It was a heavier, stronger development of the G 8 and was initially referred to as a 'strengthened standard class' (Verstärkte Normalbauart).

These engines were designed by Robert Garbe and built between 1913 and 1921, forming the largest class of state railway locomotives in Germany.

The boiler was larger than that of the G 8, and the locomotive was designed to be heavier to haul even the heaviest trains without sanding, due to its higher adhesive weight.

The twelve Mecklenburg engines (two of which had been bought in 1920 by the Prussian state railways) were incorporated as Class 55.58 with the numbers 55 5801–5810 and 55 5851–5852.

[2][3] In the Second World War numerous locomotives from Poland and Lithuania were also designated as Class 55 engines.