The Gotland Railway opened its 57 km long line in 1878 with a gauge of 891 millimeters (2 feet 11 inches) and ordered three small tank locomotives from NoHAB in Trollhättän. An axle load of just over five tonnes had to suffice on the narrow-gauge railway. The locomotives were given the names “Wisby”, “Polhem” and “Gotland” and were completed shortly before the opening of the line.

One of the three locomotives was presented at the Paris Exhibition in 1878 and was NoHAB's first showpiece there. According to Locomotive Magazine, apart from their Belpaire firebox, the locomotives were not distinguished by any special technical features, but by the high-quality execution of details. In addition to the successful execution of the valve gear, this also included a good weight balance thanks to the unevenly distributed wheelbases.

When the SJ took over operations on the Gotland Railway in 1948, the three locomotives were no longer used. Numbers 1 and 2 were then scrapped in 1952. Number 3 “Gotland” was donated to the Swedish Railway Museum in 1956 and has belonged to Gotlands Hesselby Jernväg since 1992.

Under the impression of the Prussian P 8, the class A (II) Atlantic was developed into the B (II) with the wheel arrangement 4-6-0. The SJ had 96 locomotives built between 1909 and 1919. With the advancing electrification in the 1930s, some locomotives were sold to private railways, which later came back to the SJ after nationalization. The SVB (Stockholm-Västerås-Bergslagens Järnvägar) even had three more locomotives built in 1943 and 1944. The locomotives were retired by 1972 and kept as a strategic reserve until the 1990s. For this reason, many are still preserved today.

In the search for a heavy mixed traffic locomotive for lines in the north with a low axle load limit, the SJ introduced the E^II in 1907. It had four driving axles and no carrying axles to get the maximum adhesive weight. The driver diameter of 1,388 mm allowed for a top speed of 65 km/h, what was enough for passenger trains in this region. Additionally, they were the first SJ locomotives with inside cylinders. Between 1907 and 1920, 130 were built for the SJ. One of these had received peat firing for trials.

Another company that ordered three of the same locomotives new in 1917 was the Kalmar nya järnvägsaktiebolag (KJ). In 1925 and 1926, the Ostkustbanan (OKB) bought 14 from the SJ. Also the Uddevalla–Vänersborg–Herrljunga Järnväg (UVHJ) and the Skåne-Smålands Järnväg (SSJ) bought one each in 1936 and 1937, respectively. All of these had re-joined the SJ by 1940 when all private railways had been nationalized.

As early as in 1935, the SJ had started to equip these locomotives with a leading axle. In this process, the boiler was also relocated for the right weight distribution and the top speed was increased to 70 km/h. Additionally, some locomotives got a larger four-axle bogie tender instead of the three-axle one. By 1951, a total of 90 had been rebuilt and renamed to E2.

After they had become too slow for passenger trains, they were only used in freight and shunting service on branch lines. All had been withdrawn from active service in 1972, but some were kept as reserves until 1990. Today more than 30 are still existing, with a few of them still operational.

For heavy passenger and freight trains, the SJ ordered ten 4-6-0 locomotives from Richmond Locomotive Works, since the Swedish builders were busy at that time. They were two-cylinder compounds with a saturated taper boiler. Boiler pressure of these first ten was 180 psi or 12.4 bars. Between 1901 and 1905, 29 more were built by NoHAB and 14 by Motala Verkstad. These had a boiler pressure of 13.5 bars. The designation of this class was T. After the introduction of the Tb with a larger boiler, the T was renamed to Ta. In the twenties the Ta received parallel boilers to make them as powerful as the Tb. But withdrawals already started in 1927 and by 1942, only four were remaining.

Some were sold to the Finnish State Railways after their withdrawal to address a severe locomotive shortage in World War II. There they had to be re-gauged to broad gauge and needed more modifications before they could be used as Hr2. After the war, they were used for some more years and scrapped between 1950 and 1953. The four locomotives still in service in Sweden again became the T in 1942, while the Tb became the T2. Since both now had similar boilers, they were combined to the new class B5 in 1952. The last ones were scrapped in 1964.