The Antwerp-Ghent Railway ordered these two locomotives with the intention of later converting them to standard gauge. So they were built by the manufacturer in such a way that the wheels with a gauge of 3 ft 7 in can be removed inside the frame and reinstalled outside the frame with a gauge of 4 ft 8 1/2 in. This plan was implemented in 1899, at the same time the cab was closed and the Westinghouse air brake was retrofitted.

In 1932, the Belgian firm of Ateliers Métallurgiques in Tubize built the world's only Quadruplex locomotive with the assistance of the Italian Attilo Franco. Its special design was not only to increase power, but also to increase efficiency. It was much larger than anything the Belgian Railways needed, but was used as a prototype for a planned compound hexaplex locomotive for the Soviet Railways that was even larger, but never realized.

The locomotive consisted of three sections called A, B and C. The middle B section housed a special double boiler that had two central fireboxes. These were located side by side, were each fired by one fireman and had their own coal bunker. Each end of this section had a cab since the locomotive was way too long to use turntables.

The A and C sections contained large Franco feedwater heaters which were encased by the water tanks. The chimneys were on the extreme ends of these sections since the hot gases only escaped to the atmosphere after passing through the feedwater heater. A part of the hot gases was ducted to the grates to mix with the cold air.

A total of ten driving axles were powered by four pairs of two cylinders each. The B section had two pairs of two driving axles, with carrying axles at the ends and one in the middle. The A and C sections had three driving axles and one trailing axle. This led to the wheel arrangement 0-6-2+2-4-2-4-2+2-6-0T. With this arrangement, the locomotive could pull 1,200 tonnes on an incline of 1.6 percent. Additionally, it was found to have a low specific consumption.

After the trials, the locomotive with the builder's number 2096 was shown on the Brussels exhibition in 1935 and then withdrawn. In 1943, it was split in half and rebuilt to two 0-6-2+2-6-2T locomotives by adding an additional driving axle below the half of the old B section. After getting to Germany in 1944, they were used in a shipyard. When the war ended, the Soviets brought them to two different locations in Poland where they were used for a few years.

A few years before the First World War, Jean-Baptiste Flamme developed a very powerful boiler that was to be installed in a freight locomotive and an express locomotive at the same time. So from 1909 the type 36 with the 2-10-0 wheel arrangement and from 1910 the type 10 Pacific were built. Since the boiler was relatively short with a large diameter and the chassis of the Pacific naturally had a long overall wheelbase, the appearance of the Locomotive somewhat unusual with a long overhang in front of the smoke box.

The boiler had a grate area of five square meters and narrowed in front of the firebox. It delivered 2,250 hp, making the type 10 one of the most powerful Pacific locomotives in Europe. Since the bogie hardly had to carry any weight from the smoke box, the load was kept within limits despite the four cylinders with simple steam expansion. Due to the special arrangement of the cylinders, the inner cylinders were accessible from above, which made maintenance easier. Although the cylinders were in one plane, the inner ones drove the first driving axle and the outer ones the second. The problem, however, was the weight of the large firebox, which made the load of the trailing axle too high. The Type 36 didn't have this problem as the weight was carried by the coupled axles. 

As a result, the second batch from 1912 was delivered with a smaller grate surface in order to reduce the axle load on the trailing axle. However, this reduced the power to 1,950 hp, while the service weight of the locomotives was reduced by around four tons. A total of 58 pieces were made by 1914, when production was stopped due to the war.

In the 1920s, the locomotives received double chimneys and new feed pumps. From 1931 there was a major conversion with new feedwater heaters, a larger superheater, new safety valves and smoke deflectors. The result was an output of 2,700 hp for the first batch and 2,400 hp for the second batch. 1938 followed the installation of Kylchap blast pipes. A large proportion of the engines were retired in 1956 and some continued to run on a different route for three more years.

In 1939, the Belgian State Railways ordered Cockerill to build six streamlined Atlantics to speed up express trains between Brussels and Ostend. While this wheel arrangement was already unusual at the time, the inside cylinders with outside valve gear were also unusual. With a maximum permitted speed of 140 km/h, trial runs reached 165 km/h, while the trains often exceeded an average of more than 110 km/h. Average speeds of 120.46 km/h from station to station were also achieved, which is still the European record for steam trains to this day. When the route for which the locomotives were built was electrified, they were used on other routes. They were decommissioned by 1962 and road number 12 004 is now in the “Train World” in Schaerbeek.

In order to be able to burn cheap coal with the smallest fragments, the Belgian State Railways needed a large firebox for their express locomotives. This also applied to the type 12bis, which was based on the type 12 from 1888 and where the “bis” stood for “second”. In order to achieve the required power, the grate area had to be further increased to 4.7 square meters or 50 square feet. 

On the 12bis, too, the firebox consisted of a narrow, front part between the wheels of the second driving axle and a wide, rear part above the trailing axle. It still had outside frames, as well as serve tubes and a conical chimney. It was said to run smoothly even at 110 km/h (68 mph). 

The type 13 consisted of only two four-cylinder 4-6-4T tank locomotives built in 1912 at Tubize. They were intended for heavy suburban and express trains and were tank locomotives since Belgium had many terminal stations where the locomotives could not be turned. Designed by Jean-Baptiste Flamme, here he used his favorite design of a superheated four-cylinder simple. Parts of the running gear were taken over from the type 9 4-6-0, but the diameter of the drivers had been decreased from 1,960 to 1,800 mm. The bogies had a long wheel base of 2,250 mm for steady running at a top speed of 110 km/h. A compensating lever was mounted between the last driving axle and the trailing bogie to reduce the effect of decreasing supplies on the adhesive weight. 

The locomotives were numbered 4701 and 4702 and mainly used between Brussels and Antwerp. There their task was to replace the type 15 4-4-2T tank locomotives. No series production of the type 13 was started due to the outbreak of the war. In the end, their potential tasks were taken over by the type 9 that had been built in greater numbers before the war. After some lines had been electrified, 4701 and 4702 were withdrawn in 1931 and scrapped in 1934.

A few years before the First World War, Jean-Baptiste Flamme developed a very powerful boiler that was to be installed in a goods and an express locomotive at the same time. In 1909 the type 36 with 2-10-0 wheel arrangement and in 1910 the Pacific of the type 10 were created. The boilers differed only in the firebox, which had enough space between the last driving axle and the trailing axle on the type 10, but had to be accommodated above the last two driving axles on the type 36.

The very large firebox had a direct heating surface of 19 square meters and included a grate of 5.1 square meters. The long boiler tapered in front of the firebox, but still had a large diameter in the front area. It made the type 36 the most powerful goods locomotive in Europe.

To ensure curve negotiation, the leading axle was combined with the first coupled axle to form a Zara bogie, and the last driving axle had 29 mm of lateral play. The four cylinders were all in one plane and were only controlled by two external Walschaerts valve gears for easier maintenance. The inner cylinders acted on the second driving axle, and the outer ones on the third.

In a first batch, 136 were completed, 17 more followed after the First World War. 113 of the pre-war locomotives were rescued to France during the war, where they were not used due to their high axle loads. As early as 1915, 60 were sold to Russia, where they were to be used on standard-gauge lines in Eastern Europe. Ultimately, they were converted to broad gauge and used in the Soviet Union until 1962.

The locomotives returned to Belgium were fitted with double blast pipes and longer smokeboxes in the 1920s. Together with other smaller conversions that were made up to the early forties, the service weight increased by almost four tons and the power to 2,300 hp. They were now designated type 36^bis and were used until 1947.

To address the lack of locomotives after World War I, the Belgian State Railways ordered 150 Consolidations from the USA in 1919. The diameter of the drivers was large enough to make them also suitable for passenger service. Generally designed after American practice, these locomotives were tailored for service in Belgium and not only had a Belgian-style cab, but also a tender that was entirely built from Belgian blueprints. Every part of the design was carried out in metric measures. The order was split evenly among ALCO-Schenectady and Baldwin.

The first locomotive was completed only 52 days after the sales representative arrived back in the USA. In contrast to the Pershing class built by Baldwin, they had a wide firebox, what necessitated a boiler that was mounted higher above the drivers. The last five built by ALCO had also received a Worthington feed water heater. In service, even the locomotives without a feed water heater were able to haul a 1,000-tonne train up a 0.5 percent incline at 42 km/h. In addition to the American Consolidations, Armstrong Whitworth built 200 more of their own design for Belgium which were designated type 31 and were less successful than the American locomotives.

The type 6 was an express locomotive designed for long inclines on the line between Brussels and Luxembourg. The requirements included that it should be able to haul a train of 100 tonnes over long inclines of 1.6 percent with a speed of 65 km/h. Since it had to burn coal dust, the grate had to be extraordinarily large. This led to three prototypes with a very special boiler design and a total of 32 production locomotives which were more conventional. Typical for locomotives designed by Belpaire, they had outside frames and inside cylinders.

The first prototype was built by Cockerill in 1884. Since the boiler of the previous type 2 0-6-0 was not big enough, the type 6 received a leading axle that was mounted in a radially adjustable Adams axlebox. The wide and shallow firebox had a grate of 6.7 square metres (72 square feet) and four doors. The water spaces of the firebox and boiler barrel were not directly connected, there was only a connection between both domes. Like in American camelback locomotives, the driver had a small cab that was located in front of the firebox, but in this case only on the right side of the boiler.

The prototype was difficult to operate and maintain. Later it even got a second carrying axle between the second and third driving axle. Two more prototypes were built in a similar fashion, but without the additional carrying axle. Series production of a modified variant was started in 1888. This had a minimally smaller grate of only 5.74 square meters (62 square feet), but only one cab and a boiler with only one water space. The cylinders, pistons, valves, valve gear and crank axle were shared with the types 12 and 25. The chimney was of the rectangular type also seen on other Belgian locomotives and had a variable blast pipe. 

The three prototypes were withdrawn in 1900. Although the production locomotives delivered roughly 1,000 hp, the four firebox doors were difficult to feed and the maintenance of the firebox was complicated. So the type 6bis was created in 1904 by rebuilding eight type 6 locomotives with a new boiler. This had a much smaller grate and a higher pressure. When burning coal briquettes, it delivered more power than the original boiler fired with coal dust. Many non-rebuilt locomotives were scrapped between 1907 and 1911. After World War I, only one locomotive each of type 6 and 6bis were remaining, which were withdrawn in 1922 and 1923.

Although they were no Engerth supporting tender locomotives, these 14 0-8-0 freight locomotives were also called “Engerth du Luxembourg”. The explanation for this is that apparently all powerful freight locomotives were called “Engerth” in France and Belgium at this time. They were the first eight-coupled locomotives in Belgium and were intended for heavy freight service on the line between Namur and Arlon that led towards Luxembourg. Their builder was Charles Evrard with his Compagnie Belge pour la Construction du Materiel de Chemins de Fer.

The first six were built in 1871 and were numbered 102 to 107. They had a round-topped firebox that was located in an overhanging position behind the last driving axle. Numbers 115 to 122 built in 1872 had a Belpaire firebox that was mounted above the last driving axle. Additionally, they had a somewhat larger firebox and less tube heating surface and weighed less. The state railway took over these batches as types 23 and 24 in 1873. Later they were used on secondary lines in the Hainault region. Their withdrawals were between 1891 and 1903.