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 FS locomotive 670.043, here with the earlier classification of FS 6943 | |||||||||||||||||||||||||||||||||||||
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The Rete Adriatica Class 500 (Italian: Gruppo 500), classified after 1905 in the Ferrovie dello Stato Italiane (FS; Italian State Railways) as Class 670 (Italian: Gruppo 670) was an unorthodox and iconic cab forward 4-6-0 (2'C) steam locomotive.
The Class 670 was designed by Eng. Giuseppe Zara of the Rete Adriatica (one of the two major railway companies in Italy at the beginning of the twentieth century); its design was very unorthodox, as the boiler was reversed on the frames, so that the cab and the firebox were leading and supported by the bogie, while the cylinders were at the rear. The compound arrangement was also highly peculiar, as it was the first experiment with the Plancher compound engine: this arrangement meant that there were four cylinders, in which the two high pressure (HP) ones and the two low pressure (LP) ones were paired together respectively on the left-hand and the right-hand side of the boiler, and each pair was served by a single piston valve through a crossed-port arrangement. While simplifying the valve gear, this feature made it difficult to equalize the work done by each pair of cylinders, and this provoked hunting. [1]
The locomotive also had a peculiar arrangement for its tender; the coal was kept near the cab on the left side of the locomotive, while a tender carried either 15,000 or 20,000 litres (3,300 or 4,400 imp gal; 4,000 or 5,300 US gal) of water, depending on the series.
The first locomotive, initially classified as RA 3701 (later changed to RA 500), was taken to France and subjected to trials with a dynamometer car loaned by the Chemin de Fer de l'Ouest, which were successful. As a result, the other forty-two were built by Ernesto Breda and the German firm Borsig-Werke.
When in 1905 the railways in Italy were nationalised, the Ferrovie dello Stato initially reclassified the locomotives as Class 690 (FS 69XX), but were ultimately classified as Class 670.
Nicknamed Mucca (Italian for "cow"), the Class 670 spent its career on the mainline railways of the Po Valley; while quite fast and powerful for its day, the unorthodox shape of the locomotive in the end didn't prove successful, with more orthodox designs (like the FS Class 680) eventually being built. Withdrawals of both the Class 670 and Class 671 locomotives began in the 1930s, and by the end of the decade all the locomotives had been taken out of service; none survived into preservation. [1] [2]
Between 1919 and 1930 29 Class 670 locomotives were rebuilt with a superheater, and were classified as Class 671. [3]
In 1936 the locomotive 670.030 was rebuilt with a Franco-Crosti boiler. Articulated ducts carried the combustion gases from the main boiler to the preheater (placed on a standard bogie tender), and these passed to a chimney at the end of the tender. Exhaust steam from the cylinders similarly went through articulated ducts to the blastpipe at the rear of the tender, while articulated pipes connected the preheater and main boiler to take water and steam from one to the other. The whole locomotive-tender complex was given a streamlined casing. The locomotive was reclassified FS 672.001 and was subjected to trial runs, which showed a 22 per cent fuel saving compared to other Class 671 locomotives.
Although it paved the way to other, more successful conversions, this locomotive was only meant as a trial essay, and was quickly discarded. [3]
The Ferrovie dello Stato Class 740 is a class of 2-8-0 'Consolidation' steam locomotives.
The Ferrovie dello Stato Class 685 is a class of 2-6-2 'Prairie' express train steam locomotives. These are colloquially known as Regine, mirroring their fame as one of the most successful and appreciated Italian steam locomotives.
The Ferrovie dello Stato Italiane Class 691 is a class of 4-6-2 'Pacific' locomotives; they were the fastest and most powerful locomotives ever built for the Italian railways.
The Ferrovie dello Stato Italiane Class 690 was a 4-6-2 'Pacific' steam locomotive for express trains.
The Ferrovie dello Stato Italiane Class 746 is a class of 2-8-2 'Mikado' steam locomotive. These were the biggest locomotives ever built by the Ferrovie dello Stato, even though not the fastest, which were the Class 691s.
The Ferrovie dello Stato Italiane Class 470 is a 0-10-0 steam locomotive.
The Ferrovie dello Stato Class 480 is a 2-10-0 steam locomotive.
The Ferrovie dello Stato Italiane Class 650, formerly SFAI1181-1200 and Rete Mediterranea 300 Class, also known as "Vittorio Emanuele II", was the first steam locomotive in continental Europe to have the 4-6-0 'Ten-Wheeler' arrangement.
The Ferrovie dello Stato Italiane Class 940 is a 2-8-2 steam tank locomotive, derived from the Class 740 tender locomotive.
The Ferrovie dello Stato Italiane Class 680 is a 2-6-2 express steam locomotive; it was the direct ancestor of the very successful and appreciated Class 685.
The Ferrovie dello Stato Italiane Class 552, formerly Rete Adriatica Class 180 bis, is a 4-4-0 steam locomotive; it was the final development in Italy of the 'American' express locomotive type.
The Ferrovie dello Stato Italiane Class 600, formerly Rete Adriatica Class 380 and Società per le Strade Ferrate Meridionali Class 380, is a 2-6-0 'Mogul' steam locomotive; it is considered by some as the first Italian modern steam locomotive.
The Ferrovie dello Stato Italiane Class 835 is a 0-6-0T steam locomotive; it was the standard steam shunter of the FS.
The Ferrovie dello Stato Italiane Class 290, formerly the Rete Adriatica Class 350 bis, is a 0-6-0 steam locomotive.
The Ferrovie dello Stato Italiane Class 420, formerly SFAI Class 1200, Rete Adriatica Class 420 and Rete Mediterranea Class 480, was a 0-8-0 steam locomotive.
The Ferrovie dello Stato Italiane Class 310, formerly Rete Mediterranea Class 380, was a 0-6-0 steam locomotive; they were the first Italian as-built compound locomotives.
The Ferrovie dello Stato Class 741 is a class of 2-8-0 'Consolidation' steam locomotives, rebuilds from the FS Class 740 with a Franco-Crosti boiler; it was the last class of steam locomotives introduced in Italy.
Locomotives SFM 1-34 refers to a class of 2-2-2 steam locomotives of the Società Italiana per le Strade Ferrate Meridionali (SFM). They were designed for hauling fast passenger trains.
The Ferrovie dello Stato Class 745 was a class of 2-8-0 'Consolidation' steam locomotives.
The Ferrovie dello Stato Class 744 is a class of 2-8-0 steam locomotives; they were the last orthodox steam locomotives built for the FS.
