In 1912, the Japanese state railways received four class 4100 tank locomotives from Maffei in Germany. Two years later, Kawasaki had more locomotives made that were more or less copies. Differences lay in a larger grate but smaller firebox heating surface. After 30 locomotives were built, the boiler got an additional flue with an additional superheater element.

In Japan, the locomotives were only used until 1950. Five were taken to Korea in 1939, where they later remained in service as part of the North Korean Railways until 1976. Some locomotives also came to Taiwan, these were scrapped by 1980.

The class 8620 was the first mass-produced passenger locomotive in Japan. With the wheel arrangement 2-6-0 and the same boiler as the 4-4-0 class 6760, it was mainly intended for regular passenger trains with its higher adhesive weight, but still could haul express trains. A Krauss-Helmholz bogie that connected the leading and the first driving axle reduced the rigid wheelbase to only 2.286 mm.

Between 1914 and 1929, multiple manufacturers produced a total of 672 locomotives for the JGR. The Imperial Taiwan Railway got 43 which were designated class CT150. Additionally, small operators received 17, bringing the total number to 732. From the late twenties, they got smoke deflectors. Most were withdrawn in the fifties, but the Haboro coal railway operated some until 1971. 20 have been preserved in Japan and one in Taiwan.

The class 9600 of the Japanese Government Railways consisted of 770 Consolidations for freight service built by several builders between 1913 and 1925. They were the first steam locomotives which were mass-produced in Japan. Their nickname was “Kyuroku”, what just means “nine-six”. 38 more were built for Taiwan and at first called class 800, later D98 and finally DT580. After World War II, another one was built in Taiwan from parts of scrapped locomotives.

Also in World War II, the Central China Railway and the North China Transportation Company urgently needed locomotives and so 251 of the Japanese ones were shipped to China and rebuilt to standard gauge. There they were called Soriko class and after the war, China Railway took them over as class KD5. Some were converted to meter gauge to be used on the Kunming–Hekou Railway and called KD55. In Japan, all were retired at once on March 2nd, 1976 when steam service ended. Today, more than 40 are still existing.

In 1912, the Japanese Government Railways received three types of 0-6-6-0 Mallet locomotives from different builders. These were 24 of the class 9750 from ALCO-Schenectady, 18 of the class 9800 shown here from Baldwin and 12 of the class 9850 from Henschel. All three classes had similar dimensions. They were designed for lines with grades of up to 3.3 percent and curves with a radius of 120 meters. Anyway, their drivers with a diameter of 49 inches or 1,245 mm looked relatively huge in comparison to the size of the locomotives.

The diameters of the high pressure cylinders was between 15.5 and 16.5 inches, with 16 inches on the class 9800. The high pressure cylinders had diameters between 24.5 and 25.5 inches, also here the 9800 was in the middle with 25 inches. All cylinders had a stroke of 24 inches. In the end, neither these 0-6-6-0 Mallets nor other 0-4-4-0 Mallets couldn't persuade the decision makers in Japan, so their number stayed relatively small.

The C11 was a 2-6-4T tank locomotive designed by Hideo Shiima for service on secondary lines. It was closely based on the C10, but had a reduced weight thanks to the increased use of welding. Production started in 1932 at several companies and by 1947, a total of 381 had been completed. The first batches had a boiler pressure of 14 bars, but this was raised to 15 bars from 1935. Starting with C11 141 built in 1940, the water tanks had been enlarged, leading to an increased adhesive weight. From 1943, the smoke deflectors were made from wood to save steel. The class could mainly be seen in commuter service and the first ones were withdrawn in 1960 due to the introduction of diesel railcars. But until the end of the sixties, some of the remaining locomotives were even used in express service. A total of 52 have been preserved, six of which are still in working condition.

The class C50 was a Mogul primarily intended for passenger service, but also used for short freight trains. It was the successor of the class 8620 with the same driver diameter of 1,600 mm and cylinders of 470 by 610 mm. The boiler had roughly the same dimensions, but was more powerful thanks to a feed water heater that was located in the tender. In the result, the C50 was heavier and could not be used on all lines which had been suited for the 8620. Additionally, it had inferior running characteristics since the Krauss-Helmholtz bogie had been replaced by a simpler Bissel frame. Their nicknames were “Shigomaru” and “Shigore”.

154 locomotives were built by five manufacturers between 1929 and 1933. From number 68, the drivers had been set back by 200 mm to improve weight distribution. The first five locomotives came to Taiwan in 1941 and four others, which were built without air brakes, were intended for service on Sakhalin. After World War II, the Taiwanese locomotives were used by the state railway in shunting service until 1960, designated class CT230. The four locomotives on Sakhalin fell into the hands of the Soviets, where their trace got lost. In Japan, withdrawals in greater numbers started around 1960, after diesel locomotives had taken over their service. The last one was withdrawn in 1968 and today, six locomotives from the newer batch are still existing.

The locomotive later known as class C51 was introduced in 1919 to increase the speed of long-distance express trains. Following suggestions of German engineers to keep the rotational speed of the drivers below 300 rpm, the driver diameter chosen for a design speed of 100 km/h was 1,750 mm. This was not only a large value compared to the Cape gauge of 1,067 mm, they were also the largest drivers for a narrow gauge locomotive at this time. The boiler was large and benefited from the trailing axle that allowed for a large firebox that also had arch tubes. They were originally numbered in the range from 18900 and became class C51 in 1928.

The first 18 were built by the JGR itself. Parts came from different workshops and were assembled at Hamamatsu. The biggest part of the production came from Kisha Seizō which delivered 249. Finally, Mitsubishi started to build a batch of 22 in 1924. Approved for a speed of 95 km/h, one managed to reach 120 km/h on a test run with two coaches. Over the years, individual locomotives were fitted with measures to increase their efficiency. These included extended smoke boxes, double chimneys and partial streamlining, but all were later removed again.

From 1930, the C51 also hauled the famous Tsubame (Swallow) express between Tokyo and Kōbe in nine hours. In 1939, 16 locomotives were rebuilt to standard gauge and brought to the Japanese-controlled Central China Railway to remedy a severe locomotive shortage. These were called “Pashina” and later became the China Railway SL9 to be withdrawn only in 1990. In Japan, they were mainly used on regional main lines after the war. The last ones were withdrawn in 1966 and five were preserved, four of which are still existing on static display.

The C58 was the only class of 2-6-2 “Prairie” tender locomotives in Japan. Intended as a successor to the class 8620 2-6-0, it had a trailing axle to increase its power. It was designed by Izumiichiro Hosokawa under the lead of Hideo Shima and was the first class of steam locomotives in Japan to have a closed cab. Production started in 1938 at Kawasaki and Kisha Seizō. The boiler had been designed for a pressure of 18 bars, but this was soon reduced to 16 bars due to the war. In this time, the production was also modified to save important materials, so the smoke deflectors were now made from wood.

Additionally, 25 were converted to metre gauge to be used in South East Asia. But most were already destroyed on their way to Thailand, so the State Railway of Thailand only had four on their roster after the war ended. Production continued in 1946 in a somewhat modified variant. The diameter of the boiler had been increased and new tenders with ten tonnes of coal and 20 m² of water were now used instead of the old ones with six tonnes and 17 m². Total production accounted for 427 locomotives.

Now the C58 was mostly used in passenger service due to their low factor of adhesion of only 3.16. However, they did not have the best running characteristics at speed. This could partially be remedied by increasing the centering force of the trailing axle. After the introduction of electric locomotives, they still had to step in when these failed. Additionally, some of the Japanese electric locomotives did not have a steam generator. In 1970, a total of 234 were still in service, with the last one being retired in 1973. 49 were preserved, of which two are still in working condition. C58 239 has been restored by JR East, while C58 363 belongs to the Chichibu Railway.

The D51 was a class of Mikado locomotives built for the rising freight volumes in the thirties. It was a more powerful successor of the D50 and was designed by Hideo Shima. It was lighter than the D50 due to the extensive use of electric welding and was a bit shorter to fit onto 18-metre turntables which were used on branch lines. Another modern feature were boxpok driving wheels. 

The first 95 locomotives had a long casing on top of the boiler that enclosed the domes and the feedwater heater. These were called “Namekuji”, what stood for “Slug”. Later locomotives had a boiler pressure of 15 instead of 14 bars and no casing. The feedwater heater was now located crosswise in front of the chimney. In World War II, construction methods and materials were simplified. Now some parts were made of wood, like the smoke deflectors. These locomotives suffered from reliability issues and even boiler explosions.

In total, 1115 locomotives were built for the JNR, making it their most numerous steam locomotive. 37 more were built for Taiwan, ten for the Philippines and two for Korea. After World War II, 30 were left on Sakhalin and used by the SŽD as Д51 until 1979. The country with the shortest career were the Philippines, where the Manila Railroad designated them class 300. They had been introduced in 1951 and were replaced by diesel locomotives in 1956.

In Japan, six were rebuilt into the 2-8-4 class D61 in 1960 and 1961. The direct successor of the D51 was the D52 that also had the wheel arrangement 2-8-4. The last D51 was withdrawn in December 1975, only some months before the general end of steam in Japan. A total of 180 have been preserved, 174 of these in their country of origin. Five are still able to run under their own power, but three of these have been converted to run on compressed air.

In World War II, Japan did not only have growing freight volumes, but also had to move lots of freight traffic from the sea onto the land as protection against attacks. So they designed the D52 that was a Mikado with a more powerful boiler and higher adhesive weight than the D51. The requirements included the use of a combustion chamber to increase power and measures to reduce the use of strategic materials. Train weights had to be 1,100 tonnes for regular freight trains and 1,200 tonnes for slower coal trains.

Five commercial builders completed 285 locomotives between 1943 and 1946. After freight traffic declined again after the war, 49 were rebuilt into 4-6-4 express locomotives in 1948 and 1949. These were designated C62 and used larger drivers with a diameter of 1,750 instead of 1,400 mm. They became the biggest and fastest passenger steam locomotives in Japan. In 1954, C62 17 set a speed record for narrow gauge steam locomotives in 129 km/h.

Both the original freight locomotives and the rebuilt express locomotives were used until the early seventies. The C62 even had to haul trains double-headed over a 2.5 percent incline on the Tōkaidō Main Line. After the D52 had been withdrawn between 1965 and 1973, six have been preserved. Of these, D52 70 is the only one that can move under its own power, although only on compressed air. After the last C62 had also been withdrawn in 1973, five had been preserved. C62 2 is the only one of these that is in working condition.