Data from NdeM 1946 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 24, p. 158. Works numbers were 20078-20079 in February 1902
This pair of Consolidations provided basic transportation for freight traffic in Mexico. When the Mexican Central took over the C & P in 1908, the pair was renumbered 937-938 and sold to the NdeM as 484-485. Renumbered 1365 in 1930, 20078 was scrapped in 1931. 20079 lasted much longer, not leaving service until 1957.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | G-31 |
| Locobase ID | 9490 |
| Railroad | Coahuila y Pacifico |
| Country | Mexico |
| Whyte | 2-8-0 |
| Number in Class | 2 |
| Road Numbers | 6-7/937-938/1365, 1367 |
| Gauge | Std |
| Number Built | 2 |
| Builder | Burnham, Williams & Co |
| Year | 1902 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 15.33 / 4.67 |
| Engine Wheelbase (ft / m) | 23.67 / 7.21 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.65 |
| Overall Wheelbase (engine & tender) (ft / m) | 52.42 / 15.98 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 156,000 / 70,760 |
| Engine Weight (lbs / kg) | 172,000 / 78,018 |
| Tender Loaded Weight (lbs / kg) | 102,000 / 46,266 |
| Total Engine and Tender Weight (lbs / kg) | 274,000 / 124,284 |
| Tender Water Capacity (gals / ML) | 6000 / 22.73 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3103 / 11,745 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 65 / 32.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 55 / 1397 |
| Boiler Pressure (psi / kPa) | 180 / 1240 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 21" x 28" / 533x711 |
| Tractive Effort (lbs / kg) | 34,350 / 15580.92 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.54 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 287 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 14.87 / 4.53 |
| Firebox Area (sq ft / m2) | 188 / 17.47 |
| Grate Area (sq ft / m2) | 33.60 / 3.12 |
| Evaporative Heating Surface (sq ft / m2) | 2423 / 225.19 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 2423 / 225.19 |
| Evaporative Heating Surface/Cylinder Volume | 215.95 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 6048 |
| Same as above plus superheater percentage | 6048 |
| Same as above but substitute firebox area for grate area | 33,840 |
| Power L1 | 4946 |
| Power MT | 279.59 |