In addition to the class 01, the 03 was also taken on in order to develop a variant with streamlined fairing and three cylinders. The result was the class 0310, which was designed for 150 km/h and was only certified for 140 from 1940. Instead of the 140 units ordered, only 60 were finally completed, as production had been focused on freight locomotives since the outbreak of war. In the case of locomotives supplied by Borsig and Krauss-Maffei, the fairing was pulled over the entire drive train and running gear to just above the upper edge of the rails, while Krupp left a cutout in the area of the coupled axles just above the axles. Since the original locomotive was only designed for two cylinders, the steam of the 0310 could not be optimally distributed between the three cylinders and the indicated power fell by almost 200 hp compared to the 03.
Although streamlined locomotives had about 50% less drag, the fairing not only restricted accessibility for maintenance, but also limited engine cooling. As early as 1942, the fairing was gradually removed from the fully encased locomotives up to the top of the coupled wheels. For the time being, the Krupp locomotives continued to run with their incised fairings. After the war, traffic on both sides of the Iron Curtain was initially not possible at the speeds at which streamlining offered advantages over conventional locomotives. Since these were also often in very poor condition, they were completely removed from all locomotives. From now on, a striking feature of these engines was the slanted top smoke box, but some conversions also included a new smoke box with a round door.
In the case of the 26 locomotives of the Bundesbahn, the later conversions were mainly limited to replacing the non-ageing St 47 K boilers with new ones made of a more durable alloy. Although the new boilers had a combustion chamber, the output was only slightly higher than before. They were retired between the end of 1965 and the end of 1966 and finally scrapped without exception.
03 1010 without fairing in 2002
Olaf1541 
Since the shortage of locomotives at the Reichsbahn was more serious, 16 of the 17 units of the 0310 were included in the reconstruction program. The most modern construction principles were used in the subsequent fundamental rebuilding in order to be able to use the locomotives for a few more years in front of the highest-quality express trains. In the period when their sisters were already being phased out by the Bundesbahn, almost all engines in the GDR were given oil firing. Especially with the latter, a significant increase in performance was possible, some claims of 2,350 hp are given. After some of the reconstructed engines had achieved monthly mileages of more than 20,000 km, they were retired by 1980.