Statens Jarnvagar 4-6-0 Locomotives in Sweden

Class A2 (Locobase 20207)

Data from Litt-A3, one of a series of SJ locomotive diagrams archived by Anders Lundbing on [], last accessed 10 June 2017 (Snabcon AB advertised its tools for mounting RJ45 connectors on bundled cables.)

When the SJ transferred its A-class Atlantics (Locobase 2781) to lighter trains and local service, it shed some of the class. Some went to other railways, others, like these three, were converted to Ten-wheelers. An immediately noticeable difference was the longer driving wheelbase. A higher-pressure boiler and more superheater area resulted in a more powerful locomotive.

The diagram shows a long, loaf-shaped steam "dome" and a"wind-cutter" cab face.

The three locomotives served the SJ for years, the last retiring in 1969.

(NB: Locobase's specifications show the evaporative heating surface area using the tubes' outer diameter (i.e., the water side). The SJ's calculation used the narrower, fire-side diameter of 44.5 mm, which produced a total EHS of 144.2 sq m (1,552 sq ft).)

Class B (Locobase 4828)

Data from Litt. B diagram supplied and details from Dirty Nico's Steamdepot [] . See also "Recent Superheater Locomotives for Swedish Railways," Locomotive Magazine, Volume 18 (14 December 1912), p. 253.

These simple-expansion B-class Ten-wheelers were designed by CME Carl Flodin (often characterized as the Father of the Modern Steam Locomotive) for heavy passenger and heavy express trains. Motala Verkstad produced the first and the most of the class -- 52 -- while Norqvist & Holm (Nohab) of Trolhattan contributed 40, and VoM (Vagn och Maskinfabriken) of Falun added 7. 96 entered service in 1909-1919 (B 1026-1028, 1034-1038, 1081-1085, 1106-1108, 1135-1150, B 1220-1223, 1266-1270, 1282-1290, 1311-1325, 1364-1387, 1428-1435), while Nohab built three more (1695-1697) in 1943-1944 for the Stockholm-Vasteras-Bergslagens Jarnvagar (SWB).

This most numerous class of Ten-wheelers had nearly square cylinder dimensions (i.e., diameter was nearly the same as the piston stroke.) Piston valves with diameters measuring 220 mm (8.66") supplied steam to the cylinders.

The SJ subdivided the B class into three groups based on the tender's capacity. B-1s trailed tenders loaded with 6 metric tons of coal and 20 cu m of water. B-2s used the smallest tenders, which held 5.2 tonnes of coal and 14 cu m of water, and B-3s had less coal (5 tonnes) but more water (18 cu m).

One modelling website ([]) comments that the Bs "...were more sure-footed [than the A-class Atlantics] when starting and had a somewhat higher power, but it was soon evident that this engine class too would soon prove capable for the most demanding express train duties."

Many received a new, welded boiler in the 1950s and 1960s. Bs lasted until the 1970s, when they were put in "strategic reserve".

Class H3/A6 (Locobase 20214)

Data from Litt-A6-SDJ, one of a series of SJ locomotive diagrams archived by Anders Lundbing on [], last accessed 10 June 2017 (Snabcon AB advertised its tools for mounting RJ45 connectors on bundled cables.)

Identical to the BDJ Ten-wheelers shown in Locobase 20213 except for minor weight differences..

The series of Ten-wheelers (Locobases 20208-20211) built with 520 x 610 cylinders and 1,720 mm diameter drivers all had relatively low axle loadings. 220 mm (8.66") piston valves in this batch delivered steam to the cylinders.

(NB: Locobase's specifications show the evaporative heating surface area using the tubes' outer diameter (i.e., the water side). The SJ's calculation used the narrower, fire-side diameter of 44.5 mm, which produced a total EHS of 116.03 sq m (1,365 sq ft).)

Class Ta (Locobase 5637)

Data from Markku Karvonen's personal.inet.fi/koti/markku.karvonen/prk/vanha3.htm (visited 29 March 2003); "Richmond Locomotives for Sweden", American Engineer & Railroad Journal, Volume 73, No 9 (Septermber 1899), p. 304; and Gustaf Welin (ed.), Statens Jarnvagar 1856-1906 Historisk-Teknisk-Ekonomisk Beskrifning-Del[Volume] 3 Transportmateriel Och Verkstader [Transport Equipment and Workshops] (Stockholm: Centraltryeriet, 1906), pp. 24, 93-104. (Many thanks to Ivo Rutishauser's detailed 22 March 2023 email correcting the original country, supplying details of both the Ta and Tb clssses.) Richmond works numbers were 2831-2840 in 1899. Motola's works numbers were 311-312 (road 749-750) in 1903, 314-316 (road 784-786) in 1904. Nydqvist & Holm 647-652 (road 662-667) in 1901, 672-671 (road 705-714) in 1902, 701-711 (road 751-761) in 1903, 733-734 (road 782-783) in 1904, 758-767 (road 824-833).

This first set of ten had boilers set to 12.5 kg (12.25 atm). An interesting batch of cross-compound Ten-wheelers that used an intercepting valve based on the Mellin design originally used in Richmond Locomotive Works engines. Maximum speed was 75 kph (46.5 mph). Richmond's engines inspired the nickname "Big-Wheel Kaanari".

Sufficiently impressed with the Americans, the SJ went to home-country builders for the next 43 locomotives. One change was an increase of 1 bar in boiler pressure.

NB: The Swedish figures for tube heating surface in their tables reflected the tubes' internal diameters. Together with the firebox heating surface area, the evaporative heating surface came to 132.04 sq m (1,431 sq ft). Locobase uses the external tube diameters, which also appeared in the tables as the only diameter dimension.

(Weird historical connection. Engine 293 pulled the train that brought Boleshevik leader Vladimir Ilyich Lenin from Switzerland to St Petersburg, Russia's Finland Station in September 1917. He launched the October Revolution that created the Soviet Union. The 293 wound up on display at Finland Station.)

Rutishauser noted that Ta ran as compounds to the end of their days on the SJ, which came in the 1927-1942 period. Finland bought seven Ta, changed their gauge to 5 feet (1,524 mm) and dubbed them H11/Hr2 - Hurrikaani. See Locobase 21131 for Markku Karvonen's unfavorable verdict regarding these imports.

Class Tb (Locobase 21131)

Data from Markku Karvonen's personal.inet.fi/koti/markku.karvonen/prk/vanha3.htm (visited 29 March 2003); and Gustaf Welin (ed.), Statens Jarnvagar 1856-1906 Historisk-Teknisk-Ekonomisk Beskrifning-Del[Volume] 3 Transportmateriel Och Verkstader [Transport Equipment and Workshops] (Stockholm: Centraltryeriet, 1906), pp. 24, 93-104. (Many thanks to Ivo Rutishauser's detailed 22 March 2023 email correcting the original country, supplying details of both the Ta and Tb clssses. It led to this new entry as well.)

Atlas works numbers were 88-89 in 1907. Falun works numbers were 64-65 72-75 in 1907, 76-81 in 1908. Motala works numbers were 354-370 (road 846-855, 880-891Nydqvist & Holm works numbers were 790-799 (road 856-865) in 1905, 819-821 (road 876-879) in 1906-1907; 839-841 (886-888).

Continuing the production of cross-compound Ten-wheelers based on the original ten supplied by Richmond, the SJ's new orders featured 9 more tubes (each 120 mm longer) and a bigger firebox and grate. Another significant changed an increased of 1 bar in boiler pressure.

Rutishauser noted that most of this class went to the ferro-knacker in 1927-1942. Finland's VR bought thirteen Tb and placed them in class Hr2.

NB: The Swedish figures for tube heating surface in their tables reflected the tubes' internal diameters. Together with the firebox heating surface area, the evaporative heating surface came to 142.20 sq m (1,530 sq ft). Locobase uses the external tube diameters, which also appeared in the tables as the only diameter dimension.

(Weird historical connection. Engine 293 pulled the train that brought Boleshevik leader Vladimir Ilyich Lenin from Switzerland to St Petersburg, Russia's Finland Station in September 1917. He launched the October Revolution that created the Soviet Union. The 293 wound up on display at Finland Station.)

Rutishauser noted that Ta ran as compounds to the end of their days on the SJ, which came in the 1927-1942 period. Finland bought thirteen Tb in 1942, changed their gauge to 5 feet (1,524 mm) and placed them in class Hr3. Markku Karvonen (as translated by Google) explained the design's lukewarm reputation: "The main reasons for rejecting the Hr2-3 series were the age, the inconvenient high axle weight, the lack of spare parts (Vr bought one Tb in 1948 as spare parts) and the fact that they did not meet their purpose well when designed elsewhere."