In addition to the tank locomotives of the class 61, the need for more powerful express locomotives was also recognized in order to be able to transport regular, heavier express trains at higher speeds. A tender followed among various companies, the winner of which was a streamlined 4-6-4 locomotive from Borsig. In contrast to its competitors, some of which were also designed as steam turbine locomotives, the class 05 was created as a conventional three-cylinder steam locomotive, which was based as far as possible on the design of the standard locomotives. In 1935 road numbers 05 001 and 05 002 were built in the regular design, followed in 1937 by the different 05 003.
The locomotives had coupling wheels measuring 2,300 mm and a two-axle bogie at the front and rear. The streamlining completely covered the running gear, it had a straight lower edge and went down to a few centimeters above the rail heads. The five-axle 2'3 T37 tender was also paneled, but otherwise mostly compatible with the standard design. The tender's paneling was flush with the locomotive's paneling, removable, and closed off the cab at the rear.
Test drives showed an indicated power of around 2,360 hp, but significantly more was possible for a short time. The regular maximum speed was 150 km/h, and 175 km/h was approved to make up for delays. A typical train mass for these speeds was given as 250 tonnes.
Calculations had shown that at 140 km/h a performance increase of 385 hp at the towing hook had been achieved through the fairing. As with all large standard locomotives, the problem was the large length of the heating pipes, which here reached 7,000 mm and tended to lead to tension. In contrast to most other locomotives of this time, the coupling wheels were braked on both sides and, in addition, a speed-dependent control of the brake was achieved by means of a centrifugal governor. This allowed the usual train weight to come to a standstill at a distance of 1,200 meters from the distant signal within a defined time.
During the test drives and in the subsequent scheduled use of the first two engines, they often exceeded the requirements. The rule were trains consisting of five heavy express cars and together weighing almost 250 tonnes. In the process, speeds were kept above the permitted maximum speed over longer distances on several occasions. On May 11, 1935, road number 05 002 drove between Hamburg and Berlin with only four cars. Although no record run was planned, the speedometer needle reached its stop at 200 km/h and stayed there for a long time. Using the milestones and time measurements, an average of 200.4 km/h was calculated over 5 km and 201 km/h for a short time.
In addition to a calculated output of 3,400 hp, this meant a speed record for steam locomotives, which is still disputed today. The record is often attributed to the English “Mallard” with 201.2 km/h, but not only did this trip take place on a slight downward gradient, it also resulted in damage from an overheated bearing on the connecting rods and it is usually claimed that the trip was not adequately documented. Some American locomotives also allegedly reached over 220 km/h, but in these cases there is no reliable documentation.
The third locomotive followed in a very unusual configuration, since at these speeds there were advantages in moving the driver's cab forward. In order to avoid separating the fireman and driver, the boiler was installed backwards. Since the firebox was now on the opposite side of the tender, pulverized coal firing was installed. The coal dust was transported through a pipe that ran through the entire frame and also had bends due to the inner cylinder. Another difference was the installation of a combustion chamber to allow the gases, which were very hot after the rapid combustion, to cool down a little before hitting the heating tubes. The design of 05 003 did not work, as there was a lack of combustion air in many situations and there were frequent blockages due to slag deposits. Finally in 1944, the boiler was rotated to the conventional position and converted to fire regular coal while the cladding was removed.
In contrast to almost all locomotives available in small numbers, the German Federal Railroad did not decommission the three 05s because they could not do without these fast and more powerful engines. During the rebuild in 1950, the remnants of the paneling, which had already been damaged during the war, were also removed from 05 001 and 002. This did not result in any noticeable disadvantages because the network no longer allowed the highest speeds. However, the boiler pressure was reduced from 20 to 16 bars to reduce the wear.
In 1957 and 1958, the three units were replaced by class V 200 diesel locomotives. Road numbers 002 and 003 were then scrapped by 1960, with only the 001 remaining. The paneling of the latter was then largely restored and the locomotive was taken to the Nuremberg Transport Museum.