Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Vol 65, p. 385. Works number was 55645 in September 1922.
Very few standard-gauge Mikados, whether superheated or not, were as small as this plantation engine and even fewer burned wood as this one did. The tender weighed seven tons (6.4 metric tons) more than the engine, an unusual inversion of proportions that occurred despite the fuel load amounting to 10 cords. Purchased by the United Sugar Company, the 4 was delivered to Los Mochis in Sinaloa State. They ran on the railway opened in 1909 and covered about 300 km (186 miles) between Guadalajara and Manzanillo by way of Colima
For all its diminuitive stature, the locomotive employed a relatively high degree of superheat. 8" (203 mm) piston valves supplied steam to the cylinders. And its 12 tons of tractive effort implied some pulling power on 50 lb/yard (25 kg/metre) rail over which it had to travel. Use of a 2-8-2 arrangement as a way to spread the weight over six axles is further suggested by the note in the specs that notes "Company's track is not ballasted, and ties are laid on dirt fill." Gradients and curves were gentle, however.
Principal Dimensions by Steve Llanso of Middle Run Media | |
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Class | 4 |
Locobase ID | 14989 |
Railroad | Mexicano del Pacifico |
Country | Mexico |
Whyte | 2-8-2 |
Number in Class | 1 |
Road Numbers | 4 |
Gauge | Std |
Number Built | 1 |
Builder | Baldwin |
Year | 1922 |
Valve Gear | Walschaert |
Locomotive Length and Weight | |
Driver Wheelbase (ft / m) | 12.50 / 3.81 |
Engine Wheelbase (ft / m) | 27.50 / 8.38 |
Ratio of driving wheelbase to overall engine wheelbase | 0.45 |
Overall Wheelbase (engine & tender) (ft / m) | 67.85 / 20.68 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
Weight on Drivers (lbs / kg) | 98,000 / 44,452 |
Engine Weight (lbs / kg) | 128,500 / 58,287 |
Tender Loaded Weight (lbs / kg) | 142,500 / 64,637 |
Total Engine and Tender Weight (lbs / kg) | 271,000 / 122,924 |
Tender Water Capacity (gals / ML) | 6000 / 22.73 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 41 / 20.50 |
Geometry Relating to Tractive Effort | |
Driver Diameter (in / mm) | 44 / 1118 |
Boiler Pressure (psi / kPa) | 180 / 1240 |
High Pressure Cylinders (dia x stroke) (in / mm) | 17" x 24" / 432x610 |
Tractive Effort (lbs / kg) | 24,118 / 10939.75 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.06 |
Heating Ability | |
Tubes (number - dia) (in / mm) | 94 - 2" / 51 |
Flues (number - dia) (in / mm) | 18 - 5.375" / 137 |
Flue/Tube length (ft / m) | 13.17 / 4.01 |
Firebox Area (sq ft / m2) | 102 / 9.48 |
Grate Area (sq ft / m2) | 22.20 / 2.06 |
Evaporative Heating Surface (sq ft / m2) | 1087 / 100.98 |
Superheating Surface (sq ft / m2) | 274 / 25.46 |
Combined Heating Surface (sq ft / m2) | 1361 / 126.44 |
Evaporative Heating Surface/Cylinder Volume | 172.27 |
Computations Relating to Power Output (More Information) | |
Robert LeMassena's Power Computation | 3996 |
Same as above plus superheater percentage | 4795 |
Same as above but substitute firebox area for grate area | 22,032 |
Power L1 | 8499 |
Power MT | 764.78 |