Besides employing slip-proof cog rails to prevent the train from rolling downhill at high speeds, the Alishan Forest Railway boasts four carefully designed technologies to minimize the gradient: namely, a mountain route with S- and U-curves, a back-and-forth zigzag route built due to lack of suitable land, a spiral route in higher elevations (see map at left), and specially designed upright cylinders in the engine.
除了獨缺避免火車急速下滑的防滑齒軌外，另外 4 種為降低軌道坡度而費心設計的 S 型與 U 型登山路線；因腹地不足而採用的一進一退「之」字型折返路線；還有提升海拔坡度時的螺旋路線，（右下圖）以及特殊設計的火車直立式汽缸，阿里山森鐵都有。