P 1 was the designation for three slightly different types of passenger locomotives on the Palatinate Railway. They were built between 1875 and 1884 and the last of them survived until the mid-1920s. They all had the wheel arrangement 2-4-0, but the arrangement of the axles was changed over the years in order to achieve satisfactory running characteristics.

The subtype P 1^I was built between 1870 and 1875 in a total of 29 in Karlsruhe. There were two series of eight and 21 engines each that shared a boiler with an overhanging firebox. The difference was that the first series had a Belpaire boiler and the second a Crampton type. A big problem of the P 1^I was the very poor running smoothness, which resulted from the short wheelbase between the running axle and the first coupled axle. This was increased in the second series from 1,600 to 1,750 mm and increased even further in conversions around 1880. The use of a supported firebox increased the running smoothness further, so that it was now possible to run at 75 instead of 50 km/h. Other improvements in this rebuild included the addition of a steam dome and Ramsbottom style safety valves.

The P 1^II came from Grafenstaden, where six pieces were made in 1876. They had larger wheels, which allowed the top speed to be increased to 85 km/h. They were also retrofitted with a steam dome later, but they did not have an overhanging firebox. Over time, the brakes were moved from the tender to the locomotive's driving wheels. In contrast to the type 2 T 7 tenders used on the P 1^I, slightly larger type 2 T 7.5 tenders were now used.

The P 1^III was largely identical to the P 1^II, but it was manufactured by Maffei and at the same time corresponded to the Bavarian B IX except for a few details. Between 1880 and 1884, two series of six and three machines each were built. To increase the range, they had been given a three-axle type 3 T 9,8 tender. They are the only sub-variant for which information about the indicated power is still known. This is specified with about 430 hp. 

Despite the fact that the locomotives did not have a very high power and could only show a satisfactory running smoothness even after the conversions, they remained in use for a long time. In 1923, the Reichsbahn renumbering plan included two engines of the first subtype, one of the second and five of the third. A number within the class 34⁷⁴ was intended for all of them, but by 1925 none of them were left.