to the impact of the completion of Alishan highway in 1981, the ridership of Alishan forest railway decreased sharply. To compete with highway passenger transportation, five 28-metric ton DL39-43 diesel locomotives were purchased in 1982. Since 1984, the Alishan Train with air conditioning has been officially operated.
Seventh generation of diesel locomotives
To meet the operational needs, Chiayi Branch ordered 7 new diesel locomotives from the Nippon Sharyo, Ltd. in December 2004. They began to entered service in 2006 and 2007 in succession.