Weyerhaeuser Timber 2-8-8-2 "Chesapeake" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 200 (Locobase 4046)

Data from http://loggingmallets.railfan.net/list/wt200/weyer200.htm and DeGolyer, Vol 80, pp. 373. Works number was 60837 in May 1929 and 61753 in 1933. Price in 1929 was $63,637.

Although relatively small for the wheel arrangement, this pair of Mikado Mallets were comparative behemoths on a logging road that used 60 lb/yard (30 kg/metre) rail, scaled 4% grades, and negotiate curves of up to 25 degrees. The HP cylinders were cast separately and attached to an intermediate saddle of cast steel while the LP cylinders were cast integrally with half saddles and bolted together at the center. Locobase suspects that Weyerhaeuser thought the HP cylinders were subject to too much stress to use the more common cylinder-half saddle casting method. All four cylinders got their steam through 12" (305 mm) piston valves.

Both operated in Washington State until scrapped in 1953.

Specifications by Steve Llanso of Sweat House Media
Locobase ID4046
RailroadWeyerhaeuser Timber
Number in Class2
Road Numbers200-201
Number Built2
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)13.50
Engine Wheelbase (ft)35.75
Ratio of driving wheelbase to overall engine wheebase 0.38
Overall Wheelbase (engine & tender) (ft)50
Axle Loading (Maximum Weight per Axle) (lbs)40,000
Weight on Drivers (lbs)320,000
Engine Weight (lbs)355,000
Tender Loaded Weight (lbs)143,000
Total Engine and Tender Weight (lbs)498,000
Tender Water Capacity (gals)7000
Tender Fuel Capacity (oil/coal) (gals/tons)2500
Minimum weight of rail (calculated) (lb/yd)67
Geometry Relating to Tractive Effort
Driver Diameter (in)51
Boiler Pressure (psi)215
High Pressure Cylinders (dia x stroke) (in)23" x 28"
Low Pressure Cylinders (dia x stroke) (in)35" x 28"
Tractive Effort (lbs)74,137
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.32
Heating Ability
Firebox Area (sq ft)290
Grate Area (sq ft)64.50
Evaporative Heating Surface (sq ft)3639
Superheating Surface (sq ft)985
Combined Heating Surface (sq ft)4624
Evaporative Heating Surface/Cylinder Volume270.27
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation13,868
Same as above plus superheater percentage16,780
Same as above but substitute firebox area for grate area75,444
Power L18179
Power MT450.79

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