The second locomotive with the designation X b was a eight-coupled shunting locomotive, which was built between 1907 and 1921 in several series by the Karlsruhe Engineering Company and Maffei. It must not be confused with the six-coupled tender locomotive, which was procured as X b from 1863 and designated as VII b from 1868. The reason for the procurement was the fact that the previously existing shunting locomotives with only three coupled axles were now overstrained due to the trains weighing up to 1,300 tonnes.
A few years earlier they experimented with the VIII d, which had the wheel arrangement 0-8-0T, but with a complicated Hagans gear. Their chassis was divided into two groups, only the first of which was directly driven. The two rear axles were driven by rocker arms, which required a lot of maintenance and led to the development of the X b.
The new design had a conventional saturated two-cylinder engine and chassis with the second and fourth axles shifting 25 mm to each side. Although the locomotive was only developed for shunting service, it received air brakes and steam heating for passenger cars. The high position of the boiler, with which the firebox could be arranged above the frame, is clearly visible. This resulted in space for the water supplies under the boiler and between the frame panels, which improved the view to the front. Another striking feature are the two steam domes, which were connected by a pipe and with which one hoped greater elasticity under different operating conditions. With the power thus achieved, it was possible to haul trains of 720 tonnes at its maximum speed of 45 km/h.
Of the 98 machines built, the Reichsbahn took over 90 in 1925, which they designated as class 922-3. The remaining eight came to Belgium as reparations immediately after completion. After the Second World War, 82 were still available, two of which went to the Reichsbahn. Since these could not be used economically, they were sold and used as works locomotives. With the 80 machines of the Bundesbahn, the decommissioning began in the mid-fifties, until on April 25, 1966 the last one ended its service.
