In 1864, the Großherzoglich Mecklenburgische Friedrich-Franz-Eisenbahn ordered the first type III 2-4-0 steam locomotives for passenger and express trains from the Sächsische Maschinenfabrik Hartmann in Chemnitz. They had become necessary because the types I and II with a 2-2-2 wheel arrangement no longer had sufficient power, especially on the newly opened lines in Mecklenburg Switzerland.
Their designers followed the general trend at the time to replace the rear carrying axle with a second coupled axle, resulting in the 2-4-0 wheel arrangement. The locomotives had an inside frame and outside cylinders with valve gear and steam chests on the inside of the frame. A striking feature was the large steam dome, which was the same height as the chimney. In addition, there was no single sandbox on the boiler, but two smaller ones directly in front of the first driving axles.
In the years 1864, 1866 and 1869 Hartmann delivered one batch each, each of which had a higher boiler pressure than the previous series. This was initially 7.31 bars, then 8.04 bars and finally 8.77 bars, which in turn increased power. From the very first batch, the locomotives had air brakes, which was not standard at the time.
A total of 19 were completed, most of which were named after northern German cities. Only two were given the names “Zwei Hundert” (Two Hundred) and “Vier Hundert” (Four Hundred) because of their special works numbers. Their withdrawals began in 1901 and were completed in 1910.
