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|
|Number in Class||1|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.35|
|Overall Wheelbase (engine & tender)||48.33'|
|Axle Loading (Maximum Weight per Axle)|
|Weight on Drivers||105000 lbs|
|Engine Weight||134000 lbs|
|Tender Light Weight||75000 lbs|
|Total Engine and Tender Weight||209000 lbs|
|Tender Water Capacity||3500 gals|
|Tender Fuel Capacity (oil/coal)||1500 gals|
|Minimum weight of rail (calculated)||58 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||170 psi|
|Cylinders (dia x stroke)||18" x 24"|
|Tractive Effort||25537 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.11|
|Firebox Area||114 sq. ft|
|Grate Area||28.15 sq. ft|
|Evaporative Heating Surface||1706 sq. ft|
|Superheating Surface||378 sq. ft|
|Combined Heating Surface||2084 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||241.35|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||4786|
|Same as above plus superheater percentage||5647|
|Same as above but substitute firebox area for grate area||22868|