FS Class 552
| Industry | Railway |
|---|---|
| Founded | 1905 |
| Headquarters | Italy |
The Class 552 steam locomotives of the Ferrovie dello Stato Italiane (FS; Italian State Railways), previously known as the Class 180 bis under the Rete Adriatica, represent the final iteration of Italy’s 'American' type express engines featuring a 4-4-0 wheel arrangement.
Design and construction
Developed in Florence, the Class 552 marked the culmination of a series of effective 4-4-0 locomotives, evolving from the earlier FS Class 545 and FS Class 550 models by incorporating a larger boiler and increased cylinder dimensions. Initially, these locomotives were equipped with a prototype tender resembling the final version but with a reduced water capacity of approximately 10,500 litres (2,300 imp gal; 2,800 US gal).
The initial batch consisted of 24 units produced in 1890, split evenly between manufacturers Ernesto Breda and Ansaldo. Subsequently, an additional dozen were constructed by Breda between 1900 and 1901.
Service
Before the establishment of FS in 1905, these locomotives were designated as RA 180 bis and numbered from 1865 to 1900. They were primarily deployed on Italy’s most prestigious express passenger services, including the famed India Mail or Peninsular Express (known locally as Valigia delle Indie), which was part of the P&O route connecting London with Bombay, India. Within Italy, this service operated along the route from Modane through Turin, Alessandria, Bologna, Ancona, to Brindisi, where passengers transferred to ships bound for Alexandria.
Despite their prominence, these locomotives represented the final chapter for two-driving-wheel express engines in Italy. Their performance—capable of hauling around 110 tonnes (110 long tons; 120 short tons) at speeds near 80 km/h (50 mph)—soon proved inadequate. The arrival of more powerful locomotives featuring three driving axles, such as the FS Class 630 and FS Class 670, relegated the Class 552 to less demanding duties. Unlike earlier models that were withdrawn by the 1930s, several units from this class remained operational until approximately 1946, primarily serving in the vicinity of Treviso.
Preservation
Only one unit of the Class 552, specifically number 552.036, has been preserved. It is presently displayed as a non-operational exhibit at the Museo della Scienza e della Tecnologia "Leonardo da Vinci" located in Milan.
References
- Cornolò, Giovanni (May 2014). "Locomotive a vapore". TuttoTreno (2).
- Kalla-Bishop, P. M. (1986). Italian state railways steam locomotives : together with low-voltage direct current and three-phase motive power. Abingdon: Tourret Publishing. ISBN 0905878035.