Alta Italia 4-2-0 Locomotives in Italy


Class Details by Steve Llanso of Sweat House Media

Class 168 (Locobase 20592)

Data from Ferrovie Dell' Alta Italia, Album Delle Locomotive (Torino, 1o Luglio 1876), T14.

This pair used the Stephenson long boiler and a single driving axle located--like Crampton's innovation--well back along the frame. The two leading carrying axles were fixed in the frame ahead of the drivers with their centres 80" (2.033 m) apart. Driving the rear axle meant placing the cylinders outside and between the two carrying axles, hence the gap. Otherwise, the engine seems orthodox, fitted as it was with a haystack boiler, safety valve stand over the rear carrying axle, and a very tall stack (chimney).

Locobase found an inconsistencies between the given values for the tube diameters, tube lengths, and for the evaporative heating surface area given as 67.7 sq m. The EHS value shown in Locobase's specs is composed of the firebox heating surface area given in the diagram and the tube heating surface area calculated from the stated tube length, external tube diameter, and count.

Both engines were scrapped in 1874.

Principal Dimensions by Steve Llanso of Sweat House Media

Class168
Locobase ID20592
RailroadAlta Italia (SFAI)
CountryItaly
Whyte4-2-0
Number in Class2
Road Numbers168-169
GaugeStd
Number Built2
BuilderRobert Stephenson & Co
Year1848
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)12.16 / 3.71
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)32.90 / 10.03
Axle Loading (Maximum Weight per Axle) (lbs / kg)23,149 / 10,500
Weight on Drivers (lbs / kg)23,149 / 10,500
Engine Weight (lbs / kg)46,517 / 21,100
Tender Loaded Weight (lbs / kg)35,494 / 16,100
Total Engine and Tender Weight (lbs / kg)82,011 / 37,200
Tender Water Capacity (gals / ML)1320 / 5
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.20 / 2
Minimum weight of rail (calculated) (lb/yd / kg/m)39 / 19.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)67.50 / 1715
Boiler Pressure (psi / kPa)87 / 6
High Pressure Cylinders (dia x stroke) (in / mm)13.98" x 22.01" / 355x559
Tractive Effort (lbs / kg)4713 / 2137.78
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.91
Heating Ability
Tubes (number - dia) (in / mm)113 - 2.047" / 52
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.52 / 4.12
Firebox Area (sq ft / m2)60.82 / 5.65
Grate Area (sq ft / m2)10.12 / 0.94
Evaporative Heating Surface (sq ft / m2)880 / 81.75
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)880 / 81.75
Evaporative Heating Surface/Cylinder Volume225.05
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation880
Same as above plus superheater percentage880
Same as above but substitute firebox area for grate area5291
Power L12964
Power MT282.28

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