Austrian Southern Railway classes 17a to 17d

When the Südbahn made the decision to procure new express locomotives in 1881, the focus was basically on the class 16a “Rittinger” built in 1873. Since the train weights had increased from 70 to 80 tonnes before to around 150 tonnes and the use on gradients of up to 2.5 percent was required, the tractive effort had to be greater. To achieve this, the wheel diameter was reduced from 1,900 to 1,720 mm and the rear driving axle was placed under the firebox to increase the adhesive weight. Like the 16a, it had outside frames and Stephenson valve gear.

The first ten locomotives were delivered in 1882 and designated class 17a. The Košice–Bohumín Railway (KsOd) also bought ten more between 1884 and 1891. They almost exploited the axle load of 13 tonnes that was now permitted. During the official approval runs they reached 115 to 120 km/h without a load and with the weight of a regular express train they could easily maintain 80 km/h.

In 1884 and 1890, the Southern Railway procured a total of 14 of a heavier variant, which was listed as the 17b. This was followed by another 60 of a similar variant, which had a boiler pressure increased by one bar and a slightly larger boiler. They made full use of the axle load of 14 tonnes that was now permitted. Together with two other locomotives built in 1885, they became the class 17c.

In view of the increasing train weights, a locomotive had already been built in 1888 that had larger driving wheels and cylinders and a Belpaire firebox. Together with three other locomotives delivered in 1890, it was listed as class 17d.

After the collapse of the Austro-Hungarian monarchy, the remaining locomotives were distributed over the successor states. Apart from Austria, this affected the states of Hungary, Yugoslavia and Czechoslovakia. The BBÖ no longer had any of the class 17a, the rest were distributed over several classes. These were class 103 for the last two 17b, 403 for the two 17c built in 1885, 503 for the production version of the 17c and class 603 for the 17d. In Austria the class disappeared in the 1930s, in Yugoslavia only in the 1950s.