It was not until 1915 that Johann Rihosek, Karl Gölsdorf's assistant, worked out the design of the superheated steam two-cylinder locomotive.

As was customary in Austria, the superheater surface area was rather small, as it was feared, rightly, that the domestic lubricating oil would not be able to withstand higher temperatures.

Characteristic of its appearance were its bulbous chimney with the brim, the three domes in the middle of the boiler and its driver's cab.

They were mainly used in freight train and shunting services until they were replaced primarily by the T 458.1 series diesel locomotives.

PKP procured further machines, which were delivered to Poland in the form of semi-finished parts from the Wiener Neustädter Lokomotivfabrik.

When Czechoslovakia ceded parts of the country to Hungary, machines of the 434.1 series came to Hungarian State Railways (MÁV) as 403.6.

Romania also ordered other machines of this series from Škoda Works in Plzeň in Czechoslovakia and from Schneider et Cie. in Le Creusot (France).