German Reichsbahn class 22, later class 39¹⁰

To increase the steaming capacity of the class 39 or Prussian P 10, the East German Reichsbahn started a Reko program in 1958. 85 locomotives received a new boiler with combustion chamber and mixing feed water heater. Additionally, they got new, welded cylinders with Trofimoff valves. The result was called class 22.

They did not only haul heavy passenger trains, but also express trains. Electrification of the lines they were used on led to many being retired very early. In the Reko program of the class 03 that started in 1969, the boilers of 50 class 22 locomotives found a new use. When the new class scheme was introduced in 1970, the few remaining locomotives became class 39¹⁰. In the following year, the last one was retired.