Laramie, Hahn's Peak & Pacific 2-8-2 "Mikado" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 6580)

Data from 1914 St J & G I diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 36661in July 1911, 36786 in August, and 37120-37121 in October.

Firebox heating surface included 23 sq ft (2.14 sq m) of arch tubes. This is an early example of a US Mikado. Its saturated boiler and relatively small dimensions and low boiler pressure mark it as a harbinger of much larger 2-8-2s to come. In six years, the railroad would procure one superheated example of this design; see Locobase 6581.

The LHP&P went into receivership in 1914 and was taken over by the Colorado, Wyoming & Eastern Railway. The CW&E in turn fell into the hands of a receiver in 1924, when it was reorganized as the Northern Colorado & Eastern Railway. Several months later the NC&E was again reorganized as the Laramie, North Park & Western Railroad(LNP&W).

And so it remained until 1951, when the alignment finally came under Union Pacific control. By that time, this quartet was long gone.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID6580
RailroadLaramie, Hahn's Peak & Pacific
Number in Class4
Road Numbers4-7
Number Built4
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.08 / 3.99
Engine Wheelbase (ft / m)28 / 8.53
Ratio of driving wheelbase to overall engine wheebase 0.47
Overall Wheelbase (engine & tender) (ft / m)54.12 / 16.50
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)138,000 / 62,596
Engine Weight (lbs / kg)181,500 / 82,327
Tender Loaded Weight (lbs / kg)114,000 / 51,710
Total Engine and Tender Weight (lbs / kg)295,500 / 134,037
Tender Water Capacity (gals / ML)5500 / 20.83
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)12 / 10.90
Minimum weight of rail (calculated) (lb/yd / kg/m)58 / 29
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 1219
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)20" x 28" / 508x711
Tractive Effort (lbs / kg)35,700 / 16193.27
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.87
Heating Ability
Firebox Area (sq ft / m2)201 / 18.68
Grate Area (sq ft / m2)54 / 5.02
Evaporative Heating Surface (sq ft / m2)3208 / 298.14
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)3208 / 298.14
Evaporative Heating Surface/Cylinder Volume315.09
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9720
Same as above plus superheater percentage9720
Same as above but substitute firebox area for grate area36,180
Power L15959
Power MT380.79

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