Austrian Federal Railways (BBÖ) class 81

In order to be able to operate coal trains weighing up to 1,600 tonnes from the Moravian-Silesian coal fields, a more powerful freight locomotive was needed. Although Gölsdorf had already developed a ten-coupled freight locomotive with the classes 80 and 180 before the First World War, they could not be used with express freight trains due to the lack of a leading axle. The designs came in 1916 from Gölsdorf's successor Rihosek and initially envisaged a compound engine. 

The locomotives which were only delivered after the end of the war from 1920 onwards were ultimately given a simple engine, since the additional expense of a compound engine was now considered unnecessary for freight locomotives. Not only the boiler was largely taken over from the classes 380 and 470, but also many other parts such as the chassis. The Adams axle could be moved laterally by 65 mm and the first and fifth driving axles had a side play of 26 mm. In contrast to the 80 and 180, the third driving axle, which was the main driver here, could not be moved and therefore had no wheel flanges. 

The prototype 81.01 delivered in 1920 could be recognized by the Kobel chimney. During test runs on a gradient of around one percent, 598 tonnes were hauled at 38.5 km/h. On the Tauern railway with 2.78 percent, 303 tonnes could still be hauled at 28 km/h, with power reserves apparently still being available in the boiler. The production locomotives which were then delivered had a normal chimney, a larger steam dome and different types of feedwater heaters. 

The locomotives, which were only put into service after the collapse of the monarchy, could no longer be used on the intended lines and were therefore run in other regions. There they were used not only for express freight trains, but also for express passenger trains. By 1923, 40 locomotives had been built for the BBÖ in Floridsdorf, 16 in the StEG factory, 14 in Wiener Neustadt and three at Krauss in Linz. The last 18 were designated class 81.4 and had received Lentz valve gear, a Dabeg mixing feedwater heater and partly a superheater with 92.4 square meters of smaller tubes.

Ten more locomotives were purchased by the SHS Kingdom railways in Wiener Neustadt and later listed as class 29 by the JDŽ. The locomotives of the BBÖ were run by the Reichsbahn as class 58⁷ from 1938 and kept their running numbers with the ÖBB after the Second World War. 17 of them came to JDŽ. The Austrian locomotives were retired by 1961. Today there are still one Austrian and one Yugoslavian locomotive.