Mountain Quarries / Pacific Portland Cement Company 2-8-2 "Mikado" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 101 (Locobase 14078)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 45, p. 229. (Thanks to Steve Low for his 28 March 2021 email reporting an inconsistency and leading to a clarification.) Works number was 37078 in October 1911.

Pacific Portland Cement ordered this Mikado and sized it to roll on 75 lb/yard (37.5 kg/metre) rail for the 7 miles between the quarries and the Southern Pacific junction at Auburn, Calif. It trailed a cylindrical Vanderbilt tender lettered for the Mountain Quarries Company.

According to [], a triple-span concrete bridge was built in 1912 during construction to handle the four trains a day. Quarrying the huge limestone formation took place from 1912 to 1939. In 1942 the tracks were pulled out for scrap metal for WWII, but the "No-Hands Bridge" remains standing. Its nickname reportedly refers to a horseback rider who rode "no hands" as he and his mount (who deserves at least half of the credit) picked their way across the bridge 150 feet above the gorge using only the narrow railbed.

The 101 had long since gone to the Ray & Gila Valley in August 1916 as their #5 and remained on the line until it was sold to Kennecott Copper in December 1943.


Class 102 (Locobase 14255)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volumes 52, p. 116+ and 80, p. 192+. (Thanks to Steve Low for his 28 March 2021 email reporting inconsistencies that led to a review of this entry.) Works number was 42912 in February 1916 and 59126 in April 1926.

This Mikado was small as 2-8-2s went, but sizable for the industrial line on which it operated. The specs guaranteed it would haul four loaded 50-ton standard steel cars, of either gondola or hopper bottom type, on 75 lb/yard (37.5 kg/metre) rail at 10 mph up a 3 1/2% grade with a 16 degree (359 foot/109.4 metre radius) curve.

In 1926, specifications required that the 103 had offer at least the hauling power of the 102. It weighed a ton more on the drivers and replaced the slide valves of the original design with 12" (305 mm) piston valves, but was otherwise a duplicate.

The 102 later ran on the Ray Consolidated Copper Company rails as their 17 in Hayden, Ariz. McCloud River bought the 17 in 1942 and ran it until 1955. 103 went from PPCC to the California & Oregon Coast in 1941.

Principal Dimensions by Steve Llanso of Sweat House Media

Class101102
Locobase ID14078 14255
RailroadMountain Quarries (PPC)Pacific Portland Cement Company (PPC)
CountryUSAUSA
Whyte2-8-22-8-2
Number in Class12
Road Numbers101102-103
GaugeStdStd
Number Built12
BuilderBaldwinBaldwin
Year19111916
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14 / 4.2713.08 / 3.99
Engine Wheelbase (ft / m)31.08 / 9.4727 / 8.23
Ratio of driving wheelbase to overall engine wheelbase 0.45 0.48
Overall Wheelbase (engine & tender) (ft / m)60.79 / 18.5355.33 / 16.86
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)185,000 / 83,915138,000 / 62,596
Engine Weight (lbs / kg)232,000 / 105,234177,000 / 80,286
Tender Loaded Weight (lbs / kg)133,500 / 60,55590,000 / 40,823
Total Engine and Tender Weight (lbs / kg)365,500 / 165,789267,000 / 121,109
Tender Water Capacity (gals / ML)7000 / 26.524500 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2940 / 11,1282500 / 9463
Minimum weight of rail (calculated) (lb/yd / kg/m)77 / 38.5058 / 29
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)51 / 129544 / 1118
Boiler Pressure (psi / kPa)200 / 13.80180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)22" x 28" / 559x71120.5" x 28" / 521x711
Tractive Effort (lbs / kg)45,173 / 20490.1540,917 / 18559.66
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.10 3.37
Heating Ability
Tubes (number - dia) (in / mm)342 - 2.25" / 57350 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)18.50 / 5.6416.50 / 5.03
Firebox Area (sq ft / m2)193 / 17.93160 / 14.86
Grate Area (sq ft / m2)57 / 5.3041.30 / 3.84
Evaporative Heating Surface (sq ft / m2)3903 / 362.733108 / 288.85
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)3903 / 362.733108 / 288.85
Evaporative Heating Surface/Cylinder Volume316.80290.47
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,4007434
Same as above plus superheater percentage11,4007434
Same as above but substitute firebox area for grate area38,60028,800
Power L167174821
Power MT320.18308.07

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