The Prussian Class P 8 of the
Prussian state railways
The term Prussian state railways (German: ''Preußische Staatseisenbahnen'') encompasses those railway organisations that were owned or managed by the State of Prussia. The words "state railways" are not capitalized because Prussia did not have a ...
(DRG Class 38.10-40 of the
Deutsche Reichsbahn) was a
4-6-0 steam locomotive
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the loco ...
built from 1906 to 1923 by the
Berliner Maschinenbau
Berliner Maschinenbau AG was a German manufacturer of locomotives.
The factory was founded by Louis Victor Robert Schwartzkopff on 3 October 1852 as ''Eisengießerei und Maschinen-Fabrik von L. Schwartzkopff'' in Berlin.
History
The facto ...
(previously Schwartzkopff) and twelve other German factories. The design was created by
Robert Garbe. It was intended as a successor to the
Prussian P 6, which was regarded as unsatisfactory.
Construction
Because Garbe was an advocate of the simplest possible designs, a straightforward,
superheated steam
Superheated steam is steam at a temperature higher than its vaporization point at the absolute pressure where the temperature is measured.
Superheated steam can therefore cool (lose internal energy) by some amount, resulting in a lowering of ...
, two-cylinder driving gear was envisaged. The P 8 benefited especially from superheated steam technology, which had just been developed by
Wilhelm Schmidt (nicknamed 'Hot Steam Schmidt'), that led to outstanding performance for those times. The P 8 was a very economical locomotive that did not make great demands on the ability of the
engine driver. At the outset Garbe even designed the P 8 as an
express train
An express train is a type of passenger train that makes a small number of stops between its origin and destination stations, usually major destinations, allowing faster service than local trains that stop at most or all of the stations along ...
locomotive, with the expectation of attaining a top speed of . As a result, the first units were fitted with low-wind-resistance, tapered driver's cabs.
The enthusiasm of crews for the new locomotive was at first muted. The