The locomotives were developed specially for the steep ramps in the K.Bay.Sts.B.'s territory: the railway line from Sonneberg–Probstzella, the Spessart ramp, the Franconian Forest Railway (Frankenwaldbahn), the Schiefe Ebene (lit: inclined plane), and the line from Eger to Asch (today Cheb-Aš).
Their areas of operations included the Sonneberg–Probstzella line, the Spessart ramp, the Franconian Forest Railway, the Geislingen ramp (Geislinger Steige), the Schiefe Ebene and the Rübeland Railway, where they earned their nickname Bergkönigin ('mountain queen').