Black Hills & Northwestern 2-8-2 "Mikado" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 6 (Locobase 13291)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 34, p.p. 286+. (Thanks to Chris Hohl for his 31 March 2015 email and Excel spreadsheet, which persuaded Locobase to separate this one entry into two; see Locobase 16038.) Works number was 34722 in May 1910.

Baldwin's logging Mikados burned almost anything to keep going. Some used oil and others, like this BH&N locomotive, burned wood; the latter's tender capacity was three cords. And while some of the type used Walschaert's outside radial valve gear, this one supplied steam to the cylinders with a Stephenson link motion.

The BH&N featured 6% grades and 20 degree curves (radii of 288 feet/87.8 metres).

In 1916, the 12-mile (19.3 km) subsidiary BH&N was merged with its owner, Mason County Logging Company. Both locomotives served MCLC for a long time. 6's subsequent career is unknown to Locobase.


Class 9 (Locobase 16038)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 52, pp. 371. (Thanks to Chris Hohl for his 31 March 2015 email and Excel spreadsheet, which persuaded Locobase to separate this one entry into two; see Locobase 13291.) Works number was 41299 in April 1914.

Locobase 13291 describes the earlier wood-burning logging engine supplied to the BH&N in 1910. When Baldwin built the second of the two Mikados four years later, they delivered a similar engine with higher boiler pressure and an oil-burner.

9 was sold to the Carlton & Coast in early 1945 as their #11, but that road closed very shortl. See http://www.brian894x4.com/CarltonandCoastRailroad.html, last accessed 25 October 2011, for an account of this road.

Mike #9 went on in April 1945 to the Tonopah & Goldfield in Nevada. Alas for the now aged 11, the T & G was abandoned in October 1947 and the engine was scrapped in 1948.

Specifications by Steve Llanso of Sweat House Media
Class69
Locobase ID13,291 16,038
RailroadBlack Hills & NorthwesternBlack Hills & Northwestern
CountryUSAUSA
Whyte2-8-22-8-2
Number in Class11
Road Numbers69
GaugeStdStd
Number Built11
BuilderBaldwinBaldwin
Year19101914
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.08 / 3.9913.08 / 3.99
Engine Wheelbase (ft / m)27 / 8.2327 / 8.23
Ratio of driving wheelbase to overall engine wheebase 0.48 0.48
Overall Wheelbase (engine & tender) (ft / m)53.17 / 16.2153.67 / 16.21
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)134,000 / 60,781137,000 / 60,781
Engine Weight (lbs / kg)173,000 / 78,472175,000 / 78,472
Tender Loaded Weight (lbs / kg)80,000 / 36,28780,000 / 36,287
Total Engine and Tender Weight (lbs / kg)253,000 / 114,759255,000 / 114,759
Tender Water Capacity (gals / ML)4000 / 15.154000 / 15.15
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)2000 / 7.602000 / 7.60
Minimum weight of rail (calculated) (lb/yd / kg/m)56 / 2857 / 28.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 121948 / 1219
Boiler Pressure (psi / kPa)160 / 11175 / 11
High Pressure Cylinders (dia x stroke) (in / mm)20.5" x 28" / 521x71120.5" x 28" / 521x711
Tractive Effort (lbs / kg)33,340 / 15122.7936,465 / 16540.27
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.02 3.76
Heating Ability
Firebox Area (sq ft / m2)158 / 14.68158 / 14.68
Grate Area (sq ft / m2)41.30 / 3.8441.30 / 3.84
Evaporative Heating Surface (sq ft / m2)3166 / 294.133166 / 294.13
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)3166 / 294.133166 / 294.13
Evaporative Heating Surface/Cylinder Volume295.98295.98
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation66087228
Same as above plus superheater percentage66087228
Same as above but substitute firebox area for grate area25,28027,650
Power L147345178
Power MT311.54333.30