One of the first locomotive types designed after the founding of the FS was a heavy freight locomotive for mountain lines. To get maximum traction, it was designed with five axles, all of which were coupled. The locomotives later known as class 470 had the distinction that they were designed as a “semi-tank locomotive”. This meant that the coal supplies were carried in front of the cab on the left side of the boiler. The water car included a separate compartment for the conductor.
Designed by Enrico Plancher, the locomotive used his system of four-cylinder compound engine that had two high-pressure cylinders on the right side and two low-pressure cylinders on the left. To allow for running through sharp curves, the two extreme axles had lateral play of 40 mm and the central axle had no wheel flanges. The boiler was the same as in the class 680.
Between 1907 and 1911, a total of 143 were built by four manufacturers. 64 came from Maffei, 52 from Officine Meccaniche, 17 from Officine Meccaniche e Navali di Napoli and ten from Breda. Due to the high temperatures in the closed cab, they got the nickname “crematorium”. Lines where they were used included the Giovi pass, where they could haul 170 tonnes with 25 km/h over the 3.5 percent incline. As early as 1910, they were replaced on this line by the electric E.550 that could haul 190 tonnes at twice the speed.
Between 1918 and the thirties, 129 were superheated and designated class 471. 24 of these also received larger cylinders with a diameter of 400 instead of 375 mm and were originally designated class 472, but soon renumbered in the 471.200 range. Most also got regular coal and water tenders with the rebuild. Over the time they came to secondary lines. The last non-rebuilt locomotives were withdrawn in the early sixties, followed by the last rebuilt ones in the early seventies. Today 470.092 is being preserved in the Leonardo da Vinci Museum at Milan.
