Ambalema-IbaguT 2-4-2 Locomotives in Colombia

Class Details by Steve Llanso of Sweat House Media

Class 2 (Locobase 15430)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Vol 79, pp. 114+. Works number was 59969 in April 1927.

This little wood-burning tank used a chubby Rushton Improved spark-arresting cabbage stack to reduce the chance of accidental fires along the right of way. Its relatively long wheelbase put less than 1 1/2 tons per foot on the rail. The specifications shed light on the difficulties met when delivering locomotives to mountainous narrow-gauge lines like the A-I. "Packages to be reduced to minimum sizes and weights for transportation to the interior of Colombia. All small pieces to be packed in boxes weighing 220 lbs (100 kilos) as far as possible."

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID15430
Number in Class1
Road Numbers2 /
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)5 / 1.52
Engine Wheelbase (ft / m)19 / 5.79
Ratio of driving wheelbase to overall engine wheelbase 0.26
Overall Wheelbase (engine & tender) (ft / m)19 / 5.79
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)37,000 / 16,783
Engine Weight (lbs / kg)55,000 / 24,948
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)55,000 / 24,948
Tender Water Capacity (gals / ML)700 / 2.65
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)31 / 15.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)33 / 838
Boiler Pressure (psi / kPa)165 / 11.40
High Pressure Cylinders (dia x stroke) (in / mm)11" x 16" / 279x406
Tractive Effort (lbs / kg)8228 / 3732.16
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.50
Heating Ability
Tubes (number - dia) (in / mm)106 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 8.83 / 2.69
Firebox Area (sq ft / m2)43 / 3.99
Grate Area (sq ft / m2) 9.50 / 0.88
Evaporative Heating Surface (sq ft / m2)468 / 43.48
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)468 / 43.48
Evaporative Heating Surface/Cylinder Volume265.93
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1568
Same as above plus superheater percentage1568
Same as above but substitute firebox area for grate area7095
Power L13522
Power MT419.71

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