4-8-0 steamlocomotive series 31b # 452 of the Norwegian State Railways (NSB), built by Hamar Jernstøberi & Mek. Verksted / Thunes mek. Værksted in 1926 (construction # 334) in the Norsk Railwaymuseum in Hamar. Driving wheel diameter is 1350 mm and maximum velocity 70 km/h. The series was a further development of the NSB Type 26 series. It was one of NSB's largest steam locomotive series and hauled the most important trains on the non-electrified lines, primarily on the Bergenbane and Gjøvikbane, as well as in the Hamar and Trondheim rail districts. The second series 31b with 23 locomotives was a four-cylinder compound locomotive and was therefore better suited to pulling heavy trains on long grades than the 31a. The Bergenbane with its gradients was therefore the main area of use for the 31b locomotives until the end of the 1950s. # 452 has been preserved and is in the Norsk Jernbanemuseum in Hamar. The introduction of heavier rails on the Bergensbanen made it possible to increase the axle load to 14 tons. At the same time, a larger high-flying machine with such axle pressure was constructed, type 31a. The first two came in 1915, followed by two more in 1920. These were four-cylinder high pressure machines. The type was redesigned for compound construction, and Swedish Nydqvist & Holm delivered the first four such, type 31b, in 1920/21. This was followed by a larger series built domestically and two from Italian Breda. In addition to the Bergensbanen, the type was used in heavier trains in several parts of the country.
The locomotive is primarily associated with the Bergensbanen, but after the electrification there, the type 31b was also used between Hamar and Dombås and on the Raumabanen. The preserved # 452 was first used in the Trondheim district, then on the Bergensbanen from 1944 and finally in the Hamar district from 1961 until its retirement in October 1968 and its decommissioning on 15 October 1969. The locomotive came to the museum in 1975, and is in the locomotive hall.
It was last in service as a reserve locomotive at Otta until October 8, 1968.
