Societa Nazionale Articulated Locomotives in Italy


Class Details by Steve Llanso of Sweat House Media

Class Gruppo 50 (Locobase 20069)

Data from "Mallet Locomotive at the Turin Exhibition," Locomotive Magazine, Volume 18 (15 February 1912), pp. 45-46.

Standard -gauge Mallet tanks appeared on several Continental railways, but this design had an unusually high LP:HP ratio of 3.35. Its layout was classic Mallet as practiced.

They operated for almost 50 years, mostly on freight service.

Principal Dimensions by Steve Llanso of Middle Run Media

ClassGruppo 50
Locobase ID20069
RailroadSocieta Nazionale
CountryItaly
Whyte0-4-4-0T
Number in Class7
Road Numbers51-57
GaugeStd
Number Built7
BuilderBorsig
Year1909
Valve GearHeusinger
Locomotive Length and Weight
Driver Wheelbase (ft / m) 4.76 / 1.45
Engine Wheelbase (ft / m)16.40 / 5
Ratio of driving wheelbase to overall engine wheelbase 0.29
Overall Wheelbase (engine & tender) (ft / m)16.40 / 5
Axle Loading (Maximum Weight per Axle) (lbs / kg)15,432 / 7000
Weight on Drivers (lbs / kg)116,481 / 52,835
Engine Weight (lbs / kg)116,481 / 52,835
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)116,481 / 52,835
Tender Water Capacity (gals / ML)1320 / 5
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 1.70 / 2
Minimum weight of rail (calculated) (lb/yd / kg/m)49 / 24.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)43.30 / 1100
Boiler Pressure (psi / kPa)169.70 / 11.70
High Pressure Cylinders (dia x stroke) (in / mm)14.96" x 19.69" / 380x500
Low Pressure Cylinders (dia x stroke) (in / mm)27.56" x 19.69" / 700x500
Tractive Effort (lbs / kg)22,678 / 10286.58
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.14
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)21.53 / 2
Evaporative Heating Surface (sq ft / m2)1183 / 109.90
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1183 / 109.90
Evaporative Heating Surface/Cylinder Volume295.32
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3654
Same as above plus superheater percentage3654
Same as above but substitute firebox area for grate area
Power L1
Power MT

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