Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 29, p. 288. (Thanks to Ivo Rutishauser for his email pointing out the difference in wheel arrangement of the 7 vs the 6; it led to the creation of a separate entry.) Works number was 30606 in April 1907.
Simpson Logging operated the Peninsular Railway, which eventually ran over 50 miles (80 km) of track up into Chehalis County (now Grays Harbor County). They had bought a Prairie the year before (Locobase 12914) and returned for another engine. This time, however, they specified a Ten-wheeler. Other than the changes to the running gear that included wheelbases and weight distribution, the new engine shared dimensions with the 6.
The 7, which bore the name "Sol Simpson" when it was delivered was sold in April 1917 to the Alaska Railroad as their 21.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Sol Simpson |
| Locobase ID | 16707 |
| Railroad | Peninsular |
| Country | USA |
| Whyte | 4-6-0 |
| Number in Class | 1 |
| Road Numbers | 7 |
| Gauge | Std |
| Number Built | 1 |
| Builder | Burnham, Williams & Co |
| Year | 1906 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 13 / 2.44 |
| Engine Wheelbase (ft / m) | 24 / 7.44 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.54 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 76,000 / 33,112 |
| Engine Weight (lbs / kg) | 101,000 / 44,452 |
| Tender Loaded Weight (lbs / kg) | 55,000 / 24,948 |
| Total Engine and Tender Weight (lbs / kg) | 156,000 / 69,400 |
| Tender Water Capacity (gals / ML) | 2500 / 9.47 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 42 / 21 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 46 / 1168 |
| Boiler Pressure (psi / kPa) | 160 / 1240 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 24" / 406x610 |
| Tractive Effort (lbs / kg) | 18,165 / 8239.52 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.18 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 211 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 11.87 / 3.62 |
| Firebox Area (sq ft / m2) | 107 / 9.94 |
| Grate Area (sq ft / m2) | 16 / 1.49 |
| Evaporative Heating Surface (sq ft / m2) | 1410 / 131.04 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1410 / 131.04 |
| Evaporative Heating Surface/Cylinder Volume | 252.24 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2560 |
| Same as above plus superheater percentage | 2560 |
| Same as above but substitute firebox area for grate area | 17,120 |
| Power L1 | 4268 |
| Power MT | 371.42 |