Data from Dr. R. Sanzin, "Die Lokomotiven auf der Intertionalen Austellung in Mailand 1906, 24. 3/5 gekuppelte Verbund-Guterzuglokomotive der Italienischen Staatsbahnen ...", Zeitschrift des Oesterreichischen Ingenieur- und Architeckten-Vereines, Vol LIX, Nr. 10 (8 March 1907), p. 165. Builders included Ansaldo (55), Breda (4), Officina Meccanica di Milano (68), and Saronno (15)
Dr Sanzin reported that these all-adhesion six-coupled were designed for higher speeds than previous 0-6-0s had reached. Using a von Borries cross-compound cylinder setup, the design's relatively long wheelbase and tall drivers suited them for mixed-traffic operation.
Wikipedia says that these 1906 locomotives were developments of a set of 1904 engines (3201-3259) that had 185 smaller-diameter tubes and a much smaller heating surface area of 108.85 sq metres (1,172 sq ft). The newer design used the large-diameter, internally finned Serve tubes. Generating greater tractive effort, this class was rated at 65 km/h (40.4 mph).
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Gruppo 320 |
| Locobase ID | 15545 |
| Railroad | Italian State |
| Country | Italy |
| Whyte | 0-6-0 |
| Number in Class | 142 |
| Road Numbers | 3260-3401 |
| Gauge | 105 cm |
| Number Built | 142 |
| Builder | several |
| Year | 1906 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 11.81 / 3.60 |
| Engine Wheelbase (ft / m) | 11.81 / 3.60 |
| Ratio of driving wheelbase to overall engine wheelbase | 1 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 34,172 / 15,500 |
| Weight on Drivers (lbs / kg) | 100,751 / 45,700 |
| Engine Weight (lbs / kg) | 100,751 / 45,700 |
| Tender Loaded Weight (lbs / kg) | 74,957 / 34,000 |
| Total Engine and Tender Weight (lbs / kg) | 175,708 / 79,700 |
| Tender Water Capacity (gals / ML) | 3168 / 12 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5.50 / 5 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 56 / 28 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 59.10 / 1500 |
| Boiler Pressure (psi / kPa) | 198.70 / 1370 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18.11" x 27.56" / 460x700 |
| Tractive Effort (lbs / kg) | 25,831 / 11716.76 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.90 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 92 - 2.756" / 70 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 12.47 / 3.80 |
| Firebox Area (sq ft / m2) | 101.18 / 9.40 |
| Grate Area (sq ft / m2) | 20.45 / 1.90 |
| Evaporative Heating Surface (sq ft / m2) | 1522 / 141.40 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1522 / 141.40 |
| Evaporative Heating Surface/Cylinder Volume | 185.23 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 4063 |
| Same as above plus superheater percentage | 4063 |
| Same as above but substitute firebox area for grate area | 20,104 |
| Power L1 | 4830 |
| Power MT | 317.07 |