The class XIV was procured by the Grand Duchy of Baden State Railways from 1866 as a simply designed locomotive for slower passenger trains and possibly also for freight trains. In the new scheme of 1868 it was given the designation IV a. It is characterized by the fact that all engines built were later converted to tank locomotives. 

The original model had only two driving axles and a two-axle tender. The coupled wheels were fixed to an outer frame with outside cylinders. However, only the connecting and coupling rods were on the outside, while the valve gear was on the inside.

Rebuilt as tank engine

Because the entire weight of the locomotive was carried on the coupled wheels, it had a high tractive effort and was also used to pull freight trains. Trains weighing more than 1,000 tons could be moved at 45 km/h on almost level routes. By 1868, 46 examples had been produced in three batches, which were manufactured by the Karlsruhe and Grafenstaden factories.

When significantly faster and more powerful tender locomotives became available in 1880, conversion of all engines to tank locomotives began. The driver's cab was now closed all around and got a coal bunker on the back. Due to the resulting greatly increased overhang, a fixed trailing axle was installed, which means that the locomotives now had a 0-4-2 wheel arrangement. The water tanks were now on the side of the boiler, the latter also being new.

These conversions increased the service weight from 27 to 41.2 tonnes and by increasing the boiler pressure from 116 to 131 psi, the performance could also be improved. Despite the trailing axle, there was still a large overhang, which meant that weight transfer was still a problem and would repeatedly lead to derailments. Thus, the retirement took place around 1900, when the conversion of the last machines was only 14 years ago.