Pit River Power Development 2-6-2 "Prairie" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 15299)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Vol 73, pp. 91+. See also First Annual Report of the Federal Power Commission-Fiscal Year Ended June 30, 1921 (Washington, DC: Government Printing Office, 1921), pp. 147-148. Works number was 56278 in July 1923.

This Prairie was bought by Pacific Gas & Electric for its Mount Shasta Power Corporation project as part of the Pit River Power Development project. As noted in the 1921 Federal Power Commission report, MSPC had already built three dams on land it privately held in northern California. The company's submission of a plan to construct two more projects--Pit No 3 and Pit No 4--in the Lassen and Shasta National forests is an example of the competing "public goods" of adequate water for irrigation and the provision of cheaper electrical power. (Later concerns about adequate water flows for trout fisheries would be addressed in the 21st Century; see the 2008 Pit River Summary Report issued by the Heritage and Wild Trout Program of the California Department of Fish and Game at nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=31257, last accessed 14 July 2013. )

The FPC noted that the Pit River furnished 60-85% of the water feeding the Sacramento River at the head of the Sacramento Valley and that there was more land to irrigate than could be supplied by water. So they ruled that Pit 3--a dam and power plant-- and Pit 4--which would divert water to the tailrace of Pit 3--could go ahead with the provision that water from those projects would be available to be released for irrigation when necessary.

Pit No 3 powerhouse opened in 1955, but Pit No 4 was delayed for decades and didn't open until 1965.

Once PSE&G was finished with the 4, they sold it in 1933 to the Oakland Terminal Company. The Key System sold the 4 to the Atchison, Topeka & Santa Fe in August 1943 as their 2447. A year later, the Santa Fe sold it to the Modesto & Empire Traction Company as their 9, where it ran until scrapped in April 1952.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID15,299
RailroadPit River Power Development
Number in Class1
Road Numbers4
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 9.50 / 2.90
Engine Wheelbase (ft / m)24.83 / 7.57
Ratio of driving wheelbase to overall engine wheebase 0.38
Overall Wheelbase (engine & tender) (ft / m)48 / 14.63
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)96,000 / 43,545
Engine Weight (lbs / kg)122,000 / 55,338
Tender Loaded Weight (lbs / kg)89,000 / 40,370
Total Engine and Tender Weight (lbs / kg)211,000 / 95,708
Tender Water Capacity (gals / ML)4000 / 15.15
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)1800 / 6.80
Minimum weight of rail (calculated) (lb/yd / kg/m)53 / 26.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)44 / 1118
Boiler Pressure (psi / kPa)175 / 12.10
High Pressure Cylinders (dia x stroke) (in / mm)17" x 24" / 432x610
Tractive Effort (lbs / kg)23,448 / 10635.85
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.09
Heating Ability
Firebox Area (sq ft / m2)104 / 9.66
Grate Area (sq ft / m2)21 / 1.95
Evaporative Heating Surface (sq ft / m2)1664 / 154.59
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1664 / 154.59
Evaporative Heating Surface/Cylinder Volume263.92
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3675
Same as above plus superheater percentage3675
Same as above but substitute firebox area for grate area18,200
Power L14445
Power MT306.24

All material Copyright © SteamLocomotive.com
Wes Barris