Bavarian G 5/5, DRG/DB 57.5
The Bavarian State Railroad purchased 15 class G 5/5 locomotives for the steep Bavarian grades as early as 1911. Following Bavarian tradition, these units with five driving axles were designed as four-cylinder super-heated compound units. They generated around 1,650 pounds per square inch and were thus superior to all other provincial railroad designs. A bar frame was another modern feature. One each high-pressure cylinder and an outboard low-pressure cylinder were attached to a cast piece. Outboard-mounted Heusinger valve gear with stirrup pieces provided steam distribution to the high- and low-pressure cylinders by means of common piston slide valves. All four cylinders were connected directly to the third wheel set.
In 1920, additional locomotives followed the units from the first series. These additional units were strengthened in their design and had higher performance. Eighty locomotive of the successor series were delivered and placed into service by 1924. The G 5/5 was the most powerful steam locomotive with five driving axles of all the German provincial railroads and could pull up to 1,210 metric tons up a grade of 0.5 % at a speed of 40 km/h / 25 mph. They easily left the Prussian G 10 and G 12 as well as the later DRG classes 50 and 52 in the dust.
The DRG only took over seven units from the first series with road numbers 57 501-507. The successor series by contrast was fully taken over by the German State Railroad, and the units were given the road numbers 57 511-590. After World War II, only about 20 units were still in existence mostly in storage in the area of the later DB. The greatest part of them were retired as early as 1947, and the last G 5/5 units followed in 1949.