The five K-5s used to build these "Hudsons" were bought from the American Locomotive Company in 1925 and were the only three-cylinder 2-8-2s on the Wabash.
Later, in 1946 and 1947, a pair of the two cylinder Class K-5s were also converted into "Hudsons" and were assigned road numbers 705 and 706.
All seven of the Class P-1 "Hudsons" were scrapped in 1956.
Data from WAB 1 - 1946 Locomotive, Crane, and Marine Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Collection. (Many thanks to Chris Hohl for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .)
Five of these locomotives were rebuilt by the Wabash in 1943 from K-5 class 2-8-2 engines originally built by Alco in 1925 (Locobase 23). Two more followed after World War II, but were derived from earlier K-4s. The engines gave up their center cylinder and a driving axle, had larger drivers, and were fitted with Timken roller bearings. 12" (305 mm) piston valves supplied steam to the cylinders. The firebox heating surface included 32 sq ft (2.97 sq m) of arch tubes.
The engines were semi-streamlined with long "elephant ears" and given a light blue paint scheme with a broad white stripe along the running boards; the tenders received a similar paint job.
They ran until 1956.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | P1 |
| Locobase ID | 189 |
| Railroad | Wabash |
| Country | USA |
| Whyte | 4-6-4 |
| Number in Class | 7 |
| Road Numbers | 700-706 |
| Gauge | Std |
| Number Built | 7 |
| Builder | Wabash |
| Year | 1943 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 14 / 4.27 |
| Engine Wheelbase (ft / m) | 40.58 / 12.37 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.34 |
| Overall Wheelbase (engine & tender) (ft / m) | 75.46 / 23 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 65,570 / 29,742 |
| Weight on Drivers (lbs / kg) | 196,390 / 89,081 |
| Engine Weight (lbs / kg) | 374,680 / 169,952 |
| Tender Loaded Weight (lbs / kg) | 208,000 / 94,347 |
| Total Engine and Tender Weight (lbs / kg) | 582,680 / 264,299 |
| Tender Water Capacity (gals / ML) | 12,000 / 45.45 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 16 / 15 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 109 / 54.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 80 / 2032 |
| Boiler Pressure (psi / kPa) | 220 / 1520 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 26" x 28" / 660x711 |
| Tractive Effort (lbs / kg) | 44,244 / 20068.76 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.44 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 239 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | 45 - 5.5" / 140 |
| Flue/Tube length (ft / m) | 19 / 5.79 |
| Firebox Area (sq ft / m2) | 341 / 31.69 |
| Grate Area (sq ft / m2) | 71 / 6.60 |
| Evaporative Heating Surface (sq ft / m2) | 4225 / 392.66 |
| Superheating Surface (sq ft / m2) | 1051 / 97.68 |
| Combined Heating Surface (sq ft / m2) | 5276 / 490.34 |
| Evaporative Heating Surface/Cylinder Volume | 245.50 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 15,620 |
| Same as above plus superheater percentage | 18,744 |
| Same as above but substitute firebox area for grate area | 90,024 |
| Power L1 | 26,230 |
| Power MT | 883.35 |
