The design was created by Robert Garbe. It was intended as a successor to the Prussian P 6 , which was regarded as unsatisfactory. Because Garbe was an advocate of the simplest possible designs, a straightforward, superheated steam , 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. 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 boiler was very effective at evaporation there was already evidence of a combustion chamber at the front end of the firebox , however against that there were numerous teething troubles, e. This led continually to overheating. The loosely coupled Prussian box tender led to disturbing riding qualities when running tender-first.
Its riding performance was never fully satisfactory. One characteristic feature of the P 8 is the large distance between the centre and rear coupled axles. At the outset the P 8 only had a steam dome behind the sandbox ; later a forward feed dome was added. Further constructional changes affected, inter alia , the driver's cab roofs, the smoke deflectors and various external assemblies. There would appear to have been a number of boiler variations. The following combinations can be seen in photographs:.
At least some of very early engines those with the "V" cabs carried type 1 boilers and this type appears to have been the standard in the early years. Types 3 and 4 do not seem to have appeared until after World War I but ultimately became prevalent. In order to be able to turn the locomotive even on small turntables , the Prussian state railways fitted the P 8 with tenders that originally held Later the Deutsche Bundesbahn coupled the Class 38 with the tenders of withdrawn wartime locomotives the so-called ' Kriegslokomotiven ', especially the bathtub tenders Wannentender , which could carry more fuel.
