 Various disadvantages of the 1911 variant of the S 10.1, such as the difficulty of accessing the inside driving gear and the long steam lines between high and low-pressure cylinders, caused the Prussian state railways to have the design reworked.The four cylinders were now located – as on the von Borries compound – on a slant; the twin-axle drive configuration was however retained.Even the boiler was modified; grate and firebox heating areas and the superheater were increased in size.