FS Class 910
| Company type | Steam locomotive class |
|---|---|
| Industry | Railway transport |
| Predecessor | RS Class 400 |
| Founded | 1905 |
| Founder | Guglielmo Cappa (designer) |
| Headquarters | Milan , Italy |
| Products | 2-6-2T steam tank locomotives |
FS Class 910 Overview
The FS Class 910 locomotives were 2-6-2 tank engines created under the direction of engineer Guglielmo Cappa specifically for the Rete Sicula railway network, where they were initially classified as RS Class 400. Following their integration into the Italian State Railways (FS) in 1905, these locomotives were reclassified as FS Class 910.
History
Following the 1885 agreements, Rete Sicula assumed control of the routes previously managed by Società per le Strade Ferrate Calabro-Sicule and faced challenges related to building new railways and introducing advanced locomotive technology. Engineer Guglielmo Cappa developed the Class 400 steam engines, which were reclassified as FS Class 910 after nationalization in 1905. These locomotives were specifically engineered to handle steep gradients, such as the route between Messina and Palermo, which traverses the Peloritani Mountains and includes a lengthy tunnel. Additionally, they needed to be versatile enough for local or commuter operations and capable of bidirectional travel to save turnaround time at terminal stations by eliminating the need for turntables.
A 2-6-2T wheel arrangement was selected to ensure consistent speeds in both directions. The initial batch of 19 locomotives was manufactured by Ansaldo in Sampierdarena, while the subsequent 35 units were produced by Società Italiana Ernesto Breda based in Milan. Deliveries coincided with the transfer of the Sicula Network to FS control. The first six locomotives were delivered under the Sicula network with designations RS 401-406, while later units were numbered within the FS 91xx series from the outset. One locomotive was showcased at the 1906 Milan Exposition. Eventually, the entire fleet was centralized in Milan for suburban service, with those originally operating in Sicily relocated there. Over time, minor modifications were implemented, and these locomotives continued to provide reliable service from the Milano Centrale and Pavia depots on routes connecting Milan with Bergamo, Como, Lecco, and Voghera.
Diesel conversion
In 1929, locomotive 910.042 underwent a trial conversion into a Diesel-Zarlatti locomotive. This experimental model featured a diesel engine paired with compressed-air transmission that utilized the existing steam cylinders. However, this innovation did not prove successful and was not adopted for further production.
World War II
During World War II, several units were deployed for operations in Yugoslavia. After the conflict ended, seven of these locomotives remained there permanently and were integrated into Yugoslavian Railways (JŽ) as class 115.
Technical features
These locomotives operated using saturated steam and employed a compound expansion system. The high-pressure cylinder was positioned on the left side and utilized piston valves, while the low-pressure cylinder on the right side used a slide valve. The valve gear was an external Walschaerts valve gear.
The frame rested on three coupled driving axles along with two single-axle Adams-type trucks at each end, providing stability at both high speeds and when running in reverse. The boiler contained 222 fire tubes initially, which increased to 226 in later production batches. Although classified as tank engines, they carried approximately 3,000 kg (6,600 lb) of coal and 8,000 kg (18,000 lb) of water.
From the second series onward, modifications included enlarging the diameter of the carrying wheels from 830 to 960 mm (33 to 38 in) and replacing the Nathan lubrication system with a Friedmann lubrication pump. The locomotives featured compressed air brakes alongside proportional braking systems and were equipped for steam heating of passenger cars.
Depot assignments
- Messina
- Milan
- Padua
- Milan Greco
- Venice Mestre
- Livorno
- Voghera
- Brescia
- Lecco
Conservation
Locomotive number 910.001 underwent restoration and is currently exhibited at the National Railway Museum of Pietrarsa.
References
Additional reading
- Giovanni Cornolò, L'ing. Guglielmo Cappa e le sue compound della "Sicula", in Mondo Ferroviario 87.
- Zeta-Zeta [Bruno Bonazzelli], L'album delle locomotive, in HO Rivarossi, 11 (1964), n. 63, pp. 20–21.