In the years 1879 and 1880, the Kaiserin-Elisabeth-Bahn procured a total of eight more 2-4-0 express locomotives from the workshops of the state railway company. The requirements specified were that 100 tonnes should be towed at 55 km/h or 200 tonnes at 27.5 km/h on a gradient of one percent. In order to achieve the necessary train loads on the curve radii from 280 meters, a great deal of development effort was put into the locomotives. This also included the Haswell corrugated iron firebox, which was only used in the 1870s and was not able to establish itself beyond that.

The biggest difference to the existing series I and II was that the diameter of the dring wheels was increased from 1,580 to 1,900 mm. Although the top speed was only increased from 70 to 80 km/h, this improved smooth running at higher speeds and reduced consumption and wear. The reduced pulling power due to the significantly larger wheels was compensated for by a higher boiler pressure of ten bars and a slightly larger cylinder diameter. In addition, it was about seven tonnes heavier than the KEB II and thus had a larger adhesive weight. 

Schematic drawing with dimensions

Die Lokomotive, June 1936

All in all, the A III was the most powerful of all Austrian 2-4-0 locomotives and also outperformed many 4-4-0 locomotives well into the 1890s. They were taken over by the kkStB in 1883 and initially referred to as A III. Later they became class 7 and got the numbers 7.01 to 7.08. The BBÖ also took over six more after the First World War and retired them between 1922 and 1929.