Data from "Narrow Gauge Engine for the Mexican Southern", Railway and Locomotive Engineering, Volume XV [15], No 9 (September 1902), p. 391; "Locomotives for the Mexican Southern", Railway Master Mechanic, Volume 26, No 7 (July 1902), pp. 260. Works numbers were 25797-25798 in April 1902.
Outside-frame Ten-wheelers with slide valves, straight boilers and very similar to the Schenectady-built engines (Locobase 3238) delivered to the Interoceanic in 1898. Characterised by R&LE as heavy for the 3' gauge, the engine also sported a boiler with fewer, but larger-diameter tubes than most other skinny-gauge locomotives. The photograph shows unusually large bogie-truck wheels in relation to the driver diameter and a wide gap between the second and third drivers to accommodate the firebox.
Eventually passing into the hands of the Nacional de Mexico, the pair survived until 1954.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | F-05 |
| Locobase ID | 9960 |
| Railroad | Mexicano del Sur |
| Country | Mexico |
| Whyte | 4-6-0 |
| Number in Class | 2 |
| Road Numbers | 103-104/261-262 |
| Gauge | 3' |
| Number Built | 2 |
| Builder | Alco-Cooke |
| Year | 1902 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 13.17 / 4.01 |
| Engine Wheelbase (ft / m) | 22.08 / 6.73 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.60 |
| Overall Wheelbase (engine & tender) (ft / m) | 42.58 / 12.98 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 58,000 / 26,308 |
| Engine Weight (lbs / kg) | 87,000 / 39,463 |
| Tender Loaded Weight (lbs / kg) | 67,000 / 30,391 |
| Total Engine and Tender Weight (lbs / kg) | 154,000 / 69,854 |
| Tender Water Capacity (gals / ML) | 3000 / 11.36 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5 / 5 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 32 / 16 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 47 / 1194 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 17" x 20" / 432x508 |
| Tractive Effort (lbs / kg) | 16,725 / 7586.34 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.47 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 134 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 11.58 / 3.53 |
| Firebox Area (sq ft / m2) | 77 / 7.16 |
| Grate Area (sq ft / m2) | 15.38 / 1.43 |
| Evaporative Heating Surface (sq ft / m2) | 1054 / 97.96 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1054 / 97.96 |
| Evaporative Heating Surface/Cylinder Volume | 200.76 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2461 |
| Same as above plus superheater percentage | 2461 |
| Same as above but substitute firebox area for grate area | 12,320 |
| Power L1 | 3435 |
| Power MT | 391.70 |