4-6-0 Steam Locomotives in Italy

Class Gruppo 666 (Locobase 11407)

Data from "Locomotives for the Italian Government Railways," Railroad Gazette, Volume XLII [42], No 2 (11 January 1907), pp. 50-51; and DeGolyer, Volume 29, p. 125. Additional data from diagram published on DUEGI EDITRICE's TuttoTreno website [], a modelling site with a great deal of data. (visited 11 July 2004); and "Postcards showing two Baldwin-designed and built steam locomotive classes", Posted byu/Historynerd88

September 2021 on Reddit's r/TrainPorn at [], last accessed 13 March 2022. Works numbers were 28642 in July 1906; 28701, 28706, 28718-28719, 28763, 28804, 28827, 28833-28834 in August.

Baldwin built this set of balanced compound Ten-wheelers using metric measures, but othewise, according to the RG report, "...the general design of these locomotives follows American practice closely." One result was that these engines had the largest boilers of any Italian 4-6-0. The inside HP cylinders drove the front axle, while the outside LP cylinders drove the second and a single 15" (380-mm) piston valve supplied steam to each group of 1 LP and 1 HP cylinder on a side.

One significant difference in five of the class was the provision of a copper firebox in place of the steel furnaces found in most US locomotives by that time. Another difference, this time from most other four-cylinder compounds, was the provision of a shorter stroke of 610 mm for the inside HP cylinders vs the 660 mm for the outside LP. Still another was the more rudimentary shelter for the crew.

r/TrainPorn wrote that the class arrived in 1907 and was put to work on the Rome-Florence mainline, "but in the end the results were not good enough to justify further orders. " He added that while the Vauclain system "had its advantages ...it did not show a marked superiority to the Plancher engine." The experiment with steel fireboxes proved a failure, they "wore off awfully fast." He acknowledged that the problem "was partly down to issues with the German coal used, especially after WW I."

The Baldwins were gone by the end of the 1930s.