When the existing 4-6-0 mixed traffic locomotives could no longer cope with the increasing train loads, the Nord developed new superheated locomotives for pure freight train service, which only had one leading axle. In addition to the 5.001 series 2-10-0 locomotives, 2-8-0 locomotives were developed which were to be given the numbers 4.061 to 4.340.

The boiler was taken from the 3.1150 series Pacifics and featured corrugated Serve tubes. The Belpaire firebox with inclined grate found its place by locating the fourth driving axle at a greater distance from the third and by moving the lower, front part of the grate between the wheels. As was usual with most large French locomotives at the time, it was a De Glehn type compound that acted on the second and third driving axles. After the steam was introduced into the high-pressure cylinders at a maximum of 16 bars, it entered an intermediate reservoir at 7.8 bars and from there it reached the low-pressure cylinders.

The production initially comprised several batches from different manufacturers, which were completed in 1912 and 1913. 20 from Franco-Belge followed in 1919 and another 100 from SFCM, formerly Cail, in 1922. The last 40 only followed in 1928 and 1929 from three different manufacturers and brought the total number to 280. Nord-Belge procured 35 identical locomotives, which bore the numbers 421 to 455 and later became the SNCB Type 48.

The locomotives were given the nickname “Le Boeuf”, i.e. “The Bull” because of their pulling power. They were used in large parts of the Nord network and also hauled pure coal trains. Different models of tenders were used which had three axles and a capacity of 17 or 19 m³ of water. The smaller of the two made it possible for the locomotive to use turntables that were 18 meters long. After the First World War, they were also used in passenger service, as the large diameter of the driving wheels allowed speeds of up to 105 km/h. During this period they also received four-axle tenders from the 140 “Pershing” with a capacity of 22 or 24 m³ and Prussian tenders with 31.5 or 34 m³. Some locomotives later received a Lemaître-type blast pipe, which increased the output by 100 hp. Their withdrawals took place between 1950 and 1959.