Data from the Rete Sicula website [] ... (visited 5 July 2004), [] (visited 30 June 2005); and "Locomotiva FS 910" in Wikipedia at [], last accessed 28 July 2022.
This was a relatively heavy Prairie tank design for an Italian locomotive of the period. It also seems to have been the only RS class to use cross-compounding instead of simple expansion. Its leading and trailing trucks used Adams bogies, which Wikipedia notes made it a stable locomotive at high speeds. It was rated at 75 km/h (47 mph).
At the time of the Ferrovie dello Stato takeover in 1905, all six were in service and shedded at Palermo. The FS immediately added 6 more (see Locobase 6623) and grouped all 12 under Gruppo 910. They then added 42 more; see Locobase .
NB: Direct (firebox) heating surface area is an estimate derived from calculating the tube heating surface area and subtracting it from the given evaporative heating surface area.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Gruppo H / Gruppo 910 |
| Locobase ID | 6217 |
| Railroad | Strade Ferrate della Sicilia / FS |
| Country | Italy |
| Whyte | 2-6-2T |
| Number in Class | 12 |
| Road Numbers | RS 401-406/Gr 9001-9012 |
| Gauge | Std |
| Number Built | 12 |
| Builder | Ansaldo |
| Year | 1905 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 12.47 / 3.80 |
| Engine Wheelbase (ft / m) | 27.56 / 8.40 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.45 |
| Overall Wheelbase (engine & tender) (ft / m) | 27.56 / 8.40 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 92,594 / 42,000 |
| Engine Weight (lbs / kg) | 141,096 / 64,000 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1003 / 3.80 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3.30 / 3 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 51 / 25.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 59.10 / 1500 |
| Boiler Pressure (psi / kPa) | 188.50 / 1300 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18.11" x 23.62" / 460x600 (1) |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 27.56" x 23.62" / 700x600 (1) |
| Tractive Effort (lbs / kg) | 14,668 / 6653.30 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 6.31 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 222 - 2.047" / 52 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | 120.02 / 11.15 |
| Grate Area (sq ft / m2) | 25.62 / 2.38 |
| Evaporative Heating Surface (sq ft / m2) | 1636 / 152 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1636 / 152 |
| Evaporative Heating Surface/Cylinder Volume | 464.64 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 4829 |
| Same as above plus superheater percentage | 4829 |
| Same as above but substitute firebox area for grate area | 22,624 |
| Power L1 | 5092 |
| Power MT | 363.71 |