The only set of Prairies to operate for an Espee line, this quartet was produced for the EP & NE in single units (works #20999, 21024) and a pair (21036-21037) in September 1902. At that time, they were not superheated. The EP & NE added two more (24657-24648, road #24-25) in September 1904 as class Pr-2; Locobase suspects they were very similar.
The class soon came under the El Paso & Southwestern when that railroad bought the EP & NE in 1905 and were renumbered 134-139.
For the next two decades they wore the EP & SW herald until the Southern Pacific bought the EP & SW in 1925. At that point they were assigned to the Southern Pacific de Mexico as 700-703, where, except for the 703, they ran until scrapping in 1934-1935. 703 had one more stop to make. Modified for oil-burning and re-re-numbered 1903, this engine operated on Bay Area commuter lines until 1934.
| Specifications | |
|---|---|
| Class | Pr-1 |
| Locobase ID | 8671 |
| Railroad | El Paso & Northeastern (SP) |
| Whyte | 2-6-2 |
| Road Numbers | 20-23 /134-37/ 1900-1903 |
| Gauge | Std |
| Builder | Burnham, Williams & Co |
| Year | 1902 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase | 13.33' |
| Engine Wheelbase | 31.50' |
| Ratio of driving wheelbase to overall engine wheebase | 0.42 |
| Overall Wheelbase (engine & tender) | |
| Axle Loading (Maximum Weight per Axle) | |
| Weight on Drivers | 136800 lbs |
| Engine Weight | 200500 lbs |
| Tender Light Weight | |
| Total Engine and Tender Weight | 0 |
| Tender Water Capacity | |
| Tender Fuel Capacity (oil/coal) | |
| Minimum weight per yard of rail on which locomotive could run | 76 lb rail |
| Geometry Relating to Tractive Effort | |
| Driver Diameter | 70" |
| Boiler Pressure | 170 psi |
| Cylinders (dia x stroke) | 23" x 28" |
| Tractive Effort | 30576 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.47 |
| Heating Ability | |
| Firebox Area | 188 sq. ft |
| Grate Area | 53.90 sq. ft |
| Evaporative Heating Surface | 2669 |
| Superheating Surface | 494 |
| Combined Heating Surface | 3163 |
| Evaporative Heating Surface/Cylinder Volume | 198.23 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 9163 |
| Same as above plus superheater percentage | 10594.09 |
| Same as above but substitute firebox area for grate area | 36951.54 |
| Power L1 | 11865.10 |
| Power MT | 573.64 |
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