When the Südbahn made the decision to procure new express locomotives in 1881, the focus was basically on the class 16a “Rittinger” built in 1873. Since the train weights had increased from 70 to 80 tonnes before to around 150 tonnes and the use on gradients of up to 2.5 percent was required, the tractive effort had to be greater. To achieve this, the wheel diameter was reduced from 1,900 to 1,720 mm and the rear coupled axle was placed under the firebox to increase the adhesive weight. As with the 16a, an outer frame and Stephenson valve gear were used.

The first ten engines were delivered in 1882 and designated as class 17a. The Kaschau-Oderberger Bahn (KsOd) also bought ten more between 1884 and 1891. They almost used the axle load of 13 tonnes that was now permitted. During the official approval runs they reached 115 to 120 km/h without a load and with the usual load of an express train they could easily maintain 80 km/h.

In 1884 and 1890, the Southern Railway procured a total of 14 examples of a reinforced variant, which was listed as the 17b. This was followed by another 60 examples of a similar variant, which had a boiler pressure increased by one bar and a slightly larger boiler. They made full use of the axle load of 14 tonnes that was now permitted. Together with two other locomotives built in 1885, they became the class 17c.

In view of the increasing train loads, a locomotive had already been built in 1888 that had larger coupling wheels and cylinders and a Belpaire firebox. Together with three other engines delivered in 1890, it was listed as class 17d.

After the collapse of the Austro-Hungarian monarchy, the remaining locomotives were distributed to the successor states. Apart from Austria, this affected the states of Hungary, Yugoslavia and Czechoslovakia. The BBÖ no longer had any pieces of the class 17a, the rest were distributed over several classes. These were class 103 for the last two 17bs, 403 for the two 17cs built in 1885, 503 for the production version of the 17c and class 603 for the 17d. In Austria the engines disappeared in the 1930s, in Yugoslavia only in the 1950s.

When the Crampton locomotives used for express trains on the Grand Duchy of Baden State Railways were no longer state of the art, a new express locomotive was developed from the class III passenger locomotives.

Special features of the II a were the Belpaire firebox and an outer plate frame. The power was transmitted via Hall cranks to the drivers located within the frame. Because the cylinders were located in front of the pivot of the lead bogie, the running smoothness was not entirely convincing. Especially under full load, the overhanging masses of the cylinders generated unwanted vibrations.

Despite this, the locomotive performed well and was used on the international trains that traversed the Baden region. The locomotives were able to pull a 220-tonne train with 16 cars on the flat at up to 84 km/h and thus still reached 60 km/h on a gradient of 0.5 percent. At 1.25 percent, 150 tonnes could still be pulled at 50 km/h.

Another delivery of ten locomotives in 1891 saw the need to lengthen the boiler tubes and increase the diameter of the cylinders to 457 mm. To improve the running characteristics, the wheel base of the bogie was also increased from 1,400 to 2,000 mm.

After the founding of the Reichsbahn, the II a met the same fate as other older Länderbahn locomotives. Of the 24 units built, ten were still included in the renumbering plan as class 36⁷³. Eventually all were retired by 1925.

The class II c designated express locomotives which, contrary to usual practice, had been developed based on the English practice. They were the first locomotives in Germany to be certified for a maximum operational speed of 110 km/h. The clearest distinguishing feature was the inside plate frame with wheel housings, which partially covered the 2,100 mm large coupled wheels and started at the level of the very low running board. In addition, the cylinders were on the inside, which was very rare in Germany for two-cylinder steam locomotives.

Due to the long wheelbase of the bogie and the low-lying boiler, the running characteristics were very good, so that the locomotives even ran smoothly at 120 km/h during test drives. The large wheels also helped maintain higher speeds for longer periods, and thus the 110 km/h certification was granted.

The development and production of the first series models took place at Grafenstaden in Alsace, but further vehicles followed from the Karlsruhe Engineering Society and the Saxon Machine Factory Hartmann. A total of 35 pieces were made between 1892 and 1900.

In order to reduce the effort required at high speeds, two modifications were made to the last five machines, as would also be found on later locomotives. One was a wind-cutter cab, i.e. the front wall of the cab was divided vertically in two and both halves were pulled back at a sharp angle in a V-shape. The other adjustment was an aerodynamically clad smokebox door. Instead of being conical like other German express locomotives from the beginning of the century, the tip was pulled down almost to the bottom of the boiler and the fairing formed a transition to the cylinders. Along with these modifications came an increase in boiler pressure from 12 to 13 bar.

Despite their good running characteristics, the tractive power of the locomotives was soon no longer sufficient for lighter express trains, as these could pull a maximum of 260 tons at top speed. In addition, higher demands were now placed on the acceleration of trains, which gradually reduced them to lower services. After the First World War, nine examples came to France and were operated there by the État state railway as class 220.9. In the period that followed, the number of locomotives remaining in Germany decreased, which meant that the planned takeover of the last machines by the Reichsbahn and re-designation to the class 36⁷³ did not occur.

Locomotives with no coupled axles were soon no longer sufficient on the Grand Duchy of Baden State Railways either, and so class XII was developed with a 4-4-0 wheel arrangement and a remarkably short wheelbase. Certain similarities to Swiss locomotives are not surprising, since the Swiss network was also used in part.

Earlier locomotives often had a 2-2-2 wheel arrangement, but when adding a second coupled axle, a front bogie was chosen instead of two individual carrying axles. In order to be able to continue to use the existing turntables, the overall wheelbase was designed to be as short as possible. Due to the large driving wheels, this was not achieved simply by moving the bogie back; the bogie itself had to be made very short and the distance between the remaining axles kept as short as possible.

Since development was making rapid progress at the time, the engines differed depending on the year of construction. It was noticeable that the steam dome was relatively small in the first batches and significantly larger in the later ones. What they all had in common was that the external leaf springs were noticeable and the deceleration was carried out via spindle brakes on all wheels of the tender. Due to the design of the boiler and the position of the cylinders in front of the bogie, a speed of only 60 km/h was possible despite the large wheels.

Despite the inadequacy, the engines of the series designated as type III from 1868 became indispensable, so that from 1869 a reinforced version was procured as III a. From 1881, many of the 41 examples of the XII or III and the III a were converted to the III b with an even more powerful boiler and longer frame. The locomotives that had not been converted were taken out of service at the beginning of the 1890s, and the rest were able to survive for a few more years after the turn of the century.

Shortly after the express locomotives of type X were put into service, it was noticed that the power could not be further increased while maintaining the 2-4-0 wheel arrangement. For this reason, a new locomotive was developed that had a bogie that could be moved sideways at the front and could therefore accommodate a larger boiler without exceeding the axle load. The first series consisted of 39 machines, which were delivered by Maffei in 1892 and 1893. They were powered by a simpe two-cylinder engine and could reach a top speed of 90 km/h with a 1,870 mm driver diameter. 

A second series was produced from 1895, of which a total of 100 machines were manufactured not only by Maffei but also by Krauss. Their biggest difference to the first was that they got a compound engine with two cylinders to achieve better efficiency. In addition, the boiler pressure was increased from 12 to 13 bars. On the flat, the two versions could haul 200 and 270 tonnes, respectively, at 75 km/h. In order to be able to maintain a speed of 50 km/h on gradients of 0.5 percent, the train weight was not allowed to exceed 200 or 260 tonnes.

Despite the early appearance of more powerful and, above all, faster locomotives, a large number of the machines were able to survive until the Reichsbahn era, even if they were rarely used in high-value express train service later on. Eight examples of the first series and 76 of the second series were taken over by the Reichsbahn and given the numbers 36 701 to 708 and 36 751 to 826. The simple locomotives were all retired in 1926 and the compound locomotives by 1931.

The increasing weight of the express trains in the 1880s and 1890s also presented the Caledonian Railway with the problem that inefficient double-headings had to be used more and more frequently. John F. McIntosh, who was chief engineer from 1895, increased the performance of the 4-4-0 locomotives to the maximum that was possible within the limits of physics and engineering. Key to this was the use of a larger boiler that just fit into the loading gauge of the Scottish lines and was operated at 160psi. The resulting locomotive was named the Dunalastair class after a well-known Scottish clan. It also formed the basis for Belgian tender locomotives with a 4-4-0 wheel arrangement and tank locomotives with a 4-4-2T wheel arrangement, of which 424 were built.

In 1896 15 examples of the actual class 721 were built, numbered 721 to 735 and later named Dunalastair I. This was followed in 1897 by the numbers 766 to 780 as Dunalastair II and in 1899/1900 by 887 to 902 as Dunalastair III. The latter two series received four-axle tenders in order to be able to cope better with the longer distances in the Scottish expanses. Records of the Dunalastair III show a 32 mile run with a 250 ton train at an average speed of 58 mph. Between 1904 and 1910, another 19 followed as Dunalastair IV. From 1910, a total of 21 locomotives of the classes 139 and 43 were built, which had a superheater ex works and, depending on the author, are either also classified in the Dunalastair class or regarded as a separate class.

During development, the boiler pressure was increased first to 175 and then 180 psi. Beginning in 1914, when some series II, III and IV locomotives were rebuilt with superheaters, the boiler pressure was lowered back to 170 psi and larger cylinders were installed. At the LMS they were numbered between 14311 and 14439. While all Dunalastairs in the original version were retired by 1935, the superheated engines survived longer. Of a total of four engines that were taken over by British Railways, the last Dunalastair IV survived until 1958.

In 1916, William Pickersgill had 16 class 72 4-4-0 express locomotives built. From 1920, 32 more class 113 locomotives followed, which had a slightly smaller boiler and slightly larger cylinders. Technically, they could be considered the successors to McIntosh's Dunalastair range, which is why they were unofficially called “Dunalastair V”. Like their predecessors, they had the cylinders and valve gear on the inside of the frame, but a superheater straight from the factory. They reportedly performed well, which increased their lifespans. So all members of the class came to the LMS in 1923 and to the British Railways in 1948. One was scrapped in 1953 after an accident and the rest were only retired between 1959 and 1962.

William Aston, who had been chief engineer of the Cambrian since 1882, had already revised the six Beaconsfield class locomotives to cope with the increased train weights and tighter schedules. It was all about the express trains that transported holidaymakers to the tourist areas of Wales. From 1893, class 61 locomotives were procured to meet the increased requirements in this area, which represented an extension of the Beaconsfield class.

Compared to their predecessors, the locomotives received larger cylinders, larger drivers and a new boiler with 20 psi higher pressure and a larger firebox with larger grate. In the years 1893 to 1895, 16 were made by Sharp, Stewart & Co., which received the numbers 61 to 72 and 81 to 84. Five more followed in 1897 by Robert Stephenson & Co., numbered 32, 47, 11, 85 and 86. Number 19 was special as it was only built in 1901 in the Cambrian Railway's own workshops in Oswestry.

Number 283 was a 4-4-0 locomotive, of which no class designation is known today. Built in 1883 by the Hinkley Locomotive Works, it had 62-inch diameter coupled wheels. It is said to have been used generally in front of passenger and freight trains.

It is best known for drawing the funeral train of Canadian Prime Minister John A. Macdonald. This was pulled on June 10, 1891 through Ontario from Ottawa to Kingston. The photo shows it decorated for the occasion. The 283 was eventually scrapped in 1897.