For short stretches of few kilometres around Ettlingen, the Baden State Railway ordered a single 2-2-0T omnibus locomotive from Karlsruhe in 1882. It was designed to haul light passenger trains with one to three coaches. Only the rear axle was driven by the cylinders which were relatively far at the front, leading to long connecting rods. While the bunker for 900 kg of coal was situated on the rear wall of the cab, two tonnes of water were carried between the frames.

In 1885, two more identical locomotives were ordered for the same area. When service on the Alb Valley Railway and other secondary lines was taken over by the private BLEAG in 1898, the three locomotives were used in other places of Baden. They were withdrawn in 1917 and 1918.

Some locomotives used on haciendas in Peru were of the 4-2-0 wheel arrangement to run through extremely sharp curves. One of these with a saddle tank, built by Manning Wardle in 1868 with works number 246, could later be found on the Ferrocarril de Supé á San Nicolas. Since this railway was only founded in 1898 by the Sociedad Agrícola San Nicolas, the original customer is hard to determine. The railway used another side tank locomotive with the same wheel arrangement that had been built by Black Hawthorn in 1891.

The Mla was a small tank locomotive for passenger service on branch lines with a low axle load limit. It was developed from the MI, but was lighter with smaller cylinders and now had its single powered axle in the rear position. The boiler was still of the Brotan type and the cylinders still worked in compound. While the MI had been designed to haul 110 tonnes with 60 km/h on the level, the MIa only had to cope with 100 tonnes at the same speed.

In 1910, the first 23 were produced by MÁVAG of Budapest. They were renamed to class 11 in 1911 and two years later, eight more were delivered. After World War I, four came to Romania and one to the SHS state and later Yugoslavia. In Romania, the CFR retired its locomotives as early as in 1935. In Hungary, they were superheated and simpled starting in 1925. The first ones were scrapped in 1939 and after 1947, only four were remaining. In the new class scheme of 1957, they got the number 175. They were scrapped between 1959 and 1963.

After the introduction of steam railmotors, the LSWR had found out that they were often underpowered in times with high traffic on the branch lines. So in 1906, Drummond designed a small 2-2-0T tank locomotive based on the power unit of steam railmotors, but with more power. Ten were built as class C14 and used on push-pull trains. Usually coupled to two coaches, they still proved to be underpowered on some lines.

In 1910, two more class S14 locomotives were built after the same general design, but with four coupled wheels and enlarged boiler and cylinders. But as these were still less powerful than three-axle tank locomotives, no more were ordered. Anyway, Robert Urie ordered four of the class C14 also to be rebuilt to 0-4-0T. There the cylinder diameter was increased to 14 inches, but before the war, only two were completed.

In World War I, most were sold either to the Ministry of Munitions, to the Admiralty or the War Department and used as light shunters. After the war, two unrebuilt and one rebuilt C14 were still existing. In 1922 and 1923, the two remaining ones were also rebuilt. All three came first to the Southern Railway and then to British Railways. Their withdrawals came in 1957 and 1959.

The T 0 was a so-called “omnibus locomotive” that was developed for lines with low passenger numbers. Since four-coupled tank locomotives were too large and too expensive to maintain, the T 0 was built with an 2-2-0T wheel arrangement. With it, it was possible to run trains more often in rural areas.

The resulting locomotive had a leading axle with a 1,000 mm wheel diameter and a rear, powered axle with a wheel diameter of 1,210 mm. Despite a length of only 6,500 mm, the wheelbase was 3,700 mm, which was very long and gave the locomotive good running characteristics. The driver's cab was designed in such a way that the engine could be run by one person alone. Due to the low coal consumption, it was also possible to fire the boiler without an additional fireman. Nevertheless, the locomotive with the number 64 was equipped with a Littrow chute, which consisted of a coal hopper on the roof and a chute. Since this did not prove itself, it was later removed again.

As with the Bavarian local railway engines, the conductor was able to board the locomotive while it was in motion. Due to the small width of the boiler and water tanks, running boards with a railing could be attached. These also made it possible to reach the locomotive in the event that it was coupled to the train on the boiler side. The power and tractive effort of the T 0 were sufficient to tow four or five light passenger cars on flat land with sufficient acceleration so as not to unnecessarily increase travel times on routes with many stops. Nevertheless, the good running characteristics made a speed of 60 km/h possible, which was faster than most small tank locomotives. 

Despite the cheap operation, only six pieces were built. In the end, this type of construction did not catch on and instead, branch lines soon ran more frequently with light, regular tank locomotives or railcars. Thus the use of the T 0 ended around the end of the First World War.

The class T 0 referred to two types of small tank locomotives that were only powered on one of two axles. The first four locomotives were omnibus locomotives with a baggage compartment, but since this did not prove its worth, the second batch was built as a conventional tank locomotive. In order to test different types of engines, two of the first batch were each equipped with a simple and a compound engine. The latter were designed with the help of August von Borries and were the first Prussian locomotives with this type of power plant. Schichau of Elbing in what was then West Prussia acted as the manufacturer of these four locomotives.

In service, the compound locomotives showed a significantly lower coal consumption than the others. The baggage compartment attached to the locomotive in order to dispense with a baggage car soon proved to be too small. Thus, in 1883, a second batch was procured, which no longer had a baggage compartment. Instead, the new variant was generally more powerful than the first and used only a compound engine. The increase in power was achieved with a boiler with a larger grate and heating surface and larger cylinders. This also increased the weight by two tonnes. Ten were built, which were supplied by Henschel.

The four of the first batch were either retired or resold around 1900. The remaining locomotives remained in use until they were retired in 1922. One of them can still be seen today in the German Museum of Technology in Berlin. The latter today bears the number 1907 of the Hanover Directorate, although the locomotives actually bore the numbers Hanover 1900 to 1903, Hanover 6001 to 6008 and Cassel 6001 and 6002 respectively.