The steam locomotives with operating numbers 1–8 and 21 belonged to the Palatinate Ludwig Railway.

Between 1846 and 1847, the Palatinate Ludwig Railway Company procured four locomotives from the Emil Keßler in Karlsruhe.

In 1847 four identical locomotives (5 HUMMEL, 6 RHEIN, 7 LAUTER, 8 QUEICH) were acquired from Maffei.

In 1851 the ninth locomotive KOENIG LUDWIG followed, again delivered by Keßler, with works number 200.

The locomotives from Keßler and Maffei differed mainly in the arrangement and control of the regulator.

In locomotives supplied by Keßler, the regulator was located in the smokebox and controlled by an external pull from the driver's cab.

On Maffei locomotives, the control lever was in the right-hand wall of the vertical boiler's dome.