Danske Statsbaner 4-6-0 Locomotives in Denmark

Class R (I) (Locobase 4025)

Data from WilliamBay, Danmarks Damplokomotiver (1977) and from the excellent Danish-language site jernbanen.dk. [] for 934-953. Works numbers were Borsig 8182 in 1912 and 8582-8591 in 1913. SLM added 8 in 1917-1918; works numbers were 2594-2601. See Locobase 4026 for 954-963.

The Danish Railway Museum explains that the R class was the first class of big engines to go into Danish service. They were procured to pull up to 800 tons over the hilly sections of Jutland and on the Island of Funen.

Designed in a style that OS Nock (RWC IV, pl 96) claims was sometimes referred to "Imitation British," this handsome Ten-Wheeler Litra R looks to Locobase's eye more like a North American engine. Granted that pumps lie under the lagging and the sand dome and steam dome shelter under a common housing, but the outside pistons, high running board, and fully visible Walschaerts gear, together with a fully enclosed cab that hid much of the last driver, point westward.

Borsig produced the first 12 in 1913 (works numbers were 8182-8183 for 934-935 and 8582- 8591 for 936-945). and SLM added 8 more in 1917 (works 2594-2601). After World War I, 10 more locomotives with 3 smaller cylinders supplemented the R Is; see Locobase 4026.

Class R (II) (Locobase 4026)

Data from William Bay, Danmarks Damplokomotiver (1977) and from the excellent Danish-language site jernbanen.dk. [] for 954-963. See also "Three-Cylinder Express Locomotive, Danish State Rys", Locomotive Magazine, Volume XXVII [27], No 361 (15 September 1922), pp. 251-255.

Jernbane's account notes that Danish steam design often followed nearby Prussian State Railways practice. This class arose from the success of the KPEV's 1914 S10 2 class (Locobase 1266), using the earlier DSB two-cylinder R class (Locobase 4025) as the foundation.

After World War I, Borsig produced five three-cylinder engines (works 10911- 10915) and Frichs of Aarhus added five engines (works numbers 52-56). The latter quintet were the first large locomotives built in Denmark.

The big difference between the two classes was the reduction in size of each cylinder, but the addition of a third cylinder increased both cylinder volume and power. Setting the third cylinder under the smokebox placed it a bit higher in the frame than the two outer ones. All three had the same length connecting rods and all drove the leading coupled axle. The round-topped boiler sported a bread-loaf casing over the dome and above the lead drivers.

Borsig used its own Hochwald-design inside-admission pistion valves that featured a relief valve controlled by a foot pedal. (Locobase suspects this is similar to a drifting valve). When the regulator was closed, stepping on the pedal equalized pressure on both sides of the piston. This allowed freer running than the standard piston valves used by Frichs (probably to avoid patent fees) that slowed the engines during closed-throttle running.

Tests conducted in June 1921 showed a maximum horsepower of 1,420 when running at 55 kph (34.2 mph) and valves set at 40% cutoff. At an express-speed cutoff of 12% of stroke, the R II developed 820 hp at 88 kph (54.7 mph). And when cutoff was set at 20% and running at 90 kph (55.9 mph), the engine produced an IHP of 1,115.

The class was delivered with Knorr "preheaters", but these were removed in the 1930s. In the same period, smoke deflectors appeared on either side of the firebox.

R 960 suffered sufficient damage in a 6 September 1953 wreck at Byb'k near Vejle to be retired. All other R2s were placed in reserve in 1961

NB: Tube heating surface area using internal tube diameters ("fire side") measured 155.4 sq m (1,673 sq ft). Adding the direct heating surface area yielded 172.8 sq m (1,860 sq ft). Locobase uses the external diameter ("water side") given

Class T (Locobase 4034)

Data from William Bay, Danmarks Damplokomotiver (1977). Class information from []. [].

These were Class 38s originally developed for the Deutsche Reichs Geselleschaft. They were left in Norway after the Germans retreated in 1945, restored in Copenhagen, and put into service in 1947.