NSB 2-8-4 Locomotives in Norway

Class Class 49 Dovre Giant (Locobase 1741)

Data from "NSB type 49" in Wikipedia at [], last accessed 8 October 2022; the long article originally at [], later []. Thune works numbers were 377-378 in 1935, 409-410 in 1941. Krupp works numbers were 2152-2153 in 1940.

"DovreGrubben" were designed to move both freight and passenger trains over the nearly 2% ruling grade of the Dovre Mountain route. Built by Thune and later Krupp too, they indicated 2,600 ihp in tests. Notice the large superheat percentage as well as the provision of thermic syphons. Also, unlike most compounds, the stroke length for the HP cylinders differed from that of the LP cylinders. In the 49a and b, HP cylinders measured 465 x 650 mm/18.31" x 25.59" mm, LP 650 mm x 720 mm/.25.59" x 27.56".

The design gained considerable attention for the successful attempt by Norwegian engineers to package a relatively powerful locomotive on so light an axle loading. But Wikipedia's entry (as translated by Google) considered their "complicated construction" meant they were never "completely reliable." In fact, they were "They were infected with many 'childhood diseases' and spent a lot of time in workshops before the war.

49c-class engines came out of Thune's workshops in 1941-1942 produced to a design from Germany's Krupp works. As Locobase shows in the specs, Cylinder volume decreased while heating surface area increased slightly, lengthening the frame over the rear bogie, and simpler chimney (stack). As a result, Wikipedia reports, the 49cs proved more economical.

Their full-service years began only after the end of World War II "and in the 1950s they worked most satisfactorily" hauling Otta-Trondheim passenger trains until replaced by Di 3 diesels, which couldn't compete in speed when climbing Dovrebanen's grades, but were "more economical to operate."