The class 69 of the kkStB was a 0-6-2 rack locomotive designed for iron ore traffic on the Erzberg Railway. This line had an incline of up to 7.1 percent and an Abt rack system. Although the mining operations were carried out by a private company, the state railway was tasked with the transport of the ore. A total of 18 locomotives of this class were built at Floridsdorf between 1890 and 1908.
The rack wheels were mounted in a separate frame what was suspended from two driving axles. It was powered by two smaller cylinders which could be engaged on rack sections. Initially they were limited to a speed of 12 km/h on rack sections, but this was later improved to 20 km/h after the braking systems had been improved. In pure adhesion mode, they reached 30 km/h.
Five locomotives got a Giesl ejector that increased power. In 1938, the Reichsbahn numbered them 97 201 to 97 217 and in World War II, two came to Germany and Hungary. Later the ÖBB didn't change their numbers. They were retired in 1978 when rack operations on the Erzberg Railway were stopped. Five are still existing, with 97.208 still operational at the museum in Strasshof.