Skagit 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 6 (Locobase 15489)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Vol 80, p. 415. See also Charles E Benjamin, "History of the Incline: Up and Down on the Incline Scene", Trolley Fare (September/October 1987), archived at the Seattle City Light website at, last accessed 17 October 2013. Works number was 60440 in July 1928.

Proportioned like a logging engine, this oil-burning, superheated Prairie had 8" (203 mm) piston valves.

The 6 supported several Seattle City Light water projects in the Skagit River Valley that lay 140 miles (225 km) northeast of the big city. The railway used an incline, electric power in the steepest sections, a car ferry, winch, and steam power from Rockport Junction on the Great Northern to two sites: the Gorge powerhouse and the dam at Newhalem, Wash.

The 6--the Skagit's only steamer--rode on the last of the modes from 1928 to 1954 when the railroad was abandoned. Maximum curvature was a relatively high 35 degrees (radii of 135 feet), but ruling grades came to only 1.2% compensated, although there were short grades of 4%. 6 provided the railway's passenger power for both the workers on the projects and for the excursions that took tourists to sample the dramatic views.

After the Skagit closed, the 6 was preserved in Newhalem. In 1973, a short-lived excursion road built a shed in Concrete, WA to house the 6 during its restoration, but never had the funds to complete the project. As of 2013, the 6 remained on display in Newhalem.

Specifications by Steve Llanso of Sweat House Media
Locobase ID15489
Number in Class1
Road Numbers6
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase 9.33'
Engine Wheelbase26.75'
Ratio of driving wheelbase to overall engine wheebase 0.35
Overall Wheelbase (engine & tender)48.33'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers105000 lbs
Engine Weight134000 lbs
Tender Light Weight75000 lbs
Total Engine and Tender Weight209000 lbs
Tender Water Capacity3500 gals
Tender Fuel Capacity (oil/coal)1500 gals
Minimum weight of rail (calculated)58 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter44"
Boiler Pressure170 psi
Cylinders (dia x stroke)18" x 24"
Tractive Effort25537 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.11
Heating Ability
Firebox Area114 sq. ft
Grate Area28.15 sq. ft
Evaporative Heating Surface1706 sq. ft
Superheating Surface378 sq. ft
Combined Heating Surface2084 sq. ft
Evaporative Heating Surface/Cylinder Volume241.35
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4786
Same as above plus superheater percentage5647
Same as above but substitute firebox area for grate area22868
Power L110014
Power MT630.77

If you have any railroad data such as diagram books, rail station plans or anything else that you would be willing to share, please contact us.