FC General Mitre 4-6-2 Locomotives in Argentina

Class Details by Steve Llanso of Sweat House Media

Class P.S.11 (Locobase 3702)

Data provided by Vulcan Foundry website, specifically two issues of the Vulcan Foundry magazine ([] and [], both accessed 14 July 2007). See also

Follow-ons to the very successful P.S. 11s of the FCCA (Locobase 3701), these engines had less evaporative heating surface and proportionately less superheat as well. Otherwise, they were identical to the early class of 20 except for being oil-fired and having a much larger, six-axle tender. In notes accompanying his contribution to Bryan Attewell ([] locomotive simulator, Fernandez notes that some others were supplied to FC General Roca and FC General San Martin.

The 30 locomotives arrived in two batches - 20 in 1950, 10 more in 1953. The last 10 had small differences, the greatest being an increase in the counterbalancing of the drivers to a level offsetting 50% of the reciprocating weights.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID3702
RailroadFC General Mitre (FCGM)
Number in Class30
Road Numbers1121-1129, 1150-1159
Number Built30
BuilderVulcan Foundry
Valve Gear
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)40,768 / 18,492
Weight on Drivers (lbs / kg)119,728 / 54,308
Engine Weight (lbs / kg)
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)9025 / 34.19
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)3400 / 12,869
Minimum weight of rail (calculated) (lb/yd / kg/m)67 / 33.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)74.50 / 1892
Boiler Pressure (psi / kPa)229.20 / 15.80
High Pressure Cylinders (dia x stroke) (in / mm)19.5" x 26" / 495x660 (3)
Tractive Effort (lbs / kg)38,780 / 17590.33
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.09
Heating Ability
Tubes (number - dia) (in / mm)116 - 2.25" / 57
Flues (number - dia) (in / mm)32 - 5.5" / 140
Flue/Tube length (ft / m)17.42 / 5.31
Firebox Area (sq ft / m2)205.80 / 19.12
Grate Area (sq ft / m2)43 / 3.99
Evaporative Heating Surface (sq ft / m2)2208 / 205.13
Superheating Surface (sq ft / m2)542 / 50.35
Combined Heating Surface (sq ft / m2)2750 / 255.48
Evaporative Heating Surface/Cylinder Volume163.79
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9856
Same as above plus superheater percentage11,827
Same as above but substitute firebox area for grate area56,603
Power L117,132
Power MT946.38

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