Because Garbe was an advocate of the simplest possible designs, a straightforward, superheated steam, two-cylinder driving gear was envisaged.

At the outset Garbe even designed the P 8 as an express train locomotive, with the expectation of attaining a top speed of 110 km/h (68 mph).

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.g. the driving rod bearings were too small.

The loosely coupled Prussian box tender led to disturbing riding qualities when running tender-first.

As a result of poor weight compensation, the top speed estimated by Garbe was never achieved and it was eventually assessed at 100 km/h (60 mph).

Further constructional changes affected, inter alia, the driver's cab roofs, the smoke deflectors and various external assemblies.

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 21.5 m³ of water and 7 t of coal.

In 1951, the Deutsche Bundesbahn rebuilt two P 8 with a small two-axle tender coupled with a shaft in order to improve the riding qualities when running in reverse, making them 4-6-4T locomotives.

The first engine of this, soon internationally famous, class was placed into service in the Lower Rhine with the number "Coeln 2401".

In total 3,556 or 3,561 locomotives (according to different sources), were built for German states in 1906–1923, including 60 or 65 for occupation World War I service in Warsaw and Brussels.

[1] Of these, 627 had to be transferred to the victorious powers as reparations after the end of the First World War: Poland received 192 (reclassified as the Ok1), Belgium 167 (type 64), France 162, Italy 25 (FS gruppo 675), Romania 18 (CFR 230-series), Lithuania 11 (LG class K8) and Greece 10 locomotives as SEK class Ζδ (ZETA-delta).

In 2004, the Austrian Society for Railway History (ÖGEG) acquired two machines of this type from Romania (the P 8 'copies'), one of which carries out steam 'specials' under the fictitious number of ÖBB 638.1301.

They were sent to Copenhagen for repair and eventually were purchased by the Danish State Railways where they became DSB class T numbered 297, 298 & 299.

The État and its successor the Région Ouest had hated its former German locomotives, and withdrawn them as quickly as possible.

The change of motive power meant that the last Class 23 was withdrawn by the DB only one year after the last P8 had been retired.