Data from "Freight Engine for the Mexican Railway", American Engineer and Railroad Journal, Volume LXIX [69], No 5 (May 1895), pp. 206-207; and MexRwy 1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from fis extensive Rail Data Exchange collection. See also letter WVB of Buenos Ayres [sic] in AERJ, August 1895, p 345. Works numbers were4736-4739 in 1894.
Although initially without a bogie, the locomotive did have flangeless divers on the second axle. The illustration showed a long, straight boiler with a steam dome over the second and third axles. Outside cylinders drove the third axle; valves and motion both lay between the frames. AERJ reported that the engines would run "over many miles of track where the gradient is steeper than 1 in 30; hence even a light train necessitates the use of a powerful engine." The 1939 diagram book tells us several things about this class: 81 &84 were still on the roster more than 40 years later and both then sported Bissel leading trucks. Allan straight link motion had given way to Stephenson link and a new boiler held 280 2" tubes. Bigger tenders carried more water and fuel oil.
Principal Dimensions by Steve Llanso of Sweat House Media | |
|---|---|
| Class | unknown |
| Locobase ID | 5840 |
| Railroad | Mexican Railway |
| Country | Mexico |
| Whyte | 0-8-0 |
| Number in Class | |
| Road Numbers | 81-84 |
| Gauge | Std |
| Number Built | |
| Builder | Neilson & Co |
| Year | 1894 |
| Valve Gear | Allan |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 15.50 / 4.72 |
| Engine Wheelbase (ft / m) | 15.50 / 4.72 |
| Ratio of driving wheelbase to overall engine wheelbase | 1 |
| Overall Wheelbase (engine & tender) (ft / m) | 41.08 / 12.52 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 32,816 / 14,885 |
| Weight on Drivers (lbs / kg) | 124,992 / 56,695 |
| Engine Weight (lbs / kg) | 124,992 / 56,695 |
| Tender Loaded Weight (lbs / kg) | 97,216 / 44,096 |
| Total Engine and Tender Weight (lbs / kg) | 222,208 / 100,791 |
| Tender Water Capacity (gals / ML) | 2850 / 10.80 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 52 / 26 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 48 / 1219 |
| Boiler Pressure (psi / kPa) | 165 / 11.40 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18.5" x 26" / 470x660 |
| Tractive Effort (lbs / kg) | 26,000 / 11793.42 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.81 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 286 - 1.875" / 48 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 11.50 / 3.51 |
| Firebox Area (sq ft / m2) | 147 / 13.66 |
| Grate Area (sq ft / m2) | 25 / 2.32 |
| Evaporative Heating Surface (sq ft / m2) | 1811 / 168.25 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1811 / 168.25 |
| Evaporative Heating Surface/Cylinder Volume | 223.86 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 4125 |
| Same as above plus superheater percentage | 4125 |
| Same as above but substitute firebox area for grate area | 24,255 |
| Power L1 | 4154 |
| Power MT | 293.07 |