This enabled driving wheels with a diameter of 1,830 mm (6 ft 0 in) to be fitted without placing the boiler higher than was customary at the time.

As a further feature, the locomotive number 28 Pfalz ("Palatinate") had weather protection for the engine driver and fireman, which was not common at the time.

Four units were made by Maffei in 1853, and fourteen by Keßler (Maschinenfabrik Esslingen) between 1855 and 1864.

The Maffei locomotives had the regulator housing in the middle of the boiler, a larger smokebox than those from Keßler, a smooth vertical boiler and steam chest arranged over the cylinder.

In 1925 the third example of the series, number 28 PFALZ was replicated in the Weiden repair shop.