Data from NdeM 1950 Locomotive Diagrams Standard Gauge supplied in December 2010 by Allen Stanley. See also the 10 July 2010 blog post at [] by Matfas Lozano Dfaz de León on La Burrita, the one NR-1 to have been preserved.
These Hudsons vied with the Maine Central D-class 4-6-4s described in Locobase 1044 for the title of lightest of the arrangement on a North American railroad. But they suited NdeM practice quite well.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | NR-1 |
| Locobase ID | 11950 |
| Railroad | Nacional de Mexico (NdeM) |
| Country | Mexico |
| Whyte | 4-6-4 |
| Number in Class | 10 |
| Road Numbers | 2700-2709 |
| Gauge | Std |
| Number Built | 10 |
| Builder | Alco-Schenectady |
| Year | 1937 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 13 / 3.96 |
| Engine Wheelbase (ft / m) | 37.75 / 11.51 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.34 |
| Overall Wheelbase (engine & tender) (ft / m) | 69.08 / 21.06 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 170,000 / 77,111 |
| Engine Weight (lbs / kg) | 292,000 / 132,449 |
| Tender Loaded Weight (lbs / kg) | 173,660 / 78,771 |
| Total Engine and Tender Weight (lbs / kg) | 465,660 / 211,220 |
| Tender Water Capacity (gals / ML) | 8500 / 32.20 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 4037 / 15,280 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 94 / 47 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 73 / 1854 |
| Boiler Pressure (psi / kPa) | 250 / 1720 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 22.5" x 28" / 572x711 |
| Tractive Effort (lbs / kg) | 41,263 / 18716.60 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.12 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 178 - 2" / 51 |
| Flues (number - dia) (in / mm) | 43 - 5.375" / 137 |
| Flue/Tube length (ft / m) | 17 / 5.18 |
| Firebox Area (sq ft / m2) | 281 / 26.11 |
| Grate Area (sq ft / m2) | 66.80 / 6.21 |
| Evaporative Heating Surface (sq ft / m2) | 2947 / 273.88 |
| Superheating Surface (sq ft / m2) | 850 / 79 |
| Combined Heating Surface (sq ft / m2) | 3797 / 352.88 |
| Evaporative Heating Surface/Cylinder Volume | 228.63 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 16,700 |
| Same as above plus superheater percentage | 20,374 |
| Same as above but substitute firebox area for grate area | 85,705 |
| Power L1 | 28,321 |
| Power MT | 1101.83 |
