Humboldt Northern 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 3 (Locobase 14940)

Data from DeGolyer, Vol 65, pp. 92+. Works number was 55248 in January 1922.

Dolbeer and Carlon's lumber company had bought a saturated-boiler logging Prairie from Baldwin after the 1905 Lewis & Clark Exposition (Locobase 12972). Their next purchase from Eddystone came 17 years later and featured adequate superheating, 9 1/2" (241 mm) piston valves, and oil fuel.

The 3 worked for the Redwood Empire logger over its 20.9 miles (33.6 km) of 56 lb/yard (28 kg/metre) rail until the early 1950s when it was sold to Pacific Lumber of Scotia, Calif. PLC soon sold it the Stockton Terminal & Eastern in 1952.

Class Sequoia (Locobase 12792)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Vol 27, p. 249 Works number was 25503 in April 1905.

Originally built and lettered for the Lewis & Clark Centennial Exposition held in Portland in 1905, the wood-burning 2 was ticketed for Dolbeer & Carson's road from the start. It was a typical logging Prairie that differed from McCloud's 1901 engine (Locobase 12488) only in boiler pressure.

The HN ran from North Spit on Humboldt Bay to Fieldbrook. In 1936, the 2 went to Oregon's Hammond Lumber where it worked until 1950.

Specifications by Steve Llanso of Sweat House Media
Locobase ID14,940 12,792
RailroadHumboldt NorthernHumboldt Northern
Number in Class11
Road Numbers32
Number Built11
BuilderBaldwinBurnham, Williams & Co
Valve GearWalschaertStephenson
Locomotive Length and Weight
Driver Wheelbase (ft) 9.50 7.67
Engine Wheelbase (ft)24.8323.83
Ratio of driving wheelbase to overall engine wheebase 0.38 0.32
Overall Wheelbase (engine & tender) (ft)46.83
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)96,50082,000
Engine Weight (lbs)124,000107,000
Tender Loaded Weight (lbs)75,700
Total Engine and Tender Weight (lbs)199,700
Tender Water Capacity (gals)35003000
Tender Fuel Capacity (oil/coal) (gals/tons)1500
Minimum weight of rail (calculated) (lb/yd)5446
Geometry Relating to Tractive Effort
Driver Diameter (in)4444
Boiler Pressure (psi)175180
High Pressure Cylinders (dia x stroke) (in)17" x 24"16" x 24"
Tractive Effort (lbs)23,44821,364
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.12 3.84
Heating Ability
Firebox Area (sq ft)104122.70
Grate Area (sq ft)2116
Evaporative Heating Surface (sq ft)13421562
Superheating Surface (sq ft)292
Combined Heating Surface (sq ft)16341562
Evaporative Heating Surface/Cylinder Volume212.85279.68
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation36752880
Same as above plus superheater percentage43372880
Same as above but substitute firebox area for grate area21,47622,086
Power L191395142
Power MT626.36414.74