Ostrander Rwy & Timber Co. 2-6-6-2 "Mallet Mogul" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 7 (Locobase 4058)

Data from http://loggingmallets.railfan.net, supplemented by DeGolyer, Vol 80, pp. 304+. See also Rich Wilkens, "U. S. Plywood #11: A History", archived at http://4wheelrailroader.tripod.com/usplywood11/id1.html . Works number was 59701 in November 1926.

Standard Baldwin compound articulated tank of the kind sold to several Western logging companies in the 1920s; this one had rectangular tanks. Like the other Baldwin mallet tanks, the HP cylinders on 7 had 8" (203 mm) piston valves and the LP used 12" (305 mm) piston valves. Its operating enviroment was based on 60 lb/yard (30 kg/metre) rails that bent around curves of up to 30 degrees and ascended 4% grades.

After 13 years with Ostrander, #7 was sold to Weyerhaeuser as #5 in 1939 and ran for 10 years with that company (1940-1950).

Rich Wilken's detailed account notes that soon after its arrival, Weyerhaeuser removed much of the side tank capacity, substituting a long 8,000 US gallon (30,280 litre) cylindrical tender. This vessel started its career as a tank car. During its converson to tender use, a front section reserved for more oil fuel, while the rear carried the water needed to operate in the dry Klamath Falls area. Cutting down the engine's tanks improved forward visibility, says Wilkens, and provided convenient pockets to carry scrap metal whose weight partially compensated for the reduction in adhesion weight caused by eliminating the 12 tons of water in full tanks.

Kosmos Timber and United States Plywood operated this engine as #11 until 1960. After 13 years on display, she was restored to tourist operation, in which she served for 16 years.

From 1990, the 11 rested in storage at the Northwest Railway Museum of Snoqualmie, Wash. . Museum volunteers began a cosmetic restoration in 2002.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID4058
RailroadOstrander Rwy & Timber Co.
Number in Class1
Road Numbers7
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)8 / 2.44
Engine Wheelbase (ft / m)37.75 / 11.51
Ratio of driving wheelbase to overall engine wheebase 0.21
Overall Wheelbase (engine & tender) (ft / m)37.75 / 11.51
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)210,000 / 95,255
Engine Weight (lbs / kg)245,500 / 111,357
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)245,500
Tender Water Capacity (gals / ML)3200 / 12.12
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)1200 / 4.50
Minimum weight of rail (calculated) (lb/yd / kg/m)58 / 29
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)44 / 1118
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x610
Low Pressure Cylinders (dia x stroke) (in / mm)28" x 24" / 711x610
Tractive Effort (lbs / kg)42,517 / 19285.41
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.94
Heating Ability
Firebox Area (sq ft / m2)128 / 11.89
Grate Area (sq ft / m2)26.20 / 2.43
Evaporative Heating Surface (sq ft / m2)1654 / 153.66
Superheating Surface (sq ft / m2)358 / 33.26
Combined Heating Surface (sq ft / m2)2012 / 186.92
Evaporative Heating Surface/Cylinder Volume233.99
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5240
Same as above plus superheater percentage6183
Same as above but substitute firebox area for grate area30,208
Power L14730
Power MT297.94

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