For commuter service, Gölsdorf developed the class 129 tank locomotive with a 2-6-0T wheel arrangement and a two-cylinder compound engine with a long stroke. This was the first time that this wheel arrangement was used for passenger trains in Austria. They could easily run at 110 km/h on test runs and delivered up to 1,150 hp. They formed the basis for the class 229 of the Südbahn, which had larger stocks thanks to an additional trailing axle. The kkStB then ordered further locomotives of the class 229 and also converted their locomotives of the class 129 in the same way. 