Statens Järnvägar Litt. S1 2-6-4T data sheet
Copy of Swedish State Railways' official data sheet for their class S1 tank locomotives.
Drawing edited for greater accuracy - the original has wrong proportions.
History of the class S1 locomotives:
From the 1920s on already, the Swedish State Railways (Statens Järnvägar, SJ) pushed ahead with the electrification of their route network. Nevertheless, a few steam locomotives were also procured after the Second World War: After ten 4-8-0 locomotives (class E10) had already been put into service in 1946 and 1947, twenty units of the S1 series followed in 1952/53. These elegant 2-6-4 tank locomotives were primarily intended for use on branch lines that were not due for electrification, in order to bridge the time until reliable diesel locomotives or railcars arrived. In accordance with this purpose, the locomotives were designed with an exceptionally low axle load of only 12.6 t, despite their overall quite impressive size (only slightly smaller than the German class 64 in all relevant parameters). When only the rear tank was filled, the axle load could be reduced even further to just 11.5 t.
All engines were built by "Nydqvist & Holm AB" (NOHAB) in Trollhättan and classified by the SJ as road numbers 1910 to 1929.
Being the last steam locomotive class developed and built for the SJ, the S1 had some modern design features, such as the welded construction of the boiler and roller bearings for all axles. Overall, however, the locomotives were of a rather conservative design and were ultimately already outdated when they were delivered, as many other components were carried over from older classes.
In their time, the S1 locomotives were not considered a great success: Soon after they went into service, problems arose due to sloppy manufacturing; in addition, the boiler proved to be somewhat undersized. The engines got a bad reputation, and most crews preferred the 2-6-4T locomotives of the Sb/S2 series – even though these were around 35 years older and, with their higher axle loads, could not be used freely on branch lines.
So, while the S1 engines did not live up to expectations in every respect, they still had some merits. The well thought-out architecture with many steps and handrails as well as details such as the mechanical ash box emptying, pneumatically operated windshield wipers or the running-gear lights were new and pleasant features for the engine crews.
In addition, water and fuel capacity were exceptionally large for a tank locomotive of this size, even when the side tanks were shut down to reduce axle load.
9 engines (Nos. 1910 – 1913, 1915, 1916, 1927 – 1929) also received a NALCO feedwater softening system, which did not work particularly well. Locomotive No. 1914 was fitted with a Henschel feedwater heater for a period of time, while No. 1928 was equipped with oil firing in the 1960s.
The S1s, with a permitted speed of 80 km/h both forwards and backwards and with good running characteristics, were often used for passenger trains immediately after they had been put into service, e.g. on the Malmö – Ystad (– Simrishamn) route. From the mid-1960s, however, they were seen hauling local freight trains more frequently, while the first engines were already withdrawn at the same time.
The locomotives were stationed in Borås, Halmstad, Malmö, Nässjö, Östersund and Ystad.
By 1972, after only 20 years of service, all of the S1 series locomotives had been withdrawn from service. Like many other SJ steam locomotives, however, most of them were not scrapped immediately, but were preserved as reserve locomotives. It is thanks to this circumstance that five engines (1/4 of all S1 locomotives built) have survived until today. While three of these locomotives (Nos.1914, 1921, 1923) are preserved in Sweden and one (No. 1928) in Great Britain, S1 No. 1916 has found its new home in Germany in the early 1990s.
Statens Järnvägar Litt. S1 2-6-4T data sheet
Copy of Swedish State Railways' official data sheet for their class S1 tank locomotives.
Drawing edited for greater accuracy - the original has wrong proportions.
History of the class S1 locomotives:
From the 1920s on already, the Swedish State Railways (Statens Järnvägar, SJ) pushed ahead with the electrification of their route network. Nevertheless, a few steam locomotives were also procured after the Second World War: After ten 4-8-0 locomotives (class E10) had already been put into service in 1946 and 1947, twenty units of the S1 series followed in 1952/53. These elegant 2-6-4 tank locomotives were primarily intended for use on branch lines that were not due for electrification, in order to bridge the time until reliable diesel locomotives or railcars arrived. In accordance with this purpose, the locomotives were designed with an exceptionally low axle load of only 12.6 t, despite their overall quite impressive size (only slightly smaller than the German class 64 in all relevant parameters). When only the rear tank was filled, the axle load could be reduced even further to just 11.5 t.
All engines were built by "Nydqvist & Holm AB" (NOHAB) in Trollhättan and classified by the SJ as road numbers 1910 to 1929.
Being the last steam locomotive class developed and built for the SJ, the S1 had some modern design features, such as the welded construction of the boiler and roller bearings for all axles. Overall, however, the locomotives were of a rather conservative design and were ultimately already outdated when they were delivered, as many other components were carried over from older classes.
In their time, the S1 locomotives were not considered a great success: Soon after they went into service, problems arose due to sloppy manufacturing; in addition, the boiler proved to be somewhat undersized. The engines got a bad reputation, and most crews preferred the 2-6-4T locomotives of the Sb/S2 series – even though these were around 35 years older and, with their higher axle loads, could not be used freely on branch lines.
So, while the S1 engines did not live up to expectations in every respect, they still had some merits. The well thought-out architecture with many steps and handrails as well as details such as the mechanical ash box emptying, pneumatically operated windshield wipers or the running-gear lights were new and pleasant features for the engine crews.
In addition, water and fuel capacity were exceptionally large for a tank locomotive of this size, even when the side tanks were shut down to reduce axle load.
9 engines (Nos. 1910 – 1913, 1915, 1916, 1927 – 1929) also received a NALCO feedwater softening system, which did not work particularly well. Locomotive No. 1914 was fitted with a Henschel feedwater heater for a period of time, while No. 1928 was equipped with oil firing in the 1960s.
The S1s, with a permitted speed of 80 km/h both forwards and backwards and with good running characteristics, were often used for passenger trains immediately after they had been put into service, e.g. on the Malmö – Ystad (– Simrishamn) route. From the mid-1960s, however, they were seen hauling local freight trains more frequently, while the first engines were already withdrawn at the same time.
The locomotives were stationed in Borås, Halmstad, Malmö, Nässjö, Östersund and Ystad.
By 1972, after only 20 years of service, all of the S1 series locomotives had been withdrawn from service. Like many other SJ steam locomotives, however, most of them were not scrapped immediately, but were preserved as reserve locomotives. It is thanks to this circumstance that five engines (1/4 of all S1 locomotives built) have survived until today. While three of these locomotives (Nos.1914, 1921, 1923) are preserved in Sweden and one (No. 1928) in Great Britain, S1 No. 1916 has found its new home in Germany in the early 1990s.