Alishan's steam engines come in an 18-ton and a 28-ton model. The cylinders of both are mounted vertically, with the former having two cylinders and the later having three. The more powerful three-cylinder model was used on the mountainous portion of the route, while the smaller two-cylinder model was used on non-mountainous sections and to move cars around the stations.
阿里山直立汽缸火車分成十八噸級與二十八噸級兩種，分別佩掛兩個汽缸與三個汽缸，二十八噸級專門用來爬山，十八噸級則專跑平地段、林場線、或站內調車。