Data from Baldwin Locomotive Works Specification for Engines, 1890, as digitized by the DeGolyer Library of Southern Methodist University Vol 23, p.138 Works numbers were 18355 in October 1900, 21721 in February 1903, and 37796 in August 1911.
Many small mining roads built to a certain standard and didn't substantially upgrade that level - traffic levels and revenue didn't call for it. So it wasn't uncommon for the first locomotive to arrive in year 1 (in the case of the Bermejillo, 1900), the second a few years later (San Pedro in 1903), and a third built to the same specs even later (San Juan in 1911). Each was expected to negotiate curves of 41-metre radius (> 20 deg) and manage a ruling grade of 1 3/4% (92 ft to the mile).
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Bermejillo |
| Locobase ID | 12449 |
| Railroad | Minera de Petioles |
| Country | Mexico |
| Whyte | 2-6-2T |
| Number in Class | 3 |
| Road Numbers | |
| Gauge | 2'6" |
| Number Built | 3 |
| Builder | Burnham, Williams & Co |
| Year | 1900 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 7.25 / 2.21 |
| Engine Wheelbase (ft / m) | 19.58 / 5.97 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.37 |
| Overall Wheelbase (engine & tender) (ft / m) | 19.58 / 5.97 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 35,000 / 15,876 |
| Engine Weight (lbs / kg) | 47,000 / 21,319 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1000 / 3.79 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 19 / 9.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 35 / 889 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 12" x 16" / 305x406 |
| Tractive Effort (lbs / kg) | 8953 / 4061.02 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.91 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 72 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 11.08 / 3.38 |
| Firebox Area (sq ft / m2) | 41.80 / 3.88 |
| Grate Area (sq ft / m2) | 9 / 0.84 |
| Evaporative Heating Surface (sq ft / m2) | 456 / 42.38 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 456 / 42.38 |
| Evaporative Heating Surface/Cylinder Volume | 218.18 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1440 |
| Same as above plus superheater percentage | 1440 |
| Same as above but substitute firebox area for grate area | 6688 |
| Power L1 | 2970 |
| Power MT | 561.23 |