The Sernftalbahn was an electrical narrow-gauge railway (1000 mm) in the Swiss canton of Glarus, which was operated by a private railway company. It led - usually on the valley route - of shrank from GL in the Linthal 14 km along the Sernf upward until Elm GL. The motor coaches were propelled with direct current (first 750, then 800 V) from own hydro-electric power plants and diesel engine generators. The production management was in Engi in the center of the distance.