Alta Italia 2-4-0 Locomotives in Italy

Class 292 (Locobase 20585)

Data from Ferrovie Dell' Alta Italia, Album Delle Locomotive (Torino, 1o Luglio 1876), T29.

A decade after the SFAI took over the locomotives of several predecessor railroads, it decided to convert several of the single-driver-set express engines to four-coupleds. "Conversion" may be too mild a term for the makeover this sextet received. Grate area nearly doubled and the firebox heating surface grew by more than 20%. The boiler's profile changed substantially with the addition of a sandbox just behind the dome, safety valve relocated ahead of the sandbox, built up firebox that rode above the rear axle.

Locobase found an inconsistencies between the given values for the tube diameters, tube lengths, and for the evaporative heating surface area given as 83.2 sq m. The EHS value shown in Locobase's specs is composed of the firebox heating surface area given in the diagram and the tube heating surface area calculated from the stated tube length, external tube diameter, and count.

Class 595 (Locobase 20594)

Data from Ferrovie Dell' Alta Italia, Album Delle Locomotive (Torino, 1o Luglio 1876), T41.

Locobas 20593 shows this class as it was delivered in 1857 as somewhat oddly proportioned 2-2-2s. After the Alta Italia took over the class in 1865, it subjected the set to a significant makeover. Given the long gap between the drivers and the rear truck, it wasn't hard to find room for a second driver. Each driving axle was sprung from above, but not equalized. The trailing axle was placed in its customary position ahead of the firebox

At the same time, SFAI's shops mounted a new, bigger firebox and boiler with longer tubes. The boiler now sported a rectangular sandbox over the lead driving axle and the locomotive now trailed a larger tender. And a relatively large spectacle board shielded the crew from weather in front of the locomotive.

Locobase found an inconsistencies between the given values for the tube diameters, tube lengths, and for the evaporative heating surface area given as 94.0 sq m. The EHS value shown in Locobase's specs is composed of the firebox heating surface area given in the diagram and the tube heating surface area calculated from the stated tube length, external tube diameter, and count.

Class 661 (Locobase 13215)

Data from W H Maw and William Dredge, "Locomotives", Reports on the Vienna Universal Exhibition, Part II (London: George Eyre and William Spottiswoode, 1874), pp. 416-418; and Ferrovie Dell' Alta Italia, Album Delle Locomotive (Torino, 1o Luglio 1876), T42. See also Hippolyte Fontaine, Description des machines les plus remarquables et les plus nouvelles a l Exposition de Vienne en 1873 (Paris: Libraire Polytechnique, H Baudry, Libraire-Editeur, 1874), pp. 399-401

This express-passenger design had unusually tall drivers for a locomotive intended for an Italian railway. Its steam dome sat on the raised firebox just ahead of the cab while a separate sand dome was located over the space between the first coupled axle and the leading axle. A prominent lever pivoting on extensions down from the plate frames on both sides equalized the two coupled axles.

The SFAI considered this class and the fourteen that followed from the same builder (Locobase 20579) as part of the same gruppo. The latter saw minor changes in the boiler and firebox design.

Class 683 (Locobase 20579)

Data from Ferrovie Dell' Alta Italia, Album Delle Locomotive (Torino, 1o Luglio 1876), T43.

Like the earlier 661 class (Locobase 13215), these engines were true express passenger locomotives with unusually tall drivers for an Italian railway of the time. A note at the bottom of the 661 class's entry says that SACM modified the boiler and firebox in this batch to achieve a better weight distribution between the two coupled axles. Locobase's comparison of the two sets of data shows that the leading (non-powered) axle gained 800 kg (1,764 lb) and the lead coupled axle was 100 kg (220 lb) lighter.

The tender surrendered 2 cu metres (267 gallons) of water capacity and weighed 2 metric tons less when loaded.