California Western 2-6-2 "Prairie" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 21 (Locobase 14936)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 65, p. 50. Works numbers were 53277 in June 1920, 54898 in July 1921, and 57553 in December 1923.

Locobase 14109 tells the story of the CW's founding and operation and describes the saddle tanks that came from Baldwin at an earlier date. The first of these superheated logging Prairies was built at around the same time as the two Long Bell engines shown in Locobases 14934-14935). Notice that this engine supplied very nearly the same heating and superheating areas as did the others, but used more and shorter tubes and flues. Significant differences included a longer, deeper firebox and more cylinder volume, but lower boiler pressure. It was also oil-fired.

The design obviously satisfied the CWR's requirements as the 22 arrived a year later and the 23 a little more than two years after that. The later engines trailed tenders that held 200 US gallons (757 litres) less oil and thus weighed 108,700 lb (49,306 kg). 23 was credited with an slightly lower adhesion weight of 109, 500 lb (49,668 kg) and all-up weight of 139,300 lb (63,185 kg).

The 21 would roam the Redwood Empire for almost 30 years before being sold to Pan American Engineering in 1950. PAE would send the engine down to the Mexicano del Pacifico (headquartered in Los Mochis, on the Gulf of California in Sinaloa State) , where it was renumbered 6. The 23 was scrapped in April 1950 while 22 staved off the ferroknacker until April 1952.


Class 7 (Locobase 14109)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 47, p. 254. Works number was 33390 in April 1909, 39551 in March 1913, and 41922 in February 1915.

Serving the Union Lumber Company as it exploited the timber reserves in northwestern California, the Fort Bragg Railroad was renamed the California Western Railway & Navigation Company in 1905. The CW ran for 39.6 miles from Fort Bragg, which lies on the coast about 135 miles northwest of San Francisco inland along the Nojo River to Willits where it met the California Northwestern.

The first of three Baldwin Prairie saddle tanks was renumbered from 7 to 17 in 1924 and operated on the CW for almost 30 years before being scrapped in 1938 at Fort Bragg. 11 kept its number throughout its career, which lasted until its scrapping in 1947.

Number 12 was about 5 tons heavier than either of the earlier engines, but shared all of the other dimensions. It was lettered for the Union Lumber Company, but operated on the CW. It was scrapped in 1950.

Principal Dimensions by Steve Llanso of Sweat House Media
Class217
Locobase ID14,936 14,109
RailroadCalifornia WesternCalifornia Western
CountryUSAUSA
Whyte2-6-22-6-2ST
Number in Class23
Road Numbers21-227, 11, 12 / 17
GaugeStdStd
Number Built23
BuilderBaldwinBurnham, Williams & Co
Year19201909
Valve GearWalschaertStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)11 / 3.359 / 2.74
Engine Wheelbase (ft / m)26.58 / 8.1024.67 / 7.52
Ratio of driving wheelbase to overall engine wheebase 0.41 0.36
Overall Wheelbase (engine & tender) (ft / m)49.92 / 15.2224.67 / 7.52
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)111,000 / 50,34972,000 / 32,659
Engine Weight (lbs / kg)140,000 / 63,50398,000 / 44,452
Tender Loaded Weight (lbs / kg)100,000 / 45,359
Total Engine and Tender Weight (lbs / kg)240,000 / 108,86298,000
Tender Water Capacity (gals / ML)5000 / 18.941500 / 5.68
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)2000 / 7.60800 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)62 / 3140 / 20
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)44 / 111844 / 1118
Boiler Pressure (psi / kPa)180 / 12.40160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x61015" x 22" / 381x559
Tractive Effort (lbs / kg)27,039 / 12264.7015,300 / 6939.97
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.11 4.71
Heating Ability
Firebox Area (sq ft / m2)150 / 13.9471.70 / 6.66
Grate Area (sq ft / m2)26.20 / 2.4312.80 / 1.19
Evaporative Heating Surface (sq ft / m2)1456 / 135.27903 / 83.89
Superheating Surface (sq ft / m2)332 / 30.84
Combined Heating Surface (sq ft / m2)1788 / 166.11903 / 83.89
Evaporative Heating Surface/Cylinder Volume205.98200.68
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation47162048
Same as above plus superheater percentage56122048
Same as above but substitute firebox area for grate area32,13011,472
Power L196993289
Power MT577.91302.12

Photos