The P 8 is a passenger locomotive that is
primarily developed as a successor to the P 6 and
later serves as the basis for the development of the S
10. It is distinguished by being the most produced
passenger steam locomotive in history, with nearly 4000x units
built. The P 8 remains in service with both
railways in divided Germany until the 1970s.
Designed by Prussian construction consultant Robert Garbe, the
P 8 is a relatively simple yet powerful and
economical machine. After addressing some initial technical issues,
the design proves to be a significant success. Garbe, a pioneer of
superheated steam technology in the late 19th century, utilizes
this innovation in the construction of the locomotive to achieve
the required performance levels.
Initially, the new locomotive is intended for a speed rating of 110
km/h, allowing it to operate passenger express trains. However,
operational testing reveals that the two-cylinder drive mechanism,
along with an imperfect mass balance, is not suitable for such
speeds. Consequently, the locomotive is only approved for a maximum
speed of 100 km/h. The stability of the P 8
remains one of its most significant drawbacks, particularly the
slightly loose coupling to the tender that results in poor handling
during reverse travel, limiting this speed to 50 km/h. Improvements
occur in later years when the bathtub tenders from wartime
locomotives are utilized with the P 8, allowing
for reverse speeds of up to 85 km/h.
Overall, the P 8 is a successful design,
particularly praised for the performance of its boiler. The firebox
extends slightly into the long boiler, functioning somewhat like a
combustion chamber, which contributes to its excellent evaporation
performance.
Between 1906 and the end of World War I, 2350x units are
constructed, with some locomotives produced for the railways of
Oldenburg, Baden, and Mecklenburg. As the locomotive’s positive
attributes become known among the victorious powers, 627 units are
handed over as reparations. To replenish stock, production
continues until 1923, involving all German locomotive manufacturers
except for the Saxon machine factory Hartmann and the Esslingen
machine factory. Ultimately, the total number of built P 8
locomotives reaches 3948x.
During the interwar period, the Reichsbahn employs the P
8 across nearly all train categories, reserving only heavy
express and freight trains for better-suited machines. Passenger
steam locomotives with a wheel arrangement of 2'C are classified
under the series 38, with the P 8 constituting the
majority of this classification, specifically the numbering range
of 3810-40. Even after World War II, both German railways continue
to rely on the locomotives, leading to their retirement from
service in the Reichsbahn in 1972 and the Bundesbahn in 1974.
Sources: https://www.loco-info.com/view.aspx?id=10805&t=Type&cookies=decline