The reference for locomotives and railcars
Norwegian State Railways type 26
Norway | 1910 | 22 produced
Works photo of the Swiss Locomotive and Machine Works
Works photo of the Swiss Locomotive and Machine Works
SBB Historic

The Bergensbane, or Bergen Railway, connects Oslo with Bergen and, despite a large number of tunnels, has challenging gradients, so that the express trains at the beginning of the century had to rely on pilot locomotives. For this reason, the NSB launched an invitation to tender for a powerful express train locomotive that should be able to cover this route without double-heading. The route has a constant gradient of 2 to 2.1 percent over a length of 70 km, which culminates at an altitude of 1301.7 meters at Lake Taugevatn and has curve radii of 180 meters. However, the tracks required a maximum axle load of twelve tonnes, while a locomotive with four cylinders was specified to further reduce the loads on the rails.

The winner of this tender was the locomotive later designated as the type 26, which was designed by the Schweizerische Lokomotivfabrik in Winterthur. The required power was achieved with four coupled axles and a leading bogie. Thanks to the boiler being placed very high, it was possible to accommodate a wide firebox without a trailing axle. The locomotives were able to haul trains weighing 200 tonnes at 35 km/h on the aforementioned incline.

The three locomotives delivered by SLM in 1910 were designated type 26a and were, however, somewhat lighter than expected. In order to be able to fully utilize the available axle load, two more units were ordered from Thune in Oslo, which were a bit heavier and were designated type 26b. The largest sub-series with 17 units was the type 26c, which was designed as a compound machine due to the high steam consumption of the four cylinders. It was supplied by several manufacturers between 1919 and 1924.

Schematic drawing
Schematic drawing
Locomotive Magazine, August 1917

As early as 1915, the type 26 locomotives were withdrawn from the Bergen Railway, as the latter had been converted for a higher axle load and the heavier type 31 locomotives were now being used there. Thanks to the small coupling wheels, they were suitable for all types of trains and were therefore used in different parts of Norway in different roles. Rebuilds took the form of an oil-fired engine in the 1950s and the fitting of an engine with a larger boiler in 1961. The locos survived until 1969, when the last year of steam service in Norway had struck. Two pieces were kept in reserve in 1970 in case diesel locomotives failed.

ManufacturerSLMThunesMotala Verkstad, NoHAB, Norsk Maskin Industri, SLM, Hamar Jernstøberi
Axle config4-8-0 (Twelve-wheeler) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Length58 ft 6 3/4 in58 ft 8 15/16 in
Wheelbase27 ft 8 11/16 in
Fixed wheelbase11 ft 1 7/8 in
Total wheelbase49 ft 8 7/16 in
Empty weight123,459 lbs126,766 lbs137,127 lbs
Service weight139,288 lbs144,182 lbs153,882 lbs
Adhesive weight104,234 lbs104,719 lbs107,145 lbs
Total weight219,536 lbs224,430 lbs234,131 lbs
Axle load26,544 lbs
Water capacity3,963 us gal
Fuel capacity8,818 lbs (coal)
Power sourcesteam
Estimated power972 hp (725 kW)1,073 hp (800 kW)
Optimal speed21 mph29 mph
Top speed43 mph
Starting effort29,869 lbf29,426 lbf23,244 lbf
with start valve27,893 lbf
Power Plant
Driver diameter52.4 in53.2 in
Boiler pressure174 psi188 psi
Expansion typesimplecompound
Cylindersfour, 14 15/16 x 23 5/8 infour, HP: 15 3/8 x 23 5/8 in
and LP: 23 x 23 5/8 in
Grate area29.1 sq ft32.3 sq ft
Firebox area109.8 sq ft108.7 sq ft
Tube heating area1,496.2 sq ft1,358.9 sq ft
Evaporative heating area1,606 sq ft1,467.7 sq ft
Superheater area406.9 sq ft407.4 sq ft
Total heating area2,012.8 sq ft1,875.1 sq ft
Calculated Values
steam locomotive
Von Borries compound
last changed: 03/2022

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