F C de Tacubaya 4-4-0 Locomotives in Mexico

Class Details by Steve Llanso of Sweat House Media

Class Susana (Locobase 10235)

Data from "Narrow Gauge Loco for Mexico," The Locomotive Magazine, Volume VII [7] (August 1902), p. 135. See also DeGolyer, Volume 20, p. 261. Works number was 15241 in March 1897.




flea-sized -- this little Eight-wheeler ran on 14 lb/yard (7 kg/metre) rail, scaled 1 % grades, and negotiated curves of as little as 39-ft (10-meter) radius on a 1-mile (1.6 km) logging trail; water stations were 2,186 yards (1.25 miles/2 km) apart. The "tip over" grate--designed to burn "briquettes, preferably"-- was operated by a lever and "arranged to dump fire immediately."

The locomotive's name was written in "elegant letters" on both sides of the cab.

Susana was the smallest locomotive ever built by Baldwin for commercial purposes. Locobase also notes that all other locomotives with similar heating surface areas (80-90 sq ft) were four-coupled tanks and finds the next largest 4-4-0 to have owned 225 sq ft (20.9 sq m) of heating surface area.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID10235
RailroadF C de Tacubaya
Number in Class1
Road Numbers2
Gauge60 cm
Number Built1
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)3 / 0.91
Engine Wheelbase (ft / m)10.33 / 3.15
Ratio of driving wheelbase to overall engine wheelbase 0.29
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)6500 / 2948
Engine Weight (lbs / kg)11,200 / 5080
Tender Loaded Weight (lbs / kg)11,000 / 4990
Total Engine and Tender Weight (lbs / kg)22,200 / 10,070
Tender Water Capacity (gals / ML)600 / 2.27
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)5 / 2.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)23 / 584
Boiler Pressure (psi / kPa)150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)6" x 10" / 152x254
Tractive Effort (lbs / kg)1996 / 905.37
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.26
Heating Ability
Tubes (number - dia) (in / mm)32 - 1.5" / 38
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)6 / 1.83
Firebox Area (sq ft / m2)13.40 / 1.24
Grate Area (sq ft / m2) 2.40 / 0.22
Evaporative Heating Surface (sq ft / m2)88 / 8.18
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)88 / 8.18
Evaporative Heating Surface/Cylinder Volume266.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation360
Same as above plus superheater percentage360
Same as above but substitute firebox area for grate area2010
Power L12701
Power MT1832.21

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