Data from DeGolyer, Volume 31, p. 226. Works number was 32665 in February 1908.
Compared to the 1905 Consolidation delivered to this same mining road (Locobase 12784), the 7 was also a wood-burner, but had a reorganized boiler with fewer, but larger-diameter boiler tubes and a slightly bigger firebox.
In 1940, the 7 went to the Coahuila & Zacatecas as their #3.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 7 |
| Locobase ID | 12785 |
| Railroad | Parral y Durango |
| Country | Mexico |
| Whyte | 2-8-0 |
| Number in Class | 1 |
| Road Numbers | 7 |
| Gauge | 3' |
| Number Built | 1 |
| Builder | Burnham, Williams & Co |
| Year | 1908 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 11.60 / 3.54 |
| Engine Wheelbase (ft / m) | 18.75 / 5.71 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.62 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 85,000 / 38,555 |
| Engine Weight (lbs / kg) | 98,000 / 44,452 |
| Tender Loaded Weight (lbs / kg) | 54,000 / 24,494 |
| Total Engine and Tender Weight (lbs / kg) | 152,000 / 68,946 |
| Tender Water Capacity (gals / ML) | 3200 / 12.12 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 35 / 17.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 40 / 1016 |
| Boiler Pressure (psi / kPa) | 180 / 1240 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 20" / 406x508 |
| Tractive Effort (lbs / kg) | 19,584 / 8883.16 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.34 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 152 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 15.75 / 4.80 |
| Firebox Area (sq ft / m2) | 90 / 8.36 |
| Grate Area (sq ft / m2) | 18 / 1.67 |
| Evaporative Heating Surface (sq ft / m2) | 1492 / 138.61 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1492 / 138.61 |
| Evaporative Heating Surface/Cylinder Volume | 320.86 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 3240 |
| Same as above plus superheater percentage | 3240 |
| Same as above but substitute firebox area for grate area | 16,200 |
| Power L1 | 5012 |
| Power MT | 519.98 |