Wisconsin Logging & Timber Company 2-8-2 "Mikado" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 7 (Locobase 14715)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 62, p. 421. See also LoggerHogger's 8/13/12 04:42 post on TrainOrders at [],2843761. Works number was 53251 in May 1920.

Side-tank logging Mikados were a principal variant on the tender-engine loggers. The specifications for this one suggest a daunting set of requirements: Its 18 miles (29 km) of track included 36 degree curves (radii of 162 feet/49.4 metres) on the level-track sections, 30 degree curves (radii of 193 feet/58.8 metres) in combination with 7 1/2% grades. "Locomotive will take empty loads up two miles [3.2 km] of maximum curves and back down with load." Implications of this particular note follow immediately: "It is imperative that brake shoes be hung in front of drivers instead of back." Hereafter notes concerning spring placement also reflect the strenuous duty.

Despite the apparent locale implied in the name, Wisconsin interests owned timber in several states. The 7 operated in southwestern Washington. Soon after its arrival, however, the 7 was sold to Shevlin-Hixon of Bend, Ore. In the 1930s, S-H converted the 7 into a tender engine, removing the side tanks and adding a big tender. At another time, S-H superheated the boiler and replaced slide valves with piston valves.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID14,715
RailroadWisconsin Logging & Timber Company
Number in Class1
Road Numbers7
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)11.50 / 3.51
Engine Wheelbase (ft / m)26.25 / 8
Ratio of driving wheelbase to overall engine wheebase 0.44
Overall Wheelbase (engine & tender) (ft / m)26.25 / 8
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)140,000 / 63,503
Engine Weight (lbs / kg)180,000 / 81,647
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)180,000
Tender Water Capacity (gals / ML)2400 / 9.09
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)900 / 3.40
Minimum weight of rail (calculated) (lb/yd / kg/m)58 / 29
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)42 / 1067
Boiler Pressure (psi / kPa)185 / 12.80
High Pressure Cylinders (dia x stroke) (in / mm)19" x 24" / 483x610
Tractive Effort (lbs / kg)32,438 / 14713.65
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.32
Heating Ability
Firebox Area (sq ft / m2)114 / 10.59
Grate Area (sq ft / m2)30 / 2.79
Evaporative Heating Surface (sq ft / m2)1901 / 176.61
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1901 / 176.61
Evaporative Heating Surface/Cylinder Volume241.37
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5550
Same as above plus superheater percentage5550
Same as above but substitute firebox area for grate area21,090
Power L14063
Power MT255.92

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