Data from Reder (1974) and [] (visited 30 June 2005), as supplemented by The Railway Express (April 1905), p 109, from which the grate area is adopted. See also Dr. R. Sanzin, "Die Lokomotiven auf der Intertionalen Austellung in Mailand 1906, 28. 4/6 gekuppelte Gebirgslokomotive der Italienischen Staatsbahnen ...", Zeitschrift des Oesterreichischen Ingenieur- und Architeckten-Vereines, Vol LIX, Nr. 10 (8 March 1907), p. 165.
Built to haul 500-ton freight trains up a ruling grade of 1.6% at 12.5 mph or lighter passenger trains at 28 mph, these had a broad Wootten firebox and a tapered boiler barrel. Another 25 were delivered with a higher-pitched boiler in 1905.
The disgegni-locomotive site shows that the rigid wheelbase for this class was 3.04 m (9.97 ft). The axle loading shown is for the second batch and is the highest in the class. Others had more evenly distributed axle loadings in the 14,600-kg (32,187-lb) range.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Gruppo 750 |
| Locobase ID | 2527 |
| Railroad | Mediterraneo / FS |
| Country | Italy |
| Whyte | 4-8-0 |
| Number in Class | 40 |
| Road Numbers | 7501-7540 |
| Gauge | Std |
| Number Built | 40 |
| Builder | several |
| Year | 1902 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 14.96 / 4.56 |
| Engine Wheelbase (ft / m) | 26.44 / 8.06 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.57 |
| Overall Wheelbase (engine & tender) (ft / m) | 45.83 / 13.97 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 33,069 / 15,000 |
| Weight on Drivers (lbs / kg) | 132,277 / 60,000 |
| Engine Weight (lbs / kg) | 167,551 / 76,000 |
| Tender Loaded Weight (lbs / kg) | 76,721 / 34,800 |
| Total Engine and Tender Weight (lbs / kg) | 244,272 / 110,800 |
| Tender Water Capacity (gals / ML) | 3432 / 13 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5 / 5 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 55 / 27.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 55.10 / 1400 |
| Boiler Pressure (psi / kPa) | 198.70 / 1370 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 21.26" x 26.77" / 540x680 (1) |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 31.5" x 26.81" / 800x681 (1) |
| Tractive Effort (lbs / kg) | 25,493 / 11563.44 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.19 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 271 - 1.732" / 44 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 14.11 / 4.30 |
| Firebox Area (sq ft / m2) | 147.47 / 13.70 |
| Grate Area (sq ft / m2) | 47.36 / 4.40 |
| Evaporative Heating Surface (sq ft / m2) | 1741 / 161.70 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1741 / 161.70 |
| Evaporative Heating Surface/Cylinder Volume | 316.58 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 9410 |
| Same as above plus superheater percentage | 9410 |
| Same as above but substitute firebox area for grate area | 29,302 |
| Power L1 | 3740 |
| Power MT | 249.33 |